diff --git a/.cargo/config.toml b/.cargo/config.toml
index d4c65ec6c..fc2582823 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -36,5 +36,7 @@ PKG_CONFIG_PATH_x86_64-unknown-freebsd = { value = "target/vcpkg/installed/x64-f
 PKG_CONFIG_PATH_x86_64-apple-darwin = { value = "target/vcpkg/installed/x64-osx-release/lib/pkgconfig", relative = true }
 PKG_CONFIG_PATH_aarch64-apple-darwin = { value = "target/vcpkg/installed/arm64-osx-release/lib/pkgconfig", relative = true }
 
+OPENSSL_STATIC = { value = "true" }
+
 # Only Windows uses vcpkg linking.
 VCPKGRS_TRIPLET = { value = "x64-windows-static-release" }
diff --git a/.gitignore b/.gitignore
index bb19973f5..92f434ecc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -142,4 +142,7 @@ $RECYCLE.BIN/
 # Windows shortcuts
 *.lnk
 
+# Hearing test output
+hearing-test-output/
+
 # End of https://www.toptal.com/developers/gitignore/api/c++,rust,linux,macos,windows,rust-analyzer,visualstudiocode,direnv
diff --git a/Cargo.lock b/Cargo.lock
index 58ea35f0c..6da86b6b6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,12 +1,12 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "addr2line"
-version = "0.22.0"
+version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e4503c46a5c0c7844e948c9a4d6acd9f50cccb4de1c48eb9e291ea17470c678"
+checksum = "8a30b2e23b9e17a9f90641c7ab1549cd9b44f296d3ccbf309d2863cfe398a0cb"
 dependencies = [
  "gimli",
 ]
@@ -92,6 +92,28 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "async-fs"
+version = "2.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ebcd09b382f40fcd159c2d695175b2ae620ffa5f3bd6f664131efff4e8b9e04a"
+dependencies = [
+ "async-lock",
+ "blocking",
+ "futures-lite",
+]
+
+[[package]]
+name = "async-lock"
+version = "3.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ff6e472cdea888a4bd64f342f09b3f50e1886d32afe8df3d663c01140b811b18"
+dependencies = [
+ "event-listener",
+ "event-listener-strategy",
+ "pin-project-lite",
+]
+
 [[package]]
 name = "async-stream"
 version = "0.3.5"
@@ -131,6 +153,17 @@ dependencies = [
  "syn 2.0.85",
 ]
 
+[[package]]
+name = "async-walkdir"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "20235b6899dd1cb74a9afac0abf5b4a20c0e500dd6537280f4096e1b9f14da20"
+dependencies = [
+ "async-fs",
+ "futures-lite",
+ "thiserror",
+]
+
 [[package]]
 name = "atomic"
 version = "0.6.0"
@@ -493,8 +526,42 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "504e3947307ac8326a5437504c517c4b56716c9d98fac0028c2acc7ca47d70ae"
 dependencies = [
  "async-trait",
- "axum-core",
- "axum-macros",
+ "axum-core 0.4.5",
+ "axum-macros 0.4.2",
+ "bytes",
+ "futures-util",
+ "http 1.1.0",
+ "http-body 1.0.0",
+ "http-body-util",
+ "hyper 1.3.1",
+ "hyper-util",
+ "itoa",
+ "matchit 0.7.3",
+ "memchr",
+ "mime",
+ "percent-encoding",
+ "pin-project-lite",
+ "rustversion",
+ "serde",
+ "serde_json",
+ "serde_path_to_error",
+ "serde_urlencoded",
+ "sync_wrapper 1.0.1",
+ "tokio",
+ "tower 0.5.1",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "axum"
+version = "0.8.0-alpha.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4132c8995c63b222c56f38b80748c23323d7012d1f783b0f42e92782c2676690"
+dependencies = [
+ "axum-core 0.5.0-alpha.1",
+ "axum-macros 0.5.0-alpha.1",
  "bytes",
  "futures-util",
  "http 1.1.0",
@@ -503,7 +570,7 @@ dependencies = [
  "hyper 1.3.1",
  "hyper-util",
  "itoa",
- "matchit",
+ "matchit 0.8.0",
  "memchr",
  "mime",
  "percent-encoding",
@@ -542,14 +609,34 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "axum-core"
+version = "0.5.0-alpha.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f3405ae79f3aab93ae35fe2944aff9bf0f5aac918c0229f3528043c5a454d17d"
+dependencies = [
+ "bytes",
+ "futures-util",
+ "http 1.1.0",
+ "http-body 1.0.0",
+ "http-body-util",
+ "mime",
+ "pin-project-lite",
+ "rustversion",
+ "sync_wrapper 1.0.1",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
 [[package]]
 name = "axum-extra"
 version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "73c3220b188aea709cf1b6c5f9b01c3bd936bb08bd2b5184a12b35ac8131b1f9"
 dependencies = [
- "axum",
- "axum-core",
+ "axum 0.7.7",
+ "axum-core 0.4.5",
  "bytes",
  "futures-util",
  "headers",
@@ -566,6 +653,30 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "axum-extra"
+version = "0.10.0-alpha.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fda8d71bb4e0d59ca7203822c50c4f0961aa5ed42c758d62cb413f0ba0aa9877"
+dependencies = [
+ "axum 0.8.0-alpha.1",
+ "axum-core 0.5.0-alpha.1",
+ "bytes",
+ "fastrand",
+ "futures-util",
+ "headers",
+ "http 1.1.0",
+ "http-body 1.0.0",
+ "http-body-util",
+ "mime",
+ "multer",
+ "pin-project-lite",
+ "serde",
+ "tower 0.5.1",
+ "tower-layer",
+ "tower-service",
+]
+
 [[package]]
 name = "axum-macros"
 version = "0.4.2"
@@ -577,11 +688,22 @@ dependencies = [
  "syn 2.0.85",
 ]
 
+[[package]]
+name = "axum-macros"
+version = "0.5.0-alpha.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9203d3637bf999b7611f52addb61581111a3ea32e3818df0cbbde3e95d0f22bb"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.82",
+]
+
 [[package]]
 name = "backtrace"
-version = "0.3.73"
+version = "0.3.71"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5cc23269a4f8976d0a4d2e7109211a419fe30e8d88d677cd60b6bc79c5732e0a"
+checksum = "26b05800d2e817c8b3b4b54abd461726265fa9789ae34330622f2db9ee696f9d"
 dependencies = [
  "addr2line",
  "cc",
@@ -658,6 +780,29 @@ dependencies = [
  "which",
 ]
 
+[[package]]
+name = "bitcode"
+version = "0.6.3"
+source = "git+https://github.com/vnghia/bitcode.git?rev=5f6a56f#5f6a56fb717ab470bc0ae017cbfe1d1870610f56"
+dependencies = [
+ "arrayvec",
+ "bitcode_derive",
+ "bytemuck",
+ "glam",
+ "serde",
+ "uuid",
+]
+
+[[package]]
+name = "bitcode_derive"
+version = "0.6.3"
+source = "git+https://github.com/vnghia/bitcode.git?rev=5f6a56f#5f6a56fb717ab470bc0ae017cbfe1d1870610f56"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.82",
+]
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -695,6 +840,31 @@ dependencies = [
  "piper",
 ]
 
+[[package]]
+name = "bon"
+version = "3.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "65b4408cb90c75f462c2428254f2a687c399d1feb22ebdc7511889d07be6cab0"
+dependencies = [
+ "bon-macros",
+ "rustversion",
+]
+
+[[package]]
+name = "bon-macros"
+version = "3.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bfc5494814aa273050386f95a7d1fa36dcc677fc796bffe54f34659678335bc0"
+dependencies = [
+ "darling",
+ "ident_case",
+ "prettyplease",
+ "proc-macro2",
+ "quote",
+ "rustversion",
+ "syn 2.0.82",
+]
+
 [[package]]
 name = "bstr"
 version = "1.9.1"
@@ -900,6 +1070,33 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "67ba02a97a2bd10f4b59b25c7973101c79642302776489e030cd13cdab09ed15"
 
+[[package]]
+name = "color-eyre"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55146f5e46f237f7423d74111267d4597b59b0dad0ffaf7303bce9945d843ad5"
+dependencies = [
+ "backtrace",
+ "color-spantrace",
+ "eyre",
+ "indenter",
+ "once_cell",
+ "owo-colors",
+ "tracing-error",
+]
+
+[[package]]
+name = "color-spantrace"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cd6be1b2a7e382e2b98b43b2adcca6bb0e465af0bdd38123873ae61eb17a72c2"
+dependencies = [
+ "once_cell",
+ "owo-colors",
+ "tracing-core",
+ "tracing-error",
+]
+
 [[package]]
 name = "compact_str"
 version = "0.7.1"
@@ -953,6 +1150,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3a214c7af3d04997541b18d432afaff4c455e79e2029079647e72fc2bd27673"
 dependencies = [
  "const_format_proc_macros",
+ "konst",
 ]
 
 [[package]]
@@ -1111,9 +1309,9 @@ dependencies = [
 
 [[package]]
 name = "darling"
-version = "0.20.9"
+version = "0.20.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "83b2eb4d90d12bdda5ed17de686c2acb4c57914f8f921b8da7e112b5a36f3fe1"
+checksum = "6f63b86c8a8826a49b8c21f08a2d07338eec8d900540f8630dc76284be802989"
 dependencies = [
  "darling_core",
  "darling_macro",
@@ -1121,9 +1319,9 @@ dependencies = [
 
 [[package]]
 name = "darling_core"
-version = "0.20.9"
+version = "0.20.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "622687fe0bac72a04e5599029151f5796111b90f1baaa9b544d807a5e31cd120"
+checksum = "95133861a8032aaea082871032f5815eb9e98cef03fa916ab4500513994df9e5"
 dependencies = [
  "fnv",
  "ident_case",
@@ -1135,9 +1333,9 @@ dependencies = [
 
 [[package]]
 name = "darling_macro"
-version = "0.20.9"
+version = "0.20.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "733cabb43482b1a1b53eee8583c2b9e8684d592215ea83efd305dd31bc2f0178"
+checksum = "d336a2a514f6ccccaa3e09b02d41d35330c07ddf03a62165fcec10bb561c7806"
 dependencies = [
  "darling_core",
  "quote",
@@ -1215,7 +1413,7 @@ dependencies = [
  "deluxe-core",
  "heck 0.4.1",
  "if_chain",
- "proc-macro-crate",
+ "proc-macro-crate 1.3.1",
  "proc-macro2",
  "quote",
  "syn 2.0.85",
@@ -1252,6 +1450,17 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "derive-new"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d150dea618e920167e5973d70ae6ece4385b7164e0d799fe7c122dd0a5d912ad"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.82",
+]
+
 [[package]]
 name = "derive-new"
 version = "0.7.0"
@@ -1287,7 +1496,7 @@ checksum = "158fe8e2e68695bd615d7e4f3227c0727b151330d3e253b525086c348d055d5e"
 dependencies = [
  "bitflags 2.5.0",
  "byteorder",
- "diesel_derives",
+ "diesel_derives 2.2.2",
  "itoa",
  "pq-sys",
  "time",
@@ -1309,14 +1518,26 @@ dependencies = [
  "tokio-postgres",
 ]
 
+[[package]]
+name = "diesel_derives"
+version = "2.2.0"
+source = "git+https://github.com/diesel-rs/diesel?rev=ecf6e9215a898045ed096f905f4a0e7e4a999dba#ecf6e9215a898045ed096f905f4a0e7e4a999dba"
+dependencies = [
+ "diesel_table_macro_syntax 0.2.0 (git+https://github.com/diesel-rs/diesel?rev=ecf6e9215a898045ed096f905f4a0e7e4a999dba)",
+ "dsl_auto_type 0.1.0",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.82",
+]
+
 [[package]]
 name = "diesel_derives"
 version = "2.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d6ff2be1e7312c858b2ef974f5c7089833ae57b5311b334b30923af58e5718d8"
 dependencies = [
- "diesel_table_macro_syntax",
- "dsl_auto_type",
+ "diesel_table_macro_syntax 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "dsl_auto_type 0.1.2",
  "proc-macro2",
  "quote",
  "syn 2.0.85",
@@ -1351,6 +1572,14 @@ dependencies = [
  "syn 2.0.85",
 ]
 
+[[package]]
+name = "diesel_table_macro_syntax"
+version = "0.2.0"
+source = "git+https://github.com/diesel-rs/diesel?rev=ecf6e9215a898045ed096f905f4a0e7e4a999dba#ecf6e9215a898045ed096f905f4a0e7e4a999dba"
+dependencies = [
+ "syn 2.0.82",
+]
+
 [[package]]
 name = "digest"
 version = "0.10.7"
@@ -1716,6 +1945,19 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "dsl_auto_type"
+version = "0.1.0"
+source = "git+https://github.com/diesel-rs/diesel?rev=ecf6e9215a898045ed096f905f4a0e7e4a999dba#ecf6e9215a898045ed096f905f4a0e7e4a999dba"
+dependencies = [
+ "darling",
+ "either",
+ "heck 0.5.0",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.82",
+]
+
 [[package]]
 name = "dsl_auto_type"
 version = "0.1.2"
@@ -1732,9 +1974,9 @@ dependencies = [
 
 [[package]]
 name = "dummy"
-version = "0.7.0"
+version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e57e12b69e57fad516e01e2b3960f122696fdb13420e1a88ed8e210316f2876"
+checksum = "b3ee4e39146145f7dd28e6c85ffdce489d93c0d9c88121063b8aacabbd9858d2"
 dependencies = [
  "darling",
  "proc-macro2",
@@ -1907,16 +2149,25 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "eyre"
+version = "0.6.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7cd915d99f24784cdc19fd37ef22b97e3ff0ae756c7e492e9fbfe897d61e2aec"
+dependencies = [
+ "indenter",
+ "once_cell",
+]
+
 [[package]]
 name = "fake"
-version = "2.9.2"
+version = "3.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1c25829bde82205da46e1823b2259db6273379f626fc211f126f65654a2669be"
+checksum = "661cb0601b5f4050d1e65452c5b0ea555c0b3e88fb5ed7855906adc6c42523ef"
 dependencies = [
  "deunicode",
  "dummy",
  "rand",
- "serde_json",
  "time",
  "uuid",
 ]
@@ -1927,6 +2178,16 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4443176a9f2c162692bd3d352d745ef9413eec5782a80d8fd6f8a1ac692a07f7"
 
+[[package]]
+name = "faster-hex"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7223ae2d2f179b803433d9c830478527e92b8117eab39460edae7f1614d9fb73"
+dependencies = [
+ "heapless 0.8.0",
+ "serde",
+]
+
 [[package]]
 name = "fastrand"
 version = "2.1.1"
@@ -2023,6 +2284,16 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "fs4"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e871a4cfa68bb224863b53149d973df1ac8d1ed2fa1d1bfc37ac1bb65dd37207"
+dependencies = [
+ "rustix",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "futures"
 version = "0.3.31"
@@ -2089,7 +2360,10 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "52527eb5074e35e9339c6b4e8d12600c7128b68fb25dcb9fa9dec18f7c25f3a5"
 dependencies = [
+ "fastrand",
  "futures-core",
+ "futures-io",
+ "parking",
  "pin-project-lite",
 ]
 
@@ -2116,6 +2390,12 @@ version = "0.3.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f90f7dce0722e95104fcb095585910c0977252f286e354b5e3bd38902cd99988"
 
+[[package]]
+name = "futures-timer"
+version = "3.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f288b0a4f20f9a56b5d1da57e2227c661b7b16168e2f72365f57b63326e29b24"
+
 [[package]]
 name = "futures-util"
 version = "0.3.31"
@@ -2181,9 +2461,9 @@ dependencies = [
 
 [[package]]
 name = "gimli"
-version = "0.29.0"
+version = "0.28.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "40ecd4077b5ae9fd2e9e169b102c6c330d0605168eb0e8bf79952b256dbefffd"
+checksum = "4271d37baee1b8c7e4b708028c57d816cf9d2434acb33a549475f78c181f6253"
 
 [[package]]
 name = "git2"
@@ -2198,6 +2478,12 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "glam"
+version = "0.29.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c28091a37a5d09b555cb6628fd954da299b536433834f5b8e59eba78e0cbbf8a"
+
 [[package]]
 name = "glob"
 version = "0.3.1"
@@ -2558,7 +2844,7 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "956caa58d4857bc9941749d55e4bd3000032d8212762586fa5705632967140e7"
 dependencies = [
- "proc-macro-crate",
+ "proc-macro-crate 1.3.1",
  "proc-macro2",
  "quote",
  "syn 2.0.85",
@@ -2587,7 +2873,7 @@ dependencies = [
  "futures-sink",
  "futures-util",
  "http 0.2.12",
- "indexmap 2.2.6",
+ "indexmap 2.6.0",
  "slab",
  "tokio",
  "tokio-util",
@@ -2606,7 +2892,7 @@ dependencies = [
  "futures-core",
  "futures-sink",
  "http 1.1.0",
- "indexmap 2.2.6",
+ "indexmap 2.6.0",
  "slab",
  "tokio",
  "tokio-util",
@@ -2632,6 +2918,15 @@ dependencies = [
  "byteorder",
 ]
 
+[[package]]
+name = "hash32"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "47d60b12902ba28e2730cd37e95b8c9223af2808df9e902d4df49588d1470606"
+dependencies = [
+ "byteorder",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.12.3"
@@ -2648,6 +2943,12 @@ dependencies = [
  "allocator-api2",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e087f84d4f86bf4b218b927129862374b72199ae7d8657835f1e89000eea4fb"
+
 [[package]]
 name = "headers"
 version = "0.4.0"
@@ -2679,13 +2980,23 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cdc6457c0eb62c71aac4bc17216026d8410337c4126773b9c5daba343f17964f"
 dependencies = [
  "atomic-polyfill",
- "hash32",
+ "hash32 0.2.1",
  "rustc_version",
  "serde",
  "spin",
  "stable_deref_trait",
 ]
 
+[[package]]
+name = "heapless"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0bfb9eb618601c89945a70e254898da93b13be0388091d42117462b265bb3fad"
+dependencies = [
+ "hash32 0.3.1",
+ "stable_deref_trait",
+]
+
 [[package]]
 name = "heck"
 version = "0.4.1"
@@ -2977,9 +3288,9 @@ dependencies = [
 
 [[package]]
 name = "image"
-version = "0.25.4"
+version = "0.25.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc144d44a31d753b02ce64093d532f55ff8dc4ebf2ffb8a63c0dda691385acae"
+checksum = "cd6f44aed642f18953a158afeb30206f4d50da59fbc66ecb53c66488de73563b"
 dependencies = [
  "bytemuck",
  "byteorder-lite",
@@ -2989,6 +3300,12 @@ dependencies = [
  "zune-jpeg",
 ]
 
+[[package]]
+name = "indenter"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce23b50ad8242c51a442f3ff322d56b02f08852c77e4c0b4d3fd684abc89c683"
+
 [[package]]
 name = "indexmap"
 version = "1.9.3"
@@ -3002,12 +3319,12 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.2.6"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "168fb715dda47215e360912c096649d23d58bf392ac62f73919e831745e40f26"
+checksum = "707907fe3c25f5424cce2cb7e1cbcafee6bdbe735ca90ef77c29e84591e5b9da"
 dependencies = [
  "equivalent",
- "hashbrown 0.14.5",
+ "hashbrown 0.15.0",
  "serde",
 ]
 
@@ -3095,9 +3412,9 @@ checksum = "49f1f14873335454500d59611f1cf4a4b0f786f9ac11f4312a78e4cf2566695b"
 
 [[package]]
 name = "jobserver"
-version = "0.1.31"
+version = "0.1.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d2b099aaa34a9751c5bf0878add70444e1ed2dd73f347be99003d4577277de6e"
+checksum = "48d1dbcbbeb6a7fec7e059840aa538bd62aaccf972c7346c4d9d2059312853d0"
 dependencies = [
  "libc",
 ]
@@ -3122,6 +3439,21 @@ dependencies = [
  "unicode-segmentation",
 ]
 
+[[package]]
+name = "konst"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "330f0e13e6483b8c34885f7e6c9f19b1a7bd449c673fbb948a51c99d66ef74f4"
+dependencies = [
+ "konst_macro_rules",
+]
+
+[[package]]
+name = "konst_macro_rules"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4933f3f57a8e9d9da04db23fb153356ecaf00cbd14aee46279c33dc80925c37"
+
 [[package]]
 name = "krates"
 version = "0.16.10"
@@ -3208,7 +3540,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c2a198fb6b0eada2a8df47933734e6d35d350665a33a3593d7164fa52c75c19"
 dependencies = [
  "cfg-if",
- "windows-targets 0.48.5",
+ "windows-targets 0.52.6",
 ]
 
 [[package]]
@@ -3233,9 +3565,9 @@ dependencies = [
 
 [[package]]
 name = "libz-sys"
-version = "1.1.18"
+version = "1.1.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c15da26e5af7e25c90b37a2d75cdbf940cf4a55316de9d84c679c9b8bfabf82e"
+checksum = "fdc53a7799a7496ebc9fd29f31f7df80e83c9bda5299768af5f9e59eeea74647"
 dependencies = [
  "cc",
  "libc",
@@ -3274,6 +3606,21 @@ dependencies = [
  "paste",
 ]
 
+[[package]]
+name = "lofty"
+version = "0.21.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8bc4717ff10833a623b009e9254ae8667c7a59edc3cfb01c37aeeef4b6d54a7"
+dependencies = [
+ "byteorder",
+ "data-encoding",
+ "flate2",
+ "lofty_attr",
+ "log",
+ "ogg_pager",
+ "paste",
+]
+
 [[package]]
 name = "lofty_attr"
 version = "0.11.0"
@@ -3287,9 +3634,9 @@ dependencies = [
 
 [[package]]
 name = "log"
-version = "0.4.21"
+version = "0.4.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90ed8c1e510134f979dbc4f070f87d4313098b704861a105fe34231c70a3901c"
+checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
 
 [[package]]
 name = "longest-increasing-subsequence"
@@ -3297,6 +3644,16 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b3bd0dd2cd90571056fdb71f6275fada10131182f84899f4b2a916e565d81d86"
 
+[[package]]
+name = "loole"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a2998397c725c822c6b2ba605fd9eb4c6a7a0810f1629ba3cc232ef4f0308d96"
+dependencies = [
+ "futures-core",
+ "futures-sink",
+]
+
 [[package]]
 name = "loom"
 version = "0.5.6"
@@ -3385,6 +3742,12 @@ version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0e7465ac9959cc2b1404e8e2367b43684a6d13790fe23056cc8c6c5a6b7bcb94"
 
+[[package]]
+name = "matchit"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56e8fcd7bd6025a951597d6ba2f8e48a121af7e262f2b52a006a09c8d61f9304"
+
 [[package]]
 name = "maybe-async"
 version = "0.2.10"
@@ -3492,6 +3855,23 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "multer"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "83e87776546dc87511aa5ee218730c92b666d7264ab6ed41f9d215af9cd5224b"
+dependencies = [
+ "bytes",
+ "encoding_rs",
+ "futures-util",
+ "http 1.1.0",
+ "httparse",
+ "memchr",
+ "mime",
+ "spin",
+ "version_check",
+]
+
 [[package]]
 name = "nanorand"
 version = "0.7.0"
@@ -3526,8 +3906,8 @@ dependencies = [
  "async-trait",
  "aws-config",
  "aws-sdk-s3",
- "axum",
- "axum-extra",
+ "axum 0.7.7",
+ "axum-extra 0.9.4",
  "concat-string",
  "constcat 0.5.1",
  "derivative",
@@ -3548,7 +3928,7 @@ dependencies = [
  "itertools",
  "lastfm-client",
  "libaes",
- "lofty",
+ "lofty 0.20.1",
  "lrc",
  "mimalloc",
  "mime_guess",
@@ -3575,7 +3955,7 @@ dependencies = [
  "tower-http",
  "tracing",
  "tracing-subscriber",
- "typed-path",
+ "typed-path 0.9.3",
  "unicode-normalization",
  "url",
  "uuid",
@@ -3632,7 +4012,7 @@ dependencies = [
  "concat-string",
  "constcat 0.5.1",
  "derivative",
- "derive-new",
+ "derive-new 0.7.0",
  "fake",
  "isolang",
  "md5",
@@ -3646,6 +4026,104 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "nghe_api"
+version = "0.9.10"
+dependencies = [
+ "bitcode",
+ "bon",
+ "built",
+ "const_format",
+ "fake",
+ "faster-hex",
+ "md5",
+ "nghe_proc_macro",
+ "paste",
+ "rstest",
+ "serde",
+ "serde_html_form",
+ "serde_json",
+ "serde_with",
+ "strum",
+ "uuid",
+]
+
+[[package]]
+name = "nghe_backend"
+version = "0.9.10"
+dependencies = [
+ "async-walkdir",
+ "aws-config",
+ "aws-sdk-s3",
+ "aws-smithy-runtime",
+ "axum 0.8.0-alpha.1",
+ "axum-extra 0.10.0-alpha.1",
+ "bitcode",
+ "bon",
+ "color-eyre",
+ "concat-string",
+ "const_format",
+ "derive-new 0.6.0",
+ "diesel",
+ "diesel-async",
+ "diesel_derives 2.2.0",
+ "diesel_full_text_search",
+ "diesel_migrations",
+ "educe",
+ "fake",
+ "faster-hex",
+ "figment",
+ "fs4",
+ "futures-lite",
+ "http-body-util",
+ "hyper 0.14.29",
+ "hyper-tls",
+ "image",
+ "indexmap 2.6.0",
+ "isolang",
+ "itertools",
+ "libaes",
+ "lofty 0.21.1",
+ "loole",
+ "nghe_api",
+ "nghe_proc_macro",
+ "num-traits",
+ "o2o",
+ "rand",
+ "rsmpeg",
+ "rstest",
+ "serde",
+ "serde_html_form",
+ "serde_with",
+ "strum",
+ "tempfile",
+ "thiserror",
+ "time",
+ "tokio",
+ "tokio-util",
+ "tower-http",
+ "tracing",
+ "tracing-subscriber",
+ "typed-path 0.10.0",
+ "unicode-normalization",
+ "url",
+ "uuid",
+ "xxhash-rust",
+]
+
+[[package]]
+name = "nghe_proc_macro"
+version = "0.9.10"
+dependencies = [
+ "bon",
+ "concat-string",
+ "convert_case",
+ "deluxe",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.82",
+]
+
 [[package]]
 name = "nom"
 version = "7.1.3"
@@ -3700,11 +4178,42 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "o2o"
+version = "0.4.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8e305dfc777160d7b28491f1302858d0b290752e0d7e36b26d5993f89e29831"
+dependencies = [
+ "o2o-impl",
+ "o2o-macros",
+]
+
+[[package]]
+name = "o2o-impl"
+version = "0.4.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "946513572d14a570bfac1400f1ea584e9d788acee7862af973652125212614c4"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
+[[package]]
+name = "o2o-macros"
+version = "0.4.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "18ce235841f140d13a3f76c4bb7cff9a5a913e4f10ddd6185e6584d4b4e2e502"
+dependencies = [
+ "o2o-impl",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "object"
-version = "0.36.0"
+version = "0.32.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "576dfe1fc8f9df304abb159d767a29d0476f7750fbf8aa7ad07816004a207434"
+checksum = "a6a622008b6e321afc04970976f62ee297fdbaa6f95318ca343e3eebb9648441"
 dependencies = [
  "memchr",
 ]
@@ -3789,6 +4298,12 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
 
+[[package]]
+name = "owo-colors"
+version = "3.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1b04fb49957986fdce4d6ee7a65027d55d4b6d2265e5848bbb507b58ccfdb6f"
+
 [[package]]
 name = "p256"
 version = "0.11.1"
@@ -3871,7 +4386,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b4c5cc86750666a3ed20bdaf5ca2a0344f9c67674cae0515bec2da16fbaa47db"
 dependencies = [
  "fixedbitset",
- "indexmap 2.2.6",
+ "indexmap 2.6.0",
 ]
 
 [[package]]
@@ -4007,7 +4522,7 @@ checksum = "a55c51ee6c0db07e68448e336cf8ea4131a620edefebf9893e759b2d793420f8"
 dependencies = [
  "cobs",
  "embedded-io",
- "heapless",
+ "heapless 0.7.17",
  "serde",
 ]
 
@@ -4081,6 +4596,15 @@ dependencies = [
  "toml_edit 0.19.15",
 ]
 
+[[package]]
+name = "proc-macro-crate"
+version = "3.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ecf48c7ca261d60b74ab1a7b20da18bede46776b2e55535cb958eb595c5fa7b"
+dependencies = [
+ "toml_edit 0.22.20",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.89"
@@ -4299,6 +4823,12 @@ version = "0.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7a66a03ae7c801facd77a29370b4faec201768915ac14a721ba36f20bc9c209b"
 
+[[package]]
+name = "relative-path"
+version = "1.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba39f3699c378cd8970968dcbff9c43159ea4cfbd88d43c00b22f2ef10a435d2"
+
 [[package]]
 name = "reqwest"
 version = "0.11.27"
@@ -4478,6 +5008,36 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "rstest"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b423f0e62bdd61734b67cd21ff50871dfaeb9cc74f869dcd6af974fbcb19936"
+dependencies = [
+ "futures",
+ "futures-timer",
+ "rstest_macros",
+ "rustc_version",
+]
+
+[[package]]
+name = "rstest_macros"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c5e1711e7d14f74b12a58411c542185ef7fb7f2e7f8ee6e2940a883628522b42"
+dependencies = [
+ "cfg-if",
+ "glob",
+ "proc-macro-crate 3.2.0",
+ "proc-macro2",
+ "quote",
+ "regex",
+ "relative-path",
+ "rustc_version",
+ "syn 2.0.82",
+ "unicode-ident",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.24"
@@ -4792,7 +5352,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8de514ef58196f1fc96dcaef80fe6170a1ce6215df9687a93fe8300e773fefc5"
 dependencies = [
  "form_urlencoded",
- "indexmap 2.2.6",
+ "indexmap 2.6.0",
  "itoa",
  "ryu",
  "serde",
@@ -4844,9 +5404,9 @@ dependencies = [
 
 [[package]]
 name = "serde_spanned"
-version = "0.6.6"
+version = "0.6.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "79e674e01f999af37c49f70a6ede167a8a60b2503e56c5599532a65baa5969a0"
+checksum = "eb5b1b31579f3811bf615c144393417496f152e12ac8b7663bf664f4a815306d"
 dependencies = [
  "serde",
 ]
@@ -4873,7 +5433,7 @@ dependencies = [
  "chrono",
  "hex",
  "indexmap 1.9.3",
- "indexmap 2.2.6",
+ "indexmap 2.6.0",
  "serde",
  "serde_derive",
  "serde_json",
@@ -5461,14 +6021,14 @@ dependencies = [
  "serde",
  "serde_spanned",
  "toml_datetime",
- "toml_edit 0.22.16",
+ "toml_edit 0.22.20",
 ]
 
 [[package]]
 name = "toml_datetime"
-version = "0.6.6"
+version = "0.6.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4badfd56924ae69bcc9039335b2e017639ce3f9b001c393c1b2d1ef846ce2cbf"
+checksum = "0dd7358ecb8fc2f8d014bf86f6f638ce72ba252a2c3a2572f2a795f1d23efb41"
 dependencies = [
  "serde",
 ]
@@ -5479,7 +6039,7 @@ version = "0.19.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1b5bb770da30e5cbfde35a2d7b9b8a2c4b8ef89548a7a6aeab5c9a576e3e7421"
 dependencies = [
- "indexmap 2.2.6",
+ "indexmap 2.6.0",
  "serde",
  "serde_spanned",
  "toml_datetime",
@@ -5488,15 +6048,15 @@ dependencies = [
 
 [[package]]
 name = "toml_edit"
-version = "0.22.16"
+version = "0.22.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "278f3d518e152219c994ce877758516bca5e118eaed6996192a774fb9fbf0788"
+checksum = "583c44c02ad26b0c3f3066fe629275e50627026c51ac2e595cca4c230ce1ce1d"
 dependencies = [
- "indexmap 2.2.6",
+ "indexmap 2.6.0",
  "serde",
  "serde_spanned",
  "toml_datetime",
- "winnow 0.6.13",
+ "winnow 0.6.18",
 ]
 
 [[package]]
@@ -5600,6 +6160,16 @@ dependencies = [
  "valuable",
 ]
 
+[[package]]
+name = "tracing-error"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d686ec1c0f384b1277f097b2f279a2ecc11afe8c133c1aabf036a27cb4cd206e"
+dependencies = [
+ "tracing",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "tracing-log"
 version = "0.2.0"
@@ -5652,6 +6222,11 @@ version = "0.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "82205ffd44a9697e34fc145491aa47310f9871540bb7909eaa9365e0a9a46607"
 
+[[package]]
+name = "typed-path"
+version = "0.10.0"
+source = "git+https://github.com/vnghia/typed-path?rev=bd796e64b3cee53181a3fc2f15245f5bf731bd8c#bd796e64b3cee53181a3fc2f15245f5bf731bd8c"
+
 [[package]]
 name = "typenum"
 version = "1.17.0"
@@ -6175,9 +6750,9 @@ dependencies = [
 
 [[package]]
 name = "winnow"
-version = "0.6.13"
+version = "0.6.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59b5e5f6c299a3c7890b876a2a587f3115162487e704907d9b6cd29473052ba1"
+checksum = "68a9bda4691f099d435ad181000724da8e5899daa10713c2d432552b9ccd3a6f"
 dependencies = [
  "memchr",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 259959ea8..c08134389 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,12 +5,28 @@ members = [
   "lastfm-proc-macros",
   "proc_macros",
   "types",
+  "nghe-api",
+  "nghe-proc-macro",
+  "nghe-backend",
 ]
 
 [workspace.package]
 version = "0.9.10"
 edition = "2021"
 
+[workspace.lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = ["cfg(rust_analyzer)"] }
+
+[workspace.lints.clippy]
+pedantic = { level = "deny", priority = -1 }
+cast_possible_wrap = { level = "allow", priority = 0 }
+duplicated_attributes = { level = "allow", priority = 0 }
+missing_panics_doc = { level = "allow", priority = 0 }
+must_use_candidate = { level = "allow", priority = 0 }
+return_self_not_must_use = { level = "allow", priority = 0 }
+struct_excessive_bools = { level = "allow", priority = 0 }
+wildcard_imports = { level = "allow", priority = 0 }
+
 [package]
 name = "nghe"
 version = { workspace = true }
@@ -18,9 +34,19 @@ edition = { workspace = true }
 
 [workspace.dependencies]
 anyhow = { version = "1.0.86", features = ["backtrace"] }
+bitcode = { git = "https://github.com/vnghia/bitcode.git", rev = "5f6a56f", features = [
+  "uuid",
+] }
+bon = { version = "3.0.1" }
+color-eyre = { version = "0.6.3" }
 concat-string = { version = "1.0.1" }
+const_format = { version = "0.2.32", features = ["fmt"] }
 constcat = { version = "0.5.0" }
+convert_case = { version = "0.6.0" }
 derivative = { version = "2.2.0" }
+derive-new = { version = "0.6.0" }
+educe = { version = "0.6.0" }
+faster-hex = { version = "0.10.0" }
 hex = { version = "0.4.3" }
 isolang = { version = "2.4.0", default-features = false, features = ["serde"] }
 itertools = { version = "0.12.1" }
@@ -37,18 +63,13 @@ reqwest = { version = "0.12.5", default-features = false, features = [
   "json",
   "http2",
 ] }
+rstest = { version = "0.22.0" }
 thiserror = { version = "1.0.61" }
-tokio = { version = "1.38.0", features = ["full"] }
 url = { version = "2.5.2" }
 
 # Dev
 serde_json = { version = "1.0.120" }
-fake = { version = "2.9.2", features = [
-  "derive",
-  "uuid",
-  "serde_json",
-  "time",
-] }
+fake = { version = "3.0.1", features = ["derive", "uuid", "time"] }
 
 [dependencies]
 anyhow = { workspace = true }
@@ -66,7 +87,6 @@ serde_with = { workspace = true }
 strum = { workspace = true }
 thiserror = { workspace = true }
 time = { workspace = true }
-tokio = { workspace = true }
 tracing = { workspace = true }
 uuid = { workspace = true }
 
@@ -113,6 +133,7 @@ rspotify = { version = "0.13.2", default-features = false, features = [
   "client-reqwest",
   "reqwest-rustls-tls",
 ] }
+tokio = { version = "1.40.0", features = ["full"] }
 tokio-postgres = { version = "0.7.10" }
 tokio-util = { version = "0.7.11", features = ["io"] }
 tower = { version = "0.5.0", features = ["util"] }
@@ -138,6 +159,9 @@ uuid = { version = "1.9.1", features = ["v4", "fast-rng"] }
 [target.'cfg(not(any(target_env = "musl", all(target_arch = "aarch64", target_os = "linux"))))'.dev-dependencies]
 diesel = { version = "2.2.2", features = ["postgres"] }
 
+[profile.dev.package.backtrace]
+opt-level = 3
+
 [profile.release]
 opt-level = 3
 strip = "debuginfo"
diff --git a/diesel.toml b/diesel.toml
index eabd2d6c0..d1dd4724a 100644
--- a/diesel.toml
+++ b/diesel.toml
@@ -2,10 +2,10 @@
 # see https://diesel.rs/guides/configuring-diesel-cli
 
 [print_schema]
-file = "src/schema.rs"
+file = "nghe-backend/src/schema.rs"
 custom_type_derives = ["diesel::query_builder::QueryId"]
 import_types = ["diesel::sql_types::*", "diesel_full_text_search::*"]
 generate_missing_sql_type_definitions = false
 
 [migrations_directory]
-dir = "migrations"
+dir = "nghe-backend/migrations"
diff --git a/lastfm-client/Cargo.toml b/lastfm-client/Cargo.toml
index 858739ddc..4b6b9693d 100644
--- a/lastfm-client/Cargo.toml
+++ b/lastfm-client/Cargo.toml
@@ -20,4 +20,4 @@ serde_repr = { version = "0.1.19" }
 [dev-dependencies]
 fake = { workspace = true }
 serde_json = { workspace = true }
-tokio = { workspace = true, features = ["macros"] }
+tokio = { version = "1", features = ["macros"] }
diff --git a/migrations/2024-09-01-050600_add_music_folders_created_at/down.sql b/migrations/2024-09-01-050600_add_music_folders_created_at/down.sql
new file mode 100644
index 000000000..de6d203a1
--- /dev/null
+++ b/migrations/2024-09-01-050600_add_music_folders_created_at/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+alter table music_folders drop column created_at;
diff --git a/migrations/2024-09-01-050600_add_music_folders_created_at/up.sql b/migrations/2024-09-01-050600_add_music_folders_created_at/up.sql
new file mode 100644
index 000000000..b2adff483
--- /dev/null
+++ b/migrations/2024-09-01-050600_add_music_folders_created_at/up.sql
@@ -0,0 +1,3 @@
+-- Your SQL goes here
+alter table music_folders
+add column created_at timestamptz not null default now();
diff --git a/nghe-api/Cargo.toml b/nghe-api/Cargo.toml
new file mode 100644
index 000000000..dd6546933
--- /dev/null
+++ b/nghe-api/Cargo.toml
@@ -0,0 +1,36 @@
+[package]
+name = "nghe_api"
+version = { workspace = true }
+edition = { workspace = true }
+
+[lints]
+workspace = true
+
+[dependencies]
+bitcode = { workspace = true }
+bon = { workspace = true }
+const_format = { workspace = true }
+faster-hex = { workspace = true }
+serde = { workspace = true }
+serde_with = { workspace = true }
+strum = { workspace = true }
+uuid = { workspace = true }
+
+fake = { workspace = true, optional = true }
+
+nghe_proc_macro = { path = "../nghe-proc-macro" }
+
+md5 = { version = "0.7.0" }
+paste = { version = "1.0.15" }
+
+[dev-dependencies]
+fake = { workspace = true }
+rstest = { workspace = true }
+serde_json = { workspace = true }
+serde_html_form = { workspace = true }
+
+[build-dependencies]
+built = { version = "0.7.3", features = ["git2"] }
+
+[features]
+test = ["fake"]
diff --git a/nghe-api/build.rs b/nghe-api/build.rs
new file mode 100644
index 000000000..4cae17a2f
--- /dev/null
+++ b/nghe-api/build.rs
@@ -0,0 +1,3 @@
+fn main() {
+    built::write_built_file().expect("Could not acquire build-time information");
+}
diff --git a/nghe-api/src/auth/mod.rs b/nghe-api/src/auth/mod.rs
new file mode 100644
index 000000000..bfce92b67
--- /dev/null
+++ b/nghe-api/src/auth/mod.rs
@@ -0,0 +1,75 @@
+mod token;
+
+use nghe_proc_macro::api_derive;
+pub use token::Token;
+
+#[api_derive(request = true, response = true, fake = false)]
+#[derive(Clone, Copy)]
+pub struct Auth<'u, 't> {
+    #[serde(rename = "u")]
+    pub username: &'u str,
+    #[serde(rename = "s")]
+    pub salt: &'t str,
+    #[serde(rename = "t")]
+    pub token: Token,
+}
+
+#[api_derive(json = false, fake = false)]
+pub struct AuthRequest<'u, 't, R> {
+    pub auth: Auth<'u, 't>,
+    pub request: R,
+}
+
+impl Auth<'_, '_> {
+    pub fn tokenize(password: impl AsRef<[u8]>, salt: impl AsRef<[u8]>) -> Token {
+        let password = password.as_ref();
+        let salt = salt.as_ref();
+
+        let mut data = Vec::with_capacity(password.len() + salt.len());
+        data.extend_from_slice(password);
+        data.extend_from_slice(salt);
+        Token(md5::compute(data).into())
+    }
+
+    pub fn check(password: impl AsRef<[u8]>, salt: impl AsRef<[u8]>, token: &Token) -> bool {
+        let password = password.as_ref();
+        let salt = salt.as_ref();
+
+        let password_token = Self::tokenize(password, salt);
+        &password_token == token
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::faker::internet::en::Password;
+    use fake::Fake;
+    use serde_json::{from_value, json};
+
+    use super::*;
+
+    #[test]
+    fn test_tokenize() {
+        assert_eq!(
+            from_value::<Token>(json!("26719a1196d2a940705a59634eb18eab")).unwrap(),
+            Auth::tokenize(b"sesame", b"c19b2d")
+        );
+    }
+
+    #[test]
+    fn test_check_success() {
+        let password = Password(16..32).fake::<String>().into_bytes();
+        let client_salt = Password(8..16).fake::<String>().into_bytes();
+        let client_token = Auth::tokenize(&password, &client_salt);
+        assert!(Auth::check(password, client_salt, &client_token));
+    }
+
+    #[test]
+    fn test_check_failed() {
+        let password = Password(16..32).fake::<String>().into_bytes();
+        let client_salt = Password(8..16).fake::<String>().into_bytes();
+        let wrong_client_salt = Password(8..16).fake::<String>().into_bytes();
+        let client_token = Auth::tokenize(&password, client_salt);
+        assert!(!Auth::check(password, wrong_client_salt, &client_token));
+    }
+}
diff --git a/nghe-api/src/auth/token.rs b/nghe-api/src/auth/token.rs
new file mode 100644
index 000000000..27a1acde5
--- /dev/null
+++ b/nghe-api/src/auth/token.rs
@@ -0,0 +1,32 @@
+use nghe_proc_macro::api_derive;
+
+#[api_derive(request = true, response = true, json = false, eq = false)]
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub struct Token(pub [u8; 16]);
+
+mod serde {
+    use ::serde::{de, Deserialize, Deserializer, Serialize, Serializer};
+
+    use super::*;
+
+    impl Serialize for Token {
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: Serializer,
+        {
+            faster_hex::nopfx_ignorecase::serialize(self.0, serializer)
+        }
+    }
+
+    impl<'de> Deserialize<'de> for Token {
+        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where
+            D: Deserializer<'de>,
+        {
+            let data: Vec<u8> = faster_hex::nopfx_ignorecase::deserialize(deserializer)?;
+            Ok(Token(data.try_into().map_err(|_| {
+                de::Error::custom("Could not convert vector to array of length 16")
+            })?))
+        }
+    }
+}
diff --git a/nghe-api/src/browsing/get_album.rs b/nghe-api/src/browsing/get_album.rs
new file mode 100644
index 000000000..a7d9fff8d
--- /dev/null
+++ b/nghe-api/src/browsing/get_album.rs
@@ -0,0 +1,15 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use crate::id3;
+
+#[api_derive]
+#[endpoint(path = "getAlbum")]
+pub struct Request {
+    pub id: Uuid,
+}
+
+#[api_derive]
+pub struct Response {
+    pub album: id3::album::Full,
+}
diff --git a/nghe-api/src/browsing/get_album_info2.rs b/nghe-api/src/browsing/get_album_info2.rs
new file mode 100644
index 000000000..323b05c77
--- /dev/null
+++ b/nghe-api/src/browsing/get_album_info2.rs
@@ -0,0 +1,22 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+#[api_derive]
+#[endpoint(path = "getAlbumInfo2")]
+pub struct Request {
+    pub id: Uuid,
+}
+
+#[serde_with::apply(
+    Option => #[serde(skip_serializing_if = "Option::is_none")],
+)]
+#[api_derive(response = true)]
+pub struct AlbumInfo {
+    // TODO: add notes field
+    pub music_brainz_id: Option<Uuid>,
+}
+
+#[api_derive]
+pub struct Response {
+    pub album_info: AlbumInfo,
+}
diff --git a/nghe-api/src/browsing/get_artist.rs b/nghe-api/src/browsing/get_artist.rs
new file mode 100644
index 000000000..55d4c14b2
--- /dev/null
+++ b/nghe-api/src/browsing/get_artist.rs
@@ -0,0 +1,15 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use crate::id3;
+
+#[api_derive]
+#[endpoint(path = "getArtist")]
+pub struct Request {
+    pub id: Uuid,
+}
+
+#[api_derive]
+pub struct Response {
+    pub artist: id3::artist::Full,
+}
diff --git a/nghe-api/src/browsing/get_artist_info2.rs b/nghe-api/src/browsing/get_artist_info2.rs
new file mode 100644
index 000000000..5ab60a4b7
--- /dev/null
+++ b/nghe-api/src/browsing/get_artist_info2.rs
@@ -0,0 +1,22 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+#[api_derive]
+#[endpoint(path = "getArtistInfo2")]
+pub struct Request {
+    pub id: Uuid,
+}
+
+#[serde_with::apply(
+    Option => #[serde(skip_serializing_if = "Option::is_none")],
+)]
+#[api_derive(response = true)]
+pub struct ArtistInfo2 {
+    // TODO: add biography and lastfm url field
+    pub music_brainz_id: Option<Uuid>,
+}
+
+#[api_derive]
+pub struct Response {
+    pub artist_info2: ArtistInfo2,
+}
diff --git a/nghe-api/src/browsing/get_artists.rs b/nghe-api/src/browsing/get_artists.rs
new file mode 100644
index 000000000..6540be1a0
--- /dev/null
+++ b/nghe-api/src/browsing/get_artists.rs
@@ -0,0 +1,28 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use crate::id3;
+
+#[api_derive]
+#[endpoint(path = "getArtists")]
+pub struct Request {
+    #[serde(rename = "musicFolderId")]
+    pub music_folder_ids: Option<Vec<Uuid>>,
+}
+
+#[api_derive(response = true)]
+pub struct Index {
+    pub name: String,
+    pub artist: Vec<id3::artist::Artist>,
+}
+
+#[api_derive(response = true)]
+pub struct Artists {
+    pub ignored_articles: String,
+    pub index: Vec<Index>,
+}
+
+#[api_derive]
+pub struct Response {
+    pub artists: Artists,
+}
diff --git a/nghe-api/src/browsing/get_genres.rs b/nghe-api/src/browsing/get_genres.rs
new file mode 100644
index 000000000..eb464662c
--- /dev/null
+++ b/nghe-api/src/browsing/get_genres.rs
@@ -0,0 +1,17 @@
+use nghe_proc_macro::api_derive;
+
+use crate::id3;
+
+#[api_derive]
+#[endpoint(path = "getGenres")]
+pub struct Request {}
+
+#[api_derive(response = true)]
+pub struct Genres {
+    pub genre: Vec<id3::genre::WithCount>,
+}
+
+#[api_derive]
+pub struct Response {
+    pub genres: Genres,
+}
diff --git a/nghe-api/src/browsing/get_music_folders.rs b/nghe-api/src/browsing/get_music_folders.rs
new file mode 100644
index 000000000..0bb6560ff
--- /dev/null
+++ b/nghe-api/src/browsing/get_music_folders.rs
@@ -0,0 +1,22 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+#[api_derive]
+#[endpoint(path = "getMusicFolders")]
+pub struct Request {}
+
+#[api_derive(response = true)]
+pub struct MusicFolder {
+    pub id: Uuid,
+    pub name: String,
+}
+
+#[api_derive(response = true)]
+pub struct MusicFolders {
+    pub music_folder: Vec<MusicFolder>,
+}
+
+#[api_derive]
+pub struct Response {
+    pub music_folders: MusicFolders,
+}
diff --git a/nghe-api/src/browsing/get_song.rs b/nghe-api/src/browsing/get_song.rs
new file mode 100644
index 000000000..aff305c01
--- /dev/null
+++ b/nghe-api/src/browsing/get_song.rs
@@ -0,0 +1,15 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use crate::id3;
+
+#[api_derive]
+#[endpoint(path = "getSong")]
+pub struct Request {
+    pub id: Uuid,
+}
+
+#[api_derive]
+pub struct Response {
+    pub song: id3::song::Full,
+}
diff --git a/nghe-api/src/browsing/get_top_songs.rs b/nghe-api/src/browsing/get_top_songs.rs
new file mode 100644
index 000000000..0ac50e882
--- /dev/null
+++ b/nghe-api/src/browsing/get_top_songs.rs
@@ -0,0 +1,20 @@
+use nghe_proc_macro::api_derive;
+
+use crate::id3;
+
+#[api_derive]
+#[endpoint(path = "getTopSongs")]
+pub struct Request {
+    pub artist: String,
+    pub count: Option<u32>,
+}
+
+#[api_derive(response = true)]
+pub struct TopSongs {
+    pub song: Vec<id3::song::Full>,
+}
+
+#[api_derive]
+pub struct Response {
+    pub top_songs: TopSongs,
+}
diff --git a/nghe-api/src/browsing/mod.rs b/nghe-api/src/browsing/mod.rs
new file mode 100644
index 000000000..76eb94ed7
--- /dev/null
+++ b/nghe-api/src/browsing/mod.rs
@@ -0,0 +1,9 @@
+pub mod get_album;
+pub mod get_album_info2;
+pub mod get_artist;
+pub mod get_artist_info2;
+pub mod get_artists;
+pub mod get_genres;
+pub mod get_music_folders;
+pub mod get_song;
+pub mod get_top_songs;
diff --git a/nghe-api/src/common/filesystem.rs b/nghe-api/src/common/filesystem.rs
new file mode 100644
index 000000000..d4fd2d041
--- /dev/null
+++ b/nghe-api/src/common/filesystem.rs
@@ -0,0 +1,11 @@
+use std::marker::ConstParamTy;
+
+use nghe_proc_macro::api_derive;
+
+#[repr(i16)]
+#[api_derive(request = true)]
+#[derive(ConstParamTy)]
+pub enum Type {
+    Local,
+    S3,
+}
diff --git a/nghe-api/src/common/format.rs b/nghe-api/src/common/format.rs
new file mode 100644
index 000000000..d0a8bbbb1
--- /dev/null
+++ b/nghe-api/src/common/format.rs
@@ -0,0 +1,37 @@
+use nghe_proc_macro::api_derive;
+use strum::{EnumString, IntoStaticStr};
+
+pub trait Trait: Copy {
+    fn mime(&self) -> &'static str;
+    fn extension(&self) -> &'static str;
+}
+
+#[api_derive(request = true)]
+#[derive(IntoStaticStr, EnumString)]
+#[strum(serialize_all = "lowercase")]
+#[cfg_attr(feature = "test", derive(strum::AsRefStr))]
+pub enum Transcode {
+    Aac,
+    Flac,
+    Mp3,
+    Opus,
+    Wav,
+    Wma,
+}
+
+impl Trait for Transcode {
+    fn mime(&self) -> &'static str {
+        match self {
+            Self::Aac => "audio/aac",
+            Self::Flac => "audio/flac",
+            Self::Mp3 => "audio/mpeg",
+            Self::Opus => "audio/ogg",
+            Self::Wav => "audio/wav",
+            Self::Wma => "audio/x-ms-wma",
+        }
+    }
+
+    fn extension(&self) -> &'static str {
+        self.into()
+    }
+}
diff --git a/nghe-api/src/common/mod.rs b/nghe-api/src/common/mod.rs
new file mode 100644
index 000000000..1557c2682
--- /dev/null
+++ b/nghe-api/src/common/mod.rs
@@ -0,0 +1,160 @@
+pub mod filesystem;
+pub mod format;
+pub mod typed_uuid;
+
+use bitcode::{DecodeOwned, Encode};
+use nghe_proc_macro::api_derive;
+use serde::de::DeserializeOwned;
+use serde::{Serialize, Serializer};
+
+use super::constant;
+
+#[api_derive(debug = false, binary = false)]
+struct RootResponse<B> {
+    #[serde(serialize_with = "emit_open_subsonic_version")]
+    version: (),
+    #[serde(serialize_with = "emit_server_type")]
+    r#type: (),
+    #[serde(serialize_with = "emit_server_version")]
+    server_version: (),
+    #[serde(serialize_with = "emit_open_subsonic")]
+    open_subsonic: (),
+    #[serde(serialize_with = "emit_status_ok")]
+    status: (),
+    #[serde(flatten)]
+    body: B,
+}
+
+#[api_derive(debug = false, binary = false)]
+pub struct SubsonicResponse<B> {
+    #[serde(rename = "subsonic-response")]
+    root: RootResponse<B>,
+}
+
+pub trait JsonURL {
+    const URL: &'static str;
+    const URL_VIEW: &'static str;
+}
+
+pub trait JsonRequest = JsonURL + DeserializeOwned;
+
+pub trait JsonEndpoint: JsonRequest {
+    type Response: Serialize;
+}
+
+pub trait BinaryURL {
+    const URL_BINARY: &'static str;
+}
+
+pub trait BinaryRequest = BinaryURL + Encode + DecodeOwned;
+
+pub trait BinaryEndpoint: BinaryRequest {
+    type Response: Encode + DecodeOwned;
+}
+
+impl<B> SubsonicResponse<B> {
+    pub fn new(body: B) -> Self {
+        Self {
+            root: RootResponse {
+                version: (),
+                r#type: (),
+                server_version: (),
+                open_subsonic: (),
+                status: (),
+                body,
+            },
+        }
+    }
+
+    pub fn body(self) -> B {
+        self.root.body
+    }
+}
+
+macro_rules! emit_constant_serialize {
+    ($constant_name:ident, $constant_type:ty, $constant_value:expr) => {
+        paste::paste! {
+            fn [<emit_ $constant_name>]<S: Serializer>(_: &(), s: S) -> Result<S::Ok, S::Error> {
+                s.[<serialize_ $constant_type>]($constant_value)
+            }
+        }
+    };
+}
+
+emit_constant_serialize!(open_subsonic_version, str, constant::OPEN_SUBSONIC_VERSION);
+emit_constant_serialize!(server_type, str, constant::SERVER_NAME);
+emit_constant_serialize!(server_version, str, constant::SERVER_VERSION);
+emit_constant_serialize!(open_subsonic, bool, true);
+emit_constant_serialize!(status_ok, str, "ok");
+
+#[cfg(test)]
+mod tests {
+    use serde_json::{json, to_value};
+
+    use super::*;
+
+    #[test]
+    fn test_serialize_empty() {
+        #[api_derive(request = true, response = true, debug = false, binary = false)]
+        struct TestBody {}
+
+        assert_eq!(
+            to_value(SubsonicResponse::new(TestBody {})).unwrap(),
+            json!({
+                "subsonic-response": {
+                    "status": "ok",
+                    "version": constant::OPEN_SUBSONIC_VERSION,
+                    "type": constant::SERVER_NAME,
+                    "serverVersion": constant::SERVER_VERSION,
+                    "openSubsonic": true
+                }
+            })
+        );
+    }
+
+    #[test]
+    fn test_serialize() {
+        #[api_derive(request = true, response = true, debug = false, binary = false)]
+        struct TestBody {
+            field: u16,
+        }
+        let field = 10;
+
+        assert_eq!(
+            to_value(SubsonicResponse::new(TestBody { field })).unwrap(),
+            json!({
+                "subsonic-response": {
+                    "field": field,
+                    "status": "ok",
+                    "version": constant::OPEN_SUBSONIC_VERSION,
+                    "type": constant::SERVER_NAME,
+                    "serverVersion": constant::SERVER_VERSION,
+                    "openSubsonic": true
+                }
+            })
+        );
+    }
+
+    #[test]
+    fn test_serialize_case() {
+        #[api_derive(request = true, response = true, debug = false, binary = false)]
+        struct TestBody {
+            snake_case: u16,
+        }
+        let snake_case = 10;
+
+        assert_eq!(
+            to_value(SubsonicResponse::new(TestBody { snake_case })).unwrap(),
+            json!({
+                "subsonic-response": {
+                    "snakeCase": snake_case,
+                    "status": "ok",
+                    "version": constant::OPEN_SUBSONIC_VERSION,
+                    "type": constant::SERVER_NAME,
+                    "serverVersion": constant::SERVER_VERSION,
+                    "openSubsonic": true
+                }
+            })
+        );
+    }
+}
diff --git a/nghe-api/src/common/typed_uuid.rs b/nghe-api/src/common/typed_uuid.rs
new file mode 100644
index 000000000..ea8bc9448
--- /dev/null
+++ b/nghe-api/src/common/typed_uuid.rs
@@ -0,0 +1,131 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+#[api_derive(request = true, response = true, json = false)]
+pub enum Type {
+    Artist,
+    Album,
+    Song,
+}
+
+#[api_derive(request = true, response = true, json = false)]
+pub struct TypedUuid {
+    pub ty: Type,
+    pub id: Uuid,
+}
+
+mod serde {
+    use core::str;
+    use std::str::FromStr;
+
+    use ::serde::{de, ser, Deserialize, Deserializer, Serialize, Serializer};
+    use serde_with::DeserializeAs;
+
+    use super::*;
+
+    const SIMPLE_LENGTH: usize = uuid::fmt::Simple::LENGTH;
+    const BUFFER_LENGTH: usize = SIMPLE_LENGTH + 2;
+    const ARTIST_BYTE: &[u8; 2] = b"ar";
+    const ALBUM_BYTE: &[u8; 2] = b"al";
+    const SONG_BYTE: &[u8; 2] = b"so";
+
+    impl Serialize for TypedUuid {
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: Serializer,
+        {
+            let mut buffer = [0u8; BUFFER_LENGTH];
+            buffer[SIMPLE_LENGTH..BUFFER_LENGTH].copy_from_slice(match self.ty {
+                Type::Artist => ARTIST_BYTE,
+                Type::Album => ALBUM_BYTE,
+                Type::Song => SONG_BYTE,
+            });
+            self.id.simple().encode_lower(&mut buffer);
+            serializer.serialize_str(str::from_utf8(&buffer).map_err(ser::Error::custom)?)
+        }
+    }
+
+    impl<'de> Deserialize<'de> for TypedUuid {
+        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where
+            D: Deserializer<'de>,
+        {
+            let buffer: [u8; BUFFER_LENGTH] = serde_with::Bytes::deserialize_as(deserializer)?;
+
+            let ty_buffer: &[u8; 2] =
+                &buffer[SIMPLE_LENGTH..BUFFER_LENGTH].try_into().map_err(de::Error::custom)?;
+            let ty = match ty_buffer {
+                ARTIST_BYTE => Type::Artist,
+                ALBUM_BYTE => Type::Album,
+                SONG_BYTE => Type::Song,
+                _ => return Err(de::Error::custom("uuid type is invalid")),
+            };
+
+            let id = Uuid::from_str(
+                str::from_utf8(&buffer[..SIMPLE_LENGTH]).map_err(de::Error::custom)?,
+            )
+            .map_err(de::Error::custom)?;
+
+            Ok(Self { ty, id })
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+    use uuid::uuid;
+
+    use super::*;
+
+    #[api_derive(request = true, response = true)]
+    struct Test {
+        pub id: TypedUuid,
+    }
+
+    #[rstest]
+    #[case(
+        "id=a5b704dc8a7d4ff194896f8cc8890621ar",
+        Some(TypedUuid { ty: Type::Artist, id: uuid!("a5b704dc-8a7d-4ff1-9489-6f8cc8890621") })
+    )]
+    #[case(
+        "id=d22aee56cb844605b6a18e3b6d3aff72al",
+        Some(TypedUuid { ty: Type::Album, id: uuid!("d22aee56-cb84-4605-b6a1-8e3b6d3aff72") })
+    )]
+    #[case(
+        "id=e57894fcfcfb442fa09f9c5844232bd0so",
+        Some(TypedUuid { ty: Type::Song, id: uuid!("e57894fc-fcfb-442f-a09f-9c5844232bd0") })
+    )]
+    #[case("id=e57894fcfcfb442fa09f9c5844232bd0in", None)]
+    #[case("id=invalidar", None)]
+    fn test_deserialize(#[case] input: &str, #[case] typed_uuid: Option<TypedUuid>) {
+        assert_eq!(serde_html_form::from_str(input).ok(), typed_uuid.map(|id| Test { id }));
+    }
+
+    #[rstest]
+    #[case(
+        TypedUuid { ty: Type::Artist, id: uuid!("2fcc59a3-ae4e-496c-a981-74eb04827ef1") },
+        "id=2fcc59a3ae4e496ca98174eb04827ef1ar",
+    )]
+    #[case(
+        TypedUuid { ty: Type::Album, id: uuid!("3742eefb-1a9c-4c37-8653-ef07d12bdc31") },
+        "id=3742eefb1a9c4c378653ef07d12bdc31al",
+    )]
+    #[case(
+        TypedUuid { ty: Type::Song, id: uuid!("48c02916-0d4c-417d-ae61-1b1c36eb3e42") },
+        "id=48c029160d4c417dae611b1c36eb3e42so",
+    )]
+    fn test_serialize(#[case] typed_uuid: TypedUuid, #[case] result: &str) {
+        assert_eq!(serde_html_form::to_string(Test { id: typed_uuid }).unwrap(), result);
+    }
+
+    #[rstest]
+    fn test_roundtrip() {
+        let test = Test { id: Faker.fake() };
+        assert_eq!(
+            test,
+            serde_html_form::from_str(&serde_html_form::to_string(&test).unwrap()).unwrap()
+        );
+    }
+}
diff --git a/nghe-api/src/constant.rs b/nghe-api/src/constant.rs
new file mode 100644
index 000000000..40d88677b
--- /dev/null
+++ b/nghe-api/src/constant.rs
@@ -0,0 +1,12 @@
+mod built_info {
+    include!(concat!(env!("OUT_DIR"), "/built.rs"));
+}
+
+pub const OPEN_SUBSONIC_VERSION: &str = "1.16.1";
+pub const SERVER_NAME: &str = "nghe";
+pub const SERVER_VERSION: &str = const_format::concatc!(
+    built_info::PKG_VERSION,
+    " (",
+    built_info::GIT_COMMIT_HASH_SHORT.unwrap(),
+    ")"
+);
diff --git a/nghe-api/src/id3/album/full.rs b/nghe-api/src/id3/album/full.rs
new file mode 100644
index 000000000..56ba78544
--- /dev/null
+++ b/nghe-api/src/id3/album/full.rs
@@ -0,0 +1,16 @@
+use nghe_proc_macro::api_derive;
+
+use super::Album;
+use crate::id3::{artist, song};
+
+#[serde_with::apply(
+    Vec => #[serde(skip_serializing_if = "Vec::is_empty")],
+)]
+#[api_derive(response = true)]
+pub struct Full {
+    #[serde(flatten)]
+    pub album: Album,
+    pub artists: Vec<artist::Required>,
+    pub is_compilation: bool,
+    pub song: Vec<song::Song>,
+}
diff --git a/nghe-api/src/id3/album/mod.rs b/nghe-api/src/id3/album/mod.rs
new file mode 100644
index 000000000..2a92fa825
--- /dev/null
+++ b/nghe-api/src/id3/album/mod.rs
@@ -0,0 +1,36 @@
+mod full;
+
+use bon::Builder;
+pub use full::Full;
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use super::{artist, date, genre};
+
+#[serde_with::apply(
+    Option => #[serde(skip_serializing_if = "Option::is_none")],
+    Vec => #[serde(skip_serializing_if = "Vec::is_empty")],
+    date::Date => #[serde(skip_serializing_if = "date::Date::is_none")],
+    genre::Genres => #[serde(skip_serializing_if = "genre::Genres::is_empty")],
+)]
+#[api_derive(response = true)]
+#[derive(Builder)]
+#[builder(on(_, required))]
+#[builder(state_mod(vis = "pub"))]
+pub struct Album {
+    pub id: Uuid,
+    pub name: String,
+    pub cover_art: Option<Uuid>,
+    pub song_count: u16,
+    pub duration: u32,
+    pub year: Option<u16>,
+    pub music_brainz_id: Option<Uuid>,
+    #[builder(default)]
+    pub genres: genre::Genres,
+    #[builder(default)]
+    pub artists: Vec<artist::Artist>,
+    #[builder(default)]
+    pub original_release_date: date::Date,
+    #[builder(default)]
+    pub release_date: date::Date,
+}
diff --git a/nghe-api/src/id3/artist/full.rs b/nghe-api/src/id3/artist/full.rs
new file mode 100644
index 000000000..4a5938de5
--- /dev/null
+++ b/nghe-api/src/id3/artist/full.rs
@@ -0,0 +1,14 @@
+use nghe_proc_macro::api_derive;
+
+use super::Artist;
+use crate::id3::album;
+
+#[serde_with::apply(
+    Vec => #[serde(skip_serializing_if = "Vec::is_empty")],
+)]
+#[api_derive(response = true)]
+pub struct Full {
+    #[serde(flatten)]
+    pub artist: Artist,
+    pub album: Vec<album::Album>,
+}
diff --git a/nghe-api/src/id3/artist/mod.rs b/nghe-api/src/id3/artist/mod.rs
new file mode 100644
index 000000000..6c160ea88
--- /dev/null
+++ b/nghe-api/src/id3/artist/mod.rs
@@ -0,0 +1,49 @@
+mod full;
+mod required;
+
+use bon::Builder;
+pub use full::Full;
+use nghe_proc_macro::api_derive;
+pub use required::Required;
+use strum::IntoStaticStr;
+use uuid::Uuid;
+
+#[api_derive(response = true, json = false)]
+#[derive(IntoStaticStr)]
+#[strum(serialize_all = "lowercase")]
+pub enum Role {
+    Artist,
+    AlbumArtist,
+}
+
+#[serde_with::apply(
+    Option => #[serde(skip_serializing_if = "Option::is_none")],
+    Vec => #[serde(skip_serializing_if = "Vec::is_empty")],
+)]
+#[api_derive(response = true)]
+#[derive(Builder)]
+#[builder(on(_, required))]
+#[builder(state_mod(vis = "pub"))]
+pub struct Artist {
+    #[serde(flatten)]
+    pub required: Required,
+    pub album_count: u16,
+    pub music_brainz_id: Option<Uuid>,
+    #[builder(default)]
+    pub roles: Vec<Role>,
+}
+
+mod serde {
+    use ::serde::{Serialize, Serializer};
+
+    use super::*;
+
+    impl Serialize for Role {
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: Serializer,
+        {
+            serializer.serialize_str(self.into())
+        }
+    }
+}
diff --git a/nghe-api/src/id3/artist/required.rs b/nghe-api/src/id3/artist/required.rs
new file mode 100644
index 000000000..5e14a8c16
--- /dev/null
+++ b/nghe-api/src/id3/artist/required.rs
@@ -0,0 +1,8 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+#[api_derive(response = true)]
+pub struct Required {
+    pub id: Uuid,
+    pub name: String,
+}
diff --git a/nghe-api/src/id3/date.rs b/nghe-api/src/id3/date.rs
new file mode 100644
index 000000000..e825f3e7b
--- /dev/null
+++ b/nghe-api/src/id3/date.rs
@@ -0,0 +1,18 @@
+use nghe_proc_macro::api_derive;
+
+#[serde_with::apply(
+    Option => #[serde(skip_serializing_if = "Option::is_none")],
+)]
+#[api_derive(response = true)]
+#[derive(Default)]
+pub struct Date {
+    pub year: Option<u16>,
+    pub month: Option<u8>,
+    pub day: Option<u8>,
+}
+
+impl Date {
+    pub fn is_none(&self) -> bool {
+        self.year.is_none()
+    }
+}
diff --git a/nghe-api/src/id3/genre/mod.rs b/nghe-api/src/id3/genre/mod.rs
new file mode 100644
index 000000000..0b67060be
--- /dev/null
+++ b/nghe-api/src/id3/genre/mod.rs
@@ -0,0 +1,35 @@
+mod with_count;
+
+use nghe_proc_macro::api_derive;
+pub use with_count::WithCount;
+
+#[api_derive(response = true)]
+#[cfg_attr(feature = "test", derive(Clone, Hash))]
+pub struct Genre {
+    pub name: String,
+}
+
+#[api_derive(response = true)]
+#[derive(Default)]
+#[serde(transparent)]
+pub struct Genres {
+    pub value: Vec<Genre>,
+}
+
+impl Genres {
+    pub fn is_empty(&self) -> bool {
+        self.value.is_empty()
+    }
+}
+
+impl<S: Into<String>> From<S> for Genre {
+    fn from(genre: S) -> Self {
+        Self { name: genre.into() }
+    }
+}
+
+impl<S: Into<String>> FromIterator<S> for Genres {
+    fn from_iter<T: IntoIterator<Item = S>>(iter: T) -> Self {
+        Self { value: iter.into_iter().map(Genre::from).collect() }
+    }
+}
diff --git a/nghe-api/src/id3/genre/with_count.rs b/nghe-api/src/id3/genre/with_count.rs
new file mode 100644
index 000000000..c66e97b7b
--- /dev/null
+++ b/nghe-api/src/id3/genre/with_count.rs
@@ -0,0 +1,8 @@
+use nghe_proc_macro::api_derive;
+
+#[api_derive(response = true)]
+pub struct WithCount {
+    pub value: String,
+    pub song_count: u32,
+    pub album_count: u32,
+}
diff --git a/nghe-api/src/id3/mod.rs b/nghe-api/src/id3/mod.rs
new file mode 100644
index 000000000..b7582260d
--- /dev/null
+++ b/nghe-api/src/id3/mod.rs
@@ -0,0 +1,22 @@
+pub mod album;
+pub mod artist;
+pub mod date;
+pub mod genre;
+pub mod song;
+
+pub mod builder {
+    pub mod artist {
+        pub use super::super::artist::artist_builder::*;
+        pub use super::super::artist::ArtistBuilder as Builder;
+    }
+
+    pub mod album {
+        pub use super::super::album::album_builder::*;
+        pub use super::super::album::AlbumBuilder as Builder;
+    }
+
+    pub mod song {
+        pub use super::super::song::song_builder::*;
+        pub use super::super::song::SongBuilder as Builder;
+    }
+}
diff --git a/nghe-api/src/id3/song/full.rs b/nghe-api/src/id3/song/full.rs
new file mode 100644
index 000000000..a48b3754d
--- /dev/null
+++ b/nghe-api/src/id3/song/full.rs
@@ -0,0 +1,17 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use super::Song;
+use crate::id3::genre;
+
+#[serde_with::apply(
+    genre::Genres => #[serde(skip_serializing_if = "genre::Genres::is_empty")],
+)]
+#[api_derive(response = true)]
+pub struct Full {
+    #[serde(flatten)]
+    pub song: Song,
+    pub album: String,
+    pub album_id: Uuid,
+    pub genres: genre::Genres,
+}
diff --git a/nghe-api/src/id3/song/mod.rs b/nghe-api/src/id3/song/mod.rs
new file mode 100644
index 000000000..0e886912e
--- /dev/null
+++ b/nghe-api/src/id3/song/mod.rs
@@ -0,0 +1,35 @@
+mod full;
+
+use bon::Builder;
+pub use full::Full;
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use super::artist;
+
+#[serde_with::apply(
+    Option => #[serde(skip_serializing_if = "Option::is_none")],
+    Vec => #[serde(skip_serializing_if = "Vec::is_empty")],
+)]
+#[api_derive(response = true)]
+#[derive(Builder)]
+#[builder(on(_, required))]
+#[builder(state_mod(vis = "pub"))]
+pub struct Song {
+    pub id: Uuid,
+    pub title: String,
+    pub track: Option<u16>,
+    pub year: Option<u16>,
+    pub cover_art: Option<Uuid>,
+    pub size: u32,
+    pub content_type: &'static str,
+    pub suffix: &'static str,
+    pub duration: u32,
+    pub bit_rate: u32,
+    pub bit_depth: Option<u8>,
+    pub sampling_rate: u32,
+    pub channel_count: u8,
+    pub disc_number: Option<u16>,
+    pub artists: Vec<artist::Required>,
+    pub music_brainz_id: Option<Uuid>,
+}
diff --git a/nghe-api/src/lib.rs b/nghe-api/src/lib.rs
new file mode 100644
index 000000000..fe9e26c7b
--- /dev/null
+++ b/nghe-api/src/lib.rs
@@ -0,0 +1,17 @@
+#![feature(adt_const_params)]
+#![feature(trait_alias)]
+
+pub mod auth;
+pub mod browsing;
+pub mod common;
+pub mod constant;
+pub mod id3;
+pub mod lists;
+pub mod media_annotation;
+pub mod media_retrieval;
+pub mod music_folder;
+pub mod permission;
+pub mod scan;
+pub mod search;
+pub mod system;
+pub mod user;
diff --git a/nghe-api/src/lists/get_album_list2.rs b/nghe-api/src/lists/get_album_list2.rs
new file mode 100644
index 000000000..1acd61a27
--- /dev/null
+++ b/nghe-api/src/lists/get_album_list2.rs
@@ -0,0 +1,109 @@
+use nghe_proc_macro::api_derive;
+use serde_with::serde_as;
+use uuid::Uuid;
+
+use crate::id3;
+
+// TODO: Optimize this after https://github.com/serde-rs/serde/issues/1183
+#[serde_as]
+#[api_derive(request = true, test_only = false)]
+#[derive(Clone, Copy)]
+pub struct ByYear {
+    #[serde_as(as = "serde_with::DisplayFromStr")]
+    pub from_year: u16,
+    #[serde_as(as = "serde_with::DisplayFromStr")]
+    pub to_year: u16,
+}
+
+#[api_derive(request = true, copy = false)]
+#[serde(tag = "type")]
+#[cfg_attr(test, derive(Default))]
+pub enum Type {
+    #[cfg_attr(test, default)]
+    Random,
+    Newest,
+    Frequent,
+    Recent,
+    AlphabeticalByName,
+    ByYear(ByYear),
+    ByGenre {
+        genre: String,
+    },
+}
+
+#[api_derive]
+#[endpoint(path = "getAlbumList2")]
+#[cfg_attr(test, derive(Default))]
+pub struct Request {
+    #[serde(flatten, rename = "type")]
+    pub ty: Type,
+    pub size: Option<u32>,
+    pub offset: Option<u32>,
+    #[serde(rename = "musicFolderId")]
+    pub music_folder_ids: Option<Vec<Uuid>>,
+}
+
+#[api_derive(response = true)]
+pub struct AlbumList2 {
+    pub album: Vec<id3::album::Album>,
+}
+
+#[api_derive]
+pub struct Response {
+    pub album_list2: AlbumList2,
+}
+
+#[cfg(test)]
+mod tests {
+    use rstest::rstest;
+
+    use super::*;
+
+    #[rstest]
+    #[case("type=random", Some(Request { ty: Type::Random, ..Default::default() }))]
+    #[case(
+        "type=random&size=10",
+        Some(Request { ty: Type::Random, size: Some(10), ..Default::default() })
+    )]
+    #[case("type=newest", Some(Request { ty: Type::Newest, ..Default::default() }))]
+    #[case("type=frequent", Some(Request { ty: Type::Frequent, ..Default::default() }))]
+    #[case("type=recent", Some(Request { ty: Type::Recent, ..Default::default() }))]
+    #[case(
+        "type=alphabeticalByName",
+        Some(Request { ty: Type::AlphabeticalByName, ..Default::default() })
+    )]
+    #[case(
+        "type=byYear&fromYear=1000&toYear=2000",
+        Some(Request {
+            ty: Type::ByYear (
+               ByYear{ from_year: 1000, to_year: 2000 }
+            ), size: None, ..Default::default()
+        })
+    )]
+    #[case(
+        "type=byYear&fromYear=1000&toYear=2000&size=10",
+        Some(Request {
+            ty: Type::ByYear (
+                ByYear{ from_year: 1000, to_year: 2000 }
+            ), size: Some(10), ..Default::default()
+        })
+    )]
+    #[case(
+        "type=byGenre&genre=Test",
+        Some(Request {
+            ty: Type::ByGenre { genre: "Test".to_owned() }, size: None, ..Default::default()
+        })
+    )]
+    #[case(
+        "type=byGenre&genre=Test&size=10",
+        Some(Request {
+            ty: Type::ByGenre { genre: "Test".to_owned() }, size: Some(10), ..Default::default()
+        })
+    )]
+    #[case("type=byYear&toYear=2000", None)]
+    #[case("type=byYear&fromYear=From&toYear=2000", None)]
+    #[case("type=byGenre", None)]
+    fn test_deserialize(#[case] url: &str, #[case] request: Option<Request>) {
+        assert_eq!(serde_html_form::from_str::<Request>(url).ok(), request);
+    }
+}
diff --git a/nghe-api/src/lists/get_random_songs.rs b/nghe-api/src/lists/get_random_songs.rs
new file mode 100644
index 000000000..df743490d
--- /dev/null
+++ b/nghe-api/src/lists/get_random_songs.rs
@@ -0,0 +1,25 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use crate::id3;
+
+#[api_derive]
+#[endpoint(path = "getRandomSongs")]
+pub struct Request {
+    pub size: Option<u32>,
+    pub genre: Option<String>,
+    pub from_year: Option<u16>,
+    pub to_year: Option<u16>,
+    #[serde(rename = "musicFolderId")]
+    pub music_folder_ids: Option<Vec<Uuid>>,
+}
+
+#[api_derive(response = true)]
+pub struct RandomSong {
+    pub song: Vec<id3::song::Full>,
+}
+
+#[api_derive]
+pub struct Response {
+    pub random_songs: RandomSong,
+}
diff --git a/nghe-api/src/lists/mod.rs b/nghe-api/src/lists/mod.rs
new file mode 100644
index 000000000..ed723d30c
--- /dev/null
+++ b/nghe-api/src/lists/mod.rs
@@ -0,0 +1,2 @@
+pub mod get_album_list2;
+pub mod get_random_songs;
diff --git a/nghe-api/src/media_annotation/mod.rs b/nghe-api/src/media_annotation/mod.rs
new file mode 100644
index 000000000..e8e38e71a
--- /dev/null
+++ b/nghe-api/src/media_annotation/mod.rs
@@ -0,0 +1 @@
+pub mod scrobble;
diff --git a/nghe-api/src/media_annotation/scrobble.rs b/nghe-api/src/media_annotation/scrobble.rs
new file mode 100644
index 000000000..d3cb38344
--- /dev/null
+++ b/nghe-api/src/media_annotation/scrobble.rs
@@ -0,0 +1,15 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+#[api_derive]
+#[endpoint(path = "scrobble")]
+pub struct Request {
+    #[serde(rename = "id")]
+    pub ids: Vec<Uuid>,
+    #[serde(rename = "id")]
+    pub times: Option<Vec<u64>>,
+    pub submission: Option<bool>,
+}
+
+#[api_derive]
+pub struct Response;
diff --git a/nghe-api/src/media_retrieval/download.rs b/nghe-api/src/media_retrieval/download.rs
new file mode 100644
index 000000000..37c90e8f2
--- /dev/null
+++ b/nghe-api/src/media_retrieval/download.rs
@@ -0,0 +1,8 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+#[api_derive]
+#[endpoint(path = "download", url_only = true)]
+pub struct Request {
+    pub id: Uuid,
+}
diff --git a/nghe-api/src/media_retrieval/get_cover_art.rs b/nghe-api/src/media_retrieval/get_cover_art.rs
new file mode 100644
index 000000000..2e84c5ef4
--- /dev/null
+++ b/nghe-api/src/media_retrieval/get_cover_art.rs
@@ -0,0 +1,8 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+#[api_derive]
+#[endpoint(path = "getCoverArt", url_only = true)]
+pub struct Request {
+    pub id: Uuid,
+}
diff --git a/nghe-api/src/media_retrieval/mod.rs b/nghe-api/src/media_retrieval/mod.rs
new file mode 100644
index 000000000..9a6b4f78a
--- /dev/null
+++ b/nghe-api/src/media_retrieval/mod.rs
@@ -0,0 +1,3 @@
+pub mod download;
+pub mod get_cover_art;
+pub mod stream;
diff --git a/nghe-api/src/media_retrieval/stream.rs b/nghe-api/src/media_retrieval/stream.rs
new file mode 100644
index 000000000..482e43a79
--- /dev/null
+++ b/nghe-api/src/media_retrieval/stream.rs
@@ -0,0 +1,50 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use crate::common::format;
+
+#[api_derive(request = true, json = false)]
+#[derive(Default)]
+pub enum Format {
+    #[default]
+    Raw,
+    Transcode(format::Transcode),
+}
+
+#[api_derive]
+#[endpoint(path = "stream", url_only = true)]
+#[derive(Clone, Copy)]
+pub struct Request {
+    pub id: Uuid,
+    pub max_bit_rate: Option<u32>,
+    pub format: Option<Format>,
+    pub time_offset: Option<u32>,
+}
+
+impl From<format::Transcode> for Format {
+    fn from(value: format::Transcode) -> Self {
+        Self::Transcode(value)
+    }
+}
+
+mod serde {
+    use ::serde::{de, Deserialize, Deserializer};
+
+    use super::*;
+
+    impl<'de> Deserialize<'de> for Format {
+        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where
+            D: Deserializer<'de>,
+        {
+            match <&'de str>::deserialize(deserializer)? {
+                "raw" => Ok(Self::Raw),
+                format => {
+                    Ok(Self::Transcode(format.parse().map_err(|_| {
+                        de::Error::custom("Could not parse stream format parameter")
+                    })?))
+                }
+            }
+        }
+    }
+}
diff --git a/nghe-api/src/music_folder/add.rs b/nghe-api/src/music_folder/add.rs
new file mode 100644
index 000000000..0025bdf3b
--- /dev/null
+++ b/nghe-api/src/music_folder/add.rs
@@ -0,0 +1,18 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use crate::common::filesystem;
+
+#[api_derive]
+#[endpoint(path = "addMusicFolder")]
+pub struct Request {
+    pub name: String,
+    pub path: String,
+    pub ty: filesystem::Type,
+    pub allow: bool,
+}
+
+#[api_derive]
+pub struct Response {
+    pub music_folder_id: Uuid,
+}
diff --git a/nghe-api/src/music_folder/mod.rs b/nghe-api/src/music_folder/mod.rs
new file mode 100644
index 000000000..cced7b48f
--- /dev/null
+++ b/nghe-api/src/music_folder/mod.rs
@@ -0,0 +1 @@
+pub mod add;
diff --git a/nghe-api/src/permission/add.rs b/nghe-api/src/permission/add.rs
new file mode 100644
index 000000000..ee86f13e1
--- /dev/null
+++ b/nghe-api/src/permission/add.rs
@@ -0,0 +1,12 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+#[api_derive]
+#[endpoint(path = "addPermission")]
+pub struct Request {
+    pub user_id: Option<Uuid>,
+    pub music_folder_id: Option<Uuid>,
+}
+
+#[api_derive]
+pub struct Response;
diff --git a/nghe-api/src/permission/mod.rs b/nghe-api/src/permission/mod.rs
new file mode 100644
index 000000000..cced7b48f
--- /dev/null
+++ b/nghe-api/src/permission/mod.rs
@@ -0,0 +1 @@
+pub mod add;
diff --git a/nghe-api/src/scan/mod.rs b/nghe-api/src/scan/mod.rs
new file mode 100644
index 000000000..6d43dc780
--- /dev/null
+++ b/nghe-api/src/scan/mod.rs
@@ -0,0 +1 @@
+pub mod start;
diff --git a/nghe-api/src/scan/start.rs b/nghe-api/src/scan/start.rs
new file mode 100644
index 000000000..7b0b725e7
--- /dev/null
+++ b/nghe-api/src/scan/start.rs
@@ -0,0 +1,11 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+#[api_derive]
+#[endpoint(path = "startScan")]
+pub struct Request {
+    pub music_folder_id: Uuid,
+}
+
+#[api_derive]
+pub struct Response;
diff --git a/nghe-api/src/search/mod.rs b/nghe-api/src/search/mod.rs
new file mode 100644
index 000000000..77e741cc0
--- /dev/null
+++ b/nghe-api/src/search/mod.rs
@@ -0,0 +1 @@
+pub mod search3;
diff --git a/nghe-api/src/search/search3.rs b/nghe-api/src/search/search3.rs
new file mode 100644
index 000000000..b24d13dcc
--- /dev/null
+++ b/nghe-api/src/search/search3.rs
@@ -0,0 +1,33 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use crate::id3;
+
+#[api_derive]
+#[endpoint(path = "search3")]
+pub struct Request {
+    pub query: String,
+    pub artist_count: Option<u32>,
+    pub artist_offset: Option<u32>,
+    pub album_count: Option<u32>,
+    pub album_offset: Option<u32>,
+    pub song_count: Option<u32>,
+    pub song_offset: Option<u32>,
+    #[serde(rename = "musicFolderId")]
+    pub music_folder_ids: Option<Vec<Uuid>>,
+}
+
+#[serde_with::apply(
+    Vec => #[serde(skip_serializing_if = "Vec::is_empty")],
+)]
+#[api_derive(response = true)]
+pub struct SearchResult3 {
+    pub artist: Vec<id3::artist::Artist>,
+    pub album: Vec<id3::album::Album>,
+    pub song: Vec<id3::song::Song>,
+}
+
+#[api_derive]
+pub struct Response {
+    pub search_result3: SearchResult3,
+}
diff --git a/nghe-api/src/system/get_open_subsonic_extensions.rs b/nghe-api/src/system/get_open_subsonic_extensions.rs
new file mode 100644
index 000000000..512d0300d
--- /dev/null
+++ b/nghe-api/src/system/get_open_subsonic_extensions.rs
@@ -0,0 +1,16 @@
+use nghe_proc_macro::api_derive;
+
+#[api_derive(endpoint = true, binary = false)]
+#[endpoint(path = "getOpenSubsonicExtensions")]
+pub struct Request {}
+
+#[api_derive(response = true, binary = false)]
+pub struct Extension {
+    pub name: &'static str,
+    pub versions: &'static [u8],
+}
+
+#[api_derive(binary = false)]
+pub struct Response {
+    pub open_subsonic_extensions: &'static [Extension],
+}
diff --git a/nghe-api/src/system/mod.rs b/nghe-api/src/system/mod.rs
new file mode 100644
index 000000000..5366b2c50
--- /dev/null
+++ b/nghe-api/src/system/mod.rs
@@ -0,0 +1,2 @@
+pub mod get_open_subsonic_extensions;
+pub mod ping;
diff --git a/nghe-api/src/system/ping.rs b/nghe-api/src/system/ping.rs
new file mode 100644
index 000000000..058f15842
--- /dev/null
+++ b/nghe-api/src/system/ping.rs
@@ -0,0 +1,8 @@
+use nghe_proc_macro::api_derive;
+
+#[api_derive]
+#[endpoint(path = "ping")]
+pub struct Request {}
+
+#[api_derive]
+pub struct Response;
diff --git a/nghe-api/src/user/create.rs b/nghe-api/src/user/create.rs
new file mode 100644
index 000000000..d7bbf5b9c
--- /dev/null
+++ b/nghe-api/src/user/create.rs
@@ -0,0 +1,19 @@
+use nghe_proc_macro::api_derive;
+use uuid::Uuid;
+
+use super::Role;
+
+#[api_derive]
+#[endpoint(path = "createUser")]
+pub struct Request {
+    pub username: String,
+    pub password: String,
+    pub email: String,
+    pub role: Role,
+    pub allow: bool,
+}
+
+#[api_derive]
+pub struct Response {
+    pub user_id: Uuid,
+}
diff --git a/nghe-api/src/user/mod.rs b/nghe-api/src/user/mod.rs
new file mode 100644
index 000000000..502d92e51
--- /dev/null
+++ b/nghe-api/src/user/mod.rs
@@ -0,0 +1,5 @@
+pub mod create;
+mod role;
+pub mod setup;
+
+pub use role::Role;
diff --git a/nghe-api/src/user/role.rs b/nghe-api/src/user/role.rs
new file mode 100644
index 000000000..a4188f264
--- /dev/null
+++ b/nghe-api/src/user/role.rs
@@ -0,0 +1,9 @@
+use nghe_proc_macro::api_derive;
+
+#[api_derive(request = true)]
+pub struct Role {
+    pub admin: bool,
+    pub stream: bool,
+    pub download: bool,
+    pub share: bool,
+}
diff --git a/nghe-api/src/user/setup.rs b/nghe-api/src/user/setup.rs
new file mode 100644
index 000000000..5bce9a9fa
--- /dev/null
+++ b/nghe-api/src/user/setup.rs
@@ -0,0 +1,12 @@
+use nghe_proc_macro::api_derive;
+
+#[api_derive]
+#[endpoint(path = "setupUser")]
+pub struct Request {
+    pub username: String,
+    pub password: String,
+    pub email: String,
+}
+
+#[api_derive]
+pub struct Response;
diff --git a/nghe-backend/Cargo.toml b/nghe-backend/Cargo.toml
new file mode 100644
index 000000000..c06f4c399
--- /dev/null
+++ b/nghe-backend/Cargo.toml
@@ -0,0 +1,101 @@
+[package]
+name = "nghe_backend"
+version = { workspace = true }
+edition = { workspace = true }
+
+[lints]
+workspace = true
+
+[dependencies]
+bitcode = { workspace = true }
+concat-string = { workspace = true }
+color-eyre = { workspace = true }
+const_format = { workspace = true }
+derive-new = { workspace = true }
+educe = { workspace = true }
+faster-hex = { workspace = true }
+isolang = { workspace = true }
+itertools = { workspace = true }
+rand = { workspace = true }
+serde_html_form = { workspace = true }
+serde_with = { workspace = true }
+serde = { workspace = true }
+strum = { workspace = true }
+thiserror = { workspace = true }
+time = { workspace = true }
+tracing = { workspace = true }
+uuid = { workspace = true }
+
+nghe_api = { path = "../nghe-api" }
+nghe_proc_macro = { path = "../nghe-proc-macro" }
+
+async-walkdir = { version = "2.0.0" }
+aws-config = { version = "1.5.5", default-features = false, features = [
+  "rt-tokio",
+  "behavior-version-latest",
+] }
+aws-sdk-s3 = { version = "1.47.0", default-features = false, features = [
+  "rt-tokio",
+  "sigv4a",
+] }
+aws-smithy-runtime = { version = "1.7.1", default-features = false, features = [
+  "client",
+  "connector-hyper-0-14-x",
+] }
+axum = { version = "0.8.0-alpha.1", features = ["http2", "macros"] }
+axum-extra = { version = "0.10.0-alpha.1", features = ["typed-header"] }
+diesel = { version = "2.2.2", features = ["time", "uuid"] }
+# TODO: remove this when diesel is released
+diesel_derives = { git = "https://github.com/diesel-rs/diesel", rev = "ecf6e9215a898045ed096f905f4a0e7e4a999dba" }
+diesel-async = { version = "0.5.0", features = [
+  "postgres",
+  "deadpool",
+  "async-connection-wrapper",
+] }
+diesel_full_text_search = { version = "2.2.0", default-features = false }
+diesel_migrations = { version = "2.2.0", features = ["postgres"] }
+figment = { version = "0.10.19", features = ["env"] }
+fs4 = { version = "0.11.1", features = ["sync"] }
+futures-lite = { version = "2.3.0" }
+hyper = { version = "0.14.29" }
+hyper-tls = { version = "0.5.0" }
+indexmap = { version = "2.5.0" }
+libaes = { version = "0.7.0" }
+lofty = { version = "0.21.1" }
+loole = { version = "0.4.0" }
+num-traits = { version = "0.2.19" }
+o2o = { version = "0.4.10" }
+rsmpeg = { version = "0.15.1", default-features = false, features = [
+  "ffmpeg7",
+  "link_system_ffmpeg",
+] }
+tokio = { version = "1.40.0", features = [
+  "fs",
+  "macros",
+  "rt-multi-thread",
+  "sync",
+] }
+tokio-util = { version = "0.7.12", features = ["io"] }
+tower-http = { version = "0.6.1", features = ["cors", "trace"] }
+tracing-subscriber = { version = "0.3.18", features = ["env-filter"] }
+typed-path = { git = "https://github.com/vnghia/typed-path", rev = "bd796e64b3cee53181a3fc2f15245f5bf731bd8c" }
+unicode-normalization = { version = "0.1.24" }
+xxhash-rust = { version = "0.8.10", features = ["xxh3"] }
+
+[dev-dependencies]
+bon = { workspace = true }
+fake = { workspace = true }
+url = { workspace = true }
+rstest = { workspace = true }
+
+nghe_api = { path = "../nghe-api", features = ["test"] }
+
+http-body-util = { version = "0.1.2" }
+image = { version = "0.25.5", default-features = false, features = [
+  "jpeg",
+  "png",
+] }
+tempfile = { version = "3.10.1" }
+
+[target.'cfg(not(any(target_env = "musl", all(target_arch = "aarch64", target_os = "linux"))))'.dev-dependencies]
+diesel = { version = "2.2.2", features = ["postgres"] }
diff --git a/nghe-backend/build.rs b/nghe-backend/build.rs
new file mode 100644
index 000000000..690ca944f
--- /dev/null
+++ b/nghe-backend/build.rs
@@ -0,0 +1,8 @@
+fn main() {
+    println!("cargo::rustc-check-cfg=cfg(hearing_test)");
+    if std::env::var("NGHE_HEARING_TEST_INPUT").is_ok_and(|s| !s.is_empty())
+        && std::env::var("NGHE_HEARING_TEST_OUTPUT").is_ok_and(|s| !s.is_empty())
+    {
+        println!("cargo::rustc-cfg=hearing_test");
+    }
+}
diff --git a/nghe-backend/migrations/.keep b/nghe-backend/migrations/.keep
new file mode 100644
index 000000000..e69de29bb
diff --git a/nghe-backend/migrations/00000000000000_diesel_initial_setup/down.sql b/nghe-backend/migrations/00000000000000_diesel_initial_setup/down.sql
new file mode 100644
index 000000000..d1a359fc2
--- /dev/null
+++ b/nghe-backend/migrations/00000000000000_diesel_initial_setup/down.sql
@@ -0,0 +1,6 @@
+-- This file was automatically created by Diesel to setup helper functions
+-- and other internal bookkeeping. This file is safe to edit, any future
+-- changes will be added to existing projects as new migrations.
+
+drop function if exists diesel_manage_updated_at (_tbl regclass);
+drop function if exists diesel_set_updated_at ();
diff --git a/nghe-backend/migrations/00000000000000_diesel_initial_setup/up.sql b/nghe-backend/migrations/00000000000000_diesel_initial_setup/up.sql
new file mode 100644
index 000000000..3de2f0d62
--- /dev/null
+++ b/nghe-backend/migrations/00000000000000_diesel_initial_setup/up.sql
@@ -0,0 +1,38 @@
+-- This file was automatically created by Diesel to setup helper functions
+-- and other internal bookkeeping. This file is safe to edit, any future
+-- changes will be added to existing projects as new migrations.
+
+
+
+
+-- Sets up a trigger for the given table to automatically set a column called
+-- `updated_at` whenever the row is modified (unless `updated_at` was included
+-- in the modified columns)
+--
+-- # Example
+--
+-- ```sql
+-- CREATE TABLE users (id SERIAL PRIMARY KEY, updated_at TIMESTAMP NOT NULL DEFAULT NOW());
+--
+-- SELECT diesel_manage_updated_at('users');
+-- ```
+create or replace function diesel_manage_updated_at(
+    _tbl regclass
+) returns void as $$
+BEGIN
+    EXECUTE format('CREATE TRIGGER set_updated_at BEFORE UPDATE ON %s
+                    FOR EACH ROW EXECUTE PROCEDURE diesel_set_updated_at()', _tbl);
+END;
+$$ language plpgsql;
+
+create or replace function diesel_set_updated_at() returns trigger as $$
+BEGIN
+    IF (
+        NEW IS DISTINCT FROM OLD AND
+        NEW.updated_at IS NOT DISTINCT FROM OLD.updated_at
+    ) THEN
+        NEW.updated_at := current_timestamp;
+    END IF;
+    RETURN NEW;
+END;
+$$ language plpgsql;
diff --git a/nghe-backend/migrations/2024-01-19-134746_create_updated_at_leave_scanned_at/down.sql b/nghe-backend/migrations/2024-01-19-134746_create_updated_at_leave_scanned_at/down.sql
new file mode 100644
index 000000000..58838b648
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-19-134746_create_updated_at_leave_scanned_at/down.sql
@@ -0,0 +1,8 @@
+-- This file should undo anything in `up.sql`
+drop function add_updated_at (_tbl regclass);
+
+drop function set_updated_at ();
+
+drop function add_updated_at_leave_scanned_at (_tbl regclass);
+
+drop function set_updated_at_leave_scanned_at ();
diff --git a/nghe-backend/migrations/2024-01-19-134746_create_updated_at_leave_scanned_at/up.sql b/nghe-backend/migrations/2024-01-19-134746_create_updated_at_leave_scanned_at/up.sql
new file mode 100644
index 000000000..15130655a
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-19-134746_create_updated_at_leave_scanned_at/up.sql
@@ -0,0 +1,41 @@
+-- Your SQL goes here
+create function add_updated_at(_tbl regclass) returns void as $$
+begin
+    execute format('create trigger set_updated_at before update on %s
+                    for each row execute procedure set_updated_at()', _tbl);
+end;
+$$ language plpgsql;
+
+create function set_updated_at() returns trigger as $$
+begin
+    if (
+        new is distinct from old and
+        new.updated_at is not distinct from old.updated_at
+    ) then
+        new.updated_at := current_timestamp;
+    end if;
+    return new;
+end;
+$$ language plpgsql;
+
+create function add_updated_at_leave_scanned_at(
+    _tbl regclass
+) returns void as $$
+begin
+    execute format('create trigger set_updated_at_leave_scanned_at before update on %s
+                    for each row execute procedure set_updated_at_leave_scanned_at()', _tbl);
+end;
+$$ language plpgsql;
+
+create function set_updated_at_leave_scanned_at() returns trigger as $$
+begin
+    if (
+        new is distinct from old and
+        new.updated_at is not distinct from old.updated_at and
+        new.scanned_at is not distinct from old.scanned_at
+    ) then
+        new.updated_at := current_timestamp;
+    end if;
+    return new;
+end;
+$$ language plpgsql;
diff --git a/nghe-backend/migrations/2024-01-19-144746_create_users/down.sql b/nghe-backend/migrations/2024-01-19-144746_create_users/down.sql
new file mode 100644
index 000000000..5795f6b35
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-19-144746_create_users/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+drop table users;
diff --git a/nghe-backend/migrations/2024-01-19-144746_create_users/up.sql b/nghe-backend/migrations/2024-01-19-144746_create_users/up.sql
new file mode 100644
index 000000000..30bb147aa
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-19-144746_create_users/up.sql
@@ -0,0 +1,16 @@
+-- Your SQL goes here
+create table
+users (
+    id uuid not null default gen_random_uuid() constraint users_pkey primary key,
+    username text not null constraint users_username_key unique,
+    password bytea not null,
+    email text not null,
+    admin_role boolean not null default false,
+    stream_role boolean not null default false,
+    download_role boolean not null default false,
+    share_role boolean not null default false,
+    created_at timestamptz not null default now(),
+    updated_at timestamptz not null default now()
+);
+
+select add_updated_at('users');
diff --git a/nghe-backend/migrations/2024-01-19-153106_create_music_folders/down.sql b/nghe-backend/migrations/2024-01-19-153106_create_music_folders/down.sql
new file mode 100644
index 000000000..5f6a665e7
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-19-153106_create_music_folders/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+drop table music_folders;
diff --git a/nghe-backend/migrations/2024-01-19-153106_create_music_folders/up.sql b/nghe-backend/migrations/2024-01-19-153106_create_music_folders/up.sql
new file mode 100644
index 000000000..8b00f07ec
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-19-153106_create_music_folders/up.sql
@@ -0,0 +1,7 @@
+-- Your SQL goes here
+create table
+music_folders (
+    id uuid not null default gen_random_uuid() constraint music_folders_pkey primary key,
+    path text not null constraint music_folders_path_key unique,
+    scanned_at timestamptz not null default now()
+);
diff --git a/nghe-backend/migrations/2024-01-19-153612_create_user_music_folder_permissions/down.sql b/nghe-backend/migrations/2024-01-19-153612_create_user_music_folder_permissions/down.sql
new file mode 100644
index 000000000..4aad69764
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-19-153612_create_user_music_folder_permissions/down.sql
@@ -0,0 +1,6 @@
+-- This file should undo anything in `up.sql`
+drop index user_music_folder_permissions_user_id_idx;
+
+drop index user_music_folder_permissions_music_folder_id_idx;
+
+drop table user_music_folder_permissions;
diff --git a/nghe-backend/migrations/2024-01-19-153612_create_user_music_folder_permissions/up.sql b/nghe-backend/migrations/2024-01-19-153612_create_user_music_folder_permissions/up.sql
new file mode 100644
index 000000000..acb188e8d
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-19-153612_create_user_music_folder_permissions/up.sql
@@ -0,0 +1,24 @@
+-- Your SQL goes here
+create table
+user_music_folder_permissions (
+    user_id uuid not null,
+    music_folder_id uuid not null,
+    allow boolean not null default true,
+    constraint user_music_folder_permissions_pkey primary key (
+        user_id, music_folder_id
+    ),
+    constraint user_music_folder_permissions_user_id_fkey foreign key (
+        user_id
+    ) references users (id) on delete cascade,
+    constraint user_music_folder_permissions_music_folder_id_fkey foreign key (
+        music_folder_id
+    ) references music_folders (id) on delete cascade
+);
+
+create index user_music_folder_permissions_user_id_idx on user_music_folder_permissions (
+    user_id
+);
+
+create index user_music_folder_permissions_music_folder_id_idx on user_music_folder_permissions (
+    music_folder_id
+);
diff --git a/nghe-backend/migrations/2024-01-20-154336_create_artists/down.sql b/nghe-backend/migrations/2024-01-20-154336_create_artists/down.sql
new file mode 100644
index 000000000..f2582c367
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-20-154336_create_artists/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+drop table artists;
diff --git a/nghe-backend/migrations/2024-01-20-154336_create_artists/up.sql b/nghe-backend/migrations/2024-01-20-154336_create_artists/up.sql
new file mode 100644
index 000000000..ff616c795
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-20-154336_create_artists/up.sql
@@ -0,0 +1,12 @@
+-- Your SQL goes here
+create table
+artists (
+    id uuid not null default gen_random_uuid() constraint artists_pkey primary key,
+    name text not null constraint artists_name_key unique,
+    index text not null default '?',
+    created_at timestamptz not null default now(),
+    updated_at timestamptz not null default now(),
+    scanned_at timestamptz not null default now()
+);
+
+select add_updated_at_leave_scanned_at('artists');
diff --git a/nghe-backend/migrations/2024-01-21-012915_create_albums/down.sql b/nghe-backend/migrations/2024-01-21-012915_create_albums/down.sql
new file mode 100644
index 000000000..3a7b00f23
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-21-012915_create_albums/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+drop table albums;
diff --git a/nghe-backend/migrations/2024-01-21-012915_create_albums/up.sql b/nghe-backend/migrations/2024-01-21-012915_create_albums/up.sql
new file mode 100644
index 000000000..b1c7bf129
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-21-012915_create_albums/up.sql
@@ -0,0 +1,11 @@
+-- Your SQL goes here
+create table
+albums (
+    id uuid not null default gen_random_uuid() constraint albums_pkey primary key,
+    name text not null constraint albums_name_key unique,
+    created_at timestamptz not null default now(),
+    updated_at timestamptz not null default now(),
+    scanned_at timestamptz not null default now()
+);
+
+select add_updated_at_leave_scanned_at('albums');
diff --git a/nghe-backend/migrations/2024-01-21-014803_create_songs/down.sql b/nghe-backend/migrations/2024-01-21-014803_create_songs/down.sql
new file mode 100644
index 000000000..521dc6c11
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-21-014803_create_songs/down.sql
@@ -0,0 +1,6 @@
+-- This file should undo anything in `up.sql`
+drop index songs_album_id_idx;
+
+drop index songs_music_folder_id_idx;
+
+drop table songs;
diff --git a/nghe-backend/migrations/2024-01-21-014803_create_songs/up.sql b/nghe-backend/migrations/2024-01-21-014803_create_songs/up.sql
new file mode 100644
index 000000000..e187fa352
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-21-014803_create_songs/up.sql
@@ -0,0 +1,57 @@
+-- Your SQL goes here
+create table
+songs (
+    id uuid not null default gen_random_uuid() constraint songs_pkey primary key,
+    -- Song tag
+    title text not null,
+    album_id uuid not null,
+    track_number integer default null,
+    track_total integer default null,
+    disc_number integer default null,
+    disc_total integer default null,
+    year smallint default null,
+    month smallint default null,
+    day smallint default null,
+    release_year smallint default null,
+    release_month smallint default null,
+    release_day smallint default null,
+    original_release_year smallint default null,
+    original_release_month smallint default null,
+    original_release_day smallint default null,
+    languages text [] not null default array[]::text [] check (
+        array_position(languages, null) is null
+    ),
+    -- Song property
+    format text not null,
+    duration real not null,
+    bitrate integer not null,
+    sample_rate integer not null,
+    channel_count smallint not null,
+    -- Filesystem property
+    music_folder_id uuid not null,
+    relative_path text not null,
+    file_hash bigint not null,
+    file_size integer not null,
+    created_at timestamptz not null default now(),
+    updated_at timestamptz not null default now(),
+    scanned_at timestamptz not null default now(),
+    -- Constraints
+    constraint songs_album_id_fkey foreign key (album_id) references albums (
+        id
+    ) on delete cascade,
+    constraint songs_music_folder_id_relative_path_key unique (
+        music_folder_id, relative_path
+    ),
+    constraint songs_music_folder_id_fkey foreign key (
+        music_folder_id
+    ) references music_folders (id) on delete cascade,
+    constraint songs_music_folder_id_file_hash_file_size_key unique (
+        music_folder_id, file_hash, file_size
+    )
+);
+
+select add_updated_at_leave_scanned_at('songs');
+
+create index songs_album_id_idx on songs (album_id);
+
+create index songs_music_folder_id_idx on songs (music_folder_id);
diff --git a/nghe-backend/migrations/2024-01-21-015739_create_songs_album_artists/down.sql b/nghe-backend/migrations/2024-01-21-015739_create_songs_album_artists/down.sql
new file mode 100644
index 000000000..ffb8852c5
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-21-015739_create_songs_album_artists/down.sql
@@ -0,0 +1,6 @@
+-- This file should undo anything in `up.sql`
+drop index songs_album_artists_song_id_idx;
+
+drop index songs_album_artists_album_artist_id_idx;
+
+drop table songs_album_artists;
diff --git a/nghe-backend/migrations/2024-01-21-015739_create_songs_album_artists/up.sql b/nghe-backend/migrations/2024-01-21-015739_create_songs_album_artists/up.sql
new file mode 100644
index 000000000..78f816bd6
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-21-015739_create_songs_album_artists/up.sql
@@ -0,0 +1,20 @@
+-- Your SQL goes here
+create table
+songs_album_artists (
+    song_id uuid not null,
+    album_artist_id uuid not null,
+    upserted_at timestamptz not null default now(),
+    constraint songs_album_artists_pkey primary key (song_id, album_artist_id),
+    constraint songs_album_artists_song_id_fkey foreign key (
+        song_id
+    ) references songs (id) on delete cascade,
+    constraint songs_album_artists_album_artist_id_fkey foreign key (
+        album_artist_id
+    ) references artists (id) on delete cascade
+);
+
+create index songs_album_artists_song_id_idx on songs_album_artists (song_id);
+
+create index songs_album_artists_album_artist_id_idx on songs_album_artists (
+    album_artist_id
+);
diff --git a/nghe-backend/migrations/2024-01-21-020718_create_songs_artists/down.sql b/nghe-backend/migrations/2024-01-21-020718_create_songs_artists/down.sql
new file mode 100644
index 000000000..867c5a3da
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-21-020718_create_songs_artists/down.sql
@@ -0,0 +1,6 @@
+-- This file should undo anything in `up.sql`
+drop index songs_artists_song_id_idx;
+
+drop index songs_artists_artist_id_idx;
+
+drop table songs_artists;
diff --git a/nghe-backend/migrations/2024-01-21-020718_create_songs_artists/up.sql b/nghe-backend/migrations/2024-01-21-020718_create_songs_artists/up.sql
new file mode 100644
index 000000000..4099b1843
--- /dev/null
+++ b/nghe-backend/migrations/2024-01-21-020718_create_songs_artists/up.sql
@@ -0,0 +1,18 @@
+-- Your SQL goes here
+create table
+songs_artists (
+    song_id uuid not null,
+    artist_id uuid not null,
+    upserted_at timestamptz not null default now(),
+    constraint songs_artists_pkey primary key (song_id, artist_id),
+    constraint songs_artists_song_id_fkey foreign key (
+        song_id
+    ) references songs (id) on delete cascade,
+    constraint songs_artists_artist_id_fkey foreign key (
+        artist_id
+    ) references artists (id) on delete cascade
+);
+
+create index songs_artists_song_id_idx on songs_artists (song_id);
+
+create index songs_artists_artist_id_idx on songs_artists (artist_id);
diff --git a/nghe-backend/migrations/2024-02-16-174806_create_configs/down.sql b/nghe-backend/migrations/2024-02-16-174806_create_configs/down.sql
new file mode 100644
index 000000000..82b95979e
--- /dev/null
+++ b/nghe-backend/migrations/2024-02-16-174806_create_configs/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+drop table configs;
diff --git a/nghe-backend/migrations/2024-02-16-174806_create_configs/up.sql b/nghe-backend/migrations/2024-02-16-174806_create_configs/up.sql
new file mode 100644
index 000000000..87b89ede0
--- /dev/null
+++ b/nghe-backend/migrations/2024-02-16-174806_create_configs/up.sql
@@ -0,0 +1,10 @@
+-- Your SQL goes here
+create table
+configs (
+    key text not null constraint configs_pkey primary key,
+    text text default null,
+    byte bytea default null,
+    updated_at timestamptz not null default now()
+);
+
+select add_updated_at('configs');
diff --git a/nghe-backend/migrations/2024-02-26-053602_create_scans/down.sql b/nghe-backend/migrations/2024-02-26-053602_create_scans/down.sql
new file mode 100644
index 000000000..a0738b6cd
--- /dev/null
+++ b/nghe-backend/migrations/2024-02-26-053602_create_scans/down.sql
@@ -0,0 +1,4 @@
+-- This file should undo anything in `up.sql`
+drop index scans_is_scanning_idx;
+
+drop table scans;
diff --git a/nghe-backend/migrations/2024-02-26-053602_create_scans/up.sql b/nghe-backend/migrations/2024-02-26-053602_create_scans/up.sql
new file mode 100644
index 000000000..2881427cc
--- /dev/null
+++ b/nghe-backend/migrations/2024-02-26-053602_create_scans/up.sql
@@ -0,0 +1,22 @@
+-- Your SQL goes here
+create table
+scans (
+    started_at timestamptz not null default now() constraint scans_pkey primary key,
+    is_scanning boolean not null default true,
+    finished_at timestamptz default null,
+    scanned_count bigint not null default 0,
+    error_message text default null,
+    constraint scans_not_scanning_if_finished check (
+        (
+            is_scanning
+            and finished_at is null
+        )
+        or (
+            not is_scanning
+            and finished_at is not null
+        )
+    )
+);
+
+create unique index scans_is_scanning_idx on scans (is_scanning)
+where is_scanning;
diff --git a/nghe-backend/migrations/2024-03-27-204537_create_cover_arts/down.sql b/nghe-backend/migrations/2024-03-27-204537_create_cover_arts/down.sql
new file mode 100644
index 000000000..eec51cb18
--- /dev/null
+++ b/nghe-backend/migrations/2024-03-27-204537_create_cover_arts/down.sql
@@ -0,0 +1,4 @@
+-- This file should undo anything in `up.sql`
+alter table songs drop column cover_art_id;
+
+drop table cover_arts;
diff --git a/nghe-backend/migrations/2024-03-27-204537_create_cover_arts/up.sql b/nghe-backend/migrations/2024-03-27-204537_create_cover_arts/up.sql
new file mode 100644
index 000000000..077f36c52
--- /dev/null
+++ b/nghe-backend/migrations/2024-03-27-204537_create_cover_arts/up.sql
@@ -0,0 +1,17 @@
+-- Your SQL goes here
+create table
+cover_arts (
+    id uuid not null default gen_random_uuid() constraint cover_arts_pkey primary key,
+    format text not null,
+    file_hash bigint not null,
+    file_size integer not null,
+    upserted_at timestamptz not null default now(),
+    constraint cover_arts_format_file_hash_file_size_key unique (
+        format, file_hash, file_size
+    )
+);
+
+alter table songs
+add column cover_art_id uuid, add constraint cover_art_id_fkey foreign key (
+    cover_art_id
+) references cover_arts (id) on delete set null;
diff --git a/nghe-backend/migrations/2024-04-03-170326_add_artist_mbz_id/down.sql b/nghe-backend/migrations/2024-04-03-170326_add_artist_mbz_id/down.sql
new file mode 100644
index 000000000..7c68c80e7
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-03-170326_add_artist_mbz_id/down.sql
@@ -0,0 +1,7 @@
+-- This file should undo anything in `up.sql`
+alter table artists
+add constraint artists_name_key unique (name);
+
+drop index artists_name_idx;
+
+alter table artists drop column mbz_id;
diff --git a/nghe-backend/migrations/2024-04-03-170326_add_artist_mbz_id/up.sql b/nghe-backend/migrations/2024-04-03-170326_add_artist_mbz_id/up.sql
new file mode 100644
index 000000000..5d875640b
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-03-170326_add_artist_mbz_id/up.sql
@@ -0,0 +1,7 @@
+-- Your SQL goes here
+alter table artists add mbz_id uuid,
+add constraint artists_mbz_id_key unique (mbz_id);
+
+create unique index artists_name_idx on artists (name) where (mbz_id is null);
+
+alter table artists drop constraint artists_name_key;
diff --git a/nghe-backend/migrations/2024-04-04-155149_add_album_unique/down.sql b/nghe-backend/migrations/2024-04-04-155149_add_album_unique/down.sql
new file mode 100644
index 000000000..f0a7e0047
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-04-155149_add_album_unique/down.sql
@@ -0,0 +1,17 @@
+-- This file should undo anything in `up.sql`
+alter table albums
+add constraint albums_name_key unique (name);
+
+drop index albums_name_date_release_original_idx;
+
+alter table albums drop column mbz_id;
+
+alter table albums drop column year;
+alter table albums drop column month;
+alter table albums drop column day;
+alter table albums drop column release_year;
+alter table albums drop column release_month;
+alter table albums drop column release_day;
+alter table albums drop column original_release_year;
+alter table albums drop column original_release_month;
+alter table albums drop column original_release_day;
diff --git a/nghe-backend/migrations/2024-04-04-155149_add_album_unique/up.sql b/nghe-backend/migrations/2024-04-04-155149_add_album_unique/up.sql
new file mode 100644
index 000000000..dab87373c
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-04-155149_add_album_unique/up.sql
@@ -0,0 +1,28 @@
+-- Your SQL goes here
+alter table albums add year smallint default null;
+alter table albums add month smallint default null;
+alter table albums add day smallint default null;
+alter table albums add release_year smallint default null;
+alter table albums add release_month smallint default null;
+alter table albums add release_day smallint default null;
+alter table albums add original_release_year smallint default null;
+alter table albums add original_release_month smallint default null;
+alter table albums add original_release_day smallint default null;
+
+alter table albums add mbz_id uuid,
+add constraint albums_mbz_id_key unique (mbz_id);
+
+create unique index albums_name_date_release_original_idx on albums (
+    name,
+    year,
+    month,
+    day,
+    release_year,
+    release_month,
+    release_day,
+    original_release_year,
+    original_release_month,
+    original_release_day
+) nulls not distinct where (mbz_id is null);
+
+alter table albums drop constraint albums_name_key;
diff --git a/nghe-backend/migrations/2024-04-05-232039_create_genres/down.sql b/nghe-backend/migrations/2024-04-05-232039_create_genres/down.sql
new file mode 100644
index 000000000..0498cd0b1
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-05-232039_create_genres/down.sql
@@ -0,0 +1,4 @@
+-- This file should undo anything in `up.sql`
+drop table songs_genres;
+
+drop table genres;
diff --git a/nghe-backend/migrations/2024-04-05-232039_create_genres/up.sql b/nghe-backend/migrations/2024-04-05-232039_create_genres/up.sql
new file mode 100644
index 000000000..590a42372
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-05-232039_create_genres/up.sql
@@ -0,0 +1,22 @@
+-- Your SQL goes here
+create table
+genres (
+    id uuid not null default gen_random_uuid() constraint genres_pkey primary key,
+    value text not null,
+    upserted_at timestamptz not null default now(),
+    constraint genres_value_key unique (value)
+);
+
+create table
+songs_genres (
+    song_id uuid not null,
+    genre_id uuid not null,
+    upserted_at timestamptz not null default now(),
+    constraint songs_genres_pkey primary key (song_id, genre_id),
+    constraint songs_genres_song_id_fkey foreign key (
+        song_id
+    ) references songs (id) on delete cascade,
+    constraint songs_genres_genre_id_fkey foreign key (
+        genre_id
+    ) references genres (id) on delete cascade
+);
diff --git a/nghe-backend/migrations/2024-04-06-051756_create_lyrics/down.sql b/nghe-backend/migrations/2024-04-06-051756_create_lyrics/down.sql
new file mode 100644
index 000000000..995863232
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-06-051756_create_lyrics/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+drop table lyrics;
diff --git a/nghe-backend/migrations/2024-04-06-051756_create_lyrics/up.sql b/nghe-backend/migrations/2024-04-06-051756_create_lyrics/up.sql
new file mode 100644
index 000000000..3a96fa0e1
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-06-051756_create_lyrics/up.sql
@@ -0,0 +1,27 @@
+-- Your SQL goes here
+create table
+lyrics (
+    song_id uuid not null,
+    description text not null,
+    language text not null,
+    line_values text [] not null check (
+        array_position(line_values, null) is null
+    ),
+    line_starts integer [] check (
+        array_position(line_starts, null) is null
+    ),
+    lyric_hash bigint not null,
+    lyric_size integer not null,
+    external bool not null,
+    updated_at timestamptz not null default now(),
+    scanned_at timestamptz not null default now(),
+    check (line_starts is null or array_length(line_values, 1) = array_length(line_starts, 1)),
+    constraint lyrics_song_id_key foreign key (song_id) references songs (
+        id
+    ) on delete cascade,
+    constraint lyrics_pkey primary key (
+        song_id, description, language, external
+    )
+);
+
+select add_updated_at_leave_scanned_at('lyrics');
diff --git a/nghe-backend/migrations/2024-04-10-084031_add_music_folders_name/down.sql b/nghe-backend/migrations/2024-04-10-084031_add_music_folders_name/down.sql
new file mode 100644
index 000000000..7f0353c93
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-10-084031_add_music_folders_name/down.sql
@@ -0,0 +1,6 @@
+-- This file should undo anything in `up.sql`
+drop trigger set_updated_at_leave_scanned_at on music_folders;
+
+alter table music_folders drop column updated_at;
+
+alter table music_folders drop column name;
diff --git a/nghe-backend/migrations/2024-04-10-084031_add_music_folders_name/up.sql b/nghe-backend/migrations/2024-04-10-084031_add_music_folders_name/up.sql
new file mode 100644
index 000000000..07b4c6ca7
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-10-084031_add_music_folders_name/up.sql
@@ -0,0 +1,8 @@
+-- Your SQL goes here
+alter table music_folders add name text not null,
+add constraint music_folders_name_key unique (name);
+
+alter table music_folders
+add updated_at timestamptz not null default now();
+
+select add_updated_at_leave_scanned_at('music_folders');
diff --git a/nghe-backend/migrations/2024-04-10-145416_create_playbacks/down.sql b/nghe-backend/migrations/2024-04-10-145416_create_playbacks/down.sql
new file mode 100644
index 000000000..f308e11b1
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-10-145416_create_playbacks/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+drop table playbacks;
diff --git a/nghe-backend/migrations/2024-04-10-145416_create_playbacks/up.sql b/nghe-backend/migrations/2024-04-10-145416_create_playbacks/up.sql
new file mode 100644
index 000000000..6613aebc5
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-10-145416_create_playbacks/up.sql
@@ -0,0 +1,17 @@
+-- Your SQL goes here
+create table
+playbacks (
+    user_id uuid not null,
+    song_id uuid not null,
+    count integer not null default 1 check (count > 0),
+    updated_at timestamptz not null default now(),
+    constraint playbacks_pkey primary key (user_id, song_id),
+    constraint playbacks_user_id_fkey foreign key (
+        user_id
+    ) references users (id) on delete cascade,
+    constraint playbacks_song_id_fkey foreign key (
+        song_id
+    ) references songs (id) on delete cascade
+);
+
+select add_updated_at('playbacks');
diff --git a/nghe-backend/migrations/2024-04-10-192602_add_songs_mbz_id/down.sql b/nghe-backend/migrations/2024-04-10-192602_add_songs_mbz_id/down.sql
new file mode 100644
index 000000000..cc9bd1fa9
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-10-192602_add_songs_mbz_id/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+alter table songs drop column mbz_id;
diff --git a/nghe-backend/migrations/2024-04-10-192602_add_songs_mbz_id/up.sql b/nghe-backend/migrations/2024-04-10-192602_add_songs_mbz_id/up.sql
new file mode 100644
index 000000000..22995d36b
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-10-192602_add_songs_mbz_id/up.sql
@@ -0,0 +1,2 @@
+-- Your SQL goes here
+alter table songs add mbz_id uuid;
diff --git a/nghe-backend/migrations/2024-04-14-171432_add_fts/down.sql b/nghe-backend/migrations/2024-04-14-171432_add_fts/down.sql
new file mode 100644
index 000000000..bb1088cae
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-14-171432_add_fts/down.sql
@@ -0,0 +1,10 @@
+-- This file should undo anything in `up.sql`
+alter table artists drop column ts;
+
+alter table albums drop column ts;
+
+alter table songs drop column ts;
+
+drop text search configuration usimple;
+
+drop extension unaccent;
diff --git a/nghe-backend/migrations/2024-04-14-171432_add_fts/up.sql b/nghe-backend/migrations/2024-04-14-171432_add_fts/up.sql
new file mode 100644
index 000000000..4fe941d5d
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-14-171432_add_fts/up.sql
@@ -0,0 +1,18 @@
+-- Your SQL goes here
+create extension unaccent schema public;
+
+create text search configuration usimple (copy = simple);
+alter text search configuration usimple
+alter mapping for hword, hword_part, word with public.unaccent, simple;
+
+alter table artists
+add column ts tsvector not null generated always as (to_tsvector('usimple', name)) stored;
+create index artists_ts_idx on artists using gin (ts);
+
+alter table albums
+add column ts tsvector not null generated always as (to_tsvector('usimple', name)) stored;
+create index albums_ts_idx on albums using gin (ts);
+
+alter table songs
+add column ts tsvector not null generated always as (to_tsvector('usimple', title)) stored;
+create index songs_ts_idx on songs using gin (ts);
diff --git a/nghe-backend/migrations/2024-04-15-144339_add_scans_music_folder/down.sql b/nghe-backend/migrations/2024-04-15-144339_add_scans_music_folder/down.sql
new file mode 100644
index 000000000..d8dd55524
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-15-144339_add_scans_music_folder/down.sql
@@ -0,0 +1,33 @@
+-- This file should undo anything in `up.sql`
+create unique index scans_is_scanning_idx on scans (is_scanning)
+where is_scanning;
+drop index scans_music_folder_id_is_scanning_idx;
+
+alter table scans drop column unrecoverable,
+add constraint scans_not_scanning_if_finished check (
+    (
+        is_scanning
+        and finished_at is null
+    )
+    or (
+        not is_scanning
+        and finished_at is not null
+    )
+);
+
+alter table scans drop column scanned_song_count;
+alter table scans drop column upserted_song_count;
+alter table scans drop column deleted_song_count;
+alter table scans drop column deleted_album_count;
+alter table scans drop column deleted_artist_count;
+alter table scans drop column deleted_genre_count;
+alter table scans drop column scan_error_count;
+
+alter table scans add column error_message text,
+add column scanned_count bigint not null default 0;
+
+alter table scans
+drop constraint scans_pkey,
+add constraint scans_pkey primary key (started_at);
+
+alter table scans drop column music_folder_id;
diff --git a/nghe-backend/migrations/2024-04-15-144339_add_scans_music_folder/up.sql b/nghe-backend/migrations/2024-04-15-144339_add_scans_music_folder/up.sql
new file mode 100644
index 000000000..854f92cf5
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-15-144339_add_scans_music_folder/up.sql
@@ -0,0 +1,39 @@
+-- Your SQL goes here
+alter table scans
+add column music_folder_id uuid not null,
+add constraint scans_music_folder_id foreign key (music_folder_id) references music_folders (
+    id
+) on delete cascade;
+
+alter table scans
+drop constraint scans_pkey,
+add constraint scans_pkey primary key (started_at, music_folder_id);
+
+alter table scans drop column error_message, drop column scanned_count;
+
+alter table scans add column scanned_song_count bigint not null default 0;
+alter table scans add column upserted_song_count bigint not null default 0;
+alter table scans add column deleted_song_count bigint not null default 0;
+alter table scans add column deleted_album_count bigint not null default 0;
+alter table scans add column deleted_artist_count bigint not null default 0;
+alter table scans add column deleted_genre_count bigint not null default 0;
+alter table scans add column scan_error_count bigint not null default 0;
+
+alter table scans add column unrecoverable bool,
+drop constraint scans_not_scanning_if_finished,
+add constraint scans_not_scanning_if_finished_and_set_unrecoverable check (
+    (
+        is_scanning
+        and unrecoverable is null
+        and finished_at is null
+    )
+    or (
+        not is_scanning
+        and unrecoverable is not null
+        and finished_at is not null
+    )
+);
+
+drop index scans_is_scanning_idx;
+create unique index scans_music_folder_id_is_scanning_idx on scans (music_folder_id, is_scanning)
+where is_scanning;
diff --git a/nghe-backend/migrations/2024-04-16-192827_simplify_user_music_folder_permissions/down.sql b/nghe-backend/migrations/2024-04-16-192827_simplify_user_music_folder_permissions/down.sql
new file mode 100644
index 000000000..537e591ed
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-16-192827_simplify_user_music_folder_permissions/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+alter table user_music_folder_permissions add column allow boolean not null default true;
diff --git a/nghe-backend/migrations/2024-04-16-192827_simplify_user_music_folder_permissions/up.sql b/nghe-backend/migrations/2024-04-16-192827_simplify_user_music_folder_permissions/up.sql
new file mode 100644
index 000000000..a631991e0
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-16-192827_simplify_user_music_folder_permissions/up.sql
@@ -0,0 +1,2 @@
+-- Your SQL goes here
+alter table user_music_folder_permissions drop column allow;
diff --git a/nghe-backend/migrations/2024-04-19-095649_create_playlists/down.sql b/nghe-backend/migrations/2024-04-19-095649_create_playlists/down.sql
new file mode 100644
index 000000000..3e9b3651d
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-19-095649_create_playlists/down.sql
@@ -0,0 +1,6 @@
+-- This file should undo anything in `up.sql`
+drop table playlists_songs;
+
+drop table playlists_users;
+
+drop table playlists;
diff --git a/nghe-backend/migrations/2024-04-19-095649_create_playlists/up.sql b/nghe-backend/migrations/2024-04-19-095649_create_playlists/up.sql
new file mode 100644
index 000000000..e303904e3
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-19-095649_create_playlists/up.sql
@@ -0,0 +1,43 @@
+-- Your SQL goes here
+create table playlists (
+    id uuid not null default gen_random_uuid() constraint playlists_pkey primary key,
+    name text not null,
+    comment text default null,
+    public boolean not null default false,
+    created_at timestamptz not null default now(),
+    updated_at timestamptz not null default now()
+);
+
+select add_updated_at('playlists');
+
+-- access level: 
+--  1 - read songs
+--  2 - add/remove songs
+--  3 - admin (add/remove users, edit, delete)
+create table playlists_users (
+    playlist_id uuid not null,
+    user_id uuid not null,
+    access_level smallint not null constraint playlists_users_access_level check (
+        access_level between 1 and 3
+    ),
+    constraint playlists_users_pkey primary key (playlist_id, user_id),
+    constraint playlists_users_playlist_id_fkey foreign key (
+        playlist_id
+    ) references playlists (id) on delete cascade,
+    constraint playlists_users_user_id_fkey foreign key (
+        user_id
+    ) references users (id) on delete cascade
+);
+
+create table playlists_songs (
+    playlist_id uuid not null,
+    song_id uuid not null,
+    created_at timestamptz not null default now(),
+    constraint playlists_songs_pkey primary key (playlist_id, song_id),
+    constraint playlists_songs_playlist_id_fkey foreign key (
+        playlist_id
+    ) references playlists (id) on delete cascade,
+    constraint playlists_songs_song_id_fkey foreign key (
+        song_id
+    ) references songs (id) on delete cascade
+)
diff --git a/nghe-backend/migrations/2024-04-22-075801_add_songs_bit_depth/down.sql b/nghe-backend/migrations/2024-04-22-075801_add_songs_bit_depth/down.sql
new file mode 100644
index 000000000..204bb29cc
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-22-075801_add_songs_bit_depth/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+alter table songs drop column bit_depth;
diff --git a/nghe-backend/migrations/2024-04-22-075801_add_songs_bit_depth/up.sql b/nghe-backend/migrations/2024-04-22-075801_add_songs_bit_depth/up.sql
new file mode 100644
index 000000000..025d39407
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-22-075801_add_songs_bit_depth/up.sql
@@ -0,0 +1,2 @@
+-- Your SQL goes here
+alter table songs add column bit_depth smallint;
diff --git a/nghe-backend/migrations/2024-04-22-131509_drop_artists_index_default/down.sql b/nghe-backend/migrations/2024-04-22-131509_drop_artists_index_default/down.sql
new file mode 100644
index 000000000..7ec3c6402
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-22-131509_drop_artists_index_default/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+alter table artists alter column index set default '?';
diff --git a/nghe-backend/migrations/2024-04-22-131509_drop_artists_index_default/up.sql b/nghe-backend/migrations/2024-04-22-131509_drop_artists_index_default/up.sql
new file mode 100644
index 000000000..8e28d0f93
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-22-131509_drop_artists_index_default/up.sql
@@ -0,0 +1,2 @@
+-- Your SQL goes here
+alter table artists alter column index drop default;
diff --git a/nghe-backend/migrations/2024-04-24-171407_add_artists_lastfm_info/down.sql b/nghe-backend/migrations/2024-04-24-171407_add_artists_lastfm_info/down.sql
new file mode 100644
index 000000000..d4dbcbddd
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-24-171407_add_artists_lastfm_info/down.sql
@@ -0,0 +1,5 @@
+-- This file should undo anything in `up.sql`
+alter table artists
+drop column lastfm_url,
+drop column lastfm_mbz_id,
+drop column lastfm_biography;
diff --git a/nghe-backend/migrations/2024-04-24-171407_add_artists_lastfm_info/up.sql b/nghe-backend/migrations/2024-04-24-171407_add_artists_lastfm_info/up.sql
new file mode 100644
index 000000000..4852e939d
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-24-171407_add_artists_lastfm_info/up.sql
@@ -0,0 +1,5 @@
+-- Your SQL goes here
+alter table artists
+add column lastfm_url text,
+add column lastfm_mbz_id uuid,
+add column lastfm_biography text;
diff --git a/nghe-backend/migrations/2024-04-25-113408_add_artists_cover_art/down.sql b/nghe-backend/migrations/2024-04-25-113408_add_artists_cover_art/down.sql
new file mode 100644
index 000000000..d292613f1
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-25-113408_add_artists_cover_art/down.sql
@@ -0,0 +1,4 @@
+-- This file should undo anything in `up.sql`
+alter table artists
+drop column spotify_id,
+drop column cover_art_id;
diff --git a/nghe-backend/migrations/2024-04-25-113408_add_artists_cover_art/up.sql b/nghe-backend/migrations/2024-04-25-113408_add_artists_cover_art/up.sql
new file mode 100644
index 000000000..eecc51ba4
--- /dev/null
+++ b/nghe-backend/migrations/2024-04-25-113408_add_artists_cover_art/up.sql
@@ -0,0 +1,7 @@
+-- Your SQL goes here
+alter table artists
+add column cover_art_id uuid,
+add column spotify_id text,
+add constraint cover_art_id_fkey foreign key (
+    cover_art_id
+) references cover_arts (id) on delete set null;
diff --git a/nghe-backend/migrations/2024-05-01-193504_add_music_folders_type/down.sql b/nghe-backend/migrations/2024-05-01-193504_add_music_folders_type/down.sql
new file mode 100644
index 000000000..b559fea36
--- /dev/null
+++ b/nghe-backend/migrations/2024-05-01-193504_add_music_folders_type/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+alter table music_folders drop column fs_type;
diff --git a/nghe-backend/migrations/2024-05-01-193504_add_music_folders_type/up.sql b/nghe-backend/migrations/2024-05-01-193504_add_music_folders_type/up.sql
new file mode 100644
index 000000000..032a59465
--- /dev/null
+++ b/nghe-backend/migrations/2024-05-01-193504_add_music_folders_type/up.sql
@@ -0,0 +1,8 @@
+-- Your SQL goes here
+-- fs type: 
+--  1 - local
+--  2 - s3
+alter table music_folders
+add column fs_type smallint not null default 1 constraint music_folders_fs_type check (
+    fs_type between 1 and 2
+);
diff --git a/nghe-backend/migrations/2024-05-04-102554_add_album_compilation/down.sql b/nghe-backend/migrations/2024-05-04-102554_add_album_compilation/down.sql
new file mode 100644
index 000000000..5a0c8bc26
--- /dev/null
+++ b/nghe-backend/migrations/2024-05-04-102554_add_album_compilation/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+alter table songs_album_artists drop column compilation;
diff --git a/nghe-backend/migrations/2024-05-04-102554_add_album_compilation/up.sql b/nghe-backend/migrations/2024-05-04-102554_add_album_compilation/up.sql
new file mode 100644
index 000000000..17100c311
--- /dev/null
+++ b/nghe-backend/migrations/2024-05-04-102554_add_album_compilation/up.sql
@@ -0,0 +1,2 @@
+-- Your SQL goes here
+alter table songs_album_artists add column compilation boolean not null default false;
diff --git a/nghe-backend/migrations/2024-09-01-050600_add_music_folders_created_at/down.sql b/nghe-backend/migrations/2024-09-01-050600_add_music_folders_created_at/down.sql
new file mode 100644
index 000000000..de6d203a1
--- /dev/null
+++ b/nghe-backend/migrations/2024-09-01-050600_add_music_folders_created_at/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+alter table music_folders drop column created_at;
diff --git a/nghe-backend/migrations/2024-09-01-050600_add_music_folders_created_at/up.sql b/nghe-backend/migrations/2024-09-01-050600_add_music_folders_created_at/up.sql
new file mode 100644
index 000000000..b2adff483
--- /dev/null
+++ b/nghe-backend/migrations/2024-09-01-050600_add_music_folders_created_at/up.sql
@@ -0,0 +1,3 @@
+-- Your SQL goes here
+alter table music_folders
+add column created_at timestamptz not null default now();
diff --git a/nghe-backend/migrations/2024-09-13-222721_music_folder_level_album/down.sql b/nghe-backend/migrations/2024-09-13-222721_music_folder_level_album/down.sql
new file mode 100644
index 000000000..a72e91db1
--- /dev/null
+++ b/nghe-backend/migrations/2024-09-13-222721_music_folder_level_album/down.sql
@@ -0,0 +1,39 @@
+-- This file should undo anything in `up.sql`
+drop index albums_music_folder_id_name_date_release_original_idx;
+
+create unique index albums_name_date_release_original_idx on albums (
+    name,
+    year,
+    month,
+    day,
+    release_year,
+    release_month,
+    release_day,
+    original_release_year,
+    original_release_month,
+    original_release_day
+) nulls not distinct where (mbz_id is null);
+
+alter table albums
+drop constraint albums_music_folder_id_mbz_id_key,
+add constraint albums_mbz_id_key unique (mbz_id);
+
+drop index albums_music_folder_id_idx;
+
+alter table albums drop column music_folder_id;
+
+alter table songs
+add column music_folder_id uuid not null,
+add constraint songs_music_folder_id foreign key (music_folder_id) references music_folders (
+    id
+) on delete cascade,
+drop constraint songs_album_id_relative_path_key,
+drop constraint songs_album_id_file_hash_file_size_key,
+add constraint songs_music_folder_id_relative_path_key unique (
+    music_folder_id, relative_path
+),
+add constraint songs_music_folder_id_file_hash_file_size_key unique (
+    music_folder_id, file_hash, file_size
+);
+
+create index songs_music_folder_id_idx on songs (music_folder_id);
diff --git a/nghe-backend/migrations/2024-09-13-222721_music_folder_level_album/up.sql b/nghe-backend/migrations/2024-09-13-222721_music_folder_level_album/up.sql
new file mode 100644
index 000000000..e5b1e66ef
--- /dev/null
+++ b/nghe-backend/migrations/2024-09-13-222721_music_folder_level_album/up.sql
@@ -0,0 +1,39 @@
+-- Your SQL goes here
+drop index songs_music_folder_id_idx;
+
+alter table songs
+drop column music_folder_id,
+add constraint songs_album_id_relative_path_key unique (
+    album_id, relative_path
+),
+add constraint songs_album_id_file_hash_file_size_key unique (
+    album_id, file_hash, file_size
+);
+
+alter table albums
+add column music_folder_id uuid not null,
+add constraint albums_music_folder_id foreign key (music_folder_id) references music_folders (
+    id
+) on delete cascade;
+
+create index albums_music_folder_id_idx on albums (music_folder_id);
+
+alter table albums
+drop constraint albums_mbz_id_key,
+add constraint albums_music_folder_id_mbz_id_key unique (music_folder_id, mbz_id);
+
+drop index albums_name_date_release_original_idx;
+
+create unique index albums_music_folder_id_name_date_release_original_idx on albums (
+    music_folder_id,
+    name,
+    year,
+    month,
+    day,
+    release_year,
+    release_month,
+    release_day,
+    original_release_year,
+    original_release_month,
+    original_release_day
+) nulls not distinct where (mbz_id is null);
diff --git a/nghe-backend/migrations/2024-11-22-065114_add_cover_arts_source_constraint_updated_at_scanned_at/down.sql b/nghe-backend/migrations/2024-11-22-065114_add_cover_arts_source_constraint_updated_at_scanned_at/down.sql
new file mode 100644
index 000000000..c77230868
--- /dev/null
+++ b/nghe-backend/migrations/2024-11-22-065114_add_cover_arts_source_constraint_updated_at_scanned_at/down.sql
@@ -0,0 +1,9 @@
+-- This file should undo anything in `up.sql`
+alter table cover_arts
+drop column source,
+drop column updated_at,
+drop column scanned_at,
+add column upserted_at timestamptz not null default now(),
+add constraint cover_arts_format_file_hash_file_size_key unique (
+    format, file_hash, file_size
+);
diff --git a/nghe-backend/migrations/2024-11-22-065114_add_cover_arts_source_constraint_updated_at_scanned_at/up.sql b/nghe-backend/migrations/2024-11-22-065114_add_cover_arts_source_constraint_updated_at_scanned_at/up.sql
new file mode 100644
index 000000000..32ab8b742
--- /dev/null
+++ b/nghe-backend/migrations/2024-11-22-065114_add_cover_arts_source_constraint_updated_at_scanned_at/up.sql
@@ -0,0 +1,11 @@
+-- Your SQL goes here
+alter table cover_arts
+add column source text,
+add column updated_at timestamptz not null default now(),
+add column scanned_at timestamptz not null default now(),
+drop column upserted_at,
+add constraint cover_arts_source_file_hash_file_size_key
+unique nulls not distinct (
+    source, file_hash, file_size
+),
+drop constraint cover_arts_format_file_hash_file_size_key;
diff --git a/nghe-backend/migrations/2024-11-24-190103_add_albums_cover_art_id/down.sql b/nghe-backend/migrations/2024-11-24-190103_add_albums_cover_art_id/down.sql
new file mode 100644
index 000000000..54c8de689
--- /dev/null
+++ b/nghe-backend/migrations/2024-11-24-190103_add_albums_cover_art_id/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+alter table albums drop column cover_art_id;
diff --git a/nghe-backend/migrations/2024-11-24-190103_add_albums_cover_art_id/up.sql b/nghe-backend/migrations/2024-11-24-190103_add_albums_cover_art_id/up.sql
new file mode 100644
index 000000000..6a6b9a75e
--- /dev/null
+++ b/nghe-backend/migrations/2024-11-24-190103_add_albums_cover_art_id/up.sql
@@ -0,0 +1,5 @@
+-- Your SQL goes here
+alter table albums
+add column cover_art_id uuid, add constraint cover_art_id_fkey foreign key (
+    cover_art_id
+) references cover_arts (id) on delete set null;
diff --git a/nghe-backend/src/auth/mod.rs b/nghe-backend/src/auth/mod.rs
new file mode 100644
index 000000000..02aa6d1f0
--- /dev/null
+++ b/nghe-backend/src/auth/mod.rs
@@ -0,0 +1,360 @@
+use axum::body::Bytes;
+use axum::extract::{FromRef, FromRequest, Request};
+use axum::RequestExt;
+use diesel::{ExpressionMethods, QueryDsl, SelectableHelper};
+use diesel_async::RunQueryDsl;
+use nghe_api::auth::{Auth, AuthRequest};
+use nghe_api::common::{BinaryRequest, JsonRequest};
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::users;
+use crate::Error;
+
+#[derive(Debug)]
+pub struct GetUser<R, const NEED_AUTH: bool> {
+    pub id: Uuid,
+    pub request: R,
+}
+
+#[derive(Debug)]
+pub struct PostUser<R> {
+    pub id: Uuid,
+    pub request: R,
+}
+
+#[derive(Debug)]
+pub struct BinaryUser<R, const NEED_AUTH: bool> {
+    pub id: Uuid,
+    pub request: R,
+}
+
+trait FromIdRequest<R>: Sized {
+    fn from_id_request(id: Uuid, request: R) -> Self;
+}
+
+pub trait Authorize {
+    fn authorize(role: users::Role) -> Result<(), Error>;
+}
+
+async fn authenticate<A: Authorize>(
+    database: &Database,
+    data: Auth<'_, '_>,
+) -> Result<Uuid, Error> {
+    let users::Auth { id, password, role } = users::table
+        .filter(users::username.eq(data.username))
+        .select(users::Auth::as_select())
+        .first(&mut database.get().await?)
+        .await
+        .map_err(|_| Error::Unauthenticated)?;
+    let password = database.decrypt(password)?;
+    A::authorize(role)?;
+
+    if Auth::check(password, data.salt, &data.token) { Ok(id) } else { Err(Error::Unauthenticated) }
+}
+
+// TODO: Optimize this after https://github.com/serde-rs/serde/issues/1183
+async fn json_authenticate<S, R: JsonRequest + Authorize, U: FromIdRequest<R>>(
+    state: &S,
+    input: &str,
+) -> Result<U, Error>
+where
+    Database: FromRef<S>,
+{
+    let auth: Auth = serde_html_form::from_str(input)
+        .map_err(|_| Error::SerializeAuthParameters(input.to_owned()))?;
+
+    let database = Database::from_ref(state);
+    let id = authenticate::<R>(&database, auth).await?;
+
+    let request = serde_html_form::from_str::<R>(input)
+        .map_err(|_| Error::SerializeRequestParameters(input.to_owned()))?;
+
+    Ok(U::from_id_request(id, request))
+}
+
+impl<R, const NEED_AUTH: bool> FromIdRequest<R> for GetUser<R, NEED_AUTH> {
+    fn from_id_request(id: Uuid, request: R) -> Self {
+        Self { id, request }
+    }
+}
+
+impl<R> FromIdRequest<R> for PostUser<R> {
+    fn from_id_request(id: Uuid, request: R) -> Self {
+        Self { id, request }
+    }
+}
+
+impl<S, R, const NEED_AUTH: bool> FromRequest<S> for GetUser<R, NEED_AUTH>
+where
+    S: Send + Sync,
+    Database: FromRef<S>,
+    R: JsonRequest + Authorize + Send,
+{
+    type Rejection = Error;
+
+    #[tracing::instrument(skip_all, err)]
+    async fn from_request(request: Request, state: &S) -> Result<Self, Self::Rejection> {
+        let query = request.uri().query();
+
+        if NEED_AUTH {
+            json_authenticate(state, query.ok_or_else(|| Error::GetRequestMissingQueryParameters)?)
+                .await
+        } else {
+            let query = query.unwrap_or_default();
+            Ok(Self {
+                id: Uuid::default(),
+                request: serde_html_form::from_str(query)
+                    .map_err(|_| Error::SerializeRequestParameters(query.to_owned()))?,
+            })
+        }
+    }
+}
+
+impl<S, R> FromRequest<S> for PostUser<R>
+where
+    S: Send + Sync,
+    Database: FromRef<S>,
+    R: JsonRequest + Authorize + Send,
+{
+    type Rejection = Error;
+
+    #[tracing::instrument(skip_all, err)]
+    async fn from_request(request: Request, state: &S) -> Result<Self, Self::Rejection> {
+        json_authenticate(state, &request.extract::<String, _>().await?).await
+    }
+}
+
+impl<S, R, const NEED_AUTH: bool> FromRequest<S> for BinaryUser<R, NEED_AUTH>
+where
+    S: Send + Sync,
+    Database: FromRef<S>,
+    R: BinaryRequest + Authorize + Send,
+{
+    type Rejection = Error;
+
+    #[tracing::instrument(skip_all, err)]
+    async fn from_request(request: Request, state: &S) -> Result<Self, Self::Rejection> {
+        let bytes: Bytes = request.extract().await?;
+
+        if NEED_AUTH {
+            let AuthRequest::<R> { auth, request } =
+                bitcode::decode(&bytes).map_err(|_| Error::SerializeBinaryRequest)?;
+
+            let database = Database::from_ref(state);
+            let id = authenticate::<R>(&database, auth).await?;
+            Ok(Self { id, request })
+        } else {
+            Ok(Self {
+                id: Uuid::default(),
+                request: bitcode::decode(&bytes).map_err(|_| Error::SerializeBinaryRequest)?,
+            })
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #![allow(unexpected_cfgs)]
+
+    use axum::body::Body;
+    use axum::http;
+    use concat_string::concat_string;
+    use fake::{Fake, Faker};
+    use nghe_api::common::JsonURL as _;
+    use nghe_proc_macro::api_derive;
+    use rstest::rstest;
+    use serde::Serialize;
+
+    use super::*;
+    use crate::test::{mock, Mock};
+
+    #[api_derive]
+    #[endpoint(path = "test", same_crate = false)]
+    #[derive(Clone, Copy, Serialize)]
+    struct Request {
+        param_one: i32,
+        param_two: u32,
+    }
+
+    #[api_derive]
+    #[allow(dead_code)]
+    struct Response;
+
+    impl Authorize for Request {
+        fn authorize(_: users::Role) -> Result<(), Error> {
+            Ok(())
+        }
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_authenticate(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+    ) {
+        let user = mock.user(0).await;
+        let id = authenticate::<Request>(mock.database(), (&user.auth()).into()).await.unwrap();
+        assert_eq!(id, user.id());
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_authenticate_wrong_username(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+    ) {
+        let auth = mock.user(0).await.auth();
+
+        let username: String = Faker.fake();
+        let auth = Auth { username: &username, ..(&auth).into() };
+        assert!(authenticate::<Request>(mock.database(), auth).await.is_err());
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_authenticate_wrong_password(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+    ) {
+        let auth = mock.user(0).await.auth();
+
+        let token = Auth::tokenize(Faker.fake::<String>(), &auth.salt);
+        let auth = Auth { token, ..(&auth).into() };
+        assert!(authenticate::<Request>(mock.database(), auth).await.is_err());
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_json_get_auth(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+    ) {
+        #[derive(Debug, Serialize)]
+        struct RequestAuth<'u, 't> {
+            #[serde(flatten, borrow)]
+            auth: Auth<'u, 't>,
+            #[serde(flatten)]
+            request: Request,
+        }
+
+        let request: Request = Faker.fake();
+
+        let user = mock.user(0).await;
+        let auth = user.auth();
+        let auth = (&auth).into();
+
+        let http_request = http::Request::builder()
+            .method(http::Method::GET)
+            .uri(concat_string!(
+                Request::URL,
+                "?",
+                serde_html_form::to_string(RequestAuth { auth, request }).unwrap()
+            ))
+            .body(Body::empty())
+            .unwrap();
+
+        let test_request =
+            GetUser::<Request, true>::from_request(http_request, mock.state()).await.unwrap();
+        assert_eq!(user.user.id, test_request.id);
+        assert_eq!(request, test_request.request);
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_json_get_no_auth(
+        #[future(awt)]
+        #[with(0, 0)]
+        mock: Mock,
+    ) {
+        let request: Request = Faker.fake();
+
+        let http_request = http::Request::builder()
+            .method(http::Method::GET)
+            .uri(concat_string!(Request::URL, "?", serde_html_form::to_string(request).unwrap()))
+            .body(Body::empty())
+            .unwrap();
+
+        let test_request =
+            GetUser::<Request, false>::from_request(http_request, mock.state()).await.unwrap();
+        assert_eq!(Uuid::default(), test_request.id);
+        assert_eq!(request, test_request.request);
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_json_post(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+    ) {
+        let request: Request = Faker.fake();
+
+        let user = mock.user(0).await;
+        let auth = user.auth();
+        let auth = (&auth).into();
+
+        let http_request = http::Request::builder()
+            .method(http::Method::POST)
+            .uri(Request::URL)
+            .body(Body::from(concat_string!(
+                serde_html_form::to_string::<Auth>(auth).unwrap(),
+                "&",
+                serde_html_form::to_string(request).unwrap()
+            )))
+            .unwrap();
+
+        let test_request =
+            PostUser::<Request>::from_request(http_request, mock.state()).await.unwrap();
+        assert_eq!(user.user.id, test_request.id);
+        assert_eq!(request, test_request.request);
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_binary_auth(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+    ) {
+        let request: Request = Faker.fake();
+
+        let user = mock.user(0).await;
+        let auth = user.auth();
+        let auth = (&auth).into();
+
+        let http_request = http::Request::builder()
+            .method(http::Method::POST)
+            .body(Body::from(bitcode::encode(&AuthRequest { auth, request })))
+            .unwrap();
+
+        let test_request =
+            BinaryUser::<Request, true>::from_request(http_request, mock.state()).await.unwrap();
+        assert_eq!(user.user.id, test_request.id);
+        assert_eq!(request, test_request.request);
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_binary_no_auth(
+        #[future(awt)]
+        #[with(0, 0)]
+        mock: Mock,
+    ) {
+        let request: Request = Faker.fake();
+
+        let http_request = http::Request::builder()
+            .method(http::Method::POST)
+            .body(Body::from(bitcode::encode(&request)))
+            .unwrap();
+
+        let test_request =
+            BinaryUser::<Request, false>::from_request(http_request, mock.state()).await.unwrap();
+        assert_eq!(Uuid::default(), test_request.id);
+        assert_eq!(request, test_request.request);
+    }
+}
diff --git a/nghe-backend/src/config/cover_art.rs b/nghe-backend/src/config/cover_art.rs
new file mode 100644
index 000000000..c78b2eb7c
--- /dev/null
+++ b/nghe-backend/src/config/cover_art.rs
@@ -0,0 +1,38 @@
+use educe::Educe;
+use serde::{Deserialize, Serialize};
+use serde_with::formats::SpaceSeparator;
+use serde_with::{serde_as, StringWithSeparator};
+use typed_path::utils::utf8_temp_dir;
+use typed_path::Utf8NativePathBuf;
+
+#[serde_as]
+#[derive(Debug, Clone, Serialize, Deserialize, Educe)]
+#[educe(Default)]
+pub struct CoverArt {
+    #[serde(with = "crate::filesystem::path::serde::option")]
+    #[educe(Default(
+        expression = Some(utf8_temp_dir().unwrap().join("nghe").join("cache").join("cover_art"))
+    ))]
+    pub dir: Option<Utf8NativePathBuf>,
+    #[serde_as(as = "StringWithSeparator::<SpaceSeparator, String>")]
+    #[educe(Default(expression = vec!["cover.jpg".to_owned(), "cover.png".to_owned()]))]
+    pub names: Vec<String>,
+}
+
+#[cfg(test)]
+mod test {
+    use strum::IntoEnumIterator;
+    use typed_path::Utf8NativePath;
+
+    use super::*;
+    use crate::file::picture;
+
+    impl CoverArt {
+        pub fn with_prefix(self, prefix: impl AsRef<Utf8NativePath>) -> Self {
+            Self {
+                dir: self.dir.map(|_| prefix.as_ref().join("cache").join("cover_art")),
+                names: picture::Format::iter().map(picture::Format::name).collect(),
+            }
+        }
+    }
+}
diff --git a/nghe-backend/src/config/database.rs b/nghe-backend/src/config/database.rs
new file mode 100644
index 000000000..b850ff582
--- /dev/null
+++ b/nghe-backend/src/config/database.rs
@@ -0,0 +1,16 @@
+use educe::Educe;
+use serde::Deserialize;
+use serde_with::serde_as;
+
+use crate::database::Key;
+
+#[serde_as]
+#[derive(Deserialize, Educe)]
+#[educe(Debug)]
+pub struct Database {
+    #[educe(Debug(ignore))]
+    pub url: String,
+    #[serde_as(as = "serde_with::hex::Hex")]
+    #[educe(Debug(ignore))]
+    pub key: Key,
+}
diff --git a/nghe-backend/src/config/filesystem.rs b/nghe-backend/src/config/filesystem.rs
new file mode 100644
index 000000000..a8bd77dc7
--- /dev/null
+++ b/nghe-backend/src/config/filesystem.rs
@@ -0,0 +1,67 @@
+use educe::Educe;
+use serde::{Deserialize, Serialize};
+use serde_with::serde_as;
+
+#[serde_as]
+#[derive(Debug, Serialize, Deserialize, Clone, Copy, Educe)]
+#[educe(Default)]
+pub struct Scan {
+    // 100 KiB in bytes
+    #[educe(Default(expression = 100 * 1024))]
+    pub minimum_size: usize,
+    #[serde_as(deserialize_as = "serde_with::DefaultOnError")]
+    #[educe(Default(expression = Some(10)))]
+    pub channel_size: Option<usize>,
+    #[educe(Default(expression = 10))]
+    pub pool_size: usize,
+}
+
+#[derive(Debug, Serialize, Deserialize, Educe)]
+#[educe(Default)]
+pub struct Tls {
+    #[educe(Default(expression = false))]
+    pub accept_invalid_certs: bool,
+    #[educe(Default(expression = false))]
+    pub accept_invalid_hostnames: bool,
+}
+
+#[derive(Debug, Serialize, Deserialize, Educe)]
+#[educe(Default)]
+pub struct S3 {
+    #[educe(Default(expression =
+        std::env::var("AWS_ACCESS_KEY_ID").is_ok() && std::env::var("AWS_SECRET_ACCESS_KEY").is_ok()
+    ))]
+    pub enable: bool,
+    #[educe(Default(expression = std::env::var("AWS_USE_PATH_STYLE_ENDPOINT").is_ok()))]
+    pub use_path_style_endpoint: bool,
+    #[educe(Default(expression = 15))]
+    pub presigned_duration: u64,
+    #[educe(Default(expression = 0))]
+    pub stalled_stream_grace_preriod: u64,
+    #[educe(Default(expression = 5))]
+    pub connect_timeout: u64,
+}
+
+#[derive(Debug, Serialize, Deserialize, Default)]
+pub struct Filesystem {
+    pub scan: Scan,
+    pub tls: Tls,
+    pub s3: S3,
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    impl S3 {
+        pub fn test() -> Self {
+            Self { enable: true, ..Self::default() }
+        }
+    }
+
+    impl Filesystem {
+        pub fn test() -> Self {
+            Self { s3: S3::test(), ..Self::default() }
+        }
+    }
+}
diff --git a/nghe-backend/src/config/index.rs b/nghe-backend/src/config/index.rs
new file mode 100644
index 000000000..09595d5df
--- /dev/null
+++ b/nghe-backend/src/config/index.rs
@@ -0,0 +1,63 @@
+use std::borrow::Cow;
+
+use educe::Educe;
+use itertools::Itertools;
+use serde::{Deserialize, Serialize};
+
+use crate::{database, Error};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Educe)]
+#[educe(Default)]
+pub struct Index {
+    #[serde(with = "split")]
+    #[educe(Default(expression = Index::split("The An A Die Das Ein Eine Les Le La")))]
+    pub ignore_prefixes: Vec<String>,
+}
+
+impl Index {
+    fn split(s: &str) -> Vec<String> {
+        s.split_ascii_whitespace().map(|v| concat_string::concat_string!(v, " ")).collect()
+    }
+
+    fn merge(prefixes: &[impl AsRef<str>]) -> Result<String, Error> {
+        Ok(prefixes
+            .iter()
+            .map(|prefix| prefix.as_ref().strip_suffix(' '))
+            .collect::<Option<Vec<_>>>()
+            .ok_or_else(|| Error::ConfigIndexIgnorePrefixEndWithoutSpace)?
+            .iter()
+            .join(" "))
+    }
+}
+
+impl database::Config for Index {
+    const KEY: &'static str = "ignored_articles";
+
+    const ENCRYPTED: bool = false;
+
+    fn value(&self) -> Result<Cow<'_, str>, Error> {
+        Self::merge(&self.ignore_prefixes).map(String::into)
+    }
+}
+
+mod split {
+    use serde::ser::Error;
+    use serde::{Deserialize, Deserializer, Serializer};
+
+    use super::*;
+
+    pub fn serialize<S>(prefixes: &[String], serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer
+            .serialize_str(&Index::merge(prefixes).map_err(|e| S::Error::custom(e.to_string()))?)
+    }
+
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<Vec<String>, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        Ok(Index::split(&<String>::deserialize(deserializer)?))
+    }
+}
diff --git a/nghe-backend/src/config/mod.rs b/nghe-backend/src/config/mod.rs
new file mode 100644
index 000000000..02ff65a3a
--- /dev/null
+++ b/nghe-backend/src/config/mod.rs
@@ -0,0 +1,45 @@
+mod cover_art;
+mod database;
+pub mod filesystem;
+mod index;
+pub mod parsing;
+mod server;
+mod transcode;
+
+pub use cover_art::CoverArt;
+pub use database::Database;
+use figment::providers::{Env, Serialized};
+use figment::Figment;
+use filesystem::Filesystem;
+pub use index::Index;
+use nghe_api::constant;
+pub use parsing::Parsing;
+use serde::Deserialize;
+pub use server::Server;
+pub use transcode::Transcode;
+
+#[derive(Debug, Deserialize)]
+pub struct Config {
+    pub server: Server,
+    pub database: Database,
+    pub filesystem: Filesystem,
+    pub parsing: Parsing,
+    pub index: Index,
+    pub transcode: Transcode,
+    pub cover_art: CoverArt,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Figment::new()
+            .merge(Env::prefixed(const_format::concatc!(constant::SERVER_NAME, "_")).split("__"))
+            .join(Serialized::default("server", Server::default()))
+            .join(Serialized::default("filesystem", Filesystem::default()))
+            .join(Serialized::default("parsing", Parsing::default()))
+            .join(Serialized::default("index", Index::default()))
+            .join(Serialized::default("transcode", Transcode::default()))
+            .join(Serialized::default("cover_art", CoverArt::default()))
+            .extract()
+            .expect("Could not parse config")
+    }
+}
diff --git a/nghe-backend/src/config/parsing/mod.rs b/nghe-backend/src/config/parsing/mod.rs
new file mode 100644
index 000000000..189e44501
--- /dev/null
+++ b/nghe-backend/src/config/parsing/mod.rs
@@ -0,0 +1,20 @@
+pub mod vorbis_comments;
+
+use serde::{Deserialize, Serialize};
+use vorbis_comments::VorbisComments;
+
+#[derive(Debug, Default, Clone, Serialize, Deserialize)]
+pub struct Parsing {
+    pub vorbis_comments: VorbisComments,
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    impl Parsing {
+        pub fn test() -> Self {
+            Self { vorbis_comments: VorbisComments::test() }
+        }
+    }
+}
diff --git a/nghe-backend/src/config/parsing/vorbis_comments.rs b/nghe-backend/src/config/parsing/vorbis_comments.rs
new file mode 100644
index 000000000..c6ca89b9b
--- /dev/null
+++ b/nghe-backend/src/config/parsing/vorbis_comments.rs
@@ -0,0 +1,112 @@
+use educe::Educe;
+use serde::{Deserialize, Serialize};
+use serde_with::serde_as;
+
+#[serde_as]
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Common {
+    pub name: String,
+    #[serde_as(as = "serde_with::NoneAsEmptyString")]
+    pub date: Option<String>,
+    #[serde_as(as = "serde_with::NoneAsEmptyString")]
+    pub release_date: Option<String>,
+    #[serde_as(as = "serde_with::NoneAsEmptyString")]
+    pub original_release_date: Option<String>,
+    pub mbz_id: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Artist {
+    pub name: String,
+    pub mbz_id: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Educe)]
+#[educe(Default)]
+pub struct Artists {
+    #[educe(Default(expression = Artist::default_song()))]
+    pub song: Artist,
+    #[educe(Default(expression = Artist::default_album()))]
+    pub album: Artist,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Educe)]
+#[educe(Default)]
+pub struct TrackDisc {
+    #[educe(Default(expression = "TRACKNUMBER".into()))]
+    pub track_number: String,
+    #[educe(Default(expression = "TRACKTOTAL".into()))]
+    pub track_total: String,
+    #[educe(Default(expression = "DISCNUMBER".into()))]
+    pub disc_number: String,
+    #[educe(Default(expression = "DISCTOTAL".into()))]
+    pub disc_total: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Educe)]
+#[educe(Default)]
+pub struct VorbisComments {
+    #[educe(Default(expression = Common::default_song()))]
+    pub song: Common,
+    #[educe(Default(expression = Common::default_album()))]
+    pub album: Common,
+    pub artists: Artists,
+    pub track_disc: TrackDisc,
+    #[educe(Default(expression = "LANGUAGE".into()))]
+    pub languages: String,
+    #[educe(Default(expression = "GENRE".into()))]
+    pub genres: String,
+    #[educe(Default(expression = "COMPILATION".into()))]
+    pub compilation: String,
+}
+
+impl Common {
+    fn default_song() -> Self {
+        Self {
+            name: "TITLE".into(),
+            date: None,
+            release_date: None,
+            original_release_date: None,
+            mbz_id: "MUSICBRAINZ_RELEASETRACKID".into(),
+        }
+    }
+
+    fn default_album() -> Self {
+        Self {
+            name: "ALBUM".into(),
+            date: Some("DATE".into()),
+            release_date: Some("RELEASEDATE".into()),
+            original_release_date: Some("ORIGYEAR".into()),
+            mbz_id: "MUSICBRAINZ_ALBUMID".into(),
+        }
+    }
+}
+
+impl Artist {
+    fn default_song() -> Self {
+        Self { name: "ARTIST".into(), mbz_id: "MUSICBRAINZ_ARTISTID".into() }
+    }
+
+    fn default_album() -> Self {
+        Self { name: "ALBUMARTIST".into(), mbz_id: "MUSICBRAINZ_ALBUMARTISTID".into() }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    impl VorbisComments {
+        pub fn test() -> Self {
+            Self {
+                song: Common {
+                    date: Some("SDATE".into()),
+                    release_date: Some("SRELEASEDATE".into()),
+                    original_release_date: Some("SORIGYEAR".into()),
+                    ..Common::default_song()
+                },
+                ..Self::default()
+            }
+        }
+    }
+}
diff --git a/nghe-backend/src/config/server.rs b/nghe-backend/src/config/server.rs
new file mode 100644
index 000000000..19e144a7a
--- /dev/null
+++ b/nghe-backend/src/config/server.rs
@@ -0,0 +1,24 @@
+use std::net::{IpAddr, SocketAddr};
+
+use educe::Educe;
+use serde::{Deserialize, Serialize};
+use typed_path::utils::utf8_current_dir;
+use typed_path::Utf8NativePathBuf;
+
+#[derive(Debug, Serialize, Deserialize, Educe)]
+#[educe(Default)]
+pub struct Server {
+    #[educe(Default(expression = [127u8, 0u8, 0u8, 1u8].into()))]
+    pub host: IpAddr,
+    #[educe(Default(expression = 3000))]
+    pub port: u16,
+    #[serde(with = "crate::filesystem::path::serde")]
+    #[educe(Default(expression = utf8_current_dir().unwrap().join("frontend").join("dist")))]
+    pub frontend_dir: Utf8NativePathBuf,
+}
+
+impl Server {
+    pub fn to_socket_addr(&self) -> SocketAddr {
+        SocketAddr::new(self.host, self.port)
+    }
+}
diff --git a/nghe-backend/src/config/transcode.rs b/nghe-backend/src/config/transcode.rs
new file mode 100644
index 000000000..a264b41b4
--- /dev/null
+++ b/nghe-backend/src/config/transcode.rs
@@ -0,0 +1,37 @@
+use educe::Educe;
+use serde::{Deserialize, Serialize};
+use serde_with::serde_as;
+use typed_path::utils::utf8_temp_dir;
+use typed_path::Utf8NativePathBuf;
+
+#[serde_as]
+#[derive(Debug, Clone, Serialize, Deserialize, Educe)]
+#[educe(Default)]
+pub struct Transcode {
+    #[educe(Default(expression = 32 * 1024))]
+    pub buffer_size: usize,
+    #[serde_as(deserialize_as = "serde_with::DefaultOnError")]
+    #[educe(Default(expression = Some(10)))]
+    pub channel_size: Option<usize>,
+    #[serde(with = "crate::filesystem::path::serde::option")]
+    #[educe(Default(
+        expression = Some(utf8_temp_dir().unwrap().join("nghe").join("cache").join("transcode"))
+    ))]
+    pub cache_dir: Option<Utf8NativePathBuf>,
+}
+
+#[cfg(test)]
+mod test {
+    use typed_path::Utf8NativePath;
+
+    use super::*;
+
+    impl Transcode {
+        pub fn with_prefix(self, prefix: impl AsRef<Utf8NativePath>) -> Self {
+            Self {
+                cache_dir: self.cache_dir.map(|_| prefix.as_ref().join("cache").join("transcode")),
+                ..self
+            }
+        }
+    }
+}
diff --git a/nghe-backend/src/database/config.rs b/nghe-backend/src/database/config.rs
new file mode 100644
index 000000000..f833b46bc
--- /dev/null
+++ b/nghe-backend/src/database/config.rs
@@ -0,0 +1,138 @@
+use std::borrow::Cow;
+
+use diesel::{ExpressionMethods, QueryDsl, SelectableHelper};
+use diesel_async::RunQueryDsl;
+
+use super::Database;
+use crate::orm::configs;
+use crate::Error;
+
+pub trait Config {
+    const KEY: &'static str;
+    const ENCRYPTED: bool;
+
+    fn value(&self) -> Result<Cow<'_, str>, Error>;
+}
+
+impl Database {
+    pub async fn upsert_config<C: Config>(&self, config: &C) -> Result<(), Error> {
+        let value = config.value()?;
+        let data = if C::ENCRYPTED {
+            let value: &str = value.as_ref();
+            configs::Data { text: None, byte: Some(self.encrypt(value).into()) }
+        } else {
+            configs::Data { text: Some(value), byte: None }
+        };
+        let upsert = configs::Upsert { key: C::KEY, data };
+
+        diesel::insert_into(configs::table)
+            .values(&upsert)
+            .on_conflict(configs::key)
+            .do_update()
+            .set(&upsert)
+            .execute(&mut self.get().await?)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn get_config<C: Config>(&self) -> Result<String, Error> {
+        let config = configs::table
+            .filter(configs::key.eq(C::KEY))
+            .select(configs::Data::as_select())
+            .get_result(&mut self.get().await?)
+            .await?;
+
+        if C::ENCRYPTED {
+            String::from_utf8(
+                self.decrypt(
+                    config.byte.ok_or_else(|| Error::DatabaseInvalidConfigFormat(C::KEY))?,
+                )?,
+            )
+            .map_err(Error::from)
+        } else {
+            config
+                .text
+                .ok_or_else(|| Error::DatabaseInvalidConfigFormat(C::KEY))
+                .map(Cow::into_owned)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Dummy, Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::test::{mock, Mock};
+
+    #[derive(Dummy)]
+    struct NonEncryptedConfig(String);
+
+    impl Config for NonEncryptedConfig {
+        const ENCRYPTED: bool = false;
+        const KEY: &'static str = "non-encrypted";
+
+        fn value(&self) -> Result<Cow<'_, str>, Error> {
+            Ok((&self.0).into())
+        }
+    }
+
+    #[derive(Dummy)]
+    struct EncryptedConfig(String);
+
+    impl Config for EncryptedConfig {
+        const ENCRYPTED: bool = true;
+        const KEY: &'static str = "encrypted";
+
+        fn value(&self) -> Result<Cow<'_, str>, Error> {
+            Ok((&self.0).into())
+        }
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_roundtrip_non_encrypted(
+        #[future(awt)]
+        #[with(0, 0)]
+        mock: Mock,
+        #[values(true, false)] update: bool,
+    ) {
+        let database = mock.database();
+
+        let config: NonEncryptedConfig = Faker.fake();
+        database.upsert_config(&config).await.unwrap();
+        let database_config = database.get_config::<NonEncryptedConfig>().await.unwrap();
+        assert_eq!(database_config, config.0);
+
+        if update {
+            let update: NonEncryptedConfig = Faker.fake();
+            database.upsert_config(&update).await.unwrap();
+            let database_update = database.get_config::<NonEncryptedConfig>().await.unwrap();
+            assert_eq!(database_update, update.0);
+        }
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_roundtrip_encrypted(
+        #[future(awt)]
+        #[with(0, 0)]
+        mock: Mock,
+        #[values(true, false)] update: bool,
+    ) {
+        let database = mock.database();
+
+        let config: EncryptedConfig = Faker.fake();
+        database.upsert_config(&config).await.unwrap();
+        let database_config = database.get_config::<EncryptedConfig>().await.unwrap();
+        assert_eq!(database_config, config.0);
+
+        if update {
+            let update: EncryptedConfig = Faker.fake();
+            database.upsert_config(&update).await.unwrap();
+            let database_update = database.get_config::<EncryptedConfig>().await.unwrap();
+            assert_eq!(database_update, update.0);
+        }
+    }
+}
diff --git a/nghe-backend/src/database/mod.rs b/nghe-backend/src/database/mod.rs
new file mode 100644
index 000000000..9a1346551
--- /dev/null
+++ b/nghe-backend/src/database/mod.rs
@@ -0,0 +1,77 @@
+mod config;
+
+use diesel_async::pooled_connection::{deadpool, AsyncDieselConnectionManager};
+use diesel_async::AsyncPgConnection;
+use libaes::Cipher;
+
+use crate::Error;
+
+type Connection = AsyncDieselConnectionManager<AsyncPgConnection>;
+type Pool = deadpool::Pool<AsyncPgConnection>;
+
+pub type Key = [u8; libaes::AES_128_KEY_LEN];
+
+pub use config::Config;
+
+#[derive(Clone)]
+pub struct Database {
+    pool: Pool,
+    key: Key,
+}
+
+impl Database {
+    const IV_LEN: usize = 16;
+
+    pub fn new(config: &crate::config::Database) -> Self {
+        let pool = Pool::builder(Connection::new(&config.url))
+            .build()
+            .expect("Could not build database connection pool");
+        Self { pool, key: config.key }
+    }
+
+    pub async fn get(&self) -> Result<deadpool::Object<AsyncPgConnection>, Error> {
+        self.pool.get().await.map_err(|_| Error::CheckoutConnectionPool)
+    }
+
+    pub fn encrypt(&self, data: impl AsRef<[u8]>) -> Vec<u8> {
+        Self::encrypt_impl(&self.key, data)
+    }
+
+    pub fn decrypt(&self, data: impl AsRef<[u8]>) -> Result<Vec<u8>, Error> {
+        Self::decrypt_impl(&self.key, data)
+    }
+
+    fn encrypt_impl(key: &Key, data: impl AsRef<[u8]>) -> Vec<u8> {
+        let data = data.as_ref();
+
+        let iv: [u8; Self::IV_LEN] = rand::random();
+        [iv.as_slice(), Cipher::new_128(key).cbc_encrypt(&iv, data).as_slice()].concat()
+    }
+
+    fn decrypt_impl(key: &Key, data: impl AsRef<[u8]>) -> Result<Vec<u8>, Error> {
+        let data = data.as_ref();
+
+        let cipher_text = &data[Self::IV_LEN..];
+        let iv = &data[..Self::IV_LEN];
+
+        let output = Cipher::new_128(key).cbc_decrypt(iv, cipher_text);
+        if output.is_empty() { Err(Error::DecryptDatabaseValue) } else { Ok(output) }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+
+    use super::*;
+
+    #[test]
+    fn test_roundtrip() {
+        let key: Key = Faker.fake();
+        let data = (16..32).fake::<String>().into_bytes();
+        assert_eq!(
+            data,
+            Database::decrypt_impl(&key, Database::encrypt_impl(&key, &data)).unwrap()
+        );
+    }
+}
diff --git a/nghe-backend/src/error/mod.rs b/nghe-backend/src/error/mod.rs
new file mode 100644
index 000000000..d75dd0649
--- /dev/null
+++ b/nghe-backend/src/error/mod.rs
@@ -0,0 +1,169 @@
+use std::ffi::OsString;
+
+use aws_sdk_s3::error::SdkError;
+use aws_sdk_s3::operation::get_object::GetObjectError;
+use aws_sdk_s3::operation::head_object::HeadObjectError;
+use axum::http::StatusCode;
+use axum::response::{IntoResponse, Response};
+use loole::SendError;
+use o2o::o2o;
+
+#[derive(Debug, thiserror::Error, o2o)]
+#[from_owned(std::io::Error| repeat(), return Self::Internal(@.into()))]
+#[from_owned(isolang::ParseLanguageError)]
+#[from_owned(uuid::Error)]
+#[from_owned(lofty::error::LoftyError)]
+#[from_owned(aws_sdk_s3::primitives::ByteStreamError)]
+#[from_owned(std::num::TryFromIntError)]
+#[from_owned(typed_path::StripPrefixError)]
+#[from_owned(time::error::ComponentRange)]
+#[from_owned(tokio::task::JoinError)]
+#[from_owned(tokio::sync::AcquireError)]
+#[from_owned(SdkError<GetObjectError>)]
+#[from_owned(SdkError<HeadObjectError>)]
+#[from_owned(rsmpeg::error::RsmpegError)]
+#[from_owned(std::ffi::NulError)]
+#[from_owned(std::str::Utf8Error)]
+#[from_owned(aws_sdk_s3::presigning::PresigningConfigError)]
+#[from_owned(std::string::FromUtf8Error)]
+#[from_owned(axum::extract::rejection::StringRejection)]
+#[from_owned(strum::ParseError)]
+pub enum Error {
+    #[error("{0}")]
+    InvalidParameter(&'static str),
+    #[error("Could not serialize get request with no query parameters")]
+    GetRequestMissingQueryParameters,
+    #[error("Could not serialize auth parameters with query {0}")]
+    SerializeAuthParameters(String),
+    #[error("Could not serialize request parameters with query {0}")]
+    SerializeRequestParameters(String),
+    #[error("Could not serialize binary request")]
+    SerializeBinaryRequest,
+    #[error(transparent)]
+    ExtractRequestBody(#[from] axum::extract::rejection::BytesRejection),
+    #[error("Scrobble request must have more id than time")]
+    ScrobbleRequestMustHaveBeMoreIdThanTime,
+
+    #[error("Resource not found")]
+    NotFound,
+
+    #[error("Could not checkout a connection from connection pool")]
+    CheckoutConnectionPool,
+    #[error("Could not decrypt value from database")]
+    DecryptDatabaseValue,
+    #[error("Language from database should not be null")]
+    LanguageFromDatabaseIsNull,
+    #[error("Inconsistency encountered while querying database for scan process")]
+    DatabaseScanQueryInconsistent,
+    #[error("Invalid config format for key {0}")]
+    DatabaseInvalidConfigFormat(&'static str),
+    #[error("Song duration is empty")]
+    DatabaseSongDurationIsEmpty,
+
+    #[error("{0}")]
+    Unauthorized(&'static str),
+    #[error("Could not login due to bad credentials")]
+    Unauthenticated,
+    #[error("You need to have {0} role to perform this action")]
+    MissingRole(&'static str),
+    #[error("Range header is invalid")]
+    InvalidRangeHeader,
+
+    #[error("Could not parse date from {0:?}")]
+    MediaDateFormat(String),
+    #[error(
+        "Could not parse position from track number {track_number:?}, track total \
+         {track_total:?}, disc number {disc_number:?} and disc total {disc_total:?}"
+    )]
+    MediaPositionFormat {
+        track_number: Option<String>,
+        track_total: Option<String>,
+        disc_number: Option<String>,
+        disc_total: Option<String>,
+    },
+    #[error("There should not be more musicbrainz id than artist name")]
+    MediaArtistMbzIdMoreThanArtistName,
+    #[error("Song artist should not be empty")]
+    MediaSongArtistEmpty,
+    #[error("Artist name should not be empty")]
+    MediaArtistNameEmpty,
+    #[error("Could not read vorbis comments from flac file")]
+    MediaFlacMissingVorbisComments,
+    #[error("Could not find audio track in the media file")]
+    MediaAudioTrackMissing,
+    #[error("Media picture format is missing")]
+    MediaPictureMissingFormat,
+    #[error("Media picture format {0} is unsupported")]
+    MediaPictureUnsupportedFormat(String),
+    #[error("Media cover art dir is not enabled")]
+    MediaCoverArtDirIsNotEnabled,
+
+    #[error("Transcode output format is not supported")]
+    TranscodeOutputFormatNotSupported,
+    #[error("Encoder sample fmts are missing")]
+    TranscodeEncoderSampleFmtsMissing,
+    #[error("Could not get {0} av filter")]
+    TranscodeAVFilterMissing(&'static str),
+    #[error("Name is missing for sample format {0}")]
+    TranscodeSampleFmtNameMissing(i32),
+
+    #[error("Path extension is missing")]
+    PathExtensionMissing,
+    #[error("Absolute file path does not have parent directory")]
+    AbsoluteFilePathDoesNotHaveParentDirectory,
+    #[error("S3 path is not an absolute unix path: {0}")]
+    FilesystemS3InvalidPath(String),
+    #[error("S3 object does not have size information")]
+    FilesystemS3MissingObjectSize,
+    #[error("Non UTF-8 path encountered: {0:?}")]
+    FilesystemLocalNonUTF8PathEncountered(OsString),
+    #[error("Typed path has wrong platform information")]
+    FilesystemTypedPathWrongPlatform,
+
+    #[error("Prefix does not end with whitespace")]
+    ConfigIndexIgnorePrefixEndWithoutSpace,
+
+    #[error("Could not convert float to integer with value {0}")]
+    CouldNotConvertFloatToInteger(f32),
+
+    #[error(transparent)]
+    Internal(#[from] color_eyre::Report),
+}
+
+impl IntoResponse for Error {
+    fn into_response(self) -> Response {
+        let (status_code, status_message) = match &self {
+            Error::InvalidParameter(_)
+            | Error::GetRequestMissingQueryParameters
+            | Error::SerializeAuthParameters(_)
+            | Error::SerializeRequestParameters(_)
+            | Error::SerializeBinaryRequest
+            | Error::InvalidRangeHeader => (StatusCode::BAD_REQUEST, self.to_string()),
+            Error::ExtractRequestBody(_) => {
+                (StatusCode::BAD_REQUEST, "Could not extract request body".into())
+            }
+            Error::Unauthenticated => (StatusCode::FORBIDDEN, self.to_string()),
+            Error::Unauthorized(_) | Error::MissingRole(_) => {
+                (StatusCode::UNAUTHORIZED, self.to_string())
+            }
+            Error::NotFound => (StatusCode::NOT_FOUND, self.to_string()),
+            _ => (StatusCode::INTERNAL_SERVER_ERROR, "Internal server error".into()),
+        };
+        (status_code, status_message).into_response()
+    }
+}
+
+impl<T: Send + Sync + 'static> From<SendError<T>> for Error {
+    fn from(value: SendError<T>) -> Self {
+        Self::Internal(value.into())
+    }
+}
+
+impl From<diesel::result::Error> for Error {
+    fn from(value: diesel::result::Error) -> Self {
+        match value {
+            diesel::result::Error::NotFound => Error::NotFound,
+            _ => Error::Internal(value.into()),
+        }
+    }
+}
diff --git a/nghe-backend/src/file/audio/artist.rs b/nghe-backend/src/file/audio/artist.rs
new file mode 100644
index 000000000..1ebe2864f
--- /dev/null
+++ b/nghe-backend/src/file/audio/artist.rs
@@ -0,0 +1,629 @@
+use std::borrow::{Borrow, Cow};
+
+use diesel::dsl::{exists, not};
+use diesel::{ExpressionMethods, QueryDsl};
+use diesel_async::RunQueryDsl;
+#[cfg(test)]
+use fake::{Dummy, Fake, Faker};
+use futures_lite::{stream, StreamExt};
+use indexmap::IndexSet;
+use o2o::o2o;
+use unicode_normalization::UnicodeNormalization;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::upsert::Insert as _;
+use crate::orm::{artists, songs_album_artists, songs_artists};
+use crate::Error;
+
+#[derive(Debug, PartialEq, Eq, Hash, o2o)]
+#[from_owned(artists::Data<'a>)]
+#[ref_into(artists::Data<'a>)]
+#[cfg_attr(test, derive(Dummy, Clone, PartialOrd, Ord))]
+pub struct Artist<'a> {
+    #[ref_into(~.as_str().into())]
+    #[cfg_attr(test, dummy(expr = "Faker.fake::<String>().into()"))]
+    pub name: Cow<'a, str>,
+    pub mbz_id: Option<Uuid>,
+}
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(Dummy, Eq, Clone))]
+pub struct Artists<'a> {
+    #[cfg_attr(test, dummy(expr = "fake::vec![Artist; 1..5].into_iter().collect()"))]
+    pub song: IndexSet<Artist<'a>>,
+    #[cfg_attr(test, dummy(expr = "fake::vec![Artist; 0..3].into_iter().collect()"))]
+    pub album: IndexSet<Artist<'a>>,
+    pub compilation: bool,
+}
+
+impl<'a> Artist<'a> {
+    pub fn index(&self, prefixes: &[impl AsRef<str>]) -> Result<char, Error> {
+        let mut iter = prefixes.iter();
+        let name = loop {
+            match iter.next() {
+                Some(prefix) => {
+                    if let Some(name) = self.name.strip_prefix(prefix.as_ref()) {
+                        break name;
+                    }
+                }
+                None => break self.name.as_ref(),
+            }
+        };
+        name.nfkd().next().ok_or_else(|| Error::MediaArtistNameEmpty).map(|c| {
+            if c.is_ascii_alphabetic() {
+                c.to_ascii_uppercase()
+            } else if c.is_numeric() {
+                '#'
+            } else if !c.is_alphabetic() {
+                '*'
+            } else {
+                c
+            }
+        })
+    }
+
+    pub async fn upsert(
+        &self,
+        database: &Database,
+        prefixes: &[impl AsRef<str>],
+    ) -> Result<Uuid, Error> {
+        artists::Upsert { index: self.index(prefixes)?.to_string().into(), data: self.into() }
+            .insert(database)
+            .await
+    }
+
+    async fn upserts<S: Borrow<Self> + 'a>(
+        database: &Database,
+        artists: impl IntoIterator<Item = S>,
+        prefixes: &[impl AsRef<str>],
+    ) -> Result<Vec<Uuid>, Error> {
+        stream::iter(artists)
+            .then(async |artist| artist.borrow().upsert(database, prefixes).await)
+            .try_collect()
+            .await
+    }
+}
+
+impl<'a> Artists<'a> {
+    pub fn new(
+        song: impl IntoIterator<Item = Artist<'a>>,
+        album: impl IntoIterator<Item = Artist<'a>>,
+        compilation: bool,
+    ) -> Result<Self, Error> {
+        let song: IndexSet<_> = song.into_iter().collect();
+        let album = album.into_iter().collect();
+        if song.is_empty() {
+            Err(Error::MediaSongArtistEmpty)
+        } else {
+            Ok(Self { song, album, compilation })
+        }
+    }
+
+    pub fn song(&self) -> &IndexSet<Artist<'a>> {
+        &self.song
+    }
+
+    pub fn album(&self) -> &IndexSet<Artist<'a>> {
+        if self.album.is_empty() { &self.song } else { &self.album }
+    }
+
+    pub fn compilation(&self) -> bool {
+        // If the song has compilation, all artists in the song artists will be added to song
+        // album artists with compilation set to true. If it also contains any album
+        // artists, the compilation field will be overwritten to false later. If the
+        // album artists field is empty, the album artists will be the same with
+        // song artists which then set any compilation field to false, so no need to add them in
+        // the first place.
+        if self.album.is_empty() || self.song.difference(&self.album).peekable().peek().is_none() {
+            false
+        } else {
+            self.compilation
+        }
+    }
+
+    pub async fn upsert_song_artist(
+        database: &Database,
+        song_id: Uuid,
+        artist_ids: &[Uuid],
+    ) -> Result<(), Error> {
+        diesel::insert_into(songs_artists::table)
+            .values::<Vec<_>>(
+                artist_ids
+                    .iter()
+                    .copied()
+                    .map(|artist_id| songs_artists::Data { song_id, artist_id })
+                    .collect(),
+            )
+            .on_conflict((songs_artists::song_id, songs_artists::artist_id))
+            .do_update()
+            .set(songs_artists::upserted_at.eq(time::OffsetDateTime::now_utc()))
+            .execute(&mut database.get().await?)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn upsert_song_album_artist(
+        database: &Database,
+        song_id: Uuid,
+        album_artist_ids: &[Uuid],
+        compilation: bool,
+    ) -> Result<(), Error> {
+        diesel::insert_into(songs_album_artists::table)
+            .values::<Vec<_>>(
+                album_artist_ids
+                    .iter()
+                    .copied()
+                    .map(|album_artist_id| songs_album_artists::Data {
+                        song_id,
+                        album_artist_id,
+                        compilation,
+                    })
+                    .collect(),
+            )
+            .on_conflict((songs_album_artists::song_id, songs_album_artists::album_artist_id))
+            .do_update()
+            .set((
+                songs_album_artists::compilation.eq(compilation),
+                songs_album_artists::upserted_at.eq(time::OffsetDateTime::now_utc()),
+            ))
+            .execute(&mut database.get().await?)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn upsert(
+        &self,
+        database: &Database,
+        prefixes: &[impl AsRef<str>],
+        song_id: Uuid,
+    ) -> Result<(), Error> {
+        let song_artist_ids = Artist::upserts(database, &self.song, prefixes).await?;
+        Self::upsert_song_artist(database, song_id, &song_artist_ids).await?;
+        if self.compilation() {
+            // If the song has compilation, all artists in the song artists will be added to song
+            // album artists with compilation set to true.
+            Self::upsert_song_album_artist(database, song_id, &song_artist_ids, true).await?;
+        }
+
+        // If there isn't any album artist,
+        // we assume that they are the same as artists.
+        let album_artist_ids = if self.album.is_empty() {
+            song_artist_ids
+        } else {
+            Artist::upserts(database, &self.album, prefixes).await?
+        };
+        Self::upsert_song_album_artist(database, song_id, &album_artist_ids, false).await?;
+
+        Ok(())
+    }
+
+    pub async fn cleanup_one(
+        database: &Database,
+        started_at: time::OffsetDateTime,
+        song_id: Uuid,
+    ) -> Result<(), Error> {
+        // Delete all artists of a song which haven't been refreshed since timestamp.
+        diesel::delete(songs_artists::table)
+            .filter(songs_artists::song_id.eq(song_id))
+            .filter(songs_artists::upserted_at.lt(started_at))
+            .execute(&mut database.get().await?)
+            .await?;
+
+        // Delete all album artists of a song which haven't been refreshed since timestamp.
+        diesel::delete(songs_album_artists::table)
+            .filter(songs_album_artists::song_id.eq(song_id))
+            .filter(songs_album_artists::upserted_at.lt(started_at))
+            .execute(&mut database.get().await?)
+            .await?;
+
+        Ok(())
+    }
+
+    pub async fn cleanup(database: &Database) -> Result<(), Error> {
+        // Delete all artists which does not have any relation with an album
+        // (via songs_album_artists) or a song (via songs_artists).
+        let alias_artists = diesel::alias!(artists as alias_artists);
+        diesel::delete(artists::table)
+            .filter(
+                artists::id.eq_any(
+                    alias_artists
+                        .filter(not(exists(
+                            songs_album_artists::table.filter(
+                                songs_album_artists::album_artist_id
+                                    .eq(alias_artists.field(artists::id)),
+                            ),
+                        )))
+                        .filter(not(exists(songs_artists::table.filter(
+                            songs_artists::artist_id.eq(alias_artists.field(artists::id)),
+                        ))))
+                        .select(alias_artists.field(artists::id)),
+                ),
+            )
+            .execute(&mut database.get().await?)
+            .await?;
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use diesel::{QueryDsl, SelectableHelper};
+    use itertools::Itertools;
+
+    use super::*;
+    use crate::orm::songs;
+    use crate::test::Mock;
+
+    impl<S: AsRef<str> + Sized> PartialEq<S> for Artist<'_> {
+        fn eq(&self, other: &S) -> bool {
+            self.name == other.as_ref() && self.mbz_id.is_none()
+        }
+    }
+
+    impl PartialEq for Artists<'_> {
+        fn eq(&self, other: &Self) -> bool {
+            (self.song() == other.song())
+                && (self.album() == other.album())
+                && (self.compilation() == other.compilation())
+        }
+    }
+
+    impl<'a> From<&'a str> for Artist<'a> {
+        fn from(value: &'a str) -> Self {
+            Self { name: value.into(), mbz_id: None }
+        }
+    }
+
+    impl From<String> for Artist<'static> {
+        fn from(value: String) -> Self {
+            Self { name: value.into(), mbz_id: None }
+        }
+    }
+
+    impl<'a> From<(&'a str, Uuid)> for Artist<'a> {
+        fn from(value: (&'a str, Uuid)) -> Self {
+            Self { name: value.0.into(), mbz_id: Some(value.1) }
+        }
+    }
+
+    impl Artist<'_> {
+        pub async fn upsert_mock(&self, mock: &Mock) -> Uuid {
+            self.upsert(mock.database(), &mock.config.index.ignore_prefixes).await.unwrap()
+        }
+    }
+
+    impl Artist<'static> {
+        pub async fn query(mock: &Mock, id: Uuid) -> Self {
+            artists::table
+                .filter(artists::id.eq(id))
+                .select(artists::Data::as_select())
+                .get_result(&mut mock.get().await)
+                .await
+                .unwrap()
+                .into()
+        }
+
+        async fn query_ids(mock: &Mock, ids: &[Uuid], sorted: bool) -> Vec<Self> {
+            let artists: Vec<_> = stream::iter(ids)
+                .copied()
+                .then(async |id| Self::query(mock, id).await)
+                .collect()
+                .await;
+            if sorted { artists.into_iter().sorted().collect() } else { artists }
+        }
+
+        async fn query_song_artists(mock: &Mock, song_id: Uuid) -> (Vec<Uuid>, Vec<Self>) {
+            let ids: Vec<Uuid> = songs_artists::table
+                .filter(songs_artists::song_id.eq(song_id))
+                .select(songs_artists::artist_id)
+                .order_by(songs_artists::upserted_at)
+                .get_results(&mut mock.get().await)
+                .await
+                .unwrap();
+            let artists = Self::query_ids(mock, &ids, false).await;
+            (ids, artists)
+        }
+
+        async fn query_song_album_artists(
+            mock: &Mock,
+            song_id: Uuid,
+            artist_ids: &[Uuid],
+        ) -> (Vec<Self>, bool) {
+            let ids_compilations = songs_album_artists::table
+                .filter(songs_album_artists::song_id.eq(song_id))
+                .select((songs_album_artists::album_artist_id, songs_album_artists::compilation))
+                .order_by(songs_album_artists::upserted_at)
+                .get_results::<(Uuid, bool)>(&mut mock.get().await)
+                .await
+                .unwrap();
+            let artists: Vec<_> = stream::iter(&ids_compilations)
+                .copied()
+                .filter_map(|(id, compilation)| {
+                    if compilation {
+                        assert!(
+                            artist_ids.contains(&id),
+                            "Stale compilation album artist has not been removed yet"
+                        );
+                        None
+                    } else {
+                        Some(id)
+                    }
+                })
+                .then(async |id| Self::query(mock, id).await)
+                .collect()
+                .await;
+            // If there is any compliation, it will be filtered out and make the size of two vectors
+            // not equal. On the other hand, two same size vectors can mean either there
+            // isn't any compilation or the song artists are the same as the album
+            // artists or there isn't any album artist (which then be filled with song
+            // artists).
+            let compilation = ids_compilations.len() != artists.len();
+            (artists, compilation)
+        }
+
+        pub async fn query_album(mock: &Mock, album_id: Uuid) -> Vec<Self> {
+            let ids = songs_album_artists::table
+                .inner_join(songs::table)
+                .select(songs_album_artists::album_artist_id)
+                .filter(songs::album_id.eq(album_id))
+                .get_results(&mut mock.get().await)
+                .await
+                .unwrap();
+            Self::query_ids(mock, &ids, true).await
+        }
+
+        pub async fn queries(mock: &Mock) -> Vec<Self> {
+            let ids = artists::table
+                .select(artists::id)
+                .get_results(&mut mock.get().await)
+                .await
+                .unwrap();
+            Self::query_ids(mock, &ids, true).await
+        }
+    }
+
+    impl Artists<'static> {
+        pub async fn query(mock: &Mock, song_id: Uuid) -> Self {
+            let (artist_ids, song) = Artist::query_song_artists(mock, song_id).await;
+            let (album, compilation) =
+                Artist::query_song_album_artists(mock, song_id, &artist_ids).await;
+            Self::new(song, album, compilation).unwrap()
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[case("The One", &["The ", "A "], 'O')]
+    #[case("The 1", &["The ", "A "], '#')]
+    #[case("The one", &["The ", "A "], 'O')]
+    #[case("狼", &["The ", "A "], '狼')]
+    #[case("é", &["The ", "A "], 'E')]
+    #[case("ド", &["The ", "A "], 'ト')]
+    #[case("ａ", &["The ", "A "], 'A')]
+    #[case("%", &["The ", "A "], '*')]
+    fn test_index(#[case] name: &str, #[case] prefixes: &[&str], #[case] index: char) {
+        assert_eq!(Artist::from(name).index(prefixes).unwrap(), index);
+    }
+
+    #[rstest]
+    #[case(&["Song"], &["Album"], true, true)]
+    #[case(&["Song"], &["Album"], false, false)]
+    #[case(&["Song"], &[], true, false)]
+    #[case(&["Song"], &[], false, false)]
+    #[case(&["Song"], &["Song"], true, false)]
+    #[case(&["Song"], &["Song"], false, false)]
+    #[case(&["Song"], &["Song", "Album"], true, false)]
+    #[case(&["Song"], &["Song", "Album"], false, false)]
+    #[case(&["Song1", "Song2"], &["Song1", "Song2", "Album"], true, false)]
+    #[case(&["Song1", "Song2"], &["Song1", "Song2", "Album"], false, false)]
+    #[case(&["Song1", "Song2"], &["Song2", "Album", "Song1"], true, false)]
+    #[case(&["Song1", "Song2"], &["Song2", "Album", "Song1"], false, false)]
+    fn test_compilation(
+        #[case] song: &[&str],
+        #[case] album: &[&str],
+        #[case] compilation: bool,
+        #[case] result: bool,
+    ) {
+        assert_eq!(
+            Artists::new(
+                song.iter().copied().map(Artist::from),
+                album.iter().copied().map(Artist::from),
+                compilation
+            )
+            .unwrap()
+            .compilation(),
+            result
+        );
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_artist_upsert_roundtrip(
+        #[future(awt)] mock: Mock,
+        #[values(true, false)] mbz_id: bool,
+        #[values(true, false)] update_artist: bool,
+    ) {
+        let mbz_id = if mbz_id { Some(Faker.fake()) } else { None };
+        let artist = Artist { mbz_id, ..Faker.fake() };
+        let id = artist.upsert_mock(&mock).await;
+        let database_artist = Artist::query(&mock, id).await;
+        assert_eq!(database_artist, artist);
+
+        if update_artist {
+            let update_artist = Artist { mbz_id, ..Faker.fake() };
+            let update_id = update_artist.upsert_mock(&mock).await;
+            let database_update_artist = Artist::query(&mock, id).await;
+            if mbz_id.is_some() {
+                assert_eq!(id, update_id);
+                assert_eq!(database_update_artist, update_artist);
+            } else {
+                // This will always insert a new row to the database
+                // since there is nothing to identify an old artist.
+                assert_ne!(id, update_id);
+            }
+        }
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_artist_upsert_no_mbz_id(#[future(awt)] mock: Mock) {
+        // We want to make sure that insert the same artist with no mbz_id
+        // twice does not result in any error.
+        let artist = Artist { mbz_id: None, ..Faker.fake() };
+        let id = artist.upsert_mock(&mock).await;
+        let update_id = artist.upsert_mock(&mock).await;
+        assert_eq!(update_id, id);
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_artists_upsert(
+        #[future(awt)] mock: Mock,
+        #[values(true, false)] compilation: bool,
+        #[values(true, false)] update_artists: bool,
+    ) {
+        let database = mock.database();
+        let prefixes = &mock.config.index.ignore_prefixes;
+
+        let information: audio::Information = Faker.fake();
+        let album_id = information.metadata.album.upsert_mock(&mock, 0).await;
+        let song_id = information
+            .upsert_song(database, album_id.into(), Faker.fake::<String>(), None)
+            .await
+            .unwrap();
+
+        let artists = Artists { compilation, ..Faker.fake() };
+        artists.upsert(database, prefixes, song_id).await.unwrap();
+        let database_artists = Artists::query(&mock, song_id).await;
+        assert_eq!(database_artists, artists);
+
+        if update_artists {
+            let timestamp = crate::time::now().await;
+
+            let update_artists = Artists { compilation, ..Faker.fake() };
+            update_artists.upsert(database, prefixes, song_id).await.unwrap();
+            Artists::cleanup_one(database, timestamp, song_id).await.unwrap();
+            let database_update_artists = Artists::query(&mock, song_id).await;
+            assert_eq!(database_update_artists, update_artists);
+        }
+    }
+
+    mod cleanup {
+        use super::*;
+
+        #[rstest]
+        #[tokio::test]
+        async fn test_artist_all(#[future(awt)] mock: Mock) {
+            let mut music_folder = mock.music_folder(0).await;
+            music_folder.add_audio().n_song(5).call().await;
+            assert!(!Artist::queries(&mock).await.is_empty());
+
+            diesel::delete(songs_artists::table).execute(&mut mock.get().await).await.unwrap();
+            diesel::delete(songs_album_artists::table)
+                .execute(&mut mock.get().await)
+                .await
+                .unwrap();
+
+            Artists::cleanup(mock.database()).await.unwrap();
+            assert!(Artist::queries(&mock).await.is_empty());
+        }
+
+        #[rstest]
+        #[case(1, 0)]
+        #[case(1, 1)]
+        #[case(5, 3)]
+        #[case(5, 5)]
+        #[tokio::test]
+        async fn test_artist_song(
+            #[future(awt)] mock: Mock,
+            #[case] n_song: usize,
+            #[case] n_subset: usize,
+            #[values(true, false)] compilation: bool,
+        ) {
+            let mut music_folder = mock.music_folder(0).await;
+            let artist: Artist = Faker.fake();
+            music_folder
+                .add_audio_artist(
+                    [artist.clone(), Faker.fake()],
+                    [Faker.fake()],
+                    compilation,
+                    n_song,
+                )
+                .await;
+            let song_ids: Vec<_> = music_folder.database.keys().collect();
+            assert!(Artist::queries(&mock).await.contains(&artist));
+
+            diesel::delete(songs_artists::table)
+                .filter(songs_artists::song_id.eq_any(&song_ids[0..n_subset]))
+                .execute(&mut mock.get().await)
+                .await
+                .unwrap();
+            if compilation {
+                diesel::delete(songs_album_artists::table)
+                    .filter(songs_album_artists::song_id.eq_any(&song_ids[0..n_subset]))
+                    .execute(&mut mock.get().await)
+                    .await
+                    .unwrap();
+            }
+            Artists::cleanup(mock.database()).await.unwrap();
+            assert_eq!(Artist::queries(&mock).await.contains(&artist), n_subset < n_song);
+        }
+
+        #[rstest]
+        #[case(1, 0)]
+        #[case(1, 1)]
+        #[case(5, 3)]
+        #[case(5, 5)]
+        #[tokio::test]
+        async fn test_artist_album(
+            #[future(awt)] mock: Mock,
+            #[case] n_album: usize,
+            #[case] n_subset: usize,
+        ) {
+            let artist: Artist = Faker.fake();
+            let album_song_ids: Vec<(Uuid, Vec<_>)> = stream::iter(0..n_album)
+                .then(async |_| {
+                    let mut music_folder = mock.music_folder(0).await;
+                    let album: audio::Album = Faker.fake();
+                    let album_id = album.upsert_mock(&mock, 0).await;
+                    music_folder
+                        .add_audio_artist(
+                            [Faker.fake()],
+                            [artist.clone(), Faker.fake()],
+                            false,
+                            (1..3).fake(),
+                        )
+                        .await;
+                    let song_ids = music_folder.database.keys().copied().collect();
+                    (album_id, song_ids)
+                })
+                .collect()
+                .await;
+            assert!(Artist::queries(&mock).await.contains(&artist));
+
+            diesel::delete(songs_album_artists::table)
+                .filter(
+                    songs_album_artists::song_id.eq_any(
+                        album_song_ids[0..n_subset]
+                            .iter()
+                            .flat_map(|(_, song_ids)| song_ids.clone())
+                            .collect::<Vec<_>>(),
+                    ),
+                )
+                .execute(&mut mock.get().await)
+                .await
+                .unwrap();
+            Artists::cleanup(mock.database()).await.unwrap();
+            assert_eq!(Artist::queries(&mock).await.contains(&artist), n_subset < n_album);
+        }
+    }
+}
diff --git a/nghe-backend/src/file/audio/date.rs b/nghe-backend/src/file/audio/date.rs
new file mode 100644
index 000000000..9fed890ee
--- /dev/null
+++ b/nghe-backend/src/file/audio/date.rs
@@ -0,0 +1,173 @@
+use std::num::NonZeroU8;
+use std::str::FromStr;
+
+use o2o::o2o;
+use time::macros::format_description;
+use time::Month;
+
+use crate::orm::{albums, songs};
+use crate::Error;
+
+type FormatDescription<'a> = &'a [time::format_description::BorrowedFormatItem<'a>];
+
+const YMD_MINUS_FORMAT: FormatDescription = format_description!("[year]-[month]-[day]");
+const YM_MINUS_FORMAT: FormatDescription = format_description!("[year]-[month]");
+const YMD_SLASH_FORMAT: FormatDescription = format_description!("[year]/[month]/[day]");
+const YM_SLASH_FORMAT: FormatDescription = format_description!("[year]/[month]");
+const YMD_DOT_FORMAT: FormatDescription = format_description!("[year].[month].[day]");
+const YM_DOT_FORMAT: FormatDescription = format_description!("[year].[month]");
+const Y_FORMAT: FormatDescription = format_description!("[year]");
+
+#[derive(Debug, Default, Clone, Copy, o2o)]
+#[try_map_owned(songs::date::Date, Error)]
+#[try_map_owned(songs::date::Release, Error)]
+#[try_map_owned(songs::date::OriginalRelease, Error)]
+#[try_map_owned(albums::date::Date, Error)]
+#[try_map_owned(albums::date::Release, Error)]
+#[try_map_owned(albums::date::OriginalRelease, Error)]
+#[cfg_attr(test, derive(PartialEq, Eq))]
+pub struct Date {
+    #[from(~.map(i32::from))]
+    #[into(~.map(i32::try_into).transpose()?)]
+    pub year: Option<i32>,
+    #[from(~.map(u8::try_from).transpose()?.map(Month::try_from).transpose()?)]
+    #[into(~.map(|month| (month as u8).into()))]
+    pub month: Option<Month>,
+    #[from(~.map(u8::try_from).transpose()?.map(NonZeroU8::try_from).transpose()?)]
+    #[into(~.map(NonZeroU8::get).map(u8::into))]
+    pub day: Option<NonZeroU8>,
+}
+
+impl Date {
+    pub fn is_some(&self) -> bool {
+        self.year.is_some()
+    }
+}
+
+impl FromStr for Date {
+    type Err = Error;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut parsed = time::parsing::Parsed::new();
+        let input = s.as_bytes();
+        if !s.is_empty()
+            && parsed.parse_items(input, YMD_MINUS_FORMAT).is_err()
+            && parsed.parse_items(input, YMD_SLASH_FORMAT).is_err()
+            && parsed.parse_items(input, YMD_DOT_FORMAT).is_err()
+            && parsed.parse_items(input, YM_MINUS_FORMAT).is_err()
+            && parsed.parse_items(input, YM_SLASH_FORMAT).is_err()
+            && parsed.parse_items(input, YM_DOT_FORMAT).is_err()
+        {
+            // Don't aggresively parse everything as year
+            let result = parsed.parse_items(input, Y_FORMAT);
+            if result.is_err() || result.is_ok_and(|remain| !remain.is_empty()) {
+                return Err(Error::MediaDateFormat(s.to_owned()));
+            }
+        }
+
+        Ok(Self { year: parsed.year(), month: parsed.month(), day: parsed.day() })
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use std::fmt::{Display, Formatter};
+
+    use fake::{Dummy, Fake, Faker};
+
+    use super::*;
+
+    impl Display for Date {
+        fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+            if let Some(year) = self.year {
+                let mut result = format!("{year:04}");
+                if let Some(month) = self.month {
+                    let month = month as u8;
+                    result += &format!("-{month:02}");
+                    if let Some(day) = self.day {
+                        result += &format!("-{day:02}");
+                    }
+                }
+                write!(f, "{result}")
+            } else {
+                Err(std::fmt::Error)
+            }
+        }
+    }
+
+    impl Dummy<Faker> for Date {
+        fn dummy_with_rng<R: fake::rand::Rng + ?Sized>(config: &Faker, rng: &mut R) -> Self {
+            let date: time::Date = config.fake_with_rng(rng);
+
+            let year =
+                if config.fake_with_rng(rng) { Some(date.year().clamp(0, 9999)) } else { None };
+            let month =
+                if year.is_some() && config.fake_with_rng(rng) { Some(date.month()) } else { None };
+            let day = if month.is_some() && config.fake_with_rng(rng) {
+                Some(date.day().try_into().unwrap())
+            } else {
+                None
+            };
+
+            Self { year, month, day }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use rstest::rstest;
+
+    use super::*;
+
+    #[rstest]
+    #[case("2000-12-01", Some(2000), Some(Month::December), Some(1))]
+    #[case("2000/12/01", Some(2000), Some(Month::December), Some(1))]
+    #[case("2000.12.01", Some(2000), Some(Month::December), Some(1))]
+    #[case("2000-12-01-still-ok", Some(2000), Some(Month::December), Some(1))]
+    #[case("2000.12.01/still/ok", Some(2000), Some(Month::December), Some(1))]
+    #[case("2000-12-01T02:29:01Z", Some(2000), Some(Month::December), Some(1))]
+    #[case("2000-12", Some(2000), Some(Month::December), None)]
+    #[case("2000/12", Some(2000), Some(Month::December), None)]
+    #[case("2000.12", Some(2000), Some(Month::December), None)]
+    #[case("2000", Some(2000), None, None)]
+    #[case("", None, None, None)]
+    fn test_parse_success(
+        #[case] input: &'static str,
+        #[case] year: Option<i32>,
+        #[case] month: Option<Month>,
+        #[case] day: Option<u8>,
+    ) {
+        let date: Date = input.parse().unwrap();
+        assert_eq!(date.year, year);
+        assert_eq!(date.month, month);
+        assert_eq!(date.day.map(NonZeroU8::get), day);
+    }
+
+    #[rstest]
+    #[case("2000-31")]
+    #[case("20-12-01")]
+    #[case("invalid")]
+    #[case("12-01")]
+    #[case("31")]
+    fn test_parse_error(#[case] input: &'static str) {
+        assert!(input.parse::<Date>().is_err());
+    }
+
+    #[rstest]
+    #[case(Some(2000), Some(Month::December), Some(31), "2000-12-31")]
+    #[case(Some(2000), Some(Month::December), None, "2000-12")]
+    #[case(Some(2000), None, Some(31), "2000")]
+    #[case(Some(2000), None, None, "2000")]
+    fn test_display(
+        #[case] year: Option<i32>,
+        #[case] month: Option<Month>,
+        #[case] day: Option<u8>,
+        #[case] str: &str,
+    ) {
+        assert_eq!(
+            Date { year, month, day: day.map(u8::try_into).transpose().unwrap() }.to_string(),
+            str
+        );
+    }
+}
diff --git a/nghe-backend/src/file/audio/extract/flac.rs b/nghe-backend/src/file/audio/extract/flac.rs
new file mode 100644
index 000000000..755e9f98f
--- /dev/null
+++ b/nghe-backend/src/file/audio/extract/flac.rs
@@ -0,0 +1,66 @@
+use lofty::file::AudioFile;
+use lofty::flac::FlacFile;
+use lofty::ogg::OggPictureStorage as _;
+
+use super::{Metadata, Property};
+use crate::file::audio::{self, Album, Artists, Genres, NameDateMbz, TrackDisc};
+use crate::file::picture::Picture;
+use crate::{config, Error};
+
+impl<'a> Metadata<'a> for FlacFile {
+    fn song(&'a self, config: &'a config::Parsing) -> Result<NameDateMbz<'a>, Error> {
+        self.vorbis_comments().ok_or(Error::MediaFlacMissingVorbisComments)?.song(config)
+    }
+
+    fn album(&'a self, config: &'a config::Parsing) -> Result<Album<'a>, Error> {
+        self.vorbis_comments().ok_or(Error::MediaFlacMissingVorbisComments)?.album(config)
+    }
+
+    fn artists(&'a self, config: &'a config::Parsing) -> Result<Artists<'a>, Error> {
+        self.vorbis_comments().ok_or(Error::MediaFlacMissingVorbisComments)?.artists(config)
+    }
+
+    fn track_disc(&'a self, config: &'a config::Parsing) -> Result<TrackDisc, Error> {
+        self.vorbis_comments().ok_or(Error::MediaFlacMissingVorbisComments)?.track_disc(config)
+    }
+
+    fn languages(&'a self, config: &'a config::Parsing) -> Result<Vec<isolang::Language>, Error> {
+        self.vorbis_comments().ok_or(Error::MediaFlacMissingVorbisComments)?.languages(config)
+    }
+
+    fn genres(&'a self, config: &'a config::Parsing) -> Result<Genres<'a>, Error> {
+        self.vorbis_comments().ok_or(Error::MediaFlacMissingVorbisComments)?.genres(config)
+    }
+
+    fn picture(&'a self) -> Result<Option<Picture<'static, 'a>>, Error> {
+        let mut iter = self.pictures().iter();
+        if cfg!(test) {
+            iter.find_map(|(picture, _)| {
+                if picture
+                    .description()
+                    .is_some_and(|description| description == Picture::TEST_DESCRIPTION)
+                {
+                    Some(picture.try_into())
+                } else {
+                    None
+                }
+            })
+            .transpose()
+        } else {
+            iter.next().map(|(picture, _)| picture.try_into()).transpose()
+        }
+    }
+}
+
+impl Property for FlacFile {
+    fn property(&self) -> Result<audio::Property, Error> {
+        let properties = self.properties();
+        Ok(audio::Property {
+            duration: properties.duration().as_secs_f32(),
+            bitrate: properties.audio_bitrate(),
+            bit_depth: Some(properties.bit_depth()),
+            sample_rate: properties.sample_rate(),
+            channel_count: properties.channels(),
+        })
+    }
+}
diff --git a/nghe-backend/src/file/audio/extract/mod.rs b/nghe-backend/src/file/audio/extract/mod.rs
new file mode 100644
index 000000000..193071709
--- /dev/null
+++ b/nghe-backend/src/file/audio/extract/mod.rs
@@ -0,0 +1,88 @@
+mod flac;
+mod tag;
+
+use isolang::Language;
+
+use super::{Album, Artists, File, Genres, NameDateMbz, TrackDisc};
+use crate::file::picture::Picture;
+use crate::{config, Error};
+
+pub trait Metadata<'a> {
+    fn song(&'a self, config: &'a config::Parsing) -> Result<NameDateMbz<'a>, Error>;
+    fn album(&'a self, config: &'a config::Parsing) -> Result<Album<'a>, Error>;
+    fn artists(&'a self, config: &'a config::Parsing) -> Result<Artists<'a>, Error>;
+    fn track_disc(&'a self, config: &'a config::Parsing) -> Result<TrackDisc, Error>;
+    fn languages(&'a self, config: &'a config::Parsing) -> Result<Vec<Language>, Error>;
+    fn genres(&'a self, config: &'a config::Parsing) -> Result<Genres<'a>, Error>;
+    fn picture(&'a self) -> Result<Option<Picture<'static, 'a>>, Error>;
+
+    fn metadata(&'a self, config: &'a config::Parsing) -> Result<super::Metadata<'a>, Error> {
+        Ok(super::Metadata {
+            song: super::Song {
+                main: self.song(config)?,
+                track_disc: self.track_disc(config)?,
+                languages: self.languages(config)?,
+            },
+            album: self.album(config)?,
+            artists: self.artists(config)?,
+            genres: self.genres(config)?,
+            picture: self.picture()?,
+        })
+    }
+}
+
+pub trait Property {
+    fn property(&self) -> Result<super::Property, Error>;
+}
+
+impl<'a> Metadata<'a> for File {
+    fn song(&'a self, config: &'a config::Parsing) -> Result<NameDateMbz<'a>, Error> {
+        match self {
+            File::Flac { audio, .. } => audio.song(config),
+        }
+    }
+
+    fn album(&'a self, config: &'a config::Parsing) -> Result<Album<'a>, Error> {
+        match self {
+            File::Flac { audio, .. } => audio.album(config),
+        }
+    }
+
+    fn artists(&'a self, config: &'a config::Parsing) -> Result<Artists<'a>, Error> {
+        match self {
+            File::Flac { audio, .. } => audio.artists(config),
+        }
+    }
+
+    fn track_disc(&'a self, config: &'a config::Parsing) -> Result<TrackDisc, Error> {
+        match self {
+            File::Flac { audio, .. } => audio.track_disc(config),
+        }
+    }
+
+    fn languages(&'a self, config: &'a config::Parsing) -> Result<Vec<Language>, Error> {
+        match self {
+            File::Flac { audio, .. } => audio.languages(config),
+        }
+    }
+
+    fn genres(&'a self, config: &'a config::Parsing) -> Result<Genres<'a>, Error> {
+        match self {
+            File::Flac { audio, .. } => audio.genres(config),
+        }
+    }
+
+    fn picture(&'a self) -> Result<Option<Picture<'static, 'a>>, Error> {
+        match self {
+            File::Flac { audio, .. } => audio.picture(),
+        }
+    }
+}
+
+impl Property for File {
+    fn property(&self) -> Result<super::Property, Error> {
+        match self {
+            File::Flac { audio, .. } => audio.property(),
+        }
+    }
+}
diff --git a/nghe-backend/src/file/audio/extract/tag/mod.rs b/nghe-backend/src/file/audio/extract/tag/mod.rs
new file mode 100644
index 000000000..f425370c6
--- /dev/null
+++ b/nghe-backend/src/file/audio/extract/tag/mod.rs
@@ -0,0 +1 @@
+mod vorbis_comments;
diff --git a/nghe-backend/src/file/audio/extract/tag/vorbis_comments.rs b/nghe-backend/src/file/audio/extract/tag/vorbis_comments.rs
new file mode 100644
index 000000000..4c12001af
--- /dev/null
+++ b/nghe-backend/src/file/audio/extract/tag/vorbis_comments.rs
@@ -0,0 +1,108 @@
+use std::str::FromStr;
+
+use color_eyre::eyre::OptionExt;
+use indexmap::IndexSet;
+use isolang::Language;
+use itertools::Itertools;
+use lofty::ogg::{OggPictureStorage, VorbisComments};
+use uuid::Uuid;
+
+use crate::file::audio::{extract, Album, Artist, Artists, Date, Genres, NameDateMbz, TrackDisc};
+use crate::file::picture::Picture;
+use crate::{config, Error};
+
+impl Date {
+    fn extract_vorbis_comments(tag: &VorbisComments, key: Option<&str>) -> Result<Self, Error> {
+        if let Some(key) = key {
+            tag.get(key).map(Date::from_str).transpose().map(Option::unwrap_or_default)
+        } else {
+            Ok(Self::default())
+        }
+    }
+}
+
+impl<'a> NameDateMbz<'a> {
+    fn extract_vorbis_comments(
+        tag: &'a VorbisComments,
+        config: &'a config::parsing::vorbis_comments::Common,
+    ) -> Result<Self, Error> {
+        Ok(Self {
+            name: tag.get(&config.name).ok_or_eyre("Could not extract name")?.into(),
+            date: Date::extract_vorbis_comments(tag, config.date.as_deref())?,
+            release_date: Date::extract_vorbis_comments(tag, config.release_date.as_deref())?,
+            original_release_date: Date::extract_vorbis_comments(
+                tag,
+                config.original_release_date.as_deref(),
+            )?,
+            mbz_id: tag.get(&config.mbz_id).map(Uuid::from_str).transpose()?,
+        })
+    }
+}
+
+impl<'a> Artist<'a> {
+    fn extract_vorbis_comments(
+        tag: &'a VorbisComments,
+        config: &'a config::parsing::vorbis_comments::Artist,
+    ) -> Result<IndexSet<Self>, Error> {
+        let names = tag.get_all(&config.name);
+        let mbz_ids = tag.get_all(&config.mbz_id).map(Uuid::from_str);
+        let artists = names
+            .zip_longest(mbz_ids)
+            .map(|iter| match iter {
+                itertools::EitherOrBoth::Both(name, mbz_id) => Ok(Self {
+                    name: name.into(),
+                    mbz_id: mbz_id
+                        .map(|mbz_id| if mbz_id.is_nil() { None } else { Some(mbz_id) })?,
+                }),
+                itertools::EitherOrBoth::Left(name) => Ok(Self { name: name.into(), mbz_id: None }),
+                itertools::EitherOrBoth::Right(_) => Err(Error::MediaArtistMbzIdMoreThanArtistName),
+            })
+            .try_collect()?;
+        Ok(artists)
+    }
+}
+
+impl<'a> extract::Metadata<'a> for VorbisComments {
+    fn song(&'a self, config: &'a config::Parsing) -> Result<NameDateMbz<'a>, Error> {
+        NameDateMbz::extract_vorbis_comments(self, &config.vorbis_comments.song)
+    }
+
+    fn album(&'a self, config: &'a config::Parsing) -> Result<Album<'a>, Error> {
+        Album::extract_vorbis_comments(self, &config.vorbis_comments.album)
+    }
+
+    fn artists(&'a self, config: &'a config::Parsing) -> Result<Artists<'a>, Error> {
+        Artists::new(
+            Artist::extract_vorbis_comments(self, &config.vorbis_comments.artists.song)?,
+            Artist::extract_vorbis_comments(self, &config.vorbis_comments.artists.album)?,
+            self.get(&config.vorbis_comments.compilation).is_some_and(|s| !s.is_empty()),
+        )
+    }
+
+    fn track_disc(&'a self, config: &'a config::Parsing) -> Result<TrackDisc, Error> {
+        let config::parsing::vorbis_comments::TrackDisc {
+            track_number,
+            track_total,
+            disc_number,
+            disc_total,
+        } = &config.vorbis_comments.track_disc;
+        TrackDisc::parse(
+            self.get(track_number),
+            self.get(track_total),
+            self.get(disc_number),
+            self.get(disc_total),
+        )
+    }
+
+    fn languages(&'a self, config: &'a config::Parsing) -> Result<Vec<isolang::Language>, Error> {
+        Ok(self.get_all(&config.vorbis_comments.languages).map(Language::from_str).try_collect()?)
+    }
+
+    fn genres(&'a self, config: &'a config::Parsing) -> Result<Genres<'a>, Error> {
+        Ok(self.get_all(&config.vorbis_comments.genres).collect())
+    }
+
+    fn picture(&'a self) -> Result<Option<Picture<'static, 'a>>, Error> {
+        self.pictures().iter().next().map(|(picture, _)| picture.try_into()).transpose()
+    }
+}
diff --git a/nghe-backend/src/file/audio/genre.rs b/nghe-backend/src/file/audio/genre.rs
new file mode 100644
index 000000000..e9812e890
--- /dev/null
+++ b/nghe-backend/src/file/audio/genre.rs
@@ -0,0 +1,209 @@
+use std::borrow::Cow;
+
+use diesel::dsl::{exists, not};
+use diesel::{ExpressionMethods, QueryDsl};
+use diesel_async::RunQueryDsl;
+#[cfg(test)]
+use fake::{Dummy, Fake, Faker};
+use o2o::o2o;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{genres, songs_genres};
+use crate::Error;
+
+#[derive(Debug, o2o)]
+#[from_owned(genres::Data<'a>)]
+#[ref_into(genres::Data<'a>)]
+#[cfg_attr(test, derive(PartialEq, Eq, Dummy, Clone))]
+pub struct Genre<'a> {
+    #[ref_into(~.as_str().into())]
+    #[cfg_attr(test, dummy(expr = "Faker.fake::<String>().into()"))]
+    pub value: Cow<'a, str>,
+}
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq, Eq, Dummy, Clone))]
+pub struct Genres<'a> {
+    #[cfg_attr(test, dummy(expr = "fake::vec![Genre<'static>; 0..=2]"))]
+    pub value: Vec<Genre<'a>>,
+}
+
+impl<'a, S: Into<Cow<'a, str>>> From<S> for Genre<'a> {
+    fn from(genre: S) -> Self {
+        Self { value: genre.into() }
+    }
+}
+
+impl<'a, S: Into<Cow<'a, str>>> FromIterator<S> for Genres<'a> {
+    fn from_iter<T: IntoIterator<Item = S>>(iter: T) -> Self {
+        Self { value: iter.into_iter().map(Genre::from).collect() }
+    }
+}
+
+impl<'a, 'b> From<&'a Genres<'b>> for Vec<genres::Data<'b>>
+where
+    'a: 'b,
+{
+    fn from(value: &'a Genres<'b>) -> Self {
+        value.value.iter().map(<&Genre>::into).collect()
+    }
+}
+
+impl Genres<'_> {
+    pub async fn upsert(&self, database: &Database) -> Result<Vec<Uuid>, Error> {
+        diesel::insert_into(genres::table)
+            .values::<Vec<genres::Data<'_>>>(self.into())
+            .on_conflict(genres::value)
+            .do_update()
+            .set(genres::upserted_at.eq(time::OffsetDateTime::now_utc()))
+            .returning(genres::id)
+            .get_results(&mut database.get().await?)
+            .await
+            .map_err(Error::from)
+    }
+
+    pub async fn upsert_song(
+        database: &Database,
+        song_id: Uuid,
+        genre_ids: &[Uuid],
+    ) -> Result<(), Error> {
+        diesel::insert_into(songs_genres::table)
+            .values::<Vec<_>>(
+                genre_ids
+                    .iter()
+                    .copied()
+                    .map(|genre_id| songs_genres::Data { song_id, genre_id })
+                    .collect(),
+            )
+            .on_conflict((songs_genres::song_id, songs_genres::genre_id))
+            .do_update()
+            .set(songs_genres::upserted_at.eq(time::OffsetDateTime::now_utc()))
+            .execute(&mut database.get().await?)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn cleanup_one(
+        database: &Database,
+        started_at: time::OffsetDateTime,
+        song_id: Uuid,
+    ) -> Result<(), Error> {
+        // Delete all genres of a song which haven't been refreshed since timestamp.
+        diesel::delete(songs_genres::table)
+            .filter(songs_genres::song_id.eq(song_id))
+            .filter(songs_genres::upserted_at.lt(started_at))
+            .execute(&mut database.get().await?)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn cleanup(database: &Database) -> Result<(), Error> {
+        // Delete all genres which do not have any song associated.
+        let alias_genres = diesel::alias!(genres as alias_genres);
+        diesel::delete(genres::table)
+            .filter(
+                genres::id.eq_any(
+                    alias_genres
+                        .filter(not(exists(
+                            songs_genres::table
+                                .filter(songs_genres::genre_id.eq(alias_genres.field(genres::id))),
+                        )))
+                        .select(alias_genres.field(genres::id)),
+                ),
+            )
+            .execute(&mut database.get().await?)
+            .await?;
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use diesel::SelectableHelper;
+    use futures_lite::{stream, StreamExt};
+
+    use super::*;
+    use crate::orm::songs;
+    use crate::test::Mock;
+
+    impl Genre<'static> {
+        pub async fn query(mock: &Mock, id: Uuid) -> Self {
+            genres::table
+                .filter(genres::id.eq(id))
+                .select(genres::Data::as_select())
+                .get_result(&mut mock.get().await)
+                .await
+                .unwrap()
+                .into()
+        }
+
+        pub async fn queries(mock: &Mock) -> Vec<Self> {
+            let ids = genres::table
+                .select(genres::id)
+                .order_by(genres::value)
+                .get_results(&mut mock.get().await)
+                .await
+                .unwrap();
+            stream::iter(ids).then(async |id| Self::query(mock, id).await).collect().await
+        }
+    }
+
+    impl Genres<'static> {
+        pub async fn query(mock: &Mock, song_id: Uuid) -> Self {
+            songs_genres::table
+                .inner_join(songs::table)
+                .inner_join(genres::table)
+                .filter(songs::id.eq(song_id))
+                .select(genres::value)
+                .get_results::<String>(&mut mock.get().await)
+                .await
+                .unwrap()
+                .into_iter()
+                .collect()
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use rstest::rstest;
+
+    use super::*;
+    use crate::test::{mock, Mock};
+
+    mod cleanup {
+        use super::*;
+
+        #[rstest]
+        #[case(1, 0)]
+        #[case(1, 1)]
+        #[case(5, 3)]
+        #[case(5, 5)]
+        #[tokio::test]
+        async fn test_genre(
+            #[future(awt)] mock: Mock,
+            #[case] n_song: usize,
+            #[case] n_subset: usize,
+        ) {
+            let mut music_folder = mock.music_folder(0).await;
+            let genre: Genre = Faker.fake();
+            music_folder
+                .add_audio()
+                .genres(Genres { value: vec![genre.clone()] })
+                .n_song(n_song)
+                .call()
+                .await;
+            let song_ids: Vec<_> = music_folder.database.keys().collect();
+            assert!(Genre::queries(&mock).await.contains(&genre));
+
+            diesel::delete(songs_genres::table)
+                .filter(songs_genres::song_id.eq_any(&song_ids[0..n_subset]))
+                .execute(&mut mock.get().await)
+                .await
+                .unwrap();
+            Genres::cleanup(mock.database()).await.unwrap();
+            assert_eq!(Genre::queries(&mock).await.contains(&genre), n_subset < n_song);
+        }
+    }
+}
diff --git a/nghe-backend/src/file/audio/information.rs b/nghe-backend/src/file/audio/information.rs
new file mode 100644
index 000000000..c8eef580e
--- /dev/null
+++ b/nghe-backend/src/file/audio/information.rs
@@ -0,0 +1,150 @@
+use std::borrow::Cow;
+
+use diesel::ExpressionMethods;
+use diesel_async::RunQueryDsl;
+use o2o::o2o;
+use typed_path::Utf8NativePath;
+use uuid::Uuid;
+
+use super::{Album, Artists, Genres};
+use crate::database::Database;
+use crate::orm::upsert::Upsert as _;
+use crate::orm::{albums, songs};
+use crate::scan::scanner;
+use crate::{file, Error};
+
+#[derive(Debug, o2o)]
+#[ref_try_into(songs::Data<'a>, Error)]
+#[cfg_attr(test, derive(PartialEq, Eq, fake::Dummy, Clone))]
+pub struct Information<'a> {
+    #[ref_into(songs::Data<'a>| song, (&~.song).try_into()?)]
+    pub metadata: super::Metadata<'a>,
+    #[map(~.try_into()?)]
+    pub property: super::Property,
+    #[map(~.into())]
+    pub file: file::Property<super::Format>,
+}
+
+impl Information<'_> {
+    pub async fn upsert_album(
+        &self,
+        database: &Database,
+        foreign: albums::Foreign,
+    ) -> Result<Uuid, Error> {
+        self.metadata.album.upsert(database, foreign).await
+    }
+
+    pub async fn upsert_artists(
+        &self,
+        database: &Database,
+        prefixes: &[impl AsRef<str>],
+        song_id: Uuid,
+    ) -> Result<(), Error> {
+        self.metadata.artists.upsert(database, prefixes, song_id).await
+    }
+
+    pub async fn upsert_genres(&self, database: &Database, song_id: Uuid) -> Result<(), Error> {
+        let genre_ids = self.metadata.genres.upsert(database).await?;
+        Genres::upsert_song(database, song_id, &genre_ids).await
+    }
+
+    pub async fn upsert_cover_art(
+        &self,
+        database: &Database,
+        dir: Option<&impl AsRef<Utf8NativePath>>,
+    ) -> Result<Option<Uuid>, Error> {
+        Ok(
+            if let Some(ref picture) = self.metadata.picture
+                && let Some(dir) = dir
+            {
+                Some(picture.upsert(database, dir).await?)
+            } else {
+                None
+            },
+        )
+    }
+
+    pub async fn upsert_song(
+        &self,
+        database: &Database,
+        foreign: songs::Foreign,
+        relative_path: impl Into<Cow<'_, str>>,
+        id: impl Into<Option<Uuid>>,
+    ) -> Result<Uuid, Error> {
+        songs::Upsert { foreign, relative_path: relative_path.into(), data: self.try_into()? }
+            .upsert(database, id)
+            .await
+    }
+
+    pub async fn upsert(
+        &self,
+        database: &Database,
+        config: &scanner::Config,
+        foreign: albums::Foreign,
+        relative_path: impl Into<Cow<'_, str>>,
+        song_id: impl Into<Option<Uuid>>,
+    ) -> Result<Uuid, Error> {
+        let album_id = self.upsert_album(database, foreign).await?;
+        let cover_art_id = self.upsert_cover_art(database, config.cover_art.dir.as_ref()).await?;
+        let foreign = songs::Foreign { album_id, cover_art_id };
+
+        let song_id = self.upsert_song(database, foreign, relative_path, song_id).await?;
+        self.upsert_artists(database, &config.index.ignore_prefixes, song_id).await?;
+        self.upsert_genres(database, song_id).await?;
+        Ok(song_id)
+    }
+
+    pub async fn cleanup_one(
+        database: &Database,
+        started_at: time::OffsetDateTime,
+        song_id: Uuid,
+    ) -> Result<(), Error> {
+        Artists::cleanup_one(database, started_at, song_id).await?;
+        Genres::cleanup_one(database, started_at, song_id).await?;
+        Ok(())
+    }
+
+    pub async fn cleanup(
+        database: &Database,
+        started_at: time::OffsetDateTime,
+    ) -> Result<(), Error> {
+        diesel::delete(songs::table)
+            .filter(songs::scanned_at.lt(started_at))
+            .execute(&mut database.get().await?)
+            .await?;
+        Album::cleanup(database).await?;
+        Artists::cleanup(database).await?;
+        Genres::cleanup(database).await?;
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use rstest::rstest;
+
+    use crate::test::{mock, Information, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_information_roundtrip(
+        #[future(awt)] mock: Mock,
+        #[values(true, false)] update_information: bool,
+    ) {
+        let information = Information::builder().build();
+        let id = information.upsert_mock(&mock, 0, None).await;
+        let database_information = Information::query(&mock, id).await;
+        assert_eq!(database_information, information);
+
+        if update_information {
+            let timestamp = crate::time::now().await;
+
+            let update_information = Information::builder().build();
+            let update_id = update_information.upsert_mock(&mock, 0, id).await;
+            super::Information::cleanup_one(mock.database(), timestamp, id).await.unwrap();
+            let database_update_information = Information::query(&mock, id).await;
+            assert_eq!(update_id, id);
+            assert_eq!(database_update_information, update_information);
+        }
+    }
+}
diff --git a/nghe-backend/src/file/audio/metadata.rs b/nghe-backend/src/file/audio/metadata.rs
new file mode 100644
index 000000000..b45e70932
--- /dev/null
+++ b/nghe-backend/src/file/audio/metadata.rs
@@ -0,0 +1,97 @@
+use std::str::FromStr;
+
+#[cfg(test)]
+use fake::{Dummy, Fake};
+use isolang::Language;
+#[cfg(test)]
+use itertools::Itertools;
+use o2o::o2o;
+
+use super::{artist, name_date_mbz, position, Genres};
+use crate::file::picture::Picture;
+use crate::orm::songs;
+use crate::Error;
+
+#[derive(Debug, o2o)]
+#[try_map_owned(songs::Song<'a>, Error)]
+#[ref_try_into(songs::Song<'a>, Error)]
+#[cfg_attr(test, derive(PartialEq, Eq, Dummy, Clone))]
+pub struct Song<'a> {
+    #[map_owned(~.try_into()?)]
+    #[ref_into((&~).try_into()?)]
+    pub main: name_date_mbz::NameDateMbz<'a>,
+    #[map(~.try_into()?)]
+    pub track_disc: position::TrackDisc,
+    #[from(~.into_iter().map(
+        |language|Language::from_str(language.ok_or_else(
+            || Error::LanguageFromDatabaseIsNull)?.as_ref()
+        ).map_err(Error::from)
+    ).try_collect()?)]
+    #[into(~.iter().map(|language| Some(language.to_639_3().into())).collect())]
+    #[cfg_attr(
+        test,
+        dummy(expr = "((0..=7915), \
+                      0..=2).fake::<Vec<usize>>().into_iter().unique().\
+                      map(Language::from_usize).collect::<Option<_>>().unwrap()")
+    )]
+    pub languages: Vec<Language>,
+}
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq, Eq, Dummy, Clone))]
+pub struct Metadata<'a> {
+    pub song: Song<'a>,
+    pub album: name_date_mbz::Album<'a>,
+    pub artists: artist::Artists<'a>,
+    pub genres: Genres<'a>,
+    pub picture: Option<Picture<'static, 'a>>,
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::{self, audio};
+    use crate::test::{mock, Information, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_song_roundtrip(
+        #[future(awt)] mock: Mock,
+        #[values(true, false)] update_song: bool,
+    ) {
+        let song: audio::Information = Faker.fake();
+        let album_id = song.metadata.album.upsert_mock(&mock, 0).await;
+        let id = song
+            .upsert_song(mock.database(), album_id.into(), Faker.fake::<String>(), None)
+            .await
+            .unwrap();
+
+        let database_data = Information::query_data(&mock, id).await;
+        let database_song: Song = database_data.song.try_into().unwrap();
+        let database_property: audio::Property = database_data.property.try_into().unwrap();
+        let database_file: file::Property<_> = database_data.file.into();
+        assert_eq!(database_song, song.metadata.song);
+        assert_eq!(database_property, song.property);
+        assert_eq!(database_file, song.file);
+
+        if update_song {
+            let update_song: audio::Information = Faker.fake();
+            let update_id = update_song
+                .upsert_song(mock.database(), album_id.into(), Faker.fake::<String>(), id)
+                .await
+                .unwrap();
+
+            let update_database_data = Information::query_data(&mock, update_id).await;
+            let update_database_song: Song = update_database_data.song.try_into().unwrap();
+            let update_database_property: audio::Property =
+                update_database_data.property.try_into().unwrap();
+            let update_database_file: file::Property<_> = update_database_data.file.into();
+            assert_eq!(update_database_song, update_song.metadata.song);
+            assert_eq!(update_database_property, update_song.property);
+            assert_eq!(update_database_file, update_song.file);
+        }
+    }
+}
diff --git a/nghe-backend/src/file/audio/mod.rs b/nghe-backend/src/file/audio/mod.rs
new file mode 100644
index 000000000..89cd905fd
--- /dev/null
+++ b/nghe-backend/src/file/audio/mod.rs
@@ -0,0 +1,228 @@
+mod artist;
+mod date;
+mod extract;
+mod genre;
+mod information;
+mod metadata;
+mod name_date_mbz;
+pub mod position;
+mod property;
+
+use std::io::Cursor;
+
+pub use artist::{Artist, Artists};
+pub use date::Date;
+use diesel::sql_types::Text;
+use diesel::{AsExpression, FromSqlRow};
+use extract::{Metadata as _, Property as _};
+pub use genre::Genres;
+pub use information::Information;
+use lofty::config::ParseOptions;
+use lofty::file::AudioFile;
+use lofty::flac::FlacFile;
+pub use metadata::{Metadata, Song};
+pub use name_date_mbz::{Album, NameDateMbz};
+use nghe_api::common::format;
+pub use position::TrackDisc;
+pub use property::Property;
+use strum::{EnumString, IntoStaticStr};
+
+use crate::{config, Error};
+
+#[derive(
+    Debug,
+    Clone,
+    Copy,
+    PartialEq,
+    Eq,
+    PartialOrd,
+    Ord,
+    EnumString,
+    IntoStaticStr,
+    AsExpression,
+    FromSqlRow,
+)]
+#[diesel(sql_type = Text)]
+#[strum(serialize_all = "snake_case")]
+#[cfg_attr(test, derive(fake::Dummy, strum::AsRefStr))]
+pub enum Format {
+    Flac,
+}
+
+pub enum File {
+    Flac { audio: FlacFile, file: super::File<Format> },
+}
+
+impl format::Trait for Format {
+    fn mime(&self) -> &'static str {
+        match self {
+            Self::Flac => "audio/flac",
+        }
+    }
+
+    fn extension(&self) -> &'static str {
+        self.into()
+    }
+}
+
+impl super::File<Format> {
+    pub fn audio(self, parse_options: ParseOptions) -> Result<File, Error> {
+        let mut reader = Cursor::new(&self.data);
+        match self.property.format {
+            Format::Flac => Ok(File::Flac {
+                audio: FlacFile::read_from(&mut reader, parse_options)?,
+                file: self,
+            }),
+        }
+    }
+}
+
+impl File {
+    pub fn file(&self) -> &super::File<Format> {
+        match self {
+            Self::Flac { file, .. } => file,
+        }
+    }
+
+    pub fn extract<'a>(&'a self, config: &'a config::Parsing) -> Result<Information<'a>, Error> {
+        Ok(Information {
+            metadata: self.metadata(config)?,
+            property: self.property()?,
+            file: self.file().property,
+        })
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use std::io::Cursor;
+
+    use lofty::config::WriteOptions;
+    use lofty::ogg::VorbisComments;
+
+    use super::*;
+
+    impl File {
+        pub fn clear(&mut self) -> &mut Self {
+            match self {
+                File::Flac { audio, .. } => {
+                    audio.remove_id3v2();
+                    audio.set_vorbis_comments(VorbisComments::default());
+                }
+            }
+            self
+        }
+
+        pub fn save_to(&self, cursor: &mut Cursor<Vec<u8>>, write_options: WriteOptions) {
+            match self {
+                File::Flac { audio, .. } => {
+                    audio.save_to(cursor, write_options).unwrap();
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+    use isolang::Language;
+    use nghe_api::common::filesystem;
+    use position::Position;
+    use rstest::rstest;
+    use time::Month;
+
+    use super::*;
+    use crate::file::File;
+    use crate::test::{assets, mock, Mock};
+
+    #[rstest]
+    fn test_media(#[values(Format::Flac)] format: Format) {
+        let file = File::new(format, std::fs::read(assets::path(format).as_str()).unwrap())
+            .unwrap()
+            .audio(ParseOptions::default())
+            .unwrap();
+
+        let config = config::Parsing::test();
+        let media = file.extract(&config).unwrap();
+        let metadata = media.metadata;
+
+        let song = metadata.song;
+        let main = song.main;
+        assert_eq!(main.name, "Sample");
+        assert_eq!(main.date, Date::default());
+        assert_eq!(main.release_date, Date::default());
+        assert_eq!(main.original_release_date, Date::default());
+        assert_eq!(main.mbz_id, None);
+
+        assert_eq!(
+            song.track_disc,
+            TrackDisc {
+                track: Position { number: Some(10), total: None },
+                disc: Position { number: Some(5), total: Some(10) }
+            }
+        );
+
+        assert_eq!(song.languages, &[Language::Eng, Language::Vie]);
+
+        let album = metadata.album;
+        assert_eq!(album.name, "Album");
+        assert_eq!(
+            album.date,
+            Date {
+                year: Some(2000),
+                month: Some(Month::December),
+                day: Some(31.try_into().unwrap())
+            }
+        );
+        assert_eq!(album.release_date, Date::default());
+        assert_eq!(
+            album.original_release_date,
+            Date { year: Some(3000), month: Some(Month::January), day: None }
+        );
+        assert_eq!(album.mbz_id, None);
+
+        let artists = metadata.artists;
+        let song = artists.song;
+        assert_eq!(
+            song.into_iter().collect::<Vec<_>>(),
+            &[
+                ("Artist1", uuid::uuid!("1ffedd2d-f63d-4dc2-9332-d3132e5134ac")).into(),
+                Artist::from("Artist2")
+            ]
+        );
+        let album = artists.album;
+        assert_eq!(album.into_iter().collect::<Vec<_>>(), &["Artist1", "Artist3"]);
+        assert!(artists.compilation);
+
+        assert!(metadata.genres.value.is_empty());
+
+        assert_eq!(media.property, Property::default(format));
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_roundtrip(
+        #[future(awt)]
+        #[with(0, 0)]
+        mock: Mock,
+        #[values(filesystem::Type::Local, filesystem::Type::S3)] ty: filesystem::Type,
+        #[values(Format::Flac)] format: Format,
+    ) {
+        mock.add_music_folder().ty(ty).call().await;
+        let mut music_folder = mock.music_folder(0).await;
+        let metadata: Metadata = Faker.fake();
+        let roundtrip_file = music_folder
+            .add_audio_filesystem()
+            .path("test")
+            .format(format)
+            .metadata(metadata.clone())
+            .call()
+            .await
+            .file("test".into(), format)
+            .await;
+        let roundtrip_audio = roundtrip_file.extract(&mock.config.parsing).unwrap();
+        assert_eq!(roundtrip_audio.metadata, metadata);
+        assert_eq!(roundtrip_audio.property, Property::default(format));
+    }
+}
diff --git a/nghe-backend/src/file/audio/name_date_mbz.rs b/nghe-backend/src/file/audio/name_date_mbz.rs
new file mode 100644
index 000000000..7051623ac
--- /dev/null
+++ b/nghe-backend/src/file/audio/name_date_mbz.rs
@@ -0,0 +1,224 @@
+use std::borrow::Cow;
+
+use diesel::dsl::{exists, not};
+use diesel::{ExpressionMethods, QueryDsl};
+use diesel_async::RunQueryDsl;
+#[cfg(test)]
+use fake::{Dummy, Fake, Faker};
+use o2o::o2o;
+use uuid::Uuid;
+
+use super::date::Date;
+use crate::database::Database;
+use crate::orm::upsert::Insert as _;
+use crate::orm::{albums, songs};
+use crate::Error;
+
+#[derive(Debug, o2o)]
+#[try_map_owned(songs::name_date_mbz::NameDateMbz<'a>, Error)]
+#[try_map_owned(albums::Data<'a>, Error)]
+#[ref_try_into(songs::name_date_mbz::NameDateMbz<'a>, Error)]
+#[ref_try_into(albums::Data<'a>, Error)]
+#[cfg_attr(test, derive(PartialEq, Eq, Dummy, Clone, Default))]
+pub struct NameDateMbz<'a> {
+    #[ref_into(~.as_str().into())]
+    #[cfg_attr(test, dummy(expr = "Faker.fake::<String>().into()"))]
+    pub name: Cow<'a, str>,
+    #[map(~.try_into()?)]
+    pub date: Date,
+    #[map(~.try_into()?)]
+    pub release_date: Date,
+    #[map(~.try_into()?)]
+    pub original_release_date: Date,
+    pub mbz_id: Option<Uuid>,
+}
+
+pub type Album<'a> = NameDateMbz<'a>;
+
+impl Album<'_> {
+    pub async fn upsert(
+        &self,
+        database: &Database,
+        foreign: albums::Foreign,
+    ) -> Result<Uuid, Error> {
+        albums::Upsert { foreign, data: self.try_into()? }.insert(database).await
+    }
+
+    pub async fn cleanup(database: &Database) -> Result<(), Error> {
+        // Delete all albums which do not have any song associated.
+        let alias_albums = diesel::alias!(albums as alias);
+        diesel::delete(albums::table)
+            .filter(
+                albums::id.eq_any(
+                    alias_albums
+                        .filter(not(exists(
+                            songs::table.filter(songs::album_id.eq(alias_albums.field(albums::id))),
+                        )))
+                        .select(alias_albums.field(albums::id)),
+                ),
+            )
+            .execute(&mut database.get().await?)
+            .await?;
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use diesel::{ExpressionMethods, QueryDsl, SelectableHelper};
+    use diesel_async::RunQueryDsl;
+    use futures_lite::{stream, StreamExt};
+
+    use super::*;
+    use crate::test::Mock;
+
+    impl<'a, S: Into<Cow<'a, str>>> From<S> for Album<'a> {
+        fn from(value: S) -> Self {
+            Self { name: value.into(), ..Self::default() }
+        }
+    }
+
+    impl Album<'_> {
+        pub async fn upsert_mock(&self, mock: &Mock, index: usize) -> Uuid {
+            self.upsert(mock.database(), mock.music_folder_id(index).await.into()).await.unwrap()
+        }
+    }
+
+    impl Album<'static> {
+        pub async fn query_upsert(mock: &Mock, id: Uuid) -> albums::Upsert<'static> {
+            albums::table
+                .filter(albums::id.eq(id))
+                .select(albums::Upsert::as_select())
+                .get_result(&mut mock.get().await)
+                .await
+                .unwrap()
+        }
+
+        pub async fn query(mock: &Mock, id: Uuid) -> Self {
+            Self::query_upsert(mock, id).await.data.try_into().unwrap()
+        }
+
+        pub async fn queries(mock: &Mock) -> Vec<Self> {
+            let ids = albums::table
+                .select(albums::id)
+                .order_by(albums::name)
+                .get_results(&mut mock.get().await)
+                .await
+                .unwrap();
+            stream::iter(ids).then(async |id| Self::query(mock, id).await).collect().await
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+    use itertools::Itertools;
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_album_upsert_roundtrip(
+        #[future(awt)] mock: Mock,
+        #[values(true, false)] mbz_id: bool,
+        #[values(true, false)] update_album: bool,
+    ) {
+        let mbz_id = if mbz_id { Some(Faker.fake()) } else { None };
+        let album = Album { mbz_id, ..Faker.fake() };
+        let id = album.upsert_mock(&mock, 0).await;
+        let database_album = Album::query(&mock, id).await;
+        assert_eq!(database_album, album);
+
+        if update_album {
+            let update_album = Album { mbz_id, ..Faker.fake() };
+            let update_id = update_album.upsert_mock(&mock, 0).await;
+            let database_update_album = Album::query(&mock, id).await;
+            if mbz_id.is_some() {
+                assert_eq!(id, update_id);
+                assert_eq!(database_update_album, update_album);
+            } else {
+                // This will always insert a new row to the database
+                // since there is nothing to identify an old album.
+                assert_ne!(id, update_id);
+            }
+        }
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_album_upsert_no_mbz_id(#[future(awt)] mock: Mock) {
+        // We want to make sure that insert the same album with no mbz_id
+        // twice does not result in any error.
+        let album = Album { mbz_id: None, ..Faker.fake() };
+        let id = album.upsert_mock(&mock, 0).await;
+        let update_id = album.upsert_mock(&mock, 0).await;
+        assert_eq!(update_id, id);
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_combine_album_artist(
+        #[future(awt)] mock: Mock,
+        #[values(true, false)] compilation: bool,
+    ) {
+        let mut music_folder = mock.music_folder(0).await;
+        let album: Album = Faker.fake();
+        let album_id = album.upsert_mock(&mock, 0).await;
+        let artists: Vec<_> = fake::vec![audio::Artist; 4].into_iter().sorted().collect();
+        music_folder
+            .add_audio()
+            .album(album.clone())
+            .artists(audio::Artists {
+                song: [artists[0].clone()].into(),
+                album: [artists[2].clone()].into(),
+                compilation,
+            })
+            .call()
+            .await
+            .add_audio()
+            .album(album.clone())
+            .artists(audio::Artists {
+                song: [artists[1].clone()].into(),
+                album: [artists[3].clone()].into(),
+                compilation,
+            })
+            .call()
+            .await;
+        let range = if compilation { 0..4 } else { 2..4 };
+        assert_eq!(artists[range], audio::Artist::query_album(&mock, album_id).await);
+    }
+
+    mod cleanup {
+        use super::*;
+
+        #[rstest]
+        #[case(1, 0)]
+        #[case(1, 1)]
+        #[case(5, 3)]
+        #[case(5, 5)]
+        #[tokio::test]
+        async fn test_album(
+            #[future(awt)] mock: Mock,
+            #[case] n_song: usize,
+            #[case] n_subset: usize,
+        ) {
+            let mut music_folder = mock.music_folder(0).await;
+            let album: Album = Faker.fake();
+            music_folder.add_audio().album(album.clone()).n_song(n_song).call().await;
+            let song_ids: Vec<_> = music_folder.database.keys().collect();
+            assert!(Album::queries(&mock).await.contains(&album));
+
+            diesel::delete(songs::table)
+                .filter(songs::id.eq_any(&song_ids[0..n_subset]))
+                .execute(&mut mock.get().await)
+                .await
+                .unwrap();
+            Album::cleanup(mock.database()).await.unwrap();
+            assert_eq!(Album::queries(&mock).await.contains(&album), n_subset < n_song);
+        }
+    }
+}
diff --git a/nghe-backend/src/file/audio/position.rs b/nghe-backend/src/file/audio/position.rs
new file mode 100644
index 000000000..35014a447
--- /dev/null
+++ b/nghe-backend/src/file/audio/position.rs
@@ -0,0 +1,201 @@
+use o2o::o2o;
+
+use crate::orm::songs;
+use crate::Error;
+
+#[derive(Debug, Default, Clone, Copy, o2o)]
+#[try_map_owned(songs::position::Track, Error)]
+#[try_map_owned(songs::position::Disc, Error)]
+#[cfg_attr(test, derive(PartialEq, Eq, fake::Dummy))]
+pub struct Position {
+    #[from(~.map(u16::try_from).transpose()?)]
+    #[into(~.map(u16::into))]
+    pub number: Option<u16>,
+    #[from(~.map(u16::try_from).transpose()?)]
+    #[into(~.map(u16::into))]
+    pub total: Option<u16>,
+}
+
+#[derive(Debug, Default, Clone, Copy, o2o)]
+#[try_map_owned(songs::position::TrackDisc, Error)]
+#[cfg_attr(test, derive(PartialEq, Eq, fake::Dummy))]
+pub struct TrackDisc {
+    #[map(~.try_into()?)]
+    pub track: Position,
+    #[map(~.try_into()?)]
+    pub disc: Position,
+}
+
+impl Position {
+    fn parse(number_str: Option<&str>, total_str: Option<&str>) -> Option<Self> {
+        if let Some(number) = number_str {
+            // Prioritize parsing from number_str if there is a slash inside
+            if let Some((number, total)) = number.split_once('/') {
+                let number = Some(number.parse().ok()?);
+                let total = if total.is_empty() {
+                    total_str.map(str::parse).transpose().ok()?
+                } else {
+                    Some(total.parse().ok()?)
+                };
+                Some(Self { number, total })
+            } else {
+                let number = Some(number.parse().ok()?);
+                let total = total_str.map(str::parse).transpose().ok()?;
+                Some(Self { number, total })
+            }
+        } else {
+            let total = total_str.map(str::parse).transpose().ok()?;
+            Some(Self { number: None, total })
+        }
+    }
+}
+
+impl TrackDisc {
+    pub fn parse(
+        track_number: Option<&str>,
+        track_total: Option<&str>,
+        disc_number: Option<&str>,
+        disc_total: Option<&str>,
+    ) -> Result<Self, Error> {
+        if let Some(track) = Position::parse(track_number, track_total)
+            && let Some(disc) = Position::parse(disc_number, disc_total)
+        {
+            Ok(Self { track, disc })
+        } else if let Some(track_disc) = Self::parse_vinyl_position(track_number) {
+            Ok(track_disc)
+        } else {
+            Err(Error::MediaPositionFormat {
+                track_number: track_number.map(str::to_owned),
+                track_total: track_total.map(str::to_owned),
+                disc_number: disc_number.map(str::to_owned),
+                disc_total: disc_total.map(str::to_owned),
+            })
+        }
+    }
+
+    // This position format is encountered when extracting metadata from some Vinyl records.
+    fn parse_vinyl_position(str: Option<&str>) -> Option<Self> {
+        if let Some(str) = str
+            && let Some(disc_letter) = str.chars().next()
+            && disc_letter.is_ascii_alphabetic()
+        {
+            // In ASCII, `A` is equal to 65.
+            let disc_number = (disc_letter.to_ascii_uppercase() as u8 - 64).into();
+            let track_number = str[1..].parse().ok()?;
+            Some(Self {
+                track: Position { number: Some(track_number), total: None },
+                disc: Position { number: Some(disc_number), total: None },
+            })
+        } else {
+            None
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #![allow(clippy::too_many_arguments)]
+
+    use rstest::rstest;
+
+    use super::*;
+
+    #[rstest]
+    #[case(None, None, None, None)]
+    #[case(Some("10"), None, Some(10), None)]
+    #[case(None, Some("20"), None, Some(20))]
+    #[case(Some("10"), Some("20"), Some(10), Some(20))]
+    #[case(Some("10/20"), None, Some(10), Some(20))]
+    #[case(Some("10/20"), Some("30"), Some(10), Some(20))]
+    #[case(Some("10/"), None, Some(10), None)]
+    #[case(Some("10/"), Some("30"), Some(10), Some(30))]
+    fn test_parse_position_success(
+        #[case] number_str: Option<&str>,
+        #[case] total_str: Option<&str>,
+        #[case] number: Option<u16>,
+        #[case] total: Option<u16>,
+    ) {
+        let position = Position::parse(number_str, total_str).unwrap();
+        assert_eq!(position.number, number);
+        assert_eq!(position.total, total);
+    }
+
+    #[rstest]
+    #[case(Some("/"), None)]
+    #[case(Some("-10/20"), None)]
+    #[case(Some("-10"), Some("-20"))]
+    #[case(None, Some("A"))]
+    #[case(None, Some("10/20"))]
+    fn test_parse_position_error(
+        #[case] number_str: Option<&str>,
+        #[case] total_str: Option<&str>,
+    ) {
+        assert!(Position::parse(number_str, total_str).is_none());
+    }
+
+    #[rstest]
+    #[case(Some("A1"), 1, 1)]
+    #[case(Some("E100"), 100, 5)]
+    #[case(Some("c1000"), 1000, 3)]
+    #[case(Some("Z0"), 0, 26)]
+    fn test_parse_vinyl_position_success(
+        #[case] str: Option<&str>,
+        #[case] track_number: u16,
+        #[case] disc_number: u16,
+    ) {
+        let track_disc = TrackDisc::parse_vinyl_position(str).unwrap();
+        assert_eq!(track_disc.track.number, Some(track_number));
+        assert!(track_disc.track.total.is_none());
+        assert_eq!(track_disc.disc.number, Some(disc_number));
+        assert!(track_disc.disc.total.is_none());
+    }
+
+    #[rstest]
+    #[case(None)]
+    #[case(Some("1A"))]
+    #[case(Some("A1B"))]
+    #[case(Some("1000"))]
+    fn test_parse_vinyl_position_error(#[case] str: Option<&str>) {
+        assert!(TrackDisc::parse_vinyl_position(str).is_none());
+    }
+
+    #[rstest]
+    #[case(None, None, None, None, None, None, None, None)]
+    #[case(Some("A2"), None, None, None, Some(2), None, Some(1), None)]
+    #[case(Some("1/"), None, None, Some("10"), Some(1), None, None, Some(10))]
+    #[case(Some("10"), Some("20"), Some("2/5"), None, Some(10), Some(20), Some(2), Some(5))]
+    fn test_parse_track_disc_success(
+        #[case] track_number_str: Option<&str>,
+        #[case] track_total_str: Option<&str>,
+        #[case] disc_number_str: Option<&str>,
+        #[case] disc_total_str: Option<&str>,
+        #[case] track_number: Option<u16>,
+        #[case] track_total: Option<u16>,
+        #[case] disc_number: Option<u16>,
+        #[case] disc_total: Option<u16>,
+    ) {
+        let track_disc =
+            TrackDisc::parse(track_number_str, track_total_str, disc_number_str, disc_total_str)
+                .unwrap();
+        assert_eq!(track_disc.track.number, track_number);
+        assert_eq!(track_disc.track.total, track_total);
+        assert_eq!(track_disc.disc.number, disc_number);
+        assert_eq!(track_disc.disc.total, disc_total);
+    }
+
+    #[rstest]
+    #[case(Some("1A"), None, None, None)]
+    #[case(Some("10"), Some("B"), None, None)]
+    #[case(Some("10"), None, Some("20/Z"), None)]
+    fn test_parse_track_disc_error(
+        #[case] track_number_str: Option<&str>,
+        #[case] track_total_str: Option<&str>,
+        #[case] disc_number_str: Option<&str>,
+        #[case] disc_total_str: Option<&str>,
+    ) {
+        assert!(
+            TrackDisc::parse(track_number_str, track_total_str, disc_number_str, disc_total_str)
+                .is_err()
+        );
+    }
+}
diff --git a/nghe-backend/src/file/audio/property.rs b/nghe-backend/src/file/audio/property.rs
new file mode 100644
index 000000000..23ab0b231
--- /dev/null
+++ b/nghe-backend/src/file/audio/property.rs
@@ -0,0 +1,34 @@
+#[derive(Debug, Clone, Copy)]
+#[cfg_attr(test, derive(educe::Educe, fake::Dummy))]
+#[cfg_attr(test, educe(PartialEq, Eq))]
+pub struct Property {
+    #[cfg_attr(test, educe(PartialEq(ignore)))]
+    #[cfg_attr(test, dummy(faker = "100f32..300f32"))]
+    pub duration: f32,
+    #[cfg_attr(test, dummy(faker = "32000..640000"))]
+    pub bitrate: u32,
+    pub bit_depth: Option<u8>,
+    #[cfg_attr(test, dummy(faker = "10000..44000"))]
+    pub sample_rate: u32,
+    pub channel_count: u8,
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::file::audio;
+
+    impl Property {
+        pub fn default(ty: audio::Format) -> Self {
+            match ty {
+                audio::Format::Flac => Self {
+                    duration: 0f32,
+                    bitrate: 585,
+                    bit_depth: Some(24),
+                    sample_rate: 32000,
+                    channel_count: 2,
+                },
+            }
+        }
+    }
+}
diff --git a/nghe-backend/src/file/mod.rs b/nghe-backend/src/file/mod.rs
new file mode 100644
index 000000000..5fcb575c9
--- /dev/null
+++ b/nghe-backend/src/file/mod.rs
@@ -0,0 +1,127 @@
+pub mod audio;
+pub mod picture;
+
+use std::time::Duration;
+
+use axum_extra::headers::{CacheControl, ETag};
+use nghe_api::common::format;
+use typed_path::{Utf8NativePath, Utf8NativePathBuf};
+use xxhash_rust::xxh3::xxh3_64;
+
+use crate::http::binary::property;
+use crate::http::header::ToETag;
+use crate::Error;
+
+#[derive(Debug, Clone, Copy)]
+#[cfg_attr(test, derive(PartialEq, Eq, fake::Dummy))]
+pub struct Property<F: format::Trait> {
+    pub hash: u64,
+    pub size: u32,
+    pub format: F,
+}
+
+#[derive(Debug, Clone, Copy)]
+#[cfg_attr(test, derive(PartialEq, Eq, fake::Dummy))]
+pub struct PropertySize<F: format::Trait> {
+    pub size: u64,
+    pub format: F,
+}
+
+#[derive(Debug)]
+pub struct File<F: format::Trait> {
+    pub data: Vec<u8>,
+    pub property: Property<F>,
+}
+
+impl<F: format::Trait> Property<F> {
+    pub fn new(format: F, data: impl AsRef<[u8]>) -> Result<Self, Error> {
+        let data = data.as_ref();
+        let hash = xxh3_64(data);
+        let size = data.len().try_into()?;
+        Ok(Self { hash, size, format })
+    }
+
+    pub fn replace<FN: format::Trait>(&self, format: FN) -> Property<FN> {
+        Property { hash: self.hash, size: self.size, format }
+    }
+
+    fn path_dir(&self, base: impl AsRef<Utf8NativePath>) -> Utf8NativePathBuf {
+        let hash = self.hash.to_le_bytes();
+
+        // Avoid putting too many files in a single directory
+        let first = faster_hex::hex_string(&hash[..1]);
+        let second = faster_hex::hex_string(&hash[1..]);
+
+        base.as_ref().join(first).join(second).join(self.size.to_string())
+    }
+
+    pub fn path(
+        &self,
+        base: impl AsRef<Utf8NativePath>,
+        name: impl Into<Option<&str>>,
+    ) -> Utf8NativePathBuf {
+        let path = self.path_dir(base);
+        if let Some(name) = name.into() {
+            path.join(name).with_extension(self.format.extension())
+        } else {
+            path
+        }
+    }
+
+    pub async fn path_create_dir(
+        &self,
+        base: impl AsRef<Utf8NativePath>,
+        name: &str,
+    ) -> Result<Utf8NativePathBuf, Error> {
+        let path = self.path_dir(base);
+        tokio::fs::create_dir_all(&path).await?;
+        Ok(path.join(name).with_extension(self.format.extension()))
+    }
+}
+
+impl<F: format::Trait> property::Trait for Property<F> {
+    const SEEKABLE: bool = true;
+
+    fn mime(&self) -> &'static str {
+        self.format.mime()
+    }
+
+    fn size(&self) -> Option<u64> {
+        Some(self.size.into())
+    }
+
+    fn etag(&self) -> Result<Option<ETag>, Error> {
+        Some(u64::to_etag(&self.hash)).transpose()
+    }
+
+    fn cache_control() -> CacheControl {
+        CacheControl::new().with_private().with_max_age(Duration::from_days(1))
+    }
+}
+
+impl<F: format::Trait> property::Trait for PropertySize<F> {
+    const SEEKABLE: bool = true;
+
+    fn mime(&self) -> &'static str {
+        self.format.mime()
+    }
+
+    fn size(&self) -> Option<u64> {
+        Some(self.size)
+    }
+
+    fn etag(&self) -> Result<Option<ETag>, Error> {
+        Ok(None)
+    }
+
+    fn cache_control() -> CacheControl {
+        Property::<F>::cache_control()
+    }
+}
+
+impl<F: format::Trait> File<F> {
+    pub fn new(format: F, data: Vec<u8>) -> Result<Self, Error> {
+        let property = Property::new(format, &data)?;
+        Ok(Self { data, property })
+    }
+}
diff --git a/nghe-backend/src/file/picture/mod.rs b/nghe-backend/src/file/picture/mod.rs
new file mode 100644
index 000000000..69d5292b1
--- /dev/null
+++ b/nghe-backend/src/file/picture/mod.rs
@@ -0,0 +1,294 @@
+use std::borrow::Cow;
+
+use diesel::sql_types::Text;
+use diesel::{AsExpression, FromSqlRow};
+use educe::Educe;
+use lofty::picture::{MimeType, Picture as LoftyPicture};
+use nghe_api::common::format;
+use o2o::o2o;
+use strum::{EnumString, IntoStaticStr};
+use typed_path::{Utf8NativePath, Utf8TypedPath, Utf8TypedPathBuf};
+use uuid::Uuid;
+
+use super::Property;
+use crate::database::Database;
+use crate::filesystem::Trait as _;
+use crate::orm::cover_arts;
+use crate::orm::upsert::Insert;
+use crate::{config, filesystem, Error};
+
+#[derive(
+    Debug,
+    Clone,
+    Copy,
+    PartialEq,
+    Eq,
+    PartialOrd,
+    Ord,
+    EnumString,
+    IntoStaticStr,
+    AsExpression,
+    FromSqlRow,
+)]
+#[diesel(sql_type = Text)]
+#[strum(serialize_all = "lowercase")]
+#[cfg_attr(test, derive(fake::Dummy, o2o, strum::EnumIter))]
+#[cfg_attr(test, owned_into(MimeType))]
+pub enum Format {
+    Png,
+    Jpeg,
+}
+
+#[derive(o2o, Educe)]
+#[educe(Debug)]
+#[ref_into(cover_arts::Upsert<'s>)]
+#[cfg_attr(test, derive(Clone, PartialEq, Eq))]
+pub struct Picture<'s, 'd> {
+    #[into(~.as_ref().map(|value| value.as_str().into()))]
+    pub source: Option<Cow<'s, str>>,
+    #[into(~.into())]
+    pub property: Property<Format>,
+    #[ghost]
+    #[educe(Debug(ignore))]
+    pub data: Cow<'d, [u8]>,
+}
+
+impl TryFrom<&MimeType> for Format {
+    type Error = Error;
+
+    fn try_from(value: &MimeType) -> Result<Self, Self::Error> {
+        match value {
+            MimeType::Png => Ok(Self::Png),
+            MimeType::Jpeg => Ok(Self::Jpeg),
+            _ => Err(Self::Error::MediaPictureUnsupportedFormat(value.as_str().to_owned())),
+        }
+    }
+}
+
+impl format::Trait for Format {
+    fn mime(&self) -> &'static str {
+        match self {
+            Self::Png => "image/png",
+            Self::Jpeg => "image/jpeg",
+        }
+    }
+
+    fn extension(&self) -> &'static str {
+        self.into()
+    }
+}
+
+impl<'d> TryFrom<&'d LoftyPicture> for Picture<'static, 'd> {
+    type Error = Error;
+
+    fn try_from(value: &'d LoftyPicture) -> Result<Self, Self::Error> {
+        Picture::new(
+            None,
+            value.mime_type().ok_or_else(|| Error::MediaPictureMissingFormat)?.try_into()?,
+            value.data(),
+        )
+    }
+}
+
+impl<'s, 'd> Picture<'s, 'd> {
+    pub const FILENAME: &'static str = "cover_art";
+    pub const TEST_DESCRIPTION: &'static str = "nghe-picture-test-description";
+
+    fn new(
+        source: Option<Cow<'s, str>>,
+        format: Format,
+        data: impl Into<Cow<'d, [u8]>>,
+    ) -> Result<Self, Error> {
+        let data = data.into();
+        let property = Property::new(format, &data)?;
+        Ok(Self { source, property, data })
+    }
+
+    pub async fn dump(&self, dir: impl AsRef<Utf8NativePath>) -> Result<(), Error> {
+        let path = self.property.path_create_dir(dir, Self::FILENAME).await?;
+        tokio::fs::write(path, &self.data).await?;
+        Ok(())
+    }
+
+    pub async fn upsert(
+        &self,
+        database: &Database,
+        dir: impl AsRef<Utf8NativePath>,
+    ) -> Result<Uuid, Error> {
+        // TODO: Checking for its existence before dump.
+        self.dump(dir).await?;
+        let upsert: cover_arts::Upsert = self.into();
+        upsert.insert(database).await
+    }
+
+    pub async fn scan(
+        database: &Database,
+        filesystem: &filesystem::Impl<'_>,
+        config: &config::CoverArt,
+        dir: Utf8TypedPath<'_>,
+    ) -> Result<Option<Uuid>, Error> {
+        if let Some(ref art_dir) = config.dir {
+            // TODO: Checking source before upserting.
+            for name in &config.names {
+                let path = dir.join(name);
+                if let Some(picture) = Picture::load(filesystem, path).await? {
+                    return Ok(Some(picture.upsert(database, art_dir).await?));
+                }
+            }
+        }
+        Ok(None)
+    }
+}
+
+impl Picture<'static, 'static> {
+    pub async fn load(
+        filesystem: &filesystem::Impl<'_>,
+        source: Utf8TypedPathBuf,
+    ) -> Result<Option<Self>, Error> {
+        let path = source.to_path();
+        if filesystem.exists(path).await? {
+            let format = path.extension().ok_or_else(|| Error::PathExtensionMissing)?.parse()?;
+            let data = filesystem.read(path).await?;
+            return Ok(Some(Picture::new(Some(source.into_string().into()), format, data)?));
+        }
+        Ok(None)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use std::io::Cursor;
+
+    use concat_string::concat_string;
+    use diesel::{ExpressionMethods, OptionalExtension, QueryDsl, SelectableHelper};
+    use diesel_async::RunQueryDsl;
+    use fake::{Dummy, Fake, Faker};
+    use image::{ImageFormat, Rgb, RgbImage};
+    use lofty::picture::PictureType;
+
+    use super::*;
+    use crate::file;
+    use crate::orm::albums;
+    use crate::schema::songs;
+    use crate::test::filesystem::Trait as _;
+    use crate::test::{filesystem, Mock};
+
+    impl Format {
+        pub fn name(self) -> String {
+            concat_string!("cover", ".", std::convert::Into::<&'static str>::into(self))
+        }
+    }
+
+    impl Dummy<Faker> for Picture<'_, '_> {
+        fn dummy_with_rng<R: fake::rand::Rng + ?Sized>(config: &Faker, rng: &mut R) -> Self {
+            let format: Format = config.fake_with_rng(rng);
+
+            let mut cursor = Cursor::new(vec![]);
+            RgbImage::from_fn(
+                (100..=200).fake_with_rng(rng),
+                (100..=200).fake_with_rng(rng),
+                |_, _| Rgb::from(Faker.fake_with_rng::<[u8; 3], _>(rng)),
+            )
+            .write_to(
+                &mut cursor,
+                match format {
+                    Format::Png => ImageFormat::Png,
+                    Format::Jpeg => ImageFormat::Jpeg,
+                },
+            )
+            .unwrap();
+            cursor.set_position(0);
+
+            Self::new(None, format, cursor.into_inner()).unwrap()
+        }
+    }
+
+    impl From<Picture<'_, '_>> for LoftyPicture {
+        fn from(value: Picture<'_, '_>) -> Self {
+            Self::new_unchecked(
+                PictureType::Other,
+                Some(value.property.format.into()),
+                Some(Picture::TEST_DESCRIPTION.to_owned()),
+                value.data.into_owned(),
+            )
+        }
+    }
+
+    impl Picture<'_, '_> {
+        pub async fn upsert_mock(&self, mock: &Mock) -> Uuid {
+            self.upsert(mock.database(), mock.config.cover_art.dir.as_ref().unwrap()).await.unwrap()
+        }
+    }
+
+    impl<'s> Picture<'s, '_> {
+        async fn load_cache(
+            dir: impl AsRef<Utf8NativePath>,
+            upsert: cover_arts::Upsert<'s>,
+        ) -> Self {
+            let property: file::Property<Format> = upsert.property.into();
+            let path = property.path(dir, Self::FILENAME);
+            let data = tokio::fs::read(path).await.unwrap();
+            Self { source: upsert.source, property, data: data.into() }
+        }
+
+        pub async fn query_song(mock: &Mock, id: Uuid) -> Option<Self> {
+            if let Some(ref dir) = mock.config.cover_art.dir {
+                let upsert = cover_arts::table
+                    .inner_join(songs::table)
+                    .filter(songs::id.eq(id))
+                    .select(cover_arts::Upsert::as_select())
+                    .get_result(&mut mock.get().await)
+                    .await
+                    .optional()
+                    .unwrap();
+                if let Some(upsert) = upsert {
+                    Some(Self::load_cache(dir, upsert).await)
+                } else {
+                    None
+                }
+            } else {
+                None
+            }
+        }
+
+        pub async fn query_album(mock: &Mock, id: Uuid) -> Option<Self> {
+            if let Some(ref dir) = mock.config.cover_art.dir {
+                let upsert = cover_arts::table
+                    .inner_join(albums::table)
+                    .filter(albums::id.eq(id))
+                    .select(cover_arts::Upsert::as_select())
+                    .get_result(&mut mock.get().await)
+                    .await
+                    .optional()
+                    .unwrap();
+                if let Some(upsert) = upsert {
+                    Some(Self::load_cache(dir, upsert).await)
+                } else {
+                    None
+                }
+            } else {
+                None
+            }
+        }
+
+        pub fn with_source(self, source: Option<impl Into<Cow<'s, str>>>) -> Self {
+            Self { source: source.map(std::convert::Into::into), ..self }
+        }
+    }
+
+    impl Picture<'static, 'static> {
+        pub async fn scan_filesystem(
+            filesystem: &filesystem::Impl<'_>,
+            config: &config::CoverArt,
+            dir: Utf8TypedPath<'_>,
+        ) -> Option<Self> {
+            for name in &config.names {
+                let path = dir.join(name);
+                if let Some(picture) = Self::load(&filesystem.main(), path).await.unwrap() {
+                    return Some(picture);
+                }
+            }
+            None
+        }
+    }
+}
diff --git a/nghe-backend/src/filesystem/common.rs b/nghe-backend/src/filesystem/common.rs
new file mode 100644
index 000000000..f57480f91
--- /dev/null
+++ b/nghe-backend/src/filesystem/common.rs
@@ -0,0 +1,232 @@
+use std::borrow::Cow;
+
+use nghe_api::common::filesystem;
+use o2o::o2o;
+use typed_path::Utf8TypedPath;
+
+use super::{entry, path};
+use crate::file::{self, audio};
+use crate::http::binary;
+use crate::Error;
+
+#[derive(Clone, o2o)]
+#[ref_into(filesystem::Type)]
+pub enum Impl<'fs> {
+    #[type_hint(as Unit)]
+    Local(Cow<'fs, super::local::Filesystem>),
+    #[type_hint(as Unit)]
+    S3(Cow<'fs, super::s3::Filesystem>),
+}
+
+impl Impl<'_> {
+    pub fn path(&self) -> path::Builder {
+        path::Builder(self.into())
+    }
+
+    pub fn into_owned(self) -> Impl<'static> {
+        match self {
+            Impl::Local(filesystem) => Impl::Local(Cow::Owned(filesystem.into_owned())),
+            Impl::S3(filesystem) => Impl::S3(Cow::Owned(filesystem.into_owned())),
+        }
+    }
+}
+
+pub trait Trait {
+    async fn check_folder(&self, path: Utf8TypedPath<'_>) -> Result<(), Error>;
+    async fn scan_folder(
+        &self,
+        sender: entry::Sender,
+        prefix: Utf8TypedPath<'_>,
+    ) -> Result<(), Error>;
+
+    async fn exists(&self, path: Utf8TypedPath<'_>) -> Result<bool, Error>;
+
+    async fn read(&self, path: Utf8TypedPath<'_>) -> Result<Vec<u8>, Error>;
+    async fn read_to_binary(
+        &self,
+        source: &binary::Source<file::Property<audio::Format>>,
+        offset: Option<u64>,
+    ) -> Result<binary::Response, Error>;
+
+    async fn transcode_input(&self, path: Utf8TypedPath<'_>) -> Result<String, Error>;
+}
+
+impl Trait for Impl<'_> {
+    async fn check_folder(&self, path: Utf8TypedPath<'_>) -> Result<(), Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.check_folder(path).await,
+            Impl::S3(filesystem) => filesystem.check_folder(path).await,
+        }
+    }
+
+    async fn scan_folder(
+        &self,
+        sender: entry::Sender,
+        prefix: Utf8TypedPath<'_>,
+    ) -> Result<(), Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.scan_folder(sender, prefix).await,
+            Impl::S3(filesystem) => filesystem.scan_folder(sender, prefix).await,
+        }
+    }
+
+    async fn exists(&self, path: Utf8TypedPath<'_>) -> Result<bool, Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.exists(path).await,
+            Impl::S3(filesystem) => filesystem.exists(path).await,
+        }
+    }
+
+    async fn read(&self, path: Utf8TypedPath<'_>) -> Result<Vec<u8>, Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.read(path).await,
+            Impl::S3(filesystem) => filesystem.read(path).await,
+        }
+    }
+
+    async fn read_to_binary(
+        &self,
+        source: &binary::Source<file::Property<audio::Format>>,
+        offset: Option<u64>,
+    ) -> Result<binary::Response, Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.read_to_binary(source, offset).await,
+            Impl::S3(filesystem) => filesystem.read_to_binary(source, offset).await,
+        }
+    }
+
+    async fn transcode_input(&self, path: Utf8TypedPath<'_>) -> Result<String, Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.transcode_input(path).await,
+            Impl::S3(filesystem) => filesystem.transcode_input(path).await,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+    use futures_lite::StreamExt;
+    use itertools::Itertools;
+    use nghe_api::common::filesystem;
+    use rstest::rstest;
+
+    use super::Trait as _;
+    use crate::file::audio;
+    use crate::filesystem::{entry, Entry};
+    use crate::test::filesystem::Trait as _;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[case(filesystem::Type::Local, "usr/bin", false)]
+    #[case(filesystem::Type::Local, "Windows\\Sys64", false)]
+    #[cfg_attr(unix, case(filesystem::Type::Local, "/tmp/", true))]
+    #[cfg_attr(unix, case(filesystem::Type::Local, "C:\\Windows", false))]
+    #[cfg_attr(windows, case(filesystem::Type::Local, "C:\\Windows", true))]
+    #[cfg_attr(windows, case(filesystem::Type::Local, "/tmp/", false))]
+    #[case(filesystem::Type::S3, "usr/bin", false)]
+    #[case(filesystem::Type::S3, "Windows\\Sys64", false)]
+    #[case(filesystem::Type::S3, "/tmp", false)]
+    #[case(filesystem::Type::S3, "C:\\Windows", false)]
+    #[case(filesystem::Type::S3, "/nghe-backend-test-check-folder-bucket", true)]
+    #[case(filesystem::Type::S3, "/nghe-backend-test-check-folder-bucket/test/", true)]
+    #[tokio::test]
+    async fn test_check_folder(
+        #[future(awt)]
+        #[with(0, 0, Some("nghe-backend-test-check-folder-bucket"))]
+        mock: Mock,
+        #[case] ty: filesystem::Type,
+        #[case] path: &str,
+        #[case] is_ok: bool,
+    ) {
+        let filesystem = mock.to_impl(ty);
+        assert_eq!(filesystem.check_folder(path.into()).await.is_ok(), is_ok);
+    }
+
+    #[rstest]
+    #[case(20, 10, 20, 15, 5)]
+    #[case(50, 5, 15, 10, 10)]
+    #[tokio::test]
+    async fn test_scan_folder(
+        #[future(awt)]
+        #[with(0, 0)]
+        mock: Mock,
+        #[values(filesystem::Type::Local, filesystem::Type::S3)] ty: filesystem::Type,
+        #[case] minimum_size: usize,
+        #[case] n_txt: usize,
+        #[case] n_dir: usize,
+        #[case] n_smaller: usize,
+        #[case] n_larger: usize,
+    ) {
+        let filesystem = mock.to_impl(ty);
+        let prefix = filesystem.prefix().to_path_buf();
+        let main_filesystem = filesystem.main().into_owned();
+
+        let mut entries = vec![];
+
+        for _ in 0..n_txt {
+            let relative_path = filesystem.fake_path((0..3).fake()).with_extension("txt");
+            let content = fake::vec![u8; 0..(2 * minimum_size)];
+            filesystem.write(relative_path.to_path(), &content).await;
+        }
+
+        for _ in 0..n_dir {
+            let relative_path = filesystem.fake_path((0..3).fake());
+            filesystem.create_dir(relative_path.to_path()).await;
+        }
+
+        for _ in 0..n_dir {
+            let relative_path = filesystem
+                .fake_path((0..3).fake())
+                .with_extension(Faker.fake::<audio::Format>().as_ref());
+            filesystem.create_dir(relative_path.to_path()).await;
+        }
+
+        for _ in 0..n_smaller {
+            let relative_path = filesystem
+                .fake_path((0..3).fake())
+                .with_extension(Faker.fake::<audio::Format>().as_ref());
+            let content = fake::vec![u8; 0..minimum_size];
+            filesystem.write(relative_path.to_path(), &content).await;
+        }
+
+        for _ in 0..n_larger {
+            let format: audio::Format = Faker.fake();
+            let relative_path = filesystem.fake_path((0..3).fake()).with_extension(format.as_ref());
+
+            let content = fake::vec![u8; ((minimum_size + 1)..(2 * minimum_size)).fake::<usize>()];
+            filesystem.write(relative_path.to_path(), &content).await;
+            entries.push(Entry { format, path: prefix.join(relative_path), last_modified: None });
+        }
+
+        let (tx, rx) = crate::sync::channel(mock.config.filesystem.scan.channel_size);
+        let sender = entry::Sender { tx, minimum_size };
+        let scan_handle = tokio::spawn(async move {
+            main_filesystem.scan_folder(sender, prefix.to_path()).await.unwrap();
+        });
+        let scanned_entries: Vec<_> = rx.into_stream().collect().await;
+        scan_handle.await.unwrap();
+
+        assert_eq!(scanned_entries.len(), n_larger);
+        assert_eq!(
+            scanned_entries.into_iter().sorted().collect_vec(),
+            entries.into_iter().sorted().collect_vec()
+        );
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_exists(
+        #[future(awt)]
+        #[with(0, 0)]
+        mock: Mock,
+        #[values(filesystem::Type::Local, filesystem::Type::S3)] ty: filesystem::Type,
+    ) {
+        let filesystem = mock.to_impl(ty);
+        let path = filesystem.prefix().join(Faker.fake::<String>());
+        let path = path.to_path();
+        assert!(!filesystem.exists(path).await.unwrap());
+        filesystem.write(path, &fake::vec![u8; 10..20]).await;
+        assert!(filesystem.exists(path).await.unwrap());
+    }
+}
diff --git a/nghe-backend/src/filesystem/entry.rs b/nghe-backend/src/filesystem/entry.rs
new file mode 100644
index 000000000..f8458b601
--- /dev/null
+++ b/nghe-backend/src/filesystem/entry.rs
@@ -0,0 +1,51 @@
+use time::OffsetDateTime;
+use typed_path::{Utf8TypedPath, Utf8TypedPathBuf};
+
+use crate::file::audio;
+use crate::Error;
+
+pub trait Metadata {
+    fn size(&self) -> Result<usize, Error>;
+    fn last_modified(&self) -> Result<Option<OffsetDateTime>, Error>;
+}
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(educe::Educe))]
+#[cfg_attr(test, educe(PartialEq, Eq, PartialOrd, Ord))]
+pub struct Entry {
+    pub format: audio::Format,
+    pub path: Utf8TypedPathBuf,
+    #[cfg_attr(test, educe(PartialEq(ignore)))]
+    #[cfg_attr(test, educe(PartialOrd(ignore)))]
+    pub last_modified: Option<OffsetDateTime>,
+}
+
+impl Entry {
+    pub fn relative_path(&self, base: impl AsRef<str>) -> Result<Utf8TypedPath<'_>, Error> {
+        self.path.strip_prefix(base).map_err(Error::from)
+    }
+}
+
+pub struct Sender {
+    pub tx: loole::Sender<Entry>,
+    pub minimum_size: usize,
+}
+
+impl Sender {
+    pub async fn send(
+        &self,
+        path: Utf8TypedPathBuf,
+        metadata: &impl Metadata,
+    ) -> Result<(), Error> {
+        let size = metadata.size()?;
+        if size > self.minimum_size
+            && let Some(extension) = path.extension()
+            && let Ok(format) = audio::Format::try_from(extension)
+        {
+            self.tx
+                .send_async(Entry { format, path, last_modified: metadata.last_modified()? })
+                .await?;
+        }
+        Ok(())
+    }
+}
diff --git a/nghe-backend/src/filesystem/local.rs b/nghe-backend/src/filesystem/local.rs
new file mode 100644
index 000000000..55f2e23bc
--- /dev/null
+++ b/nghe-backend/src/filesystem/local.rs
@@ -0,0 +1,109 @@
+use std::fs::Metadata;
+
+use async_walkdir::WalkDir;
+use futures_lite::stream::StreamExt;
+use time::OffsetDateTime;
+use typed_path::{TryAsRef as _, Utf8NativePath, Utf8TypedPath};
+
+use super::{entry, path};
+use crate::file::{self, audio};
+use crate::http::binary;
+use crate::Error;
+
+#[derive(Debug, Clone, Copy)]
+pub struct Filesystem;
+
+impl Filesystem {
+    #[cfg(windows)]
+    fn is_native(path: &Utf8TypedPath<'_>) -> bool {
+        path.is_windows()
+    }
+
+    #[cfg(unix)]
+    fn is_native(path: &Utf8TypedPath<'_>) -> bool {
+        path.is_unix()
+    }
+}
+
+impl super::Trait for Filesystem {
+    async fn check_folder(&self, path: Utf8TypedPath<'_>) -> Result<(), Error> {
+        if Self::is_native(&path)
+            && path.is_absolute()
+            && tokio::fs::metadata(path.as_str()).await?.is_dir()
+        {
+            Ok(())
+        } else {
+            Err(Error::InvalidParameter("Folder path must be absolute and be a directory"))
+        }
+    }
+
+    async fn scan_folder(
+        &self,
+        sender: entry::Sender,
+        prefix: Utf8TypedPath<'_>,
+    ) -> Result<(), Error> {
+        let mut stream = WalkDir::new(prefix.as_ref());
+
+        while let Some(entry) = stream.next().await {
+            match entry {
+                Ok(entry) => match entry.metadata().await {
+                    Ok(metadata) => {
+                        if metadata.is_file() {
+                            let path = entry
+                                .path()
+                                .into_os_string()
+                                .into_string()
+                                .map(path::Local::from_string)
+                                .map_err(Error::FilesystemLocalNonUTF8PathEncountered)?;
+                            sender.send(path, &metadata).await?;
+                        }
+                    }
+                    Err(err) => tracing::error!(list_folder_local_metadata_err = ?err),
+                },
+                Err(err) => tracing::error!(list_folder_local_walk_err = ?err),
+            }
+        }
+
+        Ok(())
+    }
+
+    async fn exists(&self, path: Utf8TypedPath<'_>) -> Result<bool, Error> {
+        tokio::fs::try_exists(path.as_str()).await.map_err(Error::from)
+    }
+
+    async fn read(&self, path: Utf8TypedPath<'_>) -> Result<Vec<u8>, Error> {
+        tokio::fs::read(path.as_str()).await.map_err(Error::from)
+    }
+
+    async fn read_to_binary(
+        &self,
+        source: &binary::Source<file::Property<audio::Format>>,
+        offset: Option<u64>,
+    ) -> Result<binary::Response, Error> {
+        let path = source.path.to_path();
+        let path: &Utf8NativePath =
+            path.try_as_ref().ok_or_else(|| Error::FilesystemTypedPathWrongPlatform)?;
+        binary::Response::from_path_property(
+            path,
+            &source.property,
+            offset,
+            #[cfg(test)]
+            None,
+        )
+        .await
+    }
+
+    async fn transcode_input(&self, path: Utf8TypedPath<'_>) -> Result<String, Error> {
+        Ok(path.as_str().to_owned())
+    }
+}
+
+impl entry::Metadata for Metadata {
+    fn size(&self) -> Result<usize, Error> {
+        self.len().try_into().map_err(Error::from)
+    }
+
+    fn last_modified(&self) -> Result<Option<OffsetDateTime>, Error> {
+        Ok(self.modified().ok().map(OffsetDateTime::from))
+    }
+}
diff --git a/nghe-backend/src/filesystem/mod.rs b/nghe-backend/src/filesystem/mod.rs
new file mode 100644
index 000000000..99c4c6a54
--- /dev/null
+++ b/nghe-backend/src/filesystem/mod.rs
@@ -0,0 +1,47 @@
+mod common;
+pub mod entry;
+pub mod local;
+pub mod path;
+pub mod s3;
+
+use std::borrow::Cow;
+
+use color_eyre::eyre::OptionExt;
+pub use common::{Impl, Trait};
+pub use entry::Entry;
+use nghe_api::common::filesystem;
+
+use crate::{config, Error};
+
+#[derive(Clone)]
+pub struct Filesystem {
+    local: local::Filesystem,
+    s3: Option<s3::Filesystem>,
+}
+
+impl Filesystem {
+    pub async fn new(tls: &config::filesystem::Tls, s3: &config::filesystem::S3) -> Self {
+        let local = local::Filesystem;
+        let s3 = if s3.enable { Some(s3::Filesystem::new(tls, s3).await) } else { None };
+        Self { local, s3 }
+    }
+
+    pub fn to_impl(&self, ty: filesystem::Type) -> Result<Impl<'_>, Error> {
+        Ok(match ty {
+            filesystem::Type::Local => Impl::Local(Cow::Borrowed(&self.local)),
+            filesystem::Type::S3 => Impl::S3(Cow::Borrowed(
+                self.s3.as_ref().ok_or_eyre("S3 filesystem is not enabled")?,
+            )),
+        })
+    }
+
+    #[cfg(test)]
+    pub fn local(&self) -> local::Filesystem {
+        self.local
+    }
+
+    #[cfg(test)]
+    pub fn s3(&self) -> s3::Filesystem {
+        self.s3.as_ref().unwrap().clone()
+    }
+}
diff --git a/nghe-backend/src/filesystem/path/builder.rs b/nghe-backend/src/filesystem/path/builder.rs
new file mode 100644
index 000000000..cb05b1e84
--- /dev/null
+++ b/nghe-backend/src/filesystem/path/builder.rs
@@ -0,0 +1,71 @@
+#![allow(clippy::wrong_self_convention)]
+
+use nghe_api::common::filesystem;
+use typed_path::{PathType, Utf8TypedPath, Utf8TypedPathBuf, Utf8UnixPathBuf, Utf8WindowsPathBuf};
+
+#[derive(Debug, Clone, Copy)]
+pub struct Const<const TYPE: filesystem::Type>;
+
+#[derive(Debug, Clone, Copy)]
+pub struct Builder(pub filesystem::Type);
+
+pub type Local = Const<{ filesystem::Type::Local }>;
+pub type S3 = Const<{ filesystem::Type::S3 }>;
+
+macro_rules! builder_from_str {
+    ($ty:expr, $value:ident) => {{
+        match $ty {
+            filesystem::Type::Local if cfg!(windows) => {
+                Utf8TypedPath::new($value, PathType::Windows)
+            }
+            _ => Utf8TypedPath::new($value, PathType::Unix),
+        }
+    }};
+}
+
+macro_rules! builder_from_string {
+    ($ty:expr, $value:ident) => {{
+        let $value = $value.into();
+        match $ty {
+            filesystem::Type::Local if cfg!(windows) => {
+                Utf8TypedPathBuf::Windows(Utf8WindowsPathBuf::from($value))
+            }
+            _ => Utf8TypedPathBuf::Unix(Utf8UnixPathBuf::from($value)),
+        }
+    }};
+}
+
+#[cfg(test)]
+macro_rules! builder_empty {
+    ($ty:expr) => {
+        match $ty {
+            filesystem::Type::Local if cfg!(windows) => Utf8TypedPathBuf::new(PathType::Windows),
+            _ => Utf8TypedPathBuf::new(PathType::Unix),
+        }
+    };
+}
+
+impl<const TYPE: filesystem::Type> Const<TYPE> {
+    pub fn from_str(value: &(impl AsRef<str> + ?Sized)) -> Utf8TypedPath<'_> {
+        builder_from_str!(TYPE, value)
+    }
+
+    pub fn from_string(value: impl Into<String>) -> Utf8TypedPathBuf {
+        builder_from_string!(TYPE, value)
+    }
+}
+
+impl Builder {
+    pub fn from_str(self, value: &(impl AsRef<str> + ?Sized)) -> Utf8TypedPath<'_> {
+        builder_from_str!(self.0, value)
+    }
+
+    pub fn from_string(self, value: impl Into<String>) -> Utf8TypedPathBuf {
+        builder_from_string!(self.0, value)
+    }
+
+    #[cfg(test)]
+    pub fn empty(self) -> Utf8TypedPathBuf {
+        builder_empty!(self.0)
+    }
+}
diff --git a/nghe-backend/src/filesystem/path/mod.rs b/nghe-backend/src/filesystem/path/mod.rs
new file mode 100644
index 000000000..a8112f621
--- /dev/null
+++ b/nghe-backend/src/filesystem/path/mod.rs
@@ -0,0 +1,4 @@
+mod builder;
+pub mod serde;
+
+pub use builder::{Builder, Local, S3};
diff --git a/nghe-backend/src/filesystem/path/serde.rs b/nghe-backend/src/filesystem/path/serde.rs
new file mode 100644
index 000000000..8dc737f8a
--- /dev/null
+++ b/nghe-backend/src/filesystem/path/serde.rs
@@ -0,0 +1,43 @@
+use ::serde::{Deserialize, Deserializer, Serializer};
+use typed_path::Utf8NativePathBuf;
+
+pub fn serialize<S>(path: &Utf8NativePathBuf, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+{
+    serializer.serialize_str(path.as_str())
+}
+
+pub fn deserialize<'de, D>(deserializer: D) -> Result<Utf8NativePathBuf, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    <String>::deserialize(deserializer).map(Utf8NativePathBuf::from)
+}
+
+pub mod option {
+    #![allow(clippy::ref_option)]
+
+    use super::*;
+
+    pub fn serialize<S>(path: &Option<Utf8NativePathBuf>, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        if let Some(path) = path {
+            serializer.serialize_str(path.as_str())
+        } else {
+            serializer.serialize_none()
+        }
+    }
+
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<Option<Utf8NativePathBuf>, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        <String>::deserialize(deserializer).map(|path| {
+            let path = Utf8NativePathBuf::from(path);
+            if path.is_absolute() { Some(path) } else { None }
+        })
+    }
+}
diff --git a/nghe-backend/src/filesystem/s3.rs b/nghe-backend/src/filesystem/s3.rs
new file mode 100644
index 000000000..6d5c34cb7
--- /dev/null
+++ b/nghe-backend/src/filesystem/s3.rs
@@ -0,0 +1,221 @@
+use std::time::Duration;
+
+use aws_config::stalled_stream_protection::StalledStreamProtectionConfig;
+use aws_config::timeout::TimeoutConfig;
+use aws_sdk_s3::error::SdkError;
+use aws_sdk_s3::operation::head_object::HeadObjectError;
+use aws_sdk_s3::presigning::PresigningConfig;
+use aws_sdk_s3::primitives::{AggregatedBytes, DateTime};
+use aws_sdk_s3::types::Object;
+use aws_sdk_s3::Client;
+use aws_smithy_runtime::client::http::hyper_014::HyperClientBuilder;
+use concat_string::concat_string;
+use hyper::client::HttpConnector;
+use hyper_tls::HttpsConnector;
+use time::OffsetDateTime;
+use typed_path::Utf8TypedPath;
+
+use super::{entry, path};
+use crate::file::{self, audio};
+use crate::http::binary;
+use crate::{config, Error};
+
+#[derive(Debug, Clone)]
+pub struct Filesystem {
+    client: Client,
+    presigned_duration: Duration,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct Path<'b, 'k> {
+    pub bucket: &'b str,
+    pub key: &'k str,
+}
+
+impl Filesystem {
+    pub async fn new(tls: &config::filesystem::Tls, s3: &config::filesystem::S3) -> Self {
+        let mut http_connector = HttpConnector::new();
+        http_connector.enforce_http(false);
+
+        let tls_connector = hyper_tls::native_tls::TlsConnector::builder()
+            .danger_accept_invalid_certs(tls.accept_invalid_certs)
+            .danger_accept_invalid_hostnames(tls.accept_invalid_hostnames)
+            .build()
+            .expect("Could not build tls connector");
+
+        let config_loader = aws_config::from_env()
+            .stalled_stream_protection(if s3.stalled_stream_grace_preriod > 0 {
+                StalledStreamProtectionConfig::enabled()
+                    .grace_period(Duration::from_secs(s3.stalled_stream_grace_preriod))
+                    .build()
+            } else {
+                StalledStreamProtectionConfig::disabled()
+            })
+            .http_client(
+                HyperClientBuilder::new()
+                    .build(HttpsConnector::from((http_connector, tls_connector.into()))),
+            );
+
+        let client = Client::from_conf(
+            aws_sdk_s3::config::Builder::from(&config_loader.load().await)
+                .force_path_style(s3.use_path_style_endpoint)
+                .timeout_config(
+                    TimeoutConfig::builder()
+                        .connect_timeout(Duration::from_secs(s3.connect_timeout))
+                        .build(),
+                )
+                .build(),
+        );
+
+        Self { client, presigned_duration: Duration::from_mins(s3.presigned_duration) }
+    }
+
+    pub fn split<'b, 'k, 'p: 'b + 'k>(
+        path: impl Into<Utf8TypedPath<'p>>,
+    ) -> Result<Path<'b, 'k>, Error> {
+        let path = path.into();
+        if let Utf8TypedPath::Unix(path) = path
+            && path.is_absolute()
+            && let Some(path) = path.as_str().strip_prefix('/')
+        {
+            if let Some((bucket, key)) = path.split_once('/') {
+                Ok(Path { bucket, key })
+            } else {
+                Ok(Path { bucket: path, key: "" })
+            }
+        } else {
+            Err(Error::FilesystemS3InvalidPath(path.to_string()))
+        }
+    }
+
+    #[cfg(test)]
+    pub fn client(&self) -> &Client {
+        &self.client
+    }
+}
+
+impl super::Trait for Filesystem {
+    async fn check_folder(&self, path: Utf8TypedPath<'_>) -> Result<(), Error> {
+        let Path { bucket, key } = Self::split(path)?;
+        self.client
+            .list_objects_v2()
+            .bucket(bucket)
+            .prefix(key)
+            .max_keys(1)
+            .send()
+            .await
+            .map_err(color_eyre::Report::new)?;
+        Ok(())
+    }
+
+    async fn scan_folder(
+        &self,
+        sender: entry::Sender,
+        prefix: Utf8TypedPath<'_>,
+    ) -> Result<(), Error> {
+        let Path { bucket, key } = Self::split(prefix)?;
+        let prefix = key;
+        let mut steam =
+            self.client.list_objects_v2().bucket(bucket).prefix(prefix).into_paginator().send();
+        let bucket = path::S3::from_str("/").join(bucket);
+
+        while let Some(output) = steam.try_next().await.map_err(color_eyre::Report::new)? {
+            if let Some(contents) = output.contents {
+                for content in contents {
+                    if let Some(key) = content.key() {
+                        sender.send(bucket.join(key), &content).await?;
+                    }
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    async fn exists(&self, path: Utf8TypedPath<'_>) -> Result<bool, Error> {
+        let Path { bucket, key } = Self::split(path)?;
+        let result = self.client.head_object().bucket(bucket).key(key).send().await;
+
+        if let Err(err) = result {
+            if let SdkError::ServiceError(ref err) = err
+                && let HeadObjectError::NotFound(_) = err.err()
+            {
+                Ok(false)
+            } else {
+                Err(err.into())
+            }
+        } else {
+            Ok(true)
+        }
+    }
+
+    async fn read(&self, path: Utf8TypedPath<'_>) -> Result<Vec<u8>, Error> {
+        let Path { bucket, key } = Self::split(path)?;
+        self.client
+            .get_object()
+            .bucket(bucket)
+            .key(key)
+            .send()
+            .await
+            .map_err(color_eyre::Report::new)?
+            .body
+            .collect()
+            .await
+            .map(AggregatedBytes::to_vec)
+            .map_err(Error::from)
+    }
+
+    async fn read_to_binary(
+        &self,
+        source: &binary::Source<file::Property<audio::Format>>,
+        offset: Option<u64>,
+    ) -> Result<binary::Response, Error> {
+        let path = source.path.to_path();
+        let Path { bucket, key } = Self::split(path)?;
+        let reader = self
+            .client
+            .get_object()
+            .bucket(bucket)
+            .key(key)
+            .set_range(offset.map(|offset| concat_string!("bytes=", offset.to_string(), "-")))
+            .send()
+            .await?
+            .body
+            .into_async_read();
+        binary::Response::from_async_read(
+            reader,
+            &source.property,
+            offset,
+            #[cfg(test)]
+            None,
+        )
+    }
+
+    async fn transcode_input(&self, path: Utf8TypedPath<'_>) -> Result<String, Error> {
+        let Path { bucket, key } = Self::split(path)?;
+        Ok(self
+            .client
+            .get_object()
+            .bucket(bucket)
+            .key(key)
+            .presigned(PresigningConfig::expires_in(self.presigned_duration)?)
+            .await?
+            .uri()
+            .to_owned())
+    }
+}
+
+impl entry::Metadata for Object {
+    fn size(&self) -> Result<usize, Error> {
+        Ok(self.size().ok_or_else(|| Error::FilesystemS3MissingObjectSize)?.try_into()?)
+    }
+
+    fn last_modified(&self) -> Result<Option<OffsetDateTime>, Error> {
+        Ok(self
+            .last_modified()
+            .map(DateTime::as_nanos)
+            .map(OffsetDateTime::from_unix_timestamp_nanos)
+            .transpose()
+            .map_err(color_eyre::Report::new)?)
+    }
+}
diff --git a/nghe-backend/src/http/binary/mod.rs b/nghe-backend/src/http/binary/mod.rs
new file mode 100644
index 000000000..d7e816755
--- /dev/null
+++ b/nghe-backend/src/http/binary/mod.rs
@@ -0,0 +1,187 @@
+pub mod property;
+pub mod source;
+
+use std::convert::Infallible;
+
+use axum::body::Body;
+use axum::http::{header, HeaderMap, StatusCode};
+use axum::response::IntoResponse;
+use axum_extra::headers::{
+    AcceptRanges, ContentLength, ContentRange, HeaderMapExt, TransferEncoding,
+};
+use futures_lite::{Stream, StreamExt};
+use loole::{Receiver, RecvStream};
+use nghe_api::common::format;
+pub use source::Source;
+use tokio::io::{AsyncRead, AsyncSeekExt, SeekFrom};
+use tokio_util::io::ReaderStream;
+use typed_path::Utf8NativePath;
+
+#[cfg(test)]
+use crate::test::transcode;
+use crate::{file, Error};
+
+struct RxStream(RecvStream<Vec<u8>>);
+
+#[derive(Debug)]
+pub struct Response {
+    status: StatusCode,
+    header: HeaderMap,
+    body: Body,
+}
+
+impl RxStream {
+    fn new(rx: Receiver<Vec<u8>>) -> Self {
+        Self(rx.into_stream())
+    }
+}
+
+impl Stream for RxStream {
+    type Item = Result<Vec<u8>, Infallible>;
+
+    fn poll_next(
+        mut self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Option<Self::Item>> {
+        self.0.poll_next(cx).map(|t| t.map(Result::Ok))
+    }
+}
+
+impl From<RxStream> for Body {
+    fn from(value: RxStream) -> Self {
+        Self::from_stream(value)
+    }
+}
+
+impl Response {
+    fn new<P: property::Trait>(
+        body: Body,
+        property: &P,
+        offset: impl Into<Option<u64>>,
+        #[cfg(test)] transcode_status: impl Into<Option<transcode::Status>>,
+    ) -> Result<Self, Error> {
+        let mut header = HeaderMap::new();
+
+        header.insert(header::CONTENT_TYPE, header::HeaderValue::from_static(property.mime()));
+
+        let status = if let Some(size) = property.size() {
+            let offset = offset.into().unwrap_or(0);
+            header.typed_insert(ContentLength(size - offset));
+            header.typed_insert(
+                ContentRange::bytes(offset.., size).map_err(color_eyre::Report::from)?,
+            );
+            if offset == 0 { StatusCode::OK } else { StatusCode::PARTIAL_CONTENT }
+        } else {
+            header.typed_insert(TransferEncoding::chunked());
+            StatusCode::OK
+        };
+
+        if let Some(etag) = property.etag()? {
+            header.typed_insert(etag);
+        }
+
+        if P::SEEKABLE {
+            header.typed_insert(AcceptRanges::bytes());
+        }
+
+        header.typed_insert(P::cache_control());
+
+        #[cfg(test)]
+        if let Some(transcode_status) = transcode_status.into() {
+            header.typed_insert(transcode::Header(transcode_status));
+        }
+
+        Ok(Self { status, header, body })
+    }
+
+    pub async fn from_path(
+        path: impl AsRef<Utf8NativePath>,
+        format: impl format::Trait,
+        offset: impl Into<Option<u64>> + Copy,
+        #[cfg(test)] transcode_status: impl Into<Option<transcode::Status>>,
+    ) -> Result<Self, Error> {
+        let mut file = tokio::fs::File::open(path.as_ref()).await?;
+        let size = file.seek(SeekFrom::End(0)).await?;
+        file.seek(SeekFrom::Start(offset.into().unwrap_or(0))).await?;
+        Self::from_async_read(
+            file,
+            &file::PropertySize { size, format },
+            offset,
+            #[cfg(test)]
+            transcode_status,
+        )
+    }
+
+    pub async fn from_path_property(
+        path: impl AsRef<Utf8NativePath>,
+        property: &impl property::Trait,
+        offset: impl Into<Option<u64>> + Copy,
+        #[cfg(test)] transcode_status: impl Into<Option<transcode::Status>>,
+    ) -> Result<Self, Error> {
+        let mut file = tokio::fs::File::open(path.as_ref()).await?;
+        if let Some(offset) = offset.into()
+            && offset > 0
+        {
+            file.seek(SeekFrom::Start(offset)).await?;
+        }
+        Self::from_async_read(
+            file,
+            property,
+            offset,
+            #[cfg(test)]
+            transcode_status,
+        )
+    }
+
+    pub fn from_async_read(
+        reader: impl AsyncRead + Send + 'static,
+        property: &impl property::Trait,
+        offset: impl Into<Option<u64>>,
+        #[cfg(test)] transcode_status: impl Into<Option<transcode::Status>>,
+    ) -> Result<Self, Error> {
+        Self::new(
+            Body::from_stream(ReaderStream::new(reader)),
+            property,
+            offset,
+            #[cfg(test)]
+            transcode_status,
+        )
+    }
+
+    pub fn from_rx(
+        rx: Receiver<Vec<u8>>,
+        property: format::Transcode,
+        #[cfg(test)] transcode_status: impl Into<Option<transcode::Status>>,
+    ) -> Result<Self, Error> {
+        Self::new(
+            RxStream::new(rx).into(),
+            &property,
+            None,
+            #[cfg(test)]
+            transcode_status,
+        )
+    }
+}
+
+impl IntoResponse for Response {
+    fn into_response(self) -> axum::response::Response {
+        (self.status, self.header, self.body).into_response()
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use http_body_util::BodyExt;
+
+    use super::*;
+
+    impl Response {
+        pub async fn extract(self) -> (StatusCode, HeaderMap, Vec<u8>) {
+            let response = self.into_response();
+            let status = response.status();
+            let header = response.headers().clone();
+            let body = response.into_body().collect().await.unwrap().to_bytes().to_vec();
+            (status, header, body)
+        }
+    }
+}
diff --git a/nghe-backend/src/http/binary/property.rs b/nghe-backend/src/http/binary/property.rs
new file mode 100644
index 000000000..a4630d493
--- /dev/null
+++ b/nghe-backend/src/http/binary/property.rs
@@ -0,0 +1,13 @@
+use axum_extra::headers::{CacheControl, ETag};
+
+use crate::Error;
+
+pub trait Trait: Copy {
+    const SEEKABLE: bool;
+
+    fn mime(&self) -> &'static str;
+    fn size(&self) -> Option<u64>;
+    fn etag(&self) -> Result<Option<ETag>, Error>;
+
+    fn cache_control() -> CacheControl;
+}
diff --git a/nghe-backend/src/http/binary/source.rs b/nghe-backend/src/http/binary/source.rs
new file mode 100644
index 000000000..c981af9a0
--- /dev/null
+++ b/nghe-backend/src/http/binary/source.rs
@@ -0,0 +1,34 @@
+use diesel_async::RunQueryDsl;
+use typed_path::Utf8TypedPathBuf;
+use uuid::Uuid;
+
+use super::property;
+use crate::database::Database;
+use crate::file::{self, audio};
+use crate::filesystem::{self, Filesystem};
+use crate::orm::binary;
+use crate::Error;
+
+pub struct Source<P: property::Trait> {
+    pub path: Utf8TypedPathBuf,
+    pub property: P,
+}
+
+impl Source<file::Property<audio::Format>> {
+    pub async fn audio<'fs>(
+        database: &Database,
+        filesystem: &'fs Filesystem,
+        user_id: Uuid,
+        song_id: Uuid,
+    ) -> Result<(filesystem::Impl<'fs>, Self), Error> {
+        let audio = binary::source::audio::query(user_id, song_id)
+            .get_result(&mut database.get().await?)
+            .await?;
+        let filesystem = filesystem.to_impl(audio.music_folder.ty.into())?;
+        let path = filesystem
+            .path()
+            .from_string(audio.music_folder.path.into_owned())
+            .join(audio.relative_path);
+        Ok((filesystem, Self { path, property: audio.property.into() }))
+    }
+}
diff --git a/nghe-backend/src/http/header.rs b/nghe-backend/src/http/header.rs
new file mode 100644
index 000000000..867fd2b53
--- /dev/null
+++ b/nghe-backend/src/http/header.rs
@@ -0,0 +1,33 @@
+use std::ops::Bound;
+
+use axum_extra::headers::{ETag, Range};
+use concat_string::concat_string;
+
+use crate::Error;
+
+pub trait ToOffset {
+    fn to_offset(&self, size: u64) -> Result<u64, Error>;
+}
+
+impl ToOffset for Range {
+    fn to_offset(&self, size: u64) -> Result<u64, Error> {
+        if let Bound::Included(offset) =
+            self.satisfiable_ranges(size).next().ok_or_else(|| Error::InvalidRangeHeader)?.0
+        {
+            Ok(offset)
+        } else {
+            Err(Error::InvalidRangeHeader)
+        }
+    }
+}
+
+pub trait ToETag: ToString {
+    fn to_etag(&self) -> Result<ETag, Error> {
+        concat_string!("\"", self.to_string(), "\"")
+            .parse()
+            .map_err(color_eyre::Report::from)
+            .map_err(Error::from)
+    }
+}
+
+impl ToETag for u64 {}
diff --git a/nghe-backend/src/http/mod.rs b/nghe-backend/src/http/mod.rs
new file mode 100644
index 000000000..d6a4e217e
--- /dev/null
+++ b/nghe-backend/src/http/mod.rs
@@ -0,0 +1,2 @@
+pub mod binary;
+pub mod header;
diff --git a/nghe-backend/src/lib.rs b/nghe-backend/src/lib.rs
new file mode 100644
index 000000000..04991882f
--- /dev/null
+++ b/nghe-backend/src/lib.rs
@@ -0,0 +1,74 @@
+#![feature(adt_const_params)]
+#![feature(anonymous_lifetime_in_impl_trait)]
+#![feature(async_closure)]
+#![feature(duration_constructors)]
+#![feature(integer_sign_cast)]
+#![feature(iterator_try_collect)]
+#![feature(let_chains)]
+#![feature(proc_macro_hygiene)]
+#![feature(stmt_expr_attributes)]
+#![feature(str_as_str)]
+#![feature(try_blocks)]
+
+mod auth;
+pub mod config;
+mod database;
+mod error;
+mod file;
+mod filesystem;
+mod http;
+pub mod migration;
+mod orm;
+mod route;
+mod scan;
+mod schema;
+mod sync;
+mod time;
+mod transcode;
+
+#[cfg(test)]
+mod test;
+
+use axum::body::Body;
+use axum::http::Request;
+use axum::Router;
+use error::Error;
+use tower_http::cors::CorsLayer;
+use tower_http::trace::TraceLayer;
+
+pub async fn build(config: config::Config) -> Router {
+    let filesystem =
+        filesystem::Filesystem::new(&config.filesystem.tls, &config.filesystem.s3).await;
+
+    Router::new()
+        .merge(route::music_folder::router(filesystem.clone()))
+        .merge(route::permission::router())
+        .merge(route::user::router())
+        .merge(route::media_retrieval::router(
+            filesystem.clone(),
+            config.transcode,
+            config.cover_art.clone(),
+        ))
+        .merge(route::scan::router(
+            filesystem,
+            scan::scanner::Config {
+                lofty: lofty::config::ParseOptions::default(),
+                scan: config.filesystem.scan,
+                parsing: config.parsing,
+                index: config.index,
+                cover_art: config.cover_art,
+            },
+        ))
+        .merge(route::browsing::router())
+        .merge(route::lists::router())
+        .merge(route::media_annotation::router())
+        .merge(route::search::router())
+        .merge(route::system::router())
+        .with_state(database::Database::new(&config.database))
+        .layer(TraceLayer::new_for_http().make_span_with(|request: &Request<Body>| {
+            tracing::info_span!(
+                "request", method = %request.method(), path = %request.uri().path()
+            )
+        }))
+        .layer(CorsLayer::permissive())
+}
diff --git a/nghe-backend/src/main.rs b/nghe-backend/src/main.rs
new file mode 100644
index 000000000..708cee7b8
--- /dev/null
+++ b/nghe-backend/src/main.rs
@@ -0,0 +1,26 @@
+use nghe_api::constant;
+use nghe_backend::{build, config, migration};
+use tracing_subscriber::layer::SubscriberExt;
+use tracing_subscriber::util::SubscriberInitExt;
+
+#[tokio::main]
+async fn main() {
+    color_eyre::install().expect("Could not install error handler");
+
+    tracing_subscriber::registry()
+        .with(tracing_subscriber::EnvFilter::try_from_default_env().unwrap_or_else(|_| {
+            ["nghe_backend=info".to_owned(), "tower_http=info".to_owned()].join(",").into()
+        }))
+        .with(tracing_subscriber::fmt::layer().with_target(false))
+        .try_init()
+        .expect("Could not install tracing handler");
+
+    tracing::info!(server_version =% constant::SERVER_VERSION);
+
+    let config = config::Config::default();
+    tracing::info!("{config:#?}");
+    migration::run(&config.database.url).await;
+
+    let listener = tokio::net::TcpListener::bind(config.server.to_socket_addr()).await.unwrap();
+    axum::serve(listener, build(config).await).await.unwrap();
+}
diff --git a/nghe-backend/src/migration/mod.rs b/nghe-backend/src/migration/mod.rs
new file mode 100644
index 000000000..d7bce7c02
--- /dev/null
+++ b/nghe-backend/src/migration/mod.rs
@@ -0,0 +1,26 @@
+use diesel::Connection;
+use diesel_async::async_connection_wrapper::AsyncConnectionWrapper;
+use diesel_async::AsyncPgConnection;
+use diesel_migrations::{embed_migrations, EmbeddedMigrations, MigrationHarness};
+
+pub const MIGRATIONS: EmbeddedMigrations = embed_migrations!();
+
+pub async fn run(database_url: &str) {
+    let database_url = database_url.to_owned();
+    tokio::task::spawn_blocking(move || {
+        let mut async_wrapper =
+            AsyncConnectionWrapper::<AsyncPgConnection>::establish(&database_url)
+                .expect("Could not connect to the database");
+
+        for migration in async_wrapper
+            .pending_migrations(MIGRATIONS)
+            .expect("Could not get pending migration(s)")
+        {
+            tracing::info!(pending_migration =% migration.name());
+            async_wrapper.run_migration(&migration).expect("Could not run migration");
+        }
+        tracing::info!("migration done");
+    })
+    .await
+    .expect("Could not spawn migration thread");
+}
diff --git a/nghe-backend/src/orm/albums/date.rs b/nghe-backend/src/orm/albums/date.rs
new file mode 100644
index 000000000..e19eee0cd
--- /dev/null
+++ b/nghe-backend/src/orm/albums/date.rs
@@ -0,0 +1,52 @@
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+use nghe_api::id3;
+use o2o::o2o;
+
+use super::albums;
+use crate::Error;
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset, o2o)]
+#[diesel(table_name = albums, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+#[owned_try_into(id3::date::Date, Error)]
+pub struct Date {
+    #[try_into(~.map(i16::try_into).transpose()?)]
+    pub year: Option<i16>,
+    #[try_into(~.map(i16::try_into).transpose()?)]
+    pub month: Option<i16>,
+    #[try_into(~.map(i16::try_into).transpose()?)]
+    pub day: Option<i16>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset, o2o)]
+#[diesel(table_name = albums, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+#[owned_try_into(id3::date::Date, Error)]
+pub struct Release {
+    #[try_into(~.map(i16::try_into).transpose()?)]
+    #[diesel(column_name = release_year)]
+    pub year: Option<i16>,
+    #[try_into(~.map(i16::try_into).transpose()?)]
+    #[diesel(column_name = release_month)]
+    pub month: Option<i16>,
+    #[try_into(~.map(i16::try_into).transpose()?)]
+    #[diesel(column_name = release_day)]
+    pub day: Option<i16>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset, o2o)]
+#[diesel(table_name = albums, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+#[owned_try_into(id3::date::Date, Error)]
+pub struct OriginalRelease {
+    #[try_into(~.map(i16::try_into).transpose()?)]
+    #[diesel(column_name = original_release_year)]
+    pub year: Option<i16>,
+    #[try_into(~.map(i16::try_into).transpose()?)]
+    #[diesel(column_name = original_release_month)]
+    pub month: Option<i16>,
+    #[try_into(~.map(i16::try_into).transpose()?)]
+    #[diesel(column_name = original_release_day)]
+    pub day: Option<i16>,
+}
diff --git a/nghe-backend/src/orm/albums/mod.rs b/nghe-backend/src/orm/albums/mod.rs
new file mode 100644
index 000000000..b0c7e885a
--- /dev/null
+++ b/nghe-backend/src/orm/albums/mod.rs
@@ -0,0 +1,101 @@
+use std::borrow::Cow;
+
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+use uuid::Uuid;
+
+pub use crate::schema::albums::{self, *};
+
+pub mod date;
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = albums, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+#[cfg_attr(test, derive(Default))]
+pub struct Foreign {
+    pub music_folder_id: Uuid,
+    pub cover_art_id: Option<Uuid>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = albums, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Data<'a> {
+    pub name: Cow<'a, str>,
+    #[diesel(embed)]
+    pub date: date::Date,
+    #[diesel(embed)]
+    pub release_date: date::Release,
+    #[diesel(embed)]
+    pub original_release_date: date::OriginalRelease,
+    pub mbz_id: Option<Uuid>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = albums, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Upsert<'a> {
+    #[diesel(embed)]
+    pub foreign: Foreign,
+    #[diesel(embed)]
+    pub data: Data<'a>,
+}
+
+mod upsert {
+    use diesel::{DecoratableTarget, ExpressionMethods};
+    use diesel_async::RunQueryDsl;
+    use uuid::Uuid;
+
+    use super::{albums, Upsert};
+    use crate::database::Database;
+    use crate::Error;
+
+    impl crate::orm::upsert::Insert for Upsert<'_> {
+        async fn insert(&self, database: &Database) -> Result<Uuid, Error> {
+            if self.data.mbz_id.is_some() {
+                diesel::insert_into(albums::table)
+                    .values(self)
+                    .on_conflict((albums::music_folder_id, albums::mbz_id))
+                    .do_update()
+                    .set((self, albums::scanned_at.eq(time::OffsetDateTime::now_utc())))
+                    .returning(albums::id)
+                    .get_result(&mut database.get().await?)
+                    .await
+            } else {
+                diesel::insert_into(albums::table)
+                    .values(self)
+                    .on_conflict((
+                        albums::music_folder_id,
+                        albums::name,
+                        albums::year,
+                        albums::month,
+                        albums::day,
+                        albums::release_year,
+                        albums::release_month,
+                        albums::release_day,
+                        albums::original_release_year,
+                        albums::original_release_month,
+                        albums::original_release_day,
+                    ))
+                    .filter_target(albums::mbz_id.is_null())
+                    .do_update()
+                    .set(albums::scanned_at.eq(time::OffsetDateTime::now_utc()))
+                    .returning(albums::id)
+                    .get_result(&mut database.get().await?)
+                    .await
+            }
+            .map_err(Error::from)
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    impl From<Uuid> for Foreign {
+        fn from(value: Uuid) -> Self {
+            Self { music_folder_id: value, ..Default::default() }
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/artists.rs b/nghe-backend/src/orm/artists.rs
new file mode 100644
index 000000000..99f4a48fe
--- /dev/null
+++ b/nghe-backend/src/orm/artists.rs
@@ -0,0 +1,60 @@
+use std::borrow::Cow;
+
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+use uuid::Uuid;
+
+pub use crate::schema::artists::{self, *};
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = artists, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Data<'a> {
+    pub name: Cow<'a, str>,
+    pub mbz_id: Option<Uuid>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = artists, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Upsert<'a> {
+    pub index: Cow<'a, str>,
+    #[diesel(embed)]
+    pub data: Data<'a>,
+}
+
+mod upsert {
+    use diesel::{DecoratableTarget, ExpressionMethods};
+    use diesel_async::RunQueryDsl;
+    use uuid::Uuid;
+
+    use super::{artists, Upsert};
+    use crate::database::Database;
+    use crate::Error;
+
+    impl crate::orm::upsert::Insert for Upsert<'_> {
+        async fn insert(&self, database: &Database) -> Result<Uuid, Error> {
+            if self.data.mbz_id.is_some() {
+                diesel::insert_into(artists::table)
+                    .values(self)
+                    .on_conflict(artists::mbz_id)
+                    .do_update()
+                    .set((self, artists::scanned_at.eq(time::OffsetDateTime::now_utc())))
+                    .returning(artists::id)
+                    .get_result(&mut database.get().await?)
+                    .await
+            } else {
+                diesel::insert_into(artists::table)
+                    .values(self)
+                    .on_conflict(artists::name)
+                    .filter_target(artists::mbz_id.is_null())
+                    .do_update()
+                    .set((self, artists::scanned_at.eq(time::OffsetDateTime::now_utc())))
+                    .returning(artists::id)
+                    .get_result(&mut database.get().await?)
+                    .await
+            }
+            .map_err(Error::from)
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/binary/mod.rs b/nghe-backend/src/orm/binary/mod.rs
new file mode 100644
index 000000000..1779b0b8a
--- /dev/null
+++ b/nghe-backend/src/orm/binary/mod.rs
@@ -0,0 +1 @@
+pub mod source;
diff --git a/nghe-backend/src/orm/binary/source/audio.rs b/nghe-backend/src/orm/binary/source/audio.rs
new file mode 100644
index 000000000..02c5a16ce
--- /dev/null
+++ b/nghe-backend/src/orm/binary/source/audio.rs
@@ -0,0 +1,30 @@
+use std::borrow::Cow;
+
+use diesel::dsl::{auto_type, AsSelect};
+use diesel::prelude::*;
+use diesel::SelectableHelper;
+use uuid::Uuid;
+
+use crate::orm::{albums, music_folders, permission, songs};
+
+#[derive(Debug, Queryable, Selectable)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+pub struct Song<'mf, 'path> {
+    #[diesel(embed)]
+    pub music_folder: music_folders::Data<'mf>,
+    pub relative_path: Cow<'path, str>,
+    #[diesel(embed)]
+    pub property: songs::property::File,
+}
+
+#[auto_type]
+pub fn query<'mf, 'path>(user_id: Uuid, song_id: Uuid) -> _ {
+    let permission: permission::with_album = permission::with_album(user_id);
+    let select_song: AsSelect<Song<'mf, 'path>, crate::orm::Type> = Song::as_select();
+    albums::table
+        .inner_join(songs::table)
+        .inner_join(music_folders::table)
+        .filter(songs::id.eq(song_id))
+        .filter(permission)
+        .select(select_song)
+}
diff --git a/nghe-backend/src/orm/binary/source/mod.rs b/nghe-backend/src/orm/binary/source/mod.rs
new file mode 100644
index 000000000..fa3e4e468
--- /dev/null
+++ b/nghe-backend/src/orm/binary/source/mod.rs
@@ -0,0 +1 @@
+pub mod audio;
diff --git a/nghe-backend/src/orm/configs.rs b/nghe-backend/src/orm/configs.rs
new file mode 100644
index 000000000..e4557b441
--- /dev/null
+++ b/nghe-backend/src/orm/configs.rs
@@ -0,0 +1,23 @@
+use std::borrow::Cow;
+
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+
+pub use crate::schema::configs::{self, *};
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = configs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Data<'a> {
+    pub text: Option<Cow<'a, str>>,
+    pub byte: Option<Cow<'a, [u8]>>,
+}
+
+#[derive(Debug, Insertable, AsChangeset)]
+#[diesel(table_name = configs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Upsert<'a> {
+    pub key: &'static str,
+    #[diesel(embed)]
+    pub data: Data<'a>,
+}
diff --git a/nghe-backend/src/orm/cover_arts.rs b/nghe-backend/src/orm/cover_arts.rs
new file mode 100644
index 000000000..563b6bb44
--- /dev/null
+++ b/nghe-backend/src/orm/cover_arts.rs
@@ -0,0 +1,74 @@
+use std::borrow::Cow;
+use std::str::FromStr;
+
+use diesel::deserialize::{self, FromSql};
+use diesel::pg::PgValue;
+use diesel::prelude::*;
+use diesel::serialize::{self, Output, ToSql};
+use diesel::sql_types::Text;
+use diesel_derives::AsChangeset;
+use o2o::o2o;
+
+use crate::file::{self, picture};
+pub use crate::schema::cover_arts::{self, *};
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset, o2o)]
+#[map_owned(file::Property<picture::Format>)]
+#[diesel(table_name = cover_arts, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Property {
+    #[from(~.cast_signed())]
+    #[into(~.cast_unsigned())]
+    #[diesel(column_name = file_hash)]
+    pub hash: i64,
+    #[from(~.cast_signed())]
+    #[into(~.cast_unsigned())]
+    #[diesel(column_name = file_size)]
+    pub size: i32,
+    pub format: picture::Format,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = cover_arts, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Upsert<'s> {
+    pub source: Option<Cow<'s, str>>,
+    #[diesel(embed)]
+    pub property: Property,
+}
+
+mod upsert {
+    use diesel::ExpressionMethods;
+    use diesel_async::RunQueryDsl;
+    use uuid::Uuid;
+
+    use super::{cover_arts, Upsert};
+    use crate::database::Database;
+    use crate::Error;
+
+    impl crate::orm::upsert::Insert for Upsert<'_> {
+        async fn insert(&self, database: &Database) -> Result<Uuid, Error> {
+            diesel::insert_into(cover_arts::table)
+                .values(self)
+                .on_conflict((cover_arts::source, cover_arts::file_hash, cover_arts::file_size))
+                .do_update()
+                .set(cover_arts::format.eq(self.property.format))
+                .returning(cover_arts::id)
+                .get_result(&mut database.get().await?)
+                .await
+                .map_err(Error::from)
+        }
+    }
+}
+
+impl ToSql<Text, super::Type> for picture::Format {
+    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, super::Type>) -> serialize::Result {
+        <str as ToSql<Text, super::Type>>::to_sql(self.into(), out)
+    }
+}
+
+impl FromSql<Text, super::Type> for picture::Format {
+    fn from_sql(bytes: PgValue) -> deserialize::Result<Self> {
+        Ok(picture::Format::from_str(core::str::from_utf8(bytes.as_bytes())?)?)
+    }
+}
diff --git a/nghe-backend/src/orm/function.rs b/nghe-backend/src/orm/function.rs
new file mode 100644
index 000000000..b5d0370a3
--- /dev/null
+++ b/nghe-backend/src/orm/function.rs
@@ -0,0 +1,3 @@
+use diesel::define_sql_function;
+
+define_sql_function!(fn random() -> Bool);
diff --git a/nghe-backend/src/orm/genres.rs b/nghe-backend/src/orm/genres.rs
new file mode 100644
index 000000000..4b2b7f641
--- /dev/null
+++ b/nghe-backend/src/orm/genres.rs
@@ -0,0 +1,13 @@
+use std::borrow::Cow;
+
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+
+pub use crate::schema::genres::{self, *};
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = genres, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Data<'a> {
+    pub value: Cow<'a, str>,
+}
diff --git a/nghe-backend/src/orm/id3/album/full.rs b/nghe-backend/src/orm/id3/album/full.rs
new file mode 100644
index 000000000..541bb6fc7
--- /dev/null
+++ b/nghe-backend/src/orm/id3/album/full.rs
@@ -0,0 +1,121 @@
+use diesel::dsl::sql;
+use diesel::expression::SqlLiteral;
+use diesel::prelude::*;
+use diesel::sql_types;
+use diesel_async::RunQueryDsl;
+use nghe_api::id3;
+use uuid::Uuid;
+
+use super::Album;
+use crate::database::Database;
+use crate::orm::id3::duration::Trait;
+use crate::orm::id3::{artist, song};
+use crate::orm::songs;
+use crate::Error;
+
+#[derive(Debug, Queryable, Selectable)]
+pub struct Full {
+    #[diesel(embed)]
+    pub album: Album,
+    #[diesel(embed)]
+    pub artists: artist::required::Artists,
+    #[diesel(select_expression = sql("bool_or(songs_album_artists.compilation) is_compilation"))]
+    #[diesel(select_expression_type = SqlLiteral::<sql_types::Bool>)]
+    pub is_compilation: bool,
+    #[diesel(select_expression = sql("array_agg(distinct(songs.id)) album_artists"))]
+    #[diesel(select_expression_type = SqlLiteral::<sql_types::Array<sql_types::Uuid>>)]
+    pub songs: Vec<Uuid>,
+}
+
+impl Full {
+    pub async fn try_into(self, database: &Database) -> Result<id3::album::Full, Error> {
+        let song = song::query::unchecked()
+            .filter(songs::id.eq_any(self.songs))
+            .get_results(&mut database.get().await?)
+            .await?;
+        let duration = song.duration()?;
+        let song: Vec<_> = song.into_iter().map(song::Song::try_into).try_collect()?;
+
+        let album = self
+            .album
+            .try_into_builder()?
+            .song_count(song.len().try_into()?)
+            .duration(duration)
+            .build();
+
+        Ok(id3::album::Full {
+            album,
+            artists: self.artists.into(),
+            is_compilation: self.is_compilation,
+            song,
+        })
+    }
+}
+
+pub mod query {
+    use diesel::dsl::{auto_type, AsSelect};
+
+    use super::*;
+    use crate::orm::id3::album;
+    use crate::orm::{albums, permission, songs, songs_album_artists};
+
+    #[auto_type]
+    pub fn unchecked() -> _ {
+        let full: AsSelect<Full, crate::orm::Type> = Full::as_select();
+        album::query::unchecked_no_group_by()
+            .inner_join(songs_album_artists::table.on(songs_album_artists::song_id.eq(songs::id)))
+            .inner_join(artist::required::query::album())
+            .group_by(albums::id)
+            .select(full)
+    }
+
+    #[auto_type]
+    pub fn with_user_id(user_id: Uuid) -> _ {
+        let permission: permission::with_album = permission::with_album(user_id);
+        unchecked().filter(permission)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use diesel_async::RunQueryDsl;
+    use fake::{Fake, Faker};
+    use indexmap::IndexSet;
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::orm::albums;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+        #[values(true, false)] allow: bool,
+    ) {
+        mock.add_music_folder().allow(allow).call().await;
+        let mut music_folder = mock.music_folder(0).await;
+
+        let album: audio::Album = Faker.fake();
+        let album_id = album.upsert_mock(&mock, 0).await;
+        music_folder.add_audio().album(album.clone()).n_song((2..4).fake()).call().await;
+
+        let database_album = query::with_user_id(mock.user_id(0).await)
+            .filter(albums::id.eq(album_id))
+            .get_result(&mut mock.get().await)
+            .await;
+
+        if allow {
+            let database_album = database_album.unwrap();
+            assert_eq!(
+                database_album.songs.iter().collect::<IndexSet<_>>(),
+                music_folder.database.keys().collect::<IndexSet<_>>()
+            );
+        } else {
+            assert!(database_album.is_err());
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/id3/album/mod.rs b/nghe-backend/src/orm/id3/album/mod.rs
new file mode 100644
index 000000000..3b0c3ca99
--- /dev/null
+++ b/nghe-backend/src/orm/id3/album/mod.rs
@@ -0,0 +1,144 @@
+pub mod full;
+pub mod short;
+
+use diesel::dsl::sql;
+use diesel::expression::SqlLiteral;
+use diesel::prelude::*;
+use diesel::sql_types;
+use nghe_api::id3;
+use nghe_api::id3::builder::album as builder;
+use uuid::Uuid;
+
+use super::genre::Genres;
+use crate::orm::{albums, songs};
+use crate::Error;
+
+#[derive(Debug, Queryable, Selectable)]
+#[diesel(table_name = albums, check_for_backend(crate::orm::Type))]
+pub struct Album {
+    pub id: Uuid,
+    pub name: String,
+    #[diesel(select_expression = sql(
+        "coalesce(albums.cover_art_id, (array_remove(array_agg(songs.cover_art_id \
+        order by songs.disc_number asc nulls last, songs.track_number asc \
+        nulls last, songs.cover_art_id asc), null))[1]) cover_art_id"
+    ))]
+    #[diesel(select_expression_type = SqlLiteral<sql_types::Nullable<sql_types::Uuid>>)]
+    pub cover_art: Option<Uuid>,
+    #[diesel(embed)]
+    pub date: albums::date::Date,
+    #[diesel(column_name = mbz_id)]
+    pub music_brainz_id: Option<Uuid>,
+    #[diesel(embed)]
+    pub genres: Genres,
+    #[diesel(embed)]
+    pub original_release_date: albums::date::OriginalRelease,
+    #[diesel(embed)]
+    pub release_date: albums::date::Release,
+}
+
+pub type BuilderSet = builder::SetReleaseDate<
+    builder::SetOriginalReleaseDate<
+        builder::SetGenres<
+            builder::SetMusicBrainzId<
+                builder::SetYear<builder::SetCoverArt<builder::SetName<builder::SetId>>>,
+            >,
+        >,
+    >,
+>;
+
+impl Album {
+    pub fn try_into_builder(self) -> Result<builder::Builder<BuilderSet>, Error> {
+        Ok(id3::album::Album::builder()
+            .id(self.id)
+            .name(self.name)
+            .cover_art(self.cover_art)
+            .year(self.date.year.map(u16::try_from).transpose()?)
+            .music_brainz_id(self.music_brainz_id)
+            .genres(self.genres.into())
+            .original_release_date(self.original_release_date.try_into()?)
+            .release_date(self.release_date.try_into()?))
+    }
+}
+
+pub mod query {
+    use diesel::dsl::{auto_type, AsSelect};
+
+    use super::*;
+    use crate::orm::{genres, songs_genres};
+
+    #[auto_type]
+    pub fn unchecked_no_group_by() -> _ {
+        albums::table
+            .inner_join(songs::table)
+            .left_join(songs_genres::table.on(songs_genres::song_id.eq(songs::id)))
+            .left_join(genres::table.on(genres::id.eq(songs_genres::genre_id)))
+            .order_by(albums::name)
+    }
+
+    #[auto_type]
+    pub fn unchecked() -> _ {
+        let album: AsSelect<Album, crate::orm::Type> = Album::as_select();
+        unchecked_no_group_by().group_by(albums::id).select(album)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use diesel_async::RunQueryDsl;
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::{audio, picture};
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query_cover_art(
+        #[future(awt)] mock: Mock,
+        #[values(true, false)] has_picture: bool,
+        #[values(true, false)] has_dir_picture: bool,
+    ) {
+        let mut music_folder = mock.music_folder(0).await;
+
+        let (picture, picture_id) = if has_picture {
+            let picture: picture::Picture = Faker.fake();
+            let picture_id = picture.upsert_mock(&mock).await;
+            (Some(picture), Some(picture_id))
+        } else {
+            (None, None)
+        };
+
+        let (dir_picture, dir_picture_id) = if has_dir_picture {
+            let dir_picture: picture::Picture = Faker.fake();
+            let source = music_folder.path().join(dir_picture.property.format.name()).to_string();
+            let dir_picture = dir_picture.with_source(Some(source));
+            let dir_picture_id = dir_picture.upsert_mock(&mock).await;
+            (Some(dir_picture), Some(dir_picture_id))
+        } else {
+            (None, None)
+        };
+
+        let album: audio::Album = Faker.fake();
+
+        music_folder
+            .add_audio_filesystem::<&str>()
+            .album(album.clone())
+            .picture(picture)
+            .dir_picture(dir_picture)
+            .depth(0)
+            .n_song(10)
+            .call()
+            .await;
+
+        let album = query::unchecked().get_result(&mut mock.get().await).await.unwrap();
+        if has_dir_picture {
+            assert_eq!(album.cover_art, dir_picture_id);
+        } else if has_picture {
+            assert_eq!(album.cover_art, picture_id);
+        } else {
+            assert!(album.cover_art.is_none());
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/id3/album/short.rs b/nghe-backend/src/orm/id3/album/short.rs
new file mode 100644
index 000000000..1c3a13547
--- /dev/null
+++ b/nghe-backend/src/orm/id3/album/short.rs
@@ -0,0 +1,106 @@
+use diesel::prelude::*;
+use nghe_api::id3;
+use nghe_api::id3::builder::album as builder;
+
+use super::Album;
+use crate::orm::id3::duration::Trait as _;
+use crate::orm::id3::song;
+use crate::Error;
+
+#[derive(Debug, Queryable, Selectable)]
+pub struct Short {
+    #[diesel(embed)]
+    pub album: Album,
+    #[diesel(embed)]
+    pub durations: song::durations::Durations,
+}
+
+pub type BuilderSet = builder::SetDuration<builder::SetSongCount<super::BuilderSet>>;
+
+impl Short {
+    pub fn try_into_builder(self) -> Result<builder::Builder<BuilderSet>, Error> {
+        Ok(self
+            .album
+            .try_into_builder()?
+            .song_count(self.durations.count().try_into()?)
+            .duration(self.durations.duration()?))
+    }
+}
+
+impl TryFrom<Short> for id3::album::Album {
+    type Error = Error;
+
+    fn try_from(value: Short) -> Result<Self, Self::Error> {
+        Ok(value.try_into_builder()?.build())
+    }
+}
+
+pub mod query {
+    use diesel::dsl::{auto_type, AsSelect};
+    use uuid::Uuid;
+
+    use super::*;
+    use crate::orm::id3::album;
+    use crate::orm::{albums, permission};
+
+    #[auto_type]
+    pub fn unchecked() -> _ {
+        let short: AsSelect<Short, crate::orm::Type> = Short::as_select();
+        album::query::unchecked().select(short)
+    }
+
+    #[auto_type]
+    pub fn with_user_id(user_id: Uuid) -> _ {
+        let permission: permission::with_album = permission::with_album(user_id);
+        unchecked().filter(permission)
+    }
+
+    #[auto_type]
+    pub fn with_music_folder<'ids>(user_id: Uuid, music_folder_ids: &'ids [Uuid]) -> _ {
+        let with_user_id: with_user_id = with_user_id(user_id);
+        with_user_id.filter(albums::music_folder_id.eq_any(music_folder_ids))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use diesel_async::RunQueryDsl;
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::orm::albums;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query(#[future(awt)] mock: Mock, #[values(0, 2)] n_genre: usize) {
+        let mut music_folder = mock.music_folder(0).await;
+
+        let album: audio::Album = Faker.fake();
+        let album_id = album.upsert_mock(&mock, 0).await;
+
+        let n_song = (2..4).fake();
+        music_folder
+            .add_audio()
+            .album(album)
+            .genres(fake::vec![String; n_genre].into_iter().collect())
+            .n_song(n_song)
+            .call()
+            .await;
+
+        let database_album = query::unchecked()
+            .filter(albums::id.eq(album_id))
+            .get_result(&mut mock.get().await)
+            .await
+            .unwrap();
+
+        assert_eq!(database_album.durations.count(), n_song);
+        assert_eq!(
+            database_album.durations.duration().unwrap(),
+            music_folder.database.duration().unwrap()
+        );
+        assert_eq!(database_album.album.genres.value.len(), n_genre);
+    }
+}
diff --git a/nghe-backend/src/orm/id3/artist/full.rs b/nghe-backend/src/orm/id3/artist/full.rs
new file mode 100644
index 000000000..c2e17e4a3
--- /dev/null
+++ b/nghe-backend/src/orm/id3/artist/full.rs
@@ -0,0 +1,139 @@
+use diesel::dsl::sql;
+use diesel::expression::SqlLiteral;
+use diesel::prelude::*;
+use diesel::sql_types;
+use diesel_async::RunQueryDsl;
+use nghe_api::id3;
+use uuid::Uuid;
+
+use super::super::album;
+use super::Artist;
+use crate::database::Database;
+use crate::orm::albums;
+use crate::Error;
+
+#[derive(Debug, Queryable, Selectable)]
+#[diesel(table_name = artists, check_for_backend(crate::orm::Type))]
+pub struct Full {
+    #[diesel(embed)]
+    pub artist: Artist,
+    #[diesel(select_expression = sql(
+        "array_remove(array_agg(distinct(albums.id)), null) album_ids"
+    ))]
+    #[diesel(select_expression_type = SqlLiteral::<sql_types::Array<sql_types::Uuid>>)]
+    pub albums: Vec<Uuid>,
+}
+
+impl Full {
+    pub async fn try_into(self, database: &Database) -> Result<id3::artist::Full, Error> {
+        Ok(id3::artist::Full {
+            artist: self.artist.try_into()?,
+            album: album::short::query::unchecked()
+                .filter(albums::id.eq_any(self.albums))
+                .get_results(&mut database.get().await?)
+                .await?
+                .into_iter()
+                .map(album::short::Short::try_into)
+                .try_collect()?,
+        })
+    }
+}
+
+pub mod query {
+    use diesel::dsl::{auto_type, AsSelect};
+    use uuid::Uuid;
+
+    use super::*;
+    use crate::orm::id3::artist;
+
+    #[auto_type]
+    pub fn with_user_id(user_id: Uuid) -> _ {
+        let artist: artist::query::with_user_id = artist::query::with_user_id(user_id);
+        let full: AsSelect<Full, crate::orm::Type> = Full::as_select();
+        artist.select(full)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use diesel_async::RunQueryDsl;
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::schema::artists;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query_artist(#[future(awt)] mock: Mock, #[values(0, 6)] n_album: i64) {
+        let artist: audio::Artist = Faker.fake();
+        let artist_id = artist.upsert_mock(&mock).await;
+
+        mock.add_audio_artist(0, [artist.clone()], [Faker.fake()], false, 1).await;
+        mock.add_audio_artist(
+            0,
+            [Faker.fake()],
+            [artist.clone()],
+            false,
+            n_album.try_into().unwrap(),
+        )
+        .await;
+
+        let database_artist = query::with_user_id(mock.user_id(0).await)
+            .filter(artists::id.eq(artist_id))
+            .get_result(&mut mock.get().await)
+            .await
+            .unwrap();
+
+        assert_eq!(database_artist.artist.album_count, n_album);
+        let n_album: usize = n_album.try_into().unwrap();
+        assert_eq!(database_artist.albums.len(), n_album);
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query_partial(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+        #[values(true, false)] allow: bool,
+    ) {
+        mock.add_music_folder().allow(allow).call().await;
+        mock.add_music_folder().call().await;
+
+        let artist: audio::Artist = Faker.fake();
+        let artist_id = artist.upsert_mock(&mock).await;
+
+        let n_album = (2..4).fake();
+
+        let album: audio::Album = Faker.fake();
+        let album_id = album.upsert_mock(&mock, 0).await;
+        mock.music_folder(0)
+            .await
+            .add_audio()
+            .album(album)
+            .artists(audio::Artists {
+                album: [artist.clone()].into(),
+                compilation: false,
+                ..Faker.fake()
+            })
+            .call()
+            .await;
+
+        mock.add_audio_artist(1, [Faker.fake()], [artist.clone()], false, n_album).await;
+
+        let database_artist = query::with_user_id(mock.user_id(0).await)
+            .filter(artists::id.eq(artist_id))
+            .get_result(&mut mock.get().await)
+            .await
+            .unwrap();
+
+        let n_album = if allow { n_album + 1 } else { n_album };
+        assert_eq!(database_artist.albums.len(), n_album);
+        let n_album: i64 = n_album.try_into().unwrap();
+        assert_eq!(database_artist.artist.album_count, n_album);
+        assert_eq!(database_artist.albums.contains(&album_id), allow);
+    }
+}
diff --git a/nghe-backend/src/orm/id3/artist/mod.rs b/nghe-backend/src/orm/id3/artist/mod.rs
new file mode 100644
index 000000000..2bbc41c80
--- /dev/null
+++ b/nghe-backend/src/orm/id3/artist/mod.rs
@@ -0,0 +1,242 @@
+pub mod full;
+pub mod required;
+
+use diesel::dsl::count_distinct;
+use diesel::prelude::*;
+use nghe_api::id3;
+use nghe_api::id3::builder::artist as builder;
+pub use required::Required;
+use uuid::Uuid;
+
+use crate::orm::{albums, artists, songs};
+use crate::Error;
+
+#[derive(Debug, Queryable, Selectable)]
+#[diesel(table_name = artists, check_for_backend(crate::orm::Type))]
+#[cfg_attr(test, derive(PartialEq, Eq, fake::Dummy))]
+pub struct Artist {
+    #[diesel(embed)]
+    pub required: Required,
+    pub index: String,
+    #[diesel(select_expression = count_distinct(songs::id.nullable()))]
+    pub song_count: i64,
+    #[diesel(select_expression = count_distinct(albums::id.nullable()))]
+    pub album_count: i64,
+    #[diesel(column_name = mbz_id)]
+    pub music_brainz_id: Option<Uuid>,
+}
+
+pub type BuilderSet =
+    builder::SetRoles<builder::SetMusicBrainzId<builder::SetAlbumCount<builder::SetRequired>>>;
+
+impl Artist {
+    pub fn try_into_builder(self) -> Result<builder::Builder<BuilderSet>, Error> {
+        let mut roles = vec![];
+        if self.song_count > 0 {
+            roles.push(id3::artist::Role::Artist);
+        }
+        if self.album_count > 0 {
+            roles.push(id3::artist::Role::AlbumArtist);
+        }
+
+        Ok(id3::artist::Artist::builder()
+            .required(self.required.into())
+            .album_count(self.album_count.try_into()?)
+            .music_brainz_id(self.music_brainz_id)
+            .roles(roles))
+    }
+}
+
+impl TryFrom<Artist> for id3::artist::Artist {
+    type Error = Error;
+
+    fn try_from(value: Artist) -> Result<Self, Self::Error> {
+        Ok(value.try_into_builder()?.build())
+    }
+}
+
+pub mod query {
+    use diesel::dsl::{auto_type, exists, AsSelect};
+
+    use super::*;
+    use crate::orm::{songs_album_artists, songs_artists, user_music_folder_permissions};
+
+    diesel::alias!(albums as albums_sa: AlbumsSA, songs as songs_saa: SongsSAA);
+
+    #[auto_type]
+    fn unchecked() -> _ {
+        // We will do two joins:
+        //
+        //  - songs_artists -> songs -> albums.
+        //  - use songs for extrating information.
+        //  - use albums for checking permission -> use alias `albums_sa`.
+        //
+        //  - songs_album_artists -> songs -> albums.
+        //  - use albums for extracting information and checking permission.
+        //  - use songs for joining -> use alias `songs_saa`.
+        let artist: AsSelect<Artist, crate::orm::Type> = Artist::as_select();
+        artists::table
+            .left_join(songs_artists::table)
+            .left_join(songs::table.on(songs::id.eq(songs_artists::song_id)))
+            .left_join(albums_sa.on(albums_sa.field(albums::id).eq(songs::album_id)))
+            .left_join(songs_album_artists::table)
+            .left_join(songs_saa.on(songs_saa.field(songs::id).eq(songs_album_artists::song_id)))
+            .left_join(albums::table.on(albums::id.eq(songs_saa.field(songs::album_id))))
+            .group_by(artists::id)
+            .select(artist)
+    }
+
+    #[auto_type]
+    pub fn with_user_id(user_id: Uuid) -> _ {
+        // Permission should be checked against `albums_sa` and `albums`.
+        unchecked().filter(exists(
+            user_music_folder_permissions::table
+                .filter(user_music_folder_permissions::user_id.eq(user_id))
+                .filter(
+                    user_music_folder_permissions::music_folder_id
+                        .eq(albums_sa.field(albums::music_folder_id))
+                        .or(user_music_folder_permissions::music_folder_id
+                            .eq(albums::music_folder_id)),
+                ),
+        ))
+    }
+
+    #[auto_type]
+    pub fn with_music_folder<'ids>(user_id: Uuid, music_folder_ids: &'ids [Uuid]) -> _ {
+        // Permission should be checked against `albums_sa` and `albums`.
+        let with_user_id: with_user_id = with_user_id(user_id);
+        with_user_id.filter(
+            albums_sa
+                .field(albums::music_folder_id)
+                .eq_any(music_folder_ids)
+                .or(albums::music_folder_id.eq_any(music_folder_ids)),
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use diesel_async::RunQueryDsl;
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query_artist(
+        #[future(awt)] mock: Mock,
+        #[values(0, 5)] n_song: i64,
+        #[values(0, 6)] n_album: i64,
+        #[values(0, 7)] n_both: i64,
+    ) {
+        let artist: audio::Artist = Faker.fake();
+        let artist_id = artist.upsert_mock(&mock).await;
+
+        mock.add_audio_artist(
+            0,
+            [artist.clone()],
+            [Faker.fake()],
+            false,
+            n_song.try_into().unwrap(),
+        )
+        .await;
+        mock.add_audio_artist(
+            0,
+            [Faker.fake()],
+            [artist.clone()],
+            false,
+            n_album.try_into().unwrap(),
+        )
+        .await;
+        mock.add_audio_artist(
+            0,
+            [artist.clone()],
+            [artist.clone()],
+            false,
+            n_both.try_into().unwrap(),
+        )
+        .await;
+
+        let database_artist = query::with_user_id(mock.user_id(0).await)
+            .filter(artists::id.eq(artist_id))
+            .get_result(&mut mock.get().await)
+            .await;
+
+        if n_song == 0 && n_album == 0 && n_both == 0 {
+            assert!(database_artist.is_err());
+        } else {
+            let database_artist = database_artist.unwrap();
+            assert_eq!(database_artist.song_count, n_song + n_both);
+            assert_eq!(database_artist.album_count, n_album + n_both);
+        }
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query_artists(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+        #[values(true, false)] allow: bool,
+    ) {
+        let music_folder_id_permission = mock.add_music_folder().allow(allow).call().await;
+        let music_folder_id = mock.add_music_folder().call().await;
+
+        let user_id = mock.user_id(0).await;
+        let artist: audio::Artist = Faker.fake();
+        let artist_id = artist.upsert_mock(&mock).await;
+
+        let n_both: i64 = (2..4).fake();
+        mock.add_audio_artist(
+            0,
+            [artist.clone()],
+            [artist.clone()],
+            false,
+            n_both.try_into().unwrap(),
+        )
+        .await;
+        mock.add_audio_artist(0, [Faker.fake()], [Faker.fake()], false, (2..4).fake()).await;
+        mock.add_audio_artist(1, [Faker.fake()], [Faker.fake()], false, (2..4).fake()).await;
+
+        let database_artists =
+            query::with_user_id(user_id).get_results(&mut mock.get().await).await.unwrap();
+        assert_eq!(database_artists.len(), if allow { 5 } else { 2 });
+
+        // Only allow music folders will be returned.
+        let database_artists_music_folder =
+            query::with_music_folder(user_id, &[music_folder_id_permission, music_folder_id])
+                .get_results(&mut mock.get().await)
+                .await
+                .unwrap();
+        assert_eq!(database_artists, database_artists_music_folder);
+
+        let database_artist =
+            database_artists.into_iter().find(|artist| artist.required.id == artist_id);
+
+        if allow {
+            let database_artist = database_artist.unwrap();
+            assert_eq!(database_artist.song_count, n_both);
+            assert_eq!(database_artist.album_count, n_both);
+        } else {
+            assert!(database_artist.is_none());
+        }
+    }
+
+    #[rstest]
+    #[case(0, 0, &[])]
+    #[case(1, 0, &[id3::artist::Role::Artist])]
+    #[case(0, 1, &[id3::artist::Role::AlbumArtist])]
+    #[case(1, 1, &[id3::artist::Role::Artist, id3::artist::Role::AlbumArtist])]
+    fn test_try_into_api(
+        #[case] song_count: i64,
+        #[case] album_count: i64,
+        #[case] roles: &[id3::artist::Role],
+    ) {
+        let artist: id3::artist::Artist =
+            Artist { song_count, album_count, ..Faker.fake() }.try_into().unwrap();
+        assert_eq!(artist.roles, roles);
+    }
+}
diff --git a/nghe-backend/src/orm/id3/artist/required.rs b/nghe-backend/src/orm/id3/artist/required.rs
new file mode 100644
index 000000000..598449667
--- /dev/null
+++ b/nghe-backend/src/orm/id3/artist/required.rs
@@ -0,0 +1,72 @@
+use diesel::deserialize::{self, FromSql};
+use diesel::dsl::sql;
+use diesel::expression::SqlLiteral;
+use diesel::pg::PgValue;
+use diesel::prelude::*;
+use diesel::sql_types;
+use nghe_api::id3;
+use o2o::o2o;
+use uuid::Uuid;
+
+use crate::orm::artists;
+
+#[derive(Debug, Queryable, Selectable, o2o)]
+#[owned_into(id3::artist::Required)]
+#[diesel(table_name = artists, check_for_backend(crate::orm::Type))]
+#[cfg_attr(test, derive(PartialEq, Eq, fake::Dummy))]
+pub struct Required {
+    pub id: Uuid,
+    pub name: String,
+}
+
+pub type SqlType = sql_types::Record<(sql_types::Text, sql_types::Uuid)>;
+
+#[derive(Debug, Queryable, Selectable)]
+pub struct Artists {
+    #[diesel(select_expression = sql(
+        "array_agg(distinct (artists.name, artists.id) order by (artists.name, artists.id)) artists"
+    ))]
+    #[diesel(select_expression_type = SqlLiteral::<sql_types::Array<SqlType>>)]
+    pub value: Vec<Required>,
+}
+
+impl From<Artists> for Vec<id3::artist::Required> {
+    fn from(value: Artists) -> Self {
+        value.value.into_iter().map(Required::into).collect()
+    }
+}
+
+pub mod query {
+    use diesel::dsl::auto_type;
+
+    use super::*;
+    use crate::orm::{songs_album_artists, songs_artists};
+
+    #[auto_type]
+    pub fn album() -> _ {
+        artists::table.on(artists::id.eq(songs_album_artists::album_artist_id))
+    }
+
+    #[auto_type]
+    pub fn song() -> _ {
+        artists::table.on(artists::id.eq(songs_artists::artist_id))
+    }
+}
+
+impl FromSql<SqlType, crate::orm::Type> for Required {
+    fn from_sql(bytes: PgValue) -> deserialize::Result<Self> {
+        let (name, id) = FromSql::<SqlType, crate::orm::Type>::from_sql(bytes)?;
+        Ok(Self { id, name })
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    impl From<Artists> for Vec<String> {
+        fn from(value: Artists) -> Self {
+            value.value.into_iter().map(|artist| artist.name).collect()
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/id3/duration.rs b/nghe-backend/src/orm/id3/duration.rs
new file mode 100644
index 000000000..31a10edcd
--- /dev/null
+++ b/nghe-backend/src/orm/id3/duration.rs
@@ -0,0 +1,40 @@
+use std::ops::Add;
+
+use num_traits::ToPrimitive;
+
+use super::song;
+use crate::Error;
+
+pub trait Trait {
+    fn duration(&self) -> Result<u32, Error>;
+}
+
+impl Trait for f32 {
+    fn duration(&self) -> Result<u32, Error> {
+        self.ceil().to_u32().ok_or_else(|| Error::CouldNotConvertFloatToInteger(*self))
+    }
+}
+
+impl Trait for song::durations::Durations {
+    fn duration(&self) -> Result<u32, Error> {
+        self.value
+            .iter()
+            .copied()
+            .reduce(song::durations::Duration::add)
+            .ok_or_else(|| Error::DatabaseSongDurationIsEmpty)?
+            .value
+            .duration()
+    }
+}
+
+impl Trait for song::Song {
+    fn duration(&self) -> Result<u32, Error> {
+        self.property.duration.duration()
+    }
+}
+
+impl Trait for Vec<song::Song> {
+    fn duration(&self) -> Result<u32, Error> {
+        self.iter().map(|song| song.property.duration).sum::<f32>().duration()
+    }
+}
diff --git a/nghe-backend/src/orm/id3/genre/mod.rs b/nghe-backend/src/orm/id3/genre/mod.rs
new file mode 100644
index 000000000..70a11b020
--- /dev/null
+++ b/nghe-backend/src/orm/id3/genre/mod.rs
@@ -0,0 +1,23 @@
+pub mod with_count;
+
+use diesel::dsl::sql;
+use diesel::expression::SqlLiteral;
+use diesel::prelude::*;
+use diesel::sql_types;
+use nghe_api::id3;
+
+#[derive(Debug, Queryable, Selectable)]
+pub struct Genres {
+    // Be careful, order by in postgresql might be case-insensitive.
+    #[diesel(select_expression = sql(
+        "array_remove(array_agg(distinct genres.value order by genres.value), null) genres"
+    ))]
+    #[diesel(select_expression_type = SqlLiteral::<sql_types::Array<sql_types::Text>>)]
+    pub value: Vec<String>,
+}
+
+impl From<Genres> for id3::genre::Genres {
+    fn from(value: Genres) -> Self {
+        value.value.into_iter().collect()
+    }
+}
diff --git a/nghe-backend/src/orm/id3/genre/with_count.rs b/nghe-backend/src/orm/id3/genre/with_count.rs
new file mode 100644
index 000000000..f60408ab4
--- /dev/null
+++ b/nghe-backend/src/orm/id3/genre/with_count.rs
@@ -0,0 +1,42 @@
+use diesel::dsl::count_distinct;
+use diesel::prelude::*;
+use nghe_api::id3;
+use o2o::o2o;
+
+use crate::orm::{albums, genres, songs};
+use crate::Error;
+
+#[derive(Debug, Queryable, Selectable, o2o)]
+#[owned_try_into(id3::genre::WithCount, Error)]
+#[diesel(table_name = genres, check_for_backend(crate::orm::Type))]
+pub struct WithCount {
+    pub value: String,
+    #[into(~.try_into()?)]
+    #[diesel(select_expression = count_distinct(songs::id))]
+    pub song_count: i64,
+    #[into(~.try_into()?)]
+    #[diesel(select_expression = count_distinct(albums::id))]
+    pub album_count: i64,
+}
+
+pub mod query {
+    use diesel::dsl::{auto_type, AsSelect};
+    use uuid::Uuid;
+
+    use super::*;
+    use crate::orm::{permission, songs_genres};
+
+    #[auto_type]
+    pub fn with_user_id(user_id: Uuid) -> _ {
+        let with_count: AsSelect<WithCount, crate::orm::Type> = WithCount::as_select();
+        let permission: permission::with_album = permission::with_album(user_id);
+        genres::table
+            .inner_join(songs_genres::table)
+            .inner_join(songs::table.on(songs::id.eq(songs_genres::song_id)))
+            .inner_join(albums::table.on(albums::id.eq(songs::album_id)))
+            .filter(permission)
+            .group_by(genres::id)
+            .order_by(genres::value)
+            .select(with_count)
+    }
+}
diff --git a/nghe-backend/src/orm/id3/mod.rs b/nghe-backend/src/orm/id3/mod.rs
new file mode 100644
index 000000000..12dc93fdd
--- /dev/null
+++ b/nghe-backend/src/orm/id3/mod.rs
@@ -0,0 +1,7 @@
+#![allow(clippy::type_complexity)]
+
+pub mod album;
+pub mod artist;
+pub mod duration;
+pub mod genre;
+pub mod song;
diff --git a/nghe-backend/src/orm/id3/song/durations.rs b/nghe-backend/src/orm/id3/song/durations.rs
new file mode 100644
index 000000000..8433149a8
--- /dev/null
+++ b/nghe-backend/src/orm/id3/song/durations.rs
@@ -0,0 +1,46 @@
+use std::ops::Add;
+
+use diesel::deserialize::FromSql;
+use diesel::dsl::sql;
+use diesel::expression::SqlLiteral;
+use diesel::pg::PgValue;
+use diesel::prelude::*;
+use diesel::{deserialize, sql_types};
+use uuid::Uuid;
+
+#[derive(Debug, Clone, Copy)]
+pub struct Duration {
+    pub value: f32,
+}
+
+pub type SqlType = sql_types::Record<(sql_types::Uuid, sql_types::Float)>;
+
+#[derive(Debug, Queryable, Selectable)]
+pub struct Durations {
+    #[diesel(select_expression = sql(
+        "array_agg(distinct(songs.id, songs.duration)) song_id_durations"
+    ))]
+    #[diesel(select_expression_type = SqlLiteral::<sql_types::Array<SqlType>>)]
+    pub value: Vec<Duration>,
+}
+
+impl Add for Duration {
+    type Output = Duration;
+
+    fn add(self, rhs: Self) -> Self::Output {
+        Self::Output { value: self.value + rhs.value }
+    }
+}
+
+impl Durations {
+    pub fn count(&self) -> usize {
+        self.value.len()
+    }
+}
+
+impl FromSql<SqlType, crate::orm::Type> for Duration {
+    fn from_sql(bytes: PgValue) -> deserialize::Result<Self> {
+        let (_, value): (Uuid, f32) = FromSql::<SqlType, crate::orm::Type>::from_sql(bytes)?;
+        Ok(Self { value })
+    }
+}
diff --git a/nghe-backend/src/orm/id3/song/full.rs b/nghe-backend/src/orm/id3/song/full.rs
new file mode 100644
index 000000000..53956c4b2
--- /dev/null
+++ b/nghe-backend/src/orm/id3/song/full.rs
@@ -0,0 +1,115 @@
+use diesel::dsl::sql;
+use diesel::expression::SqlLiteral;
+use diesel::prelude::*;
+use diesel::sql_types;
+use nghe_api::id3;
+use o2o::o2o;
+use uuid::Uuid;
+
+use super::Song;
+use crate::orm::id3::genre;
+use crate::Error;
+
+#[derive(Debug, Queryable, Selectable, o2o)]
+#[owned_try_into(id3::song::Full, Error)]
+pub struct Full {
+    #[into(~.try_into()?)]
+    #[diesel(embed)]
+    pub song: Song,
+    #[diesel(select_expression = sql("any_value(albums.name) album_name"))]
+    #[diesel(select_expression_type = SqlLiteral<sql_types::Text>)]
+    pub album: String,
+    #[diesel(select_expression = sql("any_value(albums.id) album_id"))]
+    #[diesel(select_expression_type = SqlLiteral<sql_types::Uuid>)]
+    pub album_id: Uuid,
+    #[into(~.into())]
+    #[diesel(embed)]
+    pub genres: genre::Genres,
+}
+
+pub mod query {
+    use diesel::dsl::{auto_type, AsSelect};
+
+    use super::*;
+    use crate::orm::id3::song;
+    use crate::orm::{albums, genres, permission, songs, songs_genres};
+
+    #[auto_type]
+    pub fn unchecked() -> _ {
+        let full: AsSelect<Full, crate::orm::Type> = Full::as_select();
+        song::query::unchecked_no_group_by()
+            .left_join(songs_genres::table.on(songs_genres::song_id.eq(songs::id)))
+            .left_join(genres::table.on(genres::id.eq(songs_genres::genre_id)))
+            .group_by(songs::id)
+            .select(full)
+    }
+
+    #[auto_type]
+    pub fn with_user_id(user_id: Uuid) -> _ {
+        let permission: permission::with_album = permission::with_album(user_id);
+        unchecked().filter(permission)
+    }
+
+    #[auto_type]
+    pub fn with_music_folder<'ids>(user_id: Uuid, music_folder_ids: &'ids [Uuid]) -> _ {
+        let with_user_id: with_user_id = with_user_id(user_id);
+        with_user_id.filter(albums::music_folder_id.eq_any(music_folder_ids))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use diesel_async::RunQueryDsl;
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::orm::songs;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+        #[values(true, false)] allow: bool,
+        #[values(0, 2)] n_genre: usize,
+    ) {
+        mock.add_music_folder().allow(allow).call().await;
+        let mut music_folder = mock.music_folder(0).await;
+
+        let album: audio::Album = Faker.fake();
+        let album_id = album.upsert_mock(&mock, 0).await;
+        let artists: Vec<_> = (0..(2..4).fake()).map(|i| i.to_string()).collect();
+        music_folder
+            .add_audio()
+            .album(album.clone())
+            .artists(audio::Artists {
+                song: artists.clone().into_iter().map(String::into).collect(),
+                album: [Faker.fake()].into(),
+                compilation: false,
+            })
+            .genres(fake::vec![String; n_genre].into_iter().collect())
+            .call()
+            .await;
+        let song_id = music_folder.song_id(0);
+
+        let database_song = query::with_user_id(mock.user_id(0).await)
+            .filter(songs::id.eq(song_id))
+            .get_result(&mut mock.get().await)
+            .await;
+
+        if allow {
+            let database_song = database_song.unwrap();
+            let database_artists: Vec<String> = database_song.song.artists.into();
+            assert_eq!(database_song.album, album.name);
+            assert_eq!(database_song.album_id, album_id);
+            assert_eq!(database_artists, artists);
+            assert_eq!(database_song.genres.value.len(), n_genre);
+        } else {
+            assert!(database_song.is_err());
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/id3/song/mod.rs b/nghe-backend/src/orm/id3/song/mod.rs
new file mode 100644
index 000000000..8a4e92771
--- /dev/null
+++ b/nghe-backend/src/orm/id3/song/mod.rs
@@ -0,0 +1,220 @@
+pub mod durations;
+pub mod full;
+
+use diesel::dsl::sql;
+use diesel::expression::SqlLiteral;
+use diesel::prelude::*;
+use diesel::sql_types;
+use nghe_api::common::format::Trait as _;
+use nghe_api::id3;
+use nghe_api::id3::builder::song as builder;
+use uuid::Uuid;
+
+use super::artist;
+use super::duration::Trait as _;
+use crate::orm::songs;
+use crate::Error;
+
+#[derive(Debug, Queryable, Selectable)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+pub struct Song {
+    pub id: Uuid,
+    pub title: String,
+    #[diesel(embed)]
+    pub track: songs::position::Track,
+    #[diesel(embed)]
+    pub date: songs::date::Date,
+    #[diesel(select_expression = sql(
+        "coalesce(songs.cover_art_id, any_value(albums.cover_art_id)) cover_art_id"
+    ))]
+    #[diesel(select_expression_type = SqlLiteral<sql_types::Nullable<sql_types::Uuid>>)]
+    pub cover_art: Option<Uuid>,
+    #[diesel(embed)]
+    pub file: songs::property::File,
+    #[diesel(embed)]
+    pub property: songs::property::Property,
+    #[diesel(embed)]
+    pub disc: songs::position::Disc,
+    #[diesel(embed)]
+    pub artists: artist::required::Artists,
+    #[diesel(column_name = mbz_id)]
+    pub music_brainz_id: Option<Uuid>,
+}
+
+pub type BuilderSet = builder::SetMusicBrainzId<
+    builder::SetArtists<
+        builder::SetDiscNumber<
+            builder::SetChannelCount<
+                builder::SetSamplingRate<
+                    builder::SetBitDepth<
+                        builder::SetBitRate<
+                            builder::SetDuration<
+                                builder::SetSuffix<
+                                    builder::SetContentType<
+                                        builder::SetSize<
+                                            builder::SetCoverArt<
+                                                builder::SetYear<
+                                                    builder::SetTrack<
+                                                        builder::SetTitle<builder::SetId>,
+                                                    >,
+                                                >,
+                                            >,
+                                        >,
+                                    >,
+                                >,
+                            >,
+                        >,
+                    >,
+                >,
+            >,
+        >,
+    >,
+>;
+
+impl Song {
+    pub fn try_into_builder(self) -> Result<builder::Builder<BuilderSet>, Error> {
+        let duration = self.duration()?;
+        Ok(id3::song::Song::builder()
+            .id(self.id)
+            .title(self.title)
+            .track(self.track.number.map(u16::try_from).transpose()?)
+            .year(self.date.year.map(u16::try_from).transpose()?)
+            .cover_art(self.cover_art)
+            .size(self.file.size.cast_unsigned())
+            .content_type(self.file.format.mime())
+            .suffix(self.file.format.extension())
+            .duration(duration)
+            .bit_rate(self.property.bitrate.try_into()?)
+            .bit_depth(self.property.bit_depth.map(u8::try_from).transpose()?)
+            .sampling_rate(self.property.sample_rate.try_into()?)
+            .channel_count(self.property.channel_count.try_into()?)
+            .disc_number(self.disc.number.map(u16::try_from).transpose()?)
+            .artists(self.artists.into())
+            .music_brainz_id(self.music_brainz_id))
+    }
+}
+
+impl TryFrom<Song> for id3::song::Song {
+    type Error = Error;
+
+    fn try_from(value: Song) -> Result<Self, Self::Error> {
+        Ok(value.try_into_builder()?.build())
+    }
+}
+
+pub mod query {
+    use diesel::dsl::{auto_type, AsSelect};
+
+    use super::*;
+    use crate::orm::{albums, permission, songs_artists};
+
+    #[auto_type]
+    pub fn unchecked_no_group_by() -> _ {
+        songs::table
+            .inner_join(songs_artists::table)
+            .inner_join(albums::table)
+            .inner_join(artist::required::query::song())
+            .order_by((
+                songs::disc_number.asc().nulls_first(),
+                songs::track_number.asc().nulls_first(),
+                songs::title.asc(),
+            ))
+    }
+
+    #[auto_type]
+    pub fn unchecked() -> _ {
+        let song: AsSelect<Song, crate::orm::Type> = Song::as_select();
+        unchecked_no_group_by().group_by(songs::id).select(song)
+    }
+
+    #[auto_type]
+    pub fn with_user_id(user_id: Uuid) -> _ {
+        let permission: permission::with_album = permission::with_album(user_id);
+        unchecked().filter(permission)
+    }
+
+    #[auto_type]
+    pub fn with_music_folder<'ids>(user_id: Uuid, music_folder_ids: &'ids [Uuid]) -> _ {
+        let with_user_id: with_user_id = with_user_id(user_id);
+        with_user_id.filter(albums::music_folder_id.eq_any(music_folder_ids))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use diesel_async::RunQueryDsl;
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::picture;
+    use crate::orm::songs;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query(#[future(awt)] mock: Mock) {
+        let mut music_folder = mock.music_folder(0).await;
+
+        music_folder.add_audio_artist(["1".into(), "2".into()], [Faker.fake()], false, 1).await;
+        let song_id = music_folder.song_id(0);
+
+        let database_song = query::unchecked()
+            .filter(songs::id.eq(song_id))
+            .get_result(&mut mock.get().await)
+            .await
+            .unwrap();
+
+        let artists: Vec<String> = database_song.artists.into();
+        assert_eq!(artists, &["1", "2"]);
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query_cover_art(
+        #[future(awt)] mock: Mock,
+        #[values(true, false)] has_picture: bool,
+        #[values(true, false)] has_dir_picture: bool,
+    ) {
+        let mut music_folder = mock.music_folder(0).await;
+
+        let (picture, picture_id) = if has_picture {
+            let picture: picture::Picture = Faker.fake();
+            let picture_id = picture.upsert_mock(&mock).await;
+            (Some(picture), Some(picture_id))
+        } else {
+            (None, None)
+        };
+
+        let (dir_picture, dir_picture_id) = if has_dir_picture {
+            let dir_picture: picture::Picture = Faker.fake();
+            let source = music_folder.path().join(dir_picture.property.format.name()).to_string();
+            let dir_picture = dir_picture.with_source(Some(source));
+            let dir_picture_id = dir_picture.upsert_mock(&mock).await;
+            (Some(dir_picture), Some(dir_picture_id))
+        } else {
+            (None, None)
+        };
+
+        music_folder
+            .add_audio_filesystem::<&str>()
+            .album(Faker.fake())
+            .picture(picture)
+            .dir_picture(dir_picture)
+            .depth(0)
+            .n_song(10)
+            .call()
+            .await;
+
+        let songs = query::unchecked().get_results(&mut mock.get().await).await.unwrap();
+        for song in songs {
+            if has_picture {
+                assert_eq!(song.cover_art, picture_id);
+            } else if has_dir_picture {
+                assert_eq!(song.cover_art, dir_picture_id);
+            } else {
+                assert!(song.cover_art.is_none());
+            }
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/mod.rs b/nghe-backend/src/orm/mod.rs
new file mode 100644
index 000000000..8b4082bad
--- /dev/null
+++ b/nghe-backend/src/orm/mod.rs
@@ -0,0 +1,20 @@
+pub mod albums;
+pub mod artists;
+pub mod binary;
+pub mod configs;
+pub mod cover_arts;
+pub mod function;
+pub mod genres;
+pub mod id3;
+pub mod music_folders;
+pub mod permission;
+pub mod playbacks;
+pub mod songs;
+pub mod songs_album_artists;
+pub mod songs_artists;
+pub mod songs_genres;
+pub mod upsert;
+pub mod user_music_folder_permissions;
+pub mod users;
+
+pub type Type = diesel::pg::Pg;
diff --git a/nghe-backend/src/orm/music_folders.rs b/nghe-backend/src/orm/music_folders.rs
new file mode 100644
index 000000000..b9b56b3a1
--- /dev/null
+++ b/nghe-backend/src/orm/music_folders.rs
@@ -0,0 +1,106 @@
+use std::borrow::Cow;
+
+use color_eyre::eyre::OptionExt;
+use diesel::deserialize::{self, FromSql, FromSqlRow};
+use diesel::expression::AsExpression;
+use diesel::pg::PgValue;
+use diesel::prelude::*;
+use diesel::serialize::{self, Output, ToSql};
+use diesel::sql_types::Int2;
+use nghe_api::music_folder::add::Request as AddRequest;
+use o2o::o2o;
+use strum::FromRepr;
+use uuid::Uuid;
+
+pub use crate::schema::music_folders::{self, *};
+
+#[repr(i16)]
+#[derive(Debug, Clone, Copy, FromRepr, AsExpression, FromSqlRow, PartialEq, Eq, o2o)]
+#[diesel(sql_type = Int2)]
+#[map_owned(nghe_api::common::filesystem::Type)]
+pub enum FilesystemType {
+    Local = 1,
+    S3 = 2,
+}
+
+#[derive(Debug, Clone, Queryable, Selectable)]
+#[diesel(table_name = music_folders, check_for_backend(crate::orm::Type))]
+pub struct Data<'a> {
+    pub path: Cow<'a, str>,
+    #[diesel(column_name = fs_type)]
+    pub ty: FilesystemType,
+}
+
+#[derive(Debug, Clone, Queryable, Selectable, Identifiable)]
+#[diesel(table_name = music_folders, check_for_backend(crate::orm::Type))]
+pub struct MusicFolder<'a> {
+    pub id: Uuid,
+    #[diesel(embed)]
+    pub data: Data<'a>,
+}
+
+#[derive(Debug, Insertable, AsChangeset, o2o)]
+#[from_ref(AddRequest)]
+#[diesel(table_name = music_folders, check_for_backend(crate::orm::Type))]
+pub struct Upsert<'a> {
+    #[from(AddRequest| Some((&~).into()))]
+    pub name: Option<Cow<'a, str>>,
+    #[from(AddRequest| Some((&~).into()))]
+    pub path: Option<Cow<'a, str>>,
+    #[from(AddRequest| Some(~.into()))]
+    #[diesel(column_name = fs_type)]
+    pub ty: Option<FilesystemType>,
+}
+
+impl ToSql<Int2, super::Type> for FilesystemType {
+    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, super::Type>) -> serialize::Result {
+        match self {
+            FilesystemType::Local => {
+                <i16 as ToSql<Int2, super::Type>>::to_sql(&(FilesystemType::Local as i16), out)
+            }
+            FilesystemType::S3 => {
+                <i16 as ToSql<Int2, super::Type>>::to_sql(&(FilesystemType::S3 as i16), out)
+            }
+        }
+    }
+}
+
+impl FromSql<Int2, super::Type> for FilesystemType {
+    fn from_sql(bytes: PgValue) -> deserialize::Result<Self> {
+        Ok(FilesystemType::from_repr(i16::from_sql(bytes)?)
+            .ok_or_eyre("Database filesystem type constraint violation")?)
+    }
+}
+
+impl Data<'_> {
+    pub fn into_owned(self) -> Data<'static> {
+        Data { path: self.path.into_owned().into(), ty: self.ty }
+    }
+}
+
+impl MusicFolder<'_> {
+    pub fn into_owned(self) -> MusicFolder<'static> {
+        MusicFolder { id: self.id, data: self.data.into_owned() }
+    }
+}
+
+mod query {
+    use diesel::{ExpressionMethods, QueryDsl, SelectableHelper};
+    use diesel_async::RunQueryDsl;
+    use uuid::Uuid;
+
+    use super::{music_folders, MusicFolder};
+    use crate::database::Database;
+    use crate::Error;
+
+    impl MusicFolder<'static> {
+        pub async fn query(database: &Database, id: Uuid) -> Result<Self, Error> {
+            music_folders::table
+                .filter(music_folders::id.eq(id))
+                .select(Self::as_select())
+                .get_result(&mut database.get().await?)
+                .await
+                .map_err(Error::from)
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/permission.rs b/nghe-backend/src/orm/permission.rs
new file mode 100644
index 000000000..a1bdc04e3
--- /dev/null
+++ b/nghe-backend/src/orm/permission.rs
@@ -0,0 +1,23 @@
+use diesel::dsl::{auto_type, exists};
+use diesel::{ExpressionMethods, QueryDsl};
+use uuid::Uuid;
+
+use super::{albums, music_folders, user_music_folder_permissions};
+
+#[auto_type]
+pub fn with_album(user_id: Uuid) -> _ {
+    exists(
+        user_music_folder_permissions::table
+            .filter(user_music_folder_permissions::user_id.eq(user_id))
+            .filter(user_music_folder_permissions::music_folder_id.eq(albums::music_folder_id)),
+    )
+}
+
+#[auto_type]
+pub fn with_music_folder(user_id: Uuid) -> _ {
+    exists(
+        user_music_folder_permissions::table
+            .filter(user_music_folder_permissions::user_id.eq(user_id))
+            .filter(user_music_folder_permissions::music_folder_id.eq(music_folders::id)),
+    )
+}
diff --git a/nghe-backend/src/orm/playbacks.rs b/nghe-backend/src/orm/playbacks.rs
new file mode 100644
index 000000000..18dc86cd2
--- /dev/null
+++ b/nghe-backend/src/orm/playbacks.rs
@@ -0,0 +1,41 @@
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+use time::OffsetDateTime;
+use uuid::Uuid;
+
+pub use crate::schema::playbacks::{self, *};
+
+#[derive(Insertable, AsChangeset)]
+#[diesel(table_name = playbacks)]
+#[diesel(check_for_backend(diesel::pg::Pg))]
+pub struct Scrobble {
+    pub user_id: Uuid,
+    pub song_id: Uuid,
+    pub updated_at: OffsetDateTime,
+}
+
+mod upsert {
+    use diesel::upsert::excluded;
+    use diesel::ExpressionMethods;
+    use diesel_async::RunQueryDsl;
+
+    use super::{playbacks, Scrobble};
+    use crate::database::Database;
+    use crate::Error;
+
+    impl Scrobble {
+        pub async fn upsert(database: &Database, values: &[Self]) -> Result<(), Error> {
+            diesel::insert_into(playbacks::table)
+                .values(values)
+                .on_conflict((playbacks::user_id, playbacks::song_id))
+                .do_update()
+                .set((
+                    playbacks::count.eq(playbacks::count + 1),
+                    playbacks::updated_at.eq(excluded(playbacks::updated_at)),
+                ))
+                .execute(&mut database.get().await?)
+                .await?;
+            Ok(())
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/songs/date.rs b/nghe-backend/src/orm/songs/date.rs
new file mode 100644
index 000000000..94b80dca3
--- /dev/null
+++ b/nghe-backend/src/orm/songs/date.rs
@@ -0,0 +1,37 @@
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+
+use super::songs;
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Date {
+    pub year: Option<i16>,
+    pub month: Option<i16>,
+    pub day: Option<i16>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Release {
+    #[diesel(column_name = release_year)]
+    pub year: Option<i16>,
+    #[diesel(column_name = release_month)]
+    pub month: Option<i16>,
+    #[diesel(column_name = release_day)]
+    pub day: Option<i16>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct OriginalRelease {
+    #[diesel(column_name = original_release_year)]
+    pub year: Option<i16>,
+    #[diesel(column_name = original_release_month)]
+    pub month: Option<i16>,
+    #[diesel(column_name = original_release_day)]
+    pub day: Option<i16>,
+}
diff --git a/nghe-backend/src/orm/songs/mod.rs b/nghe-backend/src/orm/songs/mod.rs
new file mode 100644
index 000000000..a6fda5efe
--- /dev/null
+++ b/nghe-backend/src/orm/songs/mod.rs
@@ -0,0 +1,118 @@
+use std::borrow::Cow;
+use std::str::FromStr;
+
+use diesel::deserialize::{self, FromSql};
+use diesel::pg::PgValue;
+use diesel::prelude::*;
+use diesel::serialize::{self, Output, ToSql};
+use diesel::sql_types::Text;
+use diesel_derives::AsChangeset;
+use uuid::Uuid;
+
+use crate::file::audio;
+pub use crate::schema::songs::{self, *};
+
+pub mod date;
+pub mod name_date_mbz;
+pub mod position;
+pub mod property;
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+#[cfg_attr(test, derive(Default))]
+pub struct Foreign {
+    pub album_id: Uuid,
+    pub cover_art_id: Option<Uuid>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Song<'a> {
+    #[diesel(embed)]
+    pub main: name_date_mbz::NameDateMbz<'a>,
+    #[diesel(embed)]
+    pub track_disc: position::TrackDisc,
+    pub languages: Vec<Option<Cow<'a, str>>>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Data<'a> {
+    #[diesel(embed)]
+    pub song: Song<'a>,
+    #[diesel(embed)]
+    pub property: property::Property,
+    #[diesel(embed)]
+    pub file: property::File,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Upsert<'a> {
+    #[diesel(embed)]
+    pub foreign: Foreign,
+    pub relative_path: Cow<'a, str>,
+    #[diesel(embed)]
+    pub data: Data<'a>,
+}
+
+mod upsert {
+    use diesel::ExpressionMethods;
+    use diesel_async::RunQueryDsl;
+    use uuid::Uuid;
+
+    use super::{songs, Upsert};
+    use crate::database::Database;
+    use crate::Error;
+
+    impl crate::orm::upsert::Insert for Upsert<'_> {
+        async fn insert(&self, database: &Database) -> Result<Uuid, Error> {
+            diesel::insert_into(songs::table)
+                .values(self)
+                .returning(songs::id)
+                .get_result(&mut database.get().await?)
+                .await
+                .map_err(Error::from)
+        }
+    }
+
+    impl crate::orm::upsert::Update for Upsert<'_> {
+        async fn update(&self, database: &Database, id: Uuid) -> Result<(), Error> {
+            diesel::update(songs::table)
+                .filter(songs::id.eq(id))
+                .set(self)
+                .execute(&mut database.get().await?)
+                .await?;
+            Ok(())
+        }
+    }
+
+    impl crate::orm::upsert::Upsert for Upsert<'_> {}
+}
+
+impl ToSql<Text, super::Type> for audio::Format {
+    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, super::Type>) -> serialize::Result {
+        <str as ToSql<Text, super::Type>>::to_sql(self.into(), out)
+    }
+}
+
+impl FromSql<Text, super::Type> for audio::Format {
+    fn from_sql(bytes: PgValue) -> deserialize::Result<Self> {
+        Ok(audio::Format::from_str(core::str::from_utf8(bytes.as_bytes())?)?)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    impl From<Uuid> for Foreign {
+        fn from(value: Uuid) -> Self {
+            Self { album_id: value, ..Default::default() }
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/songs/name_date_mbz.rs b/nghe-backend/src/orm/songs/name_date_mbz.rs
new file mode 100644
index 000000000..cbf2980c1
--- /dev/null
+++ b/nghe-backend/src/orm/songs/name_date_mbz.rs
@@ -0,0 +1,22 @@
+use std::borrow::Cow;
+
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+use uuid::Uuid;
+
+use super::{date, songs};
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct NameDateMbz<'a> {
+    #[diesel(column_name = title)]
+    pub name: Cow<'a, str>,
+    #[diesel(embed)]
+    pub date: date::Date,
+    #[diesel(embed)]
+    pub release_date: date::Release,
+    #[diesel(embed)]
+    pub original_release_date: date::OriginalRelease,
+    pub mbz_id: Option<Uuid>,
+}
diff --git a/nghe-backend/src/orm/songs/position.rs b/nghe-backend/src/orm/songs/position.rs
new file mode 100644
index 000000000..a18456d94
--- /dev/null
+++ b/nghe-backend/src/orm/songs/position.rs
@@ -0,0 +1,34 @@
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+
+use super::songs;
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Track {
+    #[diesel(column_name = track_number)]
+    pub number: Option<i32>,
+    #[diesel(column_name = track_total)]
+    pub total: Option<i32>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Disc {
+    #[diesel(column_name = disc_number)]
+    pub number: Option<i32>,
+    #[diesel(column_name = disc_total)]
+    pub total: Option<i32>,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct TrackDisc {
+    #[diesel(embed)]
+    pub track: Track,
+    #[diesel(embed)]
+    pub disc: Disc,
+}
diff --git a/nghe-backend/src/orm/songs/property.rs b/nghe-backend/src/orm/songs/property.rs
new file mode 100644
index 000000000..82c34b4a8
--- /dev/null
+++ b/nghe-backend/src/orm/songs/property.rs
@@ -0,0 +1,39 @@
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+use o2o::o2o;
+
+use super::songs;
+use crate::file::{self, audio};
+use crate::Error;
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset, o2o)]
+#[try_map_owned(audio::Property, Error)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Property {
+    pub duration: f32,
+    #[map(~ as _)]
+    pub bitrate: i32,
+    #[from(~.map(i16::from))]
+    #[into(~.map(i16::try_into).transpose()?)]
+    pub bit_depth: Option<i16>,
+    #[map(~ as _)]
+    pub sample_rate: i32,
+    #[from(~.into())]
+    #[into(~.try_into()?)]
+    pub channel_count: i16,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset, o2o)]
+#[map_owned(file::Property<audio::Format>)]
+#[diesel(table_name = songs, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct File {
+    #[map(~ as _)]
+    #[diesel(column_name = file_hash)]
+    pub hash: i64,
+    #[map(~ as _)]
+    #[diesel(column_name = file_size)]
+    pub size: i32,
+    pub format: audio::Format,
+}
diff --git a/nghe-backend/src/orm/songs_album_artists.rs b/nghe-backend/src/orm/songs_album_artists.rs
new file mode 100644
index 000000000..18d3d9945
--- /dev/null
+++ b/nghe-backend/src/orm/songs_album_artists.rs
@@ -0,0 +1,14 @@
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+use uuid::Uuid;
+
+pub use crate::schema::songs_album_artists::{self, *};
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs_album_artists, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Data {
+    pub song_id: Uuid,
+    pub album_artist_id: Uuid,
+    pub compilation: bool,
+}
diff --git a/nghe-backend/src/orm/songs_artists.rs b/nghe-backend/src/orm/songs_artists.rs
new file mode 100644
index 000000000..1c6695832
--- /dev/null
+++ b/nghe-backend/src/orm/songs_artists.rs
@@ -0,0 +1,13 @@
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+use uuid::Uuid;
+
+pub use crate::schema::songs_artists::{self, *};
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs_artists, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Data {
+    pub song_id: Uuid,
+    pub artist_id: Uuid,
+}
diff --git a/nghe-backend/src/orm/songs_genres.rs b/nghe-backend/src/orm/songs_genres.rs
new file mode 100644
index 000000000..a9f99f63a
--- /dev/null
+++ b/nghe-backend/src/orm/songs_genres.rs
@@ -0,0 +1,13 @@
+use diesel::prelude::*;
+use diesel_derives::AsChangeset;
+use uuid::Uuid;
+
+pub use crate::schema::songs_genres::{self, *};
+
+#[derive(Debug, Queryable, Selectable, Insertable, AsChangeset)]
+#[diesel(table_name = songs_genres, check_for_backend(crate::orm::Type))]
+#[diesel(treat_none_as_null = true)]
+pub struct Data {
+    pub song_id: Uuid,
+    pub genre_id: Uuid,
+}
diff --git a/nghe-backend/src/orm/upsert.rs b/nghe-backend/src/orm/upsert.rs
new file mode 100644
index 000000000..e3ad5247e
--- /dev/null
+++ b/nghe-backend/src/orm/upsert.rs
@@ -0,0 +1,27 @@
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::Error;
+
+pub trait Insert {
+    async fn insert(&self, database: &Database) -> Result<Uuid, Error>;
+}
+
+pub trait Update {
+    async fn update(&self, database: &Database, id: Uuid) -> Result<(), Error>;
+}
+
+pub trait Upsert: Insert + Update + Sized {
+    async fn upsert(
+        &self,
+        database: &Database,
+        id: impl Into<Option<Uuid>>,
+    ) -> Result<Uuid, Error> {
+        if let Some(id) = id.into() {
+            self.update(database, id).await?;
+            Ok(id)
+        } else {
+            self.insert(database).await
+        }
+    }
+}
diff --git a/nghe-backend/src/orm/user_music_folder_permissions.rs b/nghe-backend/src/orm/user_music_folder_permissions.rs
new file mode 100644
index 000000000..2eaa9f518
--- /dev/null
+++ b/nghe-backend/src/orm/user_music_folder_permissions.rs
@@ -0,0 +1,11 @@
+use diesel::prelude::*;
+use uuid::Uuid;
+
+pub use crate::schema::user_music_folder_permissions::{self, *};
+
+#[derive(Insertable)]
+#[diesel(table_name = user_music_folder_permissions, check_for_backend(super::Type))]
+pub struct New {
+    pub user_id: Uuid,
+    pub music_folder_id: Uuid,
+}
diff --git a/nghe-backend/src/orm/users.rs b/nghe-backend/src/orm/users.rs
new file mode 100644
index 000000000..1d5478f77
--- /dev/null
+++ b/nghe-backend/src/orm/users.rs
@@ -0,0 +1,48 @@
+use std::borrow::Cow;
+
+use diesel::prelude::*;
+use o2o::o2o;
+use uuid::Uuid;
+
+pub use crate::schema::users::{self, *};
+
+#[derive(Debug, Clone, Copy, Queryable, Selectable, Insertable, o2o)]
+#[diesel(table_name = users, check_for_backend(super::Type))]
+#[map_owned(nghe_api::user::Role)]
+pub struct Role {
+    #[diesel(column_name = admin_role)]
+    pub admin: bool,
+    #[diesel(column_name = stream_role)]
+    pub stream: bool,
+    #[diesel(column_name = download_role)]
+    pub download: bool,
+    #[diesel(column_name = share_role)]
+    pub share: bool,
+}
+
+#[derive(Debug, Queryable, Selectable)]
+#[diesel(table_name = users, check_for_backend(super::Type))]
+pub struct Auth<'a> {
+    pub id: Uuid,
+    pub password: Cow<'a, [u8]>,
+    #[diesel(embed)]
+    pub role: Role,
+}
+
+#[derive(Debug, Queryable, Selectable, Insertable)]
+#[diesel(table_name = users, check_for_backend(super::Type))]
+pub struct Data<'a> {
+    pub username: Cow<'a, str>,
+    pub password: Cow<'a, [u8]>,
+    pub email: Cow<'a, str>,
+    #[diesel(embed)]
+    pub role: Role,
+}
+
+#[derive(Debug, Queryable, Selectable, Identifiable)]
+#[diesel(table_name = users, check_for_backend(super::Type))]
+pub struct User<'a> {
+    pub id: Uuid,
+    #[diesel(embed)]
+    pub data: Data<'a>,
+}
diff --git a/nghe-backend/src/route/browsing/get_album.rs b/nghe-backend/src/route/browsing/get_album.rs
new file mode 100644
index 000000000..287c574f8
--- /dev/null
+++ b/nghe-backend/src/route/browsing/get_album.rs
@@ -0,0 +1,89 @@
+use diesel::{ExpressionMethods, QueryDsl};
+use diesel_async::RunQueryDsl;
+pub use nghe_api::browsing::get_album::{Request, Response};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{albums, id3};
+use crate::Error;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    Ok(Response {
+        album: id3::album::full::query::with_user_id(user_id)
+            .filter(albums::id.eq(request.id))
+            .get_result(&mut database.get().await?)
+            .await?
+            .try_into(database)
+            .await?,
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+    use id3::duration::Trait as _;
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_sorted(#[future(awt)] mock: Mock, #[values(true, false)] compilation: bool) {
+        let mut music_folder = mock.music_folder(0).await;
+
+        let album: audio::Album = Faker.fake();
+        let album_id = album.upsert_mock(&mock, 0).await;
+
+        let n_song = (2..4).fake();
+        for i in 0..n_song {
+            music_folder
+                .add_audio()
+                .album(album.clone())
+                .artists(audio::Artists {
+                    song: [i.to_string().into()].into(),
+                    album: [(i + 1).to_string().into()].into(),
+                    compilation,
+                })
+                .song(audio::Song {
+                    track_disc: audio::TrackDisc {
+                        track: audio::position::Position { number: Some(i + 1), ..Faker.fake() },
+                        disc: audio::position::Position { number: None, ..Faker.fake() },
+                    },
+                    ..Faker.fake()
+                })
+                .call()
+                .await;
+        }
+
+        let album = handler(mock.database(), mock.user_id(0).await, Request { id: album_id })
+            .await
+            .unwrap()
+            .album;
+
+        let artists: Vec<_> = album.artists.into_iter().map(|artist| artist.name).collect();
+        let expected_artists: Vec<_> = if compilation {
+            (0..=n_song).map(|i| i.to_string()).collect()
+        } else {
+            (0..n_song).map(|i| (i + 1).to_string()).collect()
+        };
+        assert_eq!(artists, expected_artists);
+        assert_eq!(album.is_compilation, compilation);
+
+        assert_eq!(album.album.duration, music_folder.database.duration().unwrap());
+
+        let n_song: usize = n_song.into();
+        assert_eq!(album.song.len(), n_song);
+        for (i, song) in album.song.into_iter().enumerate() {
+            let track: u16 = (i + 1).try_into().unwrap();
+            assert_eq!(song.track.unwrap(), track);
+        }
+    }
+}
diff --git a/nghe-backend/src/route/browsing/get_album_info2.rs b/nghe-backend/src/route/browsing/get_album_info2.rs
new file mode 100644
index 000000000..5b8f04efe
--- /dev/null
+++ b/nghe-backend/src/route/browsing/get_album_info2.rs
@@ -0,0 +1,25 @@
+use diesel::{ExpressionMethods, QueryDsl};
+use diesel_async::RunQueryDsl;
+use nghe_api::browsing::get_album_info2::AlbumInfo;
+pub use nghe_api::browsing::get_album_info2::{Request, Response};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{albums, permission};
+use crate::Error;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    let music_brainz_id = albums::table
+        .filter(permission::with_album(user_id))
+        .filter(albums::id.eq(request.id))
+        .select(albums::mbz_id)
+        .get_result(&mut database.get().await?)
+        .await?;
+    Ok(Response { album_info: AlbumInfo { music_brainz_id } })
+}
diff --git a/nghe-backend/src/route/browsing/get_artist.rs b/nghe-backend/src/route/browsing/get_artist.rs
new file mode 100644
index 000000000..977d66cd1
--- /dev/null
+++ b/nghe-backend/src/route/browsing/get_artist.rs
@@ -0,0 +1,73 @@
+use diesel::{ExpressionMethods, QueryDsl};
+use diesel_async::RunQueryDsl;
+pub use nghe_api::browsing::get_artist::{Request, Response};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{artists, id3};
+use crate::Error;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    Ok(Response {
+        artist: id3::artist::full::query::with_user_id(user_id)
+            .filter(artists::id.eq(request.id))
+            .get_result(&mut database.get().await?)
+            .await?
+            .try_into(database)
+            .await?,
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+    use itertools::Itertools;
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_sorted(#[future(awt)] mock: Mock) {
+        let mut music_folder = mock.music_folder(0).await;
+
+        let artist: audio::Artist = Faker.fake();
+        let artist_id = artist.upsert_mock(&mock).await;
+
+        let n_album = (2..4).fake();
+        for i in 0..n_album {
+            music_folder
+                .add_audio()
+                .album(i.to_string().into())
+                .artists(audio::Artists {
+                    album: [artist.clone()].into(),
+                    compilation: false,
+                    ..Faker.fake()
+                })
+                .genres(fake::vec![String; 0..4].iter().map(|genre| genre.to_lowercase()).collect())
+                .call()
+                .await;
+        }
+
+        let artist = handler(mock.database(), mock.user_id(0).await, Request { id: artist_id })
+            .await
+            .unwrap()
+            .artist;
+
+        let n_album: usize = n_album.try_into().unwrap();
+        assert_eq!(artist.album.len(), n_album);
+        for (i, album) in artist.album.into_iter().enumerate() {
+            assert_eq!(album.name, i.to_string());
+            let genres = album.genres.value;
+            assert_eq!(genres, genres.iter().cloned().unique().sorted().collect::<Vec<_>>());
+        }
+    }
+}
diff --git a/nghe-backend/src/route/browsing/get_artist_info2.rs b/nghe-backend/src/route/browsing/get_artist_info2.rs
new file mode 100644
index 000000000..9b18c5bf0
--- /dev/null
+++ b/nghe-backend/src/route/browsing/get_artist_info2.rs
@@ -0,0 +1,24 @@
+use diesel::{ExpressionMethods, QueryDsl};
+use diesel_async::RunQueryDsl;
+use nghe_api::browsing::get_artist_info2::ArtistInfo2;
+pub use nghe_api::browsing::get_artist_info2::{Request, Response};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{artists, id3};
+use crate::Error;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    let music_brainz_id = id3::artist::query::with_user_id(user_id)
+        .filter(artists::id.eq(request.id))
+        .select(artists::mbz_id)
+        .get_result(&mut database.get().await?)
+        .await?;
+    Ok(Response { artist_info2: ArtistInfo2 { music_brainz_id } })
+}
diff --git a/nghe-backend/src/route/browsing/get_artists.rs b/nghe-backend/src/route/browsing/get_artists.rs
new file mode 100644
index 000000000..e994bdadd
--- /dev/null
+++ b/nghe-backend/src/route/browsing/get_artists.rs
@@ -0,0 +1,111 @@
+use diesel_async::RunQueryDsl;
+use itertools::Itertools;
+use nghe_api::browsing::get_artists::Artists;
+pub use nghe_api::browsing::get_artists::{Index, Request, Response};
+use nghe_proc_macro::{check_music_folder, handler};
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::id3;
+use crate::{config, Error};
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    let ignored_articles = database.get_config::<config::Index>().await?;
+
+    let artists =
+        #[check_music_folder]
+        id3::artist::query::with_user_id(user_id).get_results(&mut database.get().await?).await?;
+
+    let index = artists
+        .into_iter()
+        .into_group_map_by(|artist| artist.index.clone())
+        .into_iter()
+        .sorted_by(|lhs, rhs| Ord::cmp(&lhs.0, &rhs.0))
+        .map(|(name, artist)| {
+            Ok::<_, Error>(Index {
+                name,
+                artist: artist
+                    .into_iter()
+                    .sorted_by(|lhs, rhs| Ord::cmp(&lhs.required.name, &rhs.required.name))
+                    .map(id3::artist::Artist::try_into)
+                    .try_collect()?,
+            })
+        })
+        .try_collect()?;
+
+    Ok(Response { artists: Artists { ignored_articles, index } })
+}
+
+#[cfg(test)]
+mod tests {
+    use concat_string::concat_string;
+    use rstest::rstest;
+
+    use super::*;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_sorted(#[future(awt)] mock: Mock) {
+        mock.add_audio_artist(
+            0,
+            ["A1".into(), "A2".into(), "C1".into(), "C2".into()],
+            ["B1".into(), "B2".into()],
+            false,
+            1,
+        )
+        .await;
+
+        let index =
+            handler(mock.database(), mock.user_id(0).await, Request { music_folder_ids: None })
+                .await
+                .unwrap()
+                .artists
+                .index;
+
+        for (i, index) in index.into_iter().enumerate() {
+            let name =
+                char::from_u32((b'A' + u8::try_from(i).unwrap()).into()).unwrap().to_string();
+            assert_eq!(index.name, name);
+            for (j, artist) in index.artist.into_iter().enumerate() {
+                let name = concat_string!(&name, (j + 1).to_string());
+                assert_eq!(artist.required.name, name);
+            }
+        }
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_check_music_folder(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+    ) {
+        mock.add_music_folder().allow(false).call().await;
+        mock.add_music_folder().call().await;
+
+        let mut music_folder_deny = mock.music_folder(0).await;
+        let mut music_folder_allow = mock.music_folder(1).await;
+        music_folder_deny.add_audio().n_song(10).call().await;
+        music_folder_allow.add_audio().n_song(10).call().await;
+
+        let user_id = mock.user_id(0).await;
+        let with_user_id =
+            handler(mock.database(), user_id, Request { music_folder_ids: None }).await.unwrap();
+        let with_music_folder = handler(
+            mock.database(),
+            user_id,
+            Request {
+                music_folder_ids: Some(vec![music_folder_deny.id(), music_folder_allow.id()]),
+            },
+        )
+        .await
+        .unwrap();
+        assert_eq!(with_user_id, with_music_folder);
+    }
+}
diff --git a/nghe-backend/src/route/browsing/get_genres.rs b/nghe-backend/src/route/browsing/get_genres.rs
new file mode 100644
index 000000000..a012e86d8
--- /dev/null
+++ b/nghe-backend/src/route/browsing/get_genres.rs
@@ -0,0 +1,79 @@
+use diesel_async::RunQueryDsl;
+use nghe_api::browsing::get_genres::Genres;
+pub use nghe_api::browsing::get_genres::{Request, Response};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::id3;
+use crate::Error;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    Ok(Response {
+        genres: Genres {
+            genre: id3::genre::with_count::query::with_user_id(user_id)
+                .get_results(&mut database.get().await?)
+                .await?
+                .into_iter()
+                .map(id3::genre::with_count::WithCount::try_into)
+                .try_collect()?,
+        },
+    })
+}
+
+#[cfg(test)]
+mod test {
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_query(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+        #[values(true, false)] allow: bool,
+    ) {
+        mock.add_music_folder().allow(allow).call().await;
+        mock.add_music_folder().call().await;
+
+        let mut music_folder_permission = mock.music_folder(0).await;
+        let mut music_folder = mock.music_folder(1).await;
+
+        let genre: String = Faker.fake();
+
+        let n_song_permission = (2..4).fake();
+        let n_song = (2..4).fake();
+
+        music_folder_permission
+            .add_audio()
+            .genres([genre.clone(), Faker.fake()].into_iter().collect())
+            .n_song(n_song_permission)
+            .call()
+            .await;
+        music_folder
+            .add_audio()
+            .genres([genre.clone(), Faker.fake()].into_iter().collect())
+            .n_song(n_song)
+            .call()
+            .await;
+
+        let genres =
+            handler(mock.database(), mock.user_id(0).await, Request {}).await.unwrap().genres.genre;
+        assert_eq!(genres.len(), if allow { 3 } else { 2 });
+
+        let genre = genres.into_iter().find(|with_count| with_count.value == genre).unwrap();
+        let count: u32 =
+            (if allow { n_song_permission + n_song } else { n_song }).try_into().unwrap();
+        assert_eq!(genre.song_count, count);
+        assert_eq!(genre.album_count, count);
+    }
+}
diff --git a/nghe-backend/src/route/browsing/get_music_folders.rs b/nghe-backend/src/route/browsing/get_music_folders.rs
new file mode 100644
index 000000000..c385b4dfc
--- /dev/null
+++ b/nghe-backend/src/route/browsing/get_music_folders.rs
@@ -0,0 +1,66 @@
+use diesel::QueryDsl;
+use diesel_async::RunQueryDsl;
+pub use nghe_api::browsing::get_music_folders::{MusicFolder, MusicFolders, Request, Response};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{music_folders, permission};
+use crate::Error;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    Ok(Response {
+        music_folders: MusicFolders {
+            music_folder: music_folders::table
+                .filter(permission::with_music_folder(user_id))
+                .order_by(music_folders::created_at)
+                .select((music_folders::id, music_folders::name))
+                .get_results::<(Uuid, String)>(&mut database.get().await?)
+                .await?
+                .into_iter()
+                .map(|(id, name)| MusicFolder { id, name })
+                .collect(),
+        },
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use rstest::rstest;
+
+    use super::*;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_handler(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+        #[values(true, false)] allow: bool,
+    ) {
+        let music_folder_id_permission = mock.add_music_folder().allow(allow).call().await;
+        let music_folder_id = mock.add_music_folder().call().await;
+
+        let user_id = mock.user_id(0).await;
+        let music_folders = handler(mock.database(), user_id, Request {})
+            .await
+            .unwrap()
+            .music_folders
+            .music_folder
+            .into_iter()
+            .map(|music_folder| music_folder.id)
+            .collect::<Vec<_>>();
+
+        if allow {
+            assert_eq!(music_folders, &[music_folder_id_permission, music_folder_id]);
+        } else {
+            assert_eq!(music_folders, &[music_folder_id]);
+        }
+    }
+}
diff --git a/nghe-backend/src/route/browsing/get_song.rs b/nghe-backend/src/route/browsing/get_song.rs
new file mode 100644
index 000000000..095290909
--- /dev/null
+++ b/nghe-backend/src/route/browsing/get_song.rs
@@ -0,0 +1,73 @@
+use diesel::{ExpressionMethods, QueryDsl};
+use diesel_async::RunQueryDsl;
+pub use nghe_api::browsing::get_song::{Request, Response};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{id3, songs};
+use crate::Error;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    Ok(Response {
+        song: id3::song::full::query::with_user_id(user_id)
+            .filter(songs::id.eq(request.id))
+            .get_result(&mut database.get().await?)
+            .await?
+            .try_into()?,
+    })
+}
+
+#[cfg(test)]
+mod test {
+    use fake::{Fake, Faker};
+    use itertools::Itertools;
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_sorted(#[future(awt)] mock: Mock) {
+        let mut music_folder = mock.music_folder(0).await;
+
+        let album: audio::Album = Faker.fake();
+        let album_id = album.upsert_mock(&mock, 0).await;
+        let artists: Vec<_> = (0..(2..4).fake()).map(|i| i.to_string()).collect();
+        music_folder
+            .add_audio()
+            .album(album.clone())
+            .artists(audio::Artists {
+                song: artists.clone().into_iter().map(String::into).collect(),
+                album: [Faker.fake()].into(),
+                compilation: false,
+            })
+            .genres(fake::vec![String; 0..4].iter().map(|genre| genre.to_lowercase()).collect())
+            .call()
+            .await;
+        let song_id = music_folder.song_id(0);
+
+        let database_song =
+            handler(mock.database(), mock.user_id(0).await, Request { id: song_id })
+                .await
+                .unwrap()
+                .song;
+
+        assert_eq!(database_song.album, album.name);
+        assert_eq!(database_song.album_id, album_id);
+
+        let database_artists: Vec<_> =
+            database_song.song.artists.into_iter().map(|artist| artist.name).collect();
+        assert_eq!(database_artists, artists);
+
+        let genres = database_song.genres.value;
+        assert_eq!(genres, genres.iter().cloned().unique().sorted().collect::<Vec<_>>());
+    }
+}
diff --git a/nghe-backend/src/route/browsing/get_top_songs.rs b/nghe-backend/src/route/browsing/get_top_songs.rs
new file mode 100644
index 000000000..bca04dd92
--- /dev/null
+++ b/nghe-backend/src/route/browsing/get_top_songs.rs
@@ -0,0 +1,35 @@
+use diesel::dsl::sum;
+use diesel::{ExpressionMethods, JoinOnDsl, PgSortExpressionMethods as _, QueryDsl};
+use diesel_async::RunQueryDsl;
+use nghe_api::browsing::get_top_songs::TopSongs;
+pub use nghe_api::browsing::get_top_songs::{Request, Response};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{artists, id3, playbacks, songs};
+use crate::Error;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    // Since each playback count is accounted for a user, we make a sum here to get the total
+    // playback count.
+    Ok(Response {
+        top_songs: TopSongs {
+            song: id3::song::full::query::with_user_id(user_id)
+                .filter(artists::name.eq(request.artist))
+                .left_join(playbacks::table.on(playbacks::song_id.eq(songs::id)))
+                .order_by(sum(playbacks::count).desc().nulls_last())
+                .limit(request.count.unwrap_or(50).into())
+                .get_results(&mut database.get().await?)
+                .await?
+                .into_iter()
+                .map(id3::song::full::Full::try_into)
+                .try_collect()?,
+        },
+    })
+}
diff --git a/nghe-backend/src/route/browsing/mod.rs b/nghe-backend/src/route/browsing/mod.rs
new file mode 100644
index 000000000..b2c5f18df
--- /dev/null
+++ b/nghe-backend/src/route/browsing/mod.rs
@@ -0,0 +1,23 @@
+mod get_album;
+mod get_album_info2;
+mod get_artist;
+mod get_artist_info2;
+mod get_artists;
+mod get_genres;
+mod get_music_folders;
+mod get_song;
+mod get_top_songs;
+
+nghe_proc_macro::build_router! {
+    modules = [
+        get_album,
+        get_album_info2,
+        get_artist,
+        get_artist_info2,
+        get_artists,
+        get_genres,
+        get_music_folders,
+        get_song,
+        get_top_songs
+    ],
+}
diff --git a/nghe-backend/src/route/lists/get_album_list2.rs b/nghe-backend/src/route/lists/get_album_list2.rs
new file mode 100644
index 000000000..71e3354ec
--- /dev/null
+++ b/nghe-backend/src/route/lists/get_album_list2.rs
@@ -0,0 +1,87 @@
+use diesel::dsl::{max, sum};
+use diesel::{ExpressionMethods, JoinOnDsl, PgSortExpressionMethods as _, QueryDsl};
+use diesel_async::RunQueryDsl;
+use nghe_api::lists::get_album_list2::{AlbumList2, ByYear, Type};
+pub use nghe_api::lists::get_album_list2::{Request, Response};
+use nghe_proc_macro::{check_music_folder, handler};
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{albums, function, genres, id3, playbacks, songs};
+use crate::Error;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    #[check_music_folder]
+    {
+        let query = id3::album::short::query::with_user_id(user_id)
+            .limit(request.size.unwrap_or(10).into())
+            .offset(request.offset.unwrap_or(0).into());
+
+        let albums = match request.ty {
+            Type::Random => {
+                query.order_by(function::random()).get_results(&mut database.get().await?).await?
+            }
+            Type::Newest => {
+                query
+                    .order_by(albums::created_at.desc())
+                    .get_results(&mut database.get().await?)
+                    .await?
+            }
+            Type::Frequent => {
+                // Since each playback count is accounted for a song, we make a sum here to get the
+                // playback count of the whole album.
+                query
+                    .inner_join(playbacks::table.on(playbacks::song_id.eq(songs::id)))
+                    .filter(playbacks::user_id.eq(user_id))
+                    .order_by(sum(playbacks::count).desc().nulls_last())
+                    .get_results(&mut database.get().await?)
+                    .await?
+            }
+            Type::Recent => {
+                query
+                    .inner_join(playbacks::table.on(playbacks::song_id.eq(songs::id)))
+                    .filter(playbacks::user_id.eq(user_id))
+                    .order_by(max(playbacks::updated_at).desc().nulls_last())
+                    .get_results(&mut database.get().await?)
+                    .await?
+            }
+            Type::AlphabeticalByName => query.get_results(&mut database.get().await?).await?,
+            Type::ByYear(ByYear { from_year, to_year }) => {
+                let from_year: i16 = from_year.try_into()?;
+                let to_year: i16 = to_year.try_into()?;
+                if from_year < to_year {
+                    query
+                        .filter(albums::year.ge(from_year))
+                        .filter(albums::year.le(to_year))
+                        .order_by(albums::year.asc())
+                        .get_results(&mut database.get().await?)
+                        .await?
+                } else {
+                    query
+                        .filter(albums::year.ge(to_year))
+                        .filter(albums::year.le(from_year))
+                        .order_by(albums::year.desc())
+                        .get_results(&mut database.get().await?)
+                        .await?
+                }
+            }
+            Type::ByGenre { genre } => {
+                query
+                    .filter(genres::value.eq(genre))
+                    .get_results(&mut database.get().await?)
+                    .await?
+            }
+        };
+
+        Ok(Response {
+            album_list2: AlbumList2 {
+                album: albums.into_iter().map(id3::album::short::Short::try_into).try_collect()?,
+            },
+        })
+    }
+}
diff --git a/nghe-backend/src/route/lists/get_random_songs.rs b/nghe-backend/src/route/lists/get_random_songs.rs
new file mode 100644
index 000000000..56c766c99
--- /dev/null
+++ b/nghe-backend/src/route/lists/get_random_songs.rs
@@ -0,0 +1,48 @@
+use diesel::{BoolExpressionMethods, ExpressionMethods, QueryDsl};
+use diesel_async::RunQueryDsl;
+use nghe_api::lists::get_random_songs::RandomSong;
+pub use nghe_api::lists::get_random_songs::{Request, Response};
+use nghe_proc_macro::{check_music_folder, handler};
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{albums, function, genres, id3, songs};
+use crate::Error;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    #[check_music_folder]
+    {
+        let mut query = id3::song::full::query::with_user_id(user_id)
+            .limit(request.size.unwrap_or(10).into())
+            .order_by(function::random())
+            .into_boxed();
+
+        if let Some(genre) = request.genre {
+            query = query.filter(genres::value.eq(genre));
+        }
+        if let Some(from_year) = request.from_year {
+            let from_year: i16 = from_year.try_into()?;
+            query = query.filter(songs::year.ge(from_year).or(albums::year.ge(from_year)));
+        }
+        if let Some(to_year) = request.to_year {
+            let to_year: i16 = to_year.try_into()?;
+            query = query.filter(songs::year.le(to_year).or(albums::year.le(to_year)));
+        }
+
+        Ok(Response {
+            random_songs: RandomSong {
+                song: query
+                    .get_results(&mut database.get().await?)
+                    .await?
+                    .into_iter()
+                    .map(id3::song::full::Full::try_into)
+                    .try_collect()?,
+            },
+        })
+    }
+}
diff --git a/nghe-backend/src/route/lists/mod.rs b/nghe-backend/src/route/lists/mod.rs
new file mode 100644
index 000000000..5cfdb9118
--- /dev/null
+++ b/nghe-backend/src/route/lists/mod.rs
@@ -0,0 +1,6 @@
+mod get_album_list2;
+mod get_random_songs;
+
+nghe_proc_macro::build_router! {
+    modules = [get_album_list2, get_random_songs],
+}
diff --git a/nghe-backend/src/route/media_annotation/mod.rs b/nghe-backend/src/route/media_annotation/mod.rs
new file mode 100644
index 000000000..6a2df490e
--- /dev/null
+++ b/nghe-backend/src/route/media_annotation/mod.rs
@@ -0,0 +1,5 @@
+mod scrobble;
+
+nghe_proc_macro::build_router! {
+    modules = [scrobble],
+}
diff --git a/nghe-backend/src/route/media_annotation/scrobble.rs b/nghe-backend/src/route/media_annotation/scrobble.rs
new file mode 100644
index 000000000..95cac10c1
--- /dev/null
+++ b/nghe-backend/src/route/media_annotation/scrobble.rs
@@ -0,0 +1,136 @@
+use itertools::{EitherOrBoth, Itertools};
+pub use nghe_api::media_annotation::scrobble::{Request, Response};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::playbacks;
+use crate::Error;
+
+const MILLIS_TO_NANOS: i128 = 1_000_000;
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    let submission = request.submission.unwrap_or(true);
+    if submission {
+        let values: Vec<_> = request
+            .ids
+            .into_iter()
+            .zip_longest(request.times.unwrap_or_default())
+            .map(|data| match data {
+                EitherOrBoth::Both(song_id, updated_at) => {
+                    let updated_at: i128 = updated_at.into();
+                    let updated_at = time::OffsetDateTime::from_unix_timestamp_nanos(
+                        updated_at * MILLIS_TO_NANOS,
+                    )?;
+                    Ok(playbacks::Scrobble { user_id, song_id, updated_at })
+                }
+                EitherOrBoth::Left(song_id) => Ok(playbacks::Scrobble {
+                    user_id,
+                    song_id,
+                    updated_at: time::OffsetDateTime::now_utc(),
+                }),
+                EitherOrBoth::Right(_) => Err(Error::ScrobbleRequestMustHaveBeMoreIdThanTime),
+            })
+            .try_collect()?;
+        playbacks::Scrobble::upsert(database, &values).await?;
+    }
+
+    Ok(Response)
+}
+
+#[cfg(test)]
+mod tests {
+    use diesel::{ExpressionMethods, QueryDsl};
+    use diesel_async::RunQueryDsl;
+    use fake::faker::time::en::*;
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+    use time::macros::datetime;
+    use time::OffsetDateTime;
+
+    use super::*;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_scrobble(
+        #[future(awt)] mock: Mock,
+        #[values(2, 5)] n_song: usize,
+        #[values(0, 3)] n_time: usize,
+        #[values(10, 20)] n_play: usize,
+    ) {
+        let user_id = mock.user_id(0).await;
+
+        let mut music_folder = mock.music_folder(0).await;
+        music_folder.add_audio().n_song(n_song).call().await;
+        let ids: Vec<_> = music_folder.database.keys().copied().collect();
+
+        let start_dt = datetime!(2000-01-01 0:00 UTC);
+        let end_dt = datetime!(2020-01-01 0:00 UTC);
+        let times: Vec<_> = (0..n_time)
+            .map(|_| {
+                DateTimeBetween(start_dt, end_dt)
+                    .fake::<OffsetDateTime>()
+                    .replace_microsecond(0)
+                    .unwrap()
+            })
+            .collect();
+
+        for i in 0..n_play {
+            let times_u64 = if i < n_play - 1 {
+                if Faker.fake() {
+                    Some(fake::vec![
+                        u64 as 1_000_000_000_000..2_000_000_000_000;
+                        0..(n_song - (0..2).fake::<usize>())
+                    ])
+                } else {
+                    None
+                }
+            } else {
+                Some(
+                    times
+                        .iter()
+                        .map(|time| {
+                            (time.unix_timestamp_nanos() / MILLIS_TO_NANOS).try_into().unwrap()
+                        })
+                        .collect(),
+                )
+            };
+
+            let result = handler(
+                mock.database(),
+                user_id,
+                Request { ids: ids.clone(), times: times_u64, submission: None },
+            )
+            .await;
+            assert_eq!(result.is_ok(), i < n_play - 1 || n_song >= n_time);
+        }
+
+        for (i, id) in ids.into_iter().enumerate() {
+            let (count, time) = playbacks::table
+                .filter(playbacks::user_id.eq(user_id))
+                .filter(playbacks::song_id.eq(id))
+                .select((playbacks::count, playbacks::updated_at))
+                .get_result::<(i32, OffsetDateTime)>(&mut mock.get().await)
+                .await
+                .unwrap();
+
+            let count: usize = count.try_into().unwrap();
+            assert_eq!(count, if n_song >= n_time { n_play } else { n_play - 1 });
+
+            if n_song >= n_time {
+                if i >= n_time {
+                    let now = OffsetDateTime::now_utc();
+                    assert!((now - time).as_seconds_f32() < 1.0);
+                } else {
+                    assert_eq!(time, times[i]);
+                }
+            }
+        }
+    }
+}
diff --git a/nghe-backend/src/route/media_retrieval/download.rs b/nghe-backend/src/route/media_retrieval/download.rs
new file mode 100644
index 000000000..468efffab
--- /dev/null
+++ b/nghe-backend/src/route/media_retrieval/download.rs
@@ -0,0 +1,107 @@
+use axum_extra::headers::Range;
+pub use nghe_api::media_retrieval::download::Request;
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::file::{self, audio};
+use crate::filesystem::{self, Filesystem, Trait};
+use crate::http::binary;
+use crate::http::header::ToOffset;
+use crate::Error;
+
+pub async fn handler_impl(
+    filesystem: filesystem::Impl<'_>,
+    source: binary::Source<file::Property<audio::Format>>,
+    offset: Option<u64>,
+) -> Result<binary::Response, Error> {
+    filesystem.read_to_binary(&source, offset).await
+}
+
+#[handler(role = download, headers = [range])]
+pub async fn handler(
+    database: &Database,
+    filesystem: &Filesystem,
+    range: Option<Range>,
+    user_id: Uuid,
+    request: Request,
+) -> Result<binary::Response, Error> {
+    let (filesystem, source) =
+        binary::Source::audio(database, filesystem, user_id, request.id).await?;
+    let offset = range.map(|range| range.to_offset(source.property.size.into())).transpose()?;
+    handler_impl(filesystem, source, offset).await
+}
+
+#[cfg(test)]
+mod tests {
+    use axum::http::StatusCode;
+    use axum_extra::headers::{
+        AcceptRanges, CacheControl, ContentLength, ContentRange, ETag, HeaderMapExt,
+    };
+    use binary::property::Trait as _;
+    use nghe_api::common::filesystem;
+    use rstest::rstest;
+    use xxhash_rust::xxh3::xxh3_64;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::http::header::ToETag;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[case(None)]
+    #[case(Some(0))]
+    #[case(Some(500))]
+    #[tokio::test]
+    async fn test_download(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+        #[values(filesystem::Type::Local, filesystem::Type::S3)] ty: filesystem::Type,
+        #[values(true, false)] allow: bool,
+        #[case] offset: Option<u64>,
+    ) {
+        mock.add_music_folder().ty(ty).allow(allow).call().await;
+        let mut music_folder = mock.music_folder(0).await;
+        music_folder.add_audio_filesystem::<&str>().format(audio::Format::Flac).call().await;
+
+        let local_bytes =
+            music_folder.to_impl().read(music_folder.absolute_path(0).to_path()).await.unwrap();
+        let local_hash = xxh3_64(&local_bytes);
+        let local_bytes = &local_bytes[offset.unwrap_or(0).try_into().unwrap()..];
+
+        let range = offset.map(|offset| Range::bytes(offset..).unwrap());
+        let user_id = mock.user_id(0).await;
+        let request = Request { id: music_folder.song_id_filesystem(0).await };
+        let binary = handler(mock.database(), mock.filesystem(), range, user_id, request).await;
+
+        assert_eq!(binary.is_ok(), allow);
+
+        if allow {
+            let binary = binary.unwrap();
+            let (status, headers, body) = binary.extract().await;
+
+            let body_len: u64 = body.len().try_into().unwrap();
+            let offset = offset.unwrap_or(0);
+
+            assert_eq!(
+                status,
+                if offset == 0 { StatusCode::OK } else { StatusCode::PARTIAL_CONTENT }
+            );
+
+            assert_eq!(headers.typed_get::<ContentLength>().unwrap().0, body_len);
+            assert_eq!(
+                headers.typed_get::<ContentRange>().unwrap(),
+                ContentRange::bytes(offset.., Some(offset + body_len)).unwrap()
+            );
+            assert_eq!(headers.typed_get::<ETag>().unwrap(), local_hash.to_etag().unwrap());
+            assert_eq!(headers.typed_get::<AcceptRanges>().unwrap(), AcceptRanges::bytes());
+            assert_eq!(
+                headers.typed_get::<CacheControl>().unwrap(),
+                file::Property::<audio::Format>::cache_control()
+            );
+
+            assert_eq!(body, local_bytes);
+        }
+    }
+}
diff --git a/nghe-backend/src/route/media_retrieval/get_cover_art.rs b/nghe-backend/src/route/media_retrieval/get_cover_art.rs
new file mode 100644
index 000000000..13e634b7c
--- /dev/null
+++ b/nghe-backend/src/route/media_retrieval/get_cover_art.rs
@@ -0,0 +1,37 @@
+use axum_extra::headers::Range;
+use diesel::{ExpressionMethods, QueryDsl, SelectableHelper};
+use diesel_async::RunQueryDsl;
+pub use nghe_api::media_retrieval::get_cover_art::Request;
+use nghe_proc_macro::handler;
+
+use crate::database::Database;
+use crate::file::{self, picture};
+use crate::http::binary;
+use crate::http::header::ToOffset;
+use crate::orm::cover_arts;
+use crate::{config, Error};
+
+#[handler(role = download, headers = [range])]
+pub async fn handler(
+    database: &Database,
+    range: Option<Range>,
+    config: config::CoverArt,
+    request: Request,
+) -> Result<binary::Response, Error> {
+    let dir = &config.dir.ok_or_else(|| Error::MediaCoverArtDirIsNotEnabled)?;
+    let property: file::Property<picture::Format> = cover_arts::table
+        .filter(cover_arts::id.eq(request.id))
+        .select(cover_arts::Property::as_select())
+        .get_result(&mut database.get().await?)
+        .await?
+        .into();
+    let offset = range.map(|range| range.to_offset(property.size.into())).transpose()?;
+    binary::Response::from_path_property(
+        property.path(dir, picture::Picture::FILENAME),
+        &property,
+        offset,
+        #[cfg(test)]
+        None,
+    )
+    .await
+}
diff --git a/nghe-backend/src/route/media_retrieval/mod.rs b/nghe-backend/src/route/media_retrieval/mod.rs
new file mode 100644
index 000000000..27eb41c00
--- /dev/null
+++ b/nghe-backend/src/route/media_retrieval/mod.rs
@@ -0,0 +1,11 @@
+pub mod download;
+mod get_cover_art;
+mod stream;
+
+use crate::config;
+
+nghe_proc_macro::build_router! {
+    modules = [download, get_cover_art, stream],
+    filesystem = true,
+    extensions = [config::Transcode, config::CoverArt],
+}
diff --git a/nghe-backend/src/route/media_retrieval/stream.rs b/nghe-backend/src/route/media_retrieval/stream.rs
new file mode 100644
index 000000000..032ca7202
--- /dev/null
+++ b/nghe-backend/src/route/media_retrieval/stream.rs
@@ -0,0 +1,259 @@
+use axum_extra::headers::Range;
+pub use nghe_api::media_retrieval::stream::{Format, Request};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use super::download;
+use crate::database::Database;
+use crate::filesystem::{Filesystem, Trait};
+use crate::http::binary;
+use crate::http::header::ToOffset;
+#[cfg(test)]
+use crate::test::transcode::Status as TranscodeStatus;
+use crate::{config, transcode, Error};
+
+#[handler(role = stream, headers = [range])]
+pub async fn handler(
+    database: &Database,
+    filesystem: &Filesystem,
+    range: Option<Range>,
+    config: config::Transcode,
+    user_id: Uuid,
+    request: Request,
+) -> Result<binary::Response, Error> {
+    let (filesystem, source) =
+        binary::Source::audio(database, filesystem, user_id, request.id).await?;
+    let size_offset =
+        range.map(|range| range.to_offset(source.property.size.into())).transpose()?;
+
+    let bitrate = request.max_bit_rate.unwrap_or(32);
+    let time_offset = request.time_offset.unwrap_or(0);
+
+    let format = match request.format.unwrap_or_default() {
+        Format::Raw => return download::handler_impl(filesystem, source, size_offset).await,
+        Format::Transcode(format) => format,
+    };
+    let property = source.property.replace(format);
+    let source_path = source.path.to_path();
+
+    let transcode_config = if let Some(ref cache_dir) = config.cache_dir {
+        let output = property.path_create_dir(cache_dir, bitrate.to_string().as_str()).await?;
+
+        let span = tracing::Span::current();
+        let (can_acquire_lock, output) = tokio::task::spawn_blocking(move || {
+            let _entered = span.enter();
+            (transcode::Sink::lock_read(&output).is_ok(), output)
+        })
+        .await?;
+
+        // If local cache is turned on and we can acquire the read lock, it means that:
+        //  - The file exists.
+        //  - No process is writing to it. The transcoding process is finish.
+        //
+        // In that case, we have two cases:
+        //  - If time offset is greater than 0, we can use the transcoded file as transcoder input
+        //    so it only needs to activate `atrim` filter.
+        //  - Otherwise, we only need to stream the transcoded file from local cache.
+        // If the lock can not be acquired, we have two cases:
+        //  - If time offset is greater than 0, we spawn a transcoding process without writing it
+        //    back to the local cache.
+        //  - Otherwise, we spawn a transcoding process and let the sink tries acquiring the write
+        //    lock for further processing.
+        if can_acquire_lock {
+            if time_offset > 0 {
+                (
+                    output.as_str().to_owned(),
+                    None,
+                    #[cfg(test)]
+                    TranscodeStatus::UseCachedOutput,
+                )
+            } else {
+                return binary::Response::from_path(
+                    output,
+                    format,
+                    size_offset,
+                    #[cfg(test)]
+                    TranscodeStatus::ServeCachedOutput,
+                )
+                .await;
+            }
+        } else {
+            (
+                filesystem.transcode_input(source_path).await?,
+                if time_offset > 0 { None } else { Some(output) },
+                #[cfg(test)]
+                if time_offset > 0 { TranscodeStatus::NoCache } else { TranscodeStatus::WithCache },
+            )
+        }
+    } else {
+        (
+            filesystem.transcode_input(source_path).await?,
+            None,
+            #[cfg(test)]
+            TranscodeStatus::NoCache,
+        )
+    };
+
+    let input = transcode_config.0;
+    let output = transcode_config.1;
+
+    let (sink, rx) = transcode::Sink::new(&config, format, output).await?;
+    #[cfg(test)]
+    let transcode_status = sink.status(transcode_config.2);
+    transcode::Transcoder::spawn(input, sink, bitrate, time_offset)?;
+
+    binary::Response::from_rx(
+        rx,
+        format,
+        #[cfg(test)]
+        transcode_status,
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use axum::http::StatusCode;
+    use axum_extra::headers::HeaderMapExt;
+    use itertools::Itertools;
+    use nghe_api::common::{filesystem, format};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::file::audio;
+    use crate::test::transcode::{Header as TranscodeHeader, Status as TranscodeStatus};
+    use crate::test::{mock, Mock};
+
+    async fn spawn_stream(
+        mock: &Mock,
+        n_task: usize,
+        user_id: Uuid,
+        request: Request,
+    ) -> (Vec<(StatusCode, Vec<u8>)>, Vec<TranscodeStatus>) {
+        let mut stream_set = tokio::task::JoinSet::new();
+        for _ in 0..n_task {
+            let database = mock.database().clone();
+            let filesystem = mock.filesystem().clone();
+            let config = mock.config.transcode.clone();
+            stream_set.spawn(async move {
+                handler(&database, &filesystem, None, config, user_id, request)
+                    .await
+                    .unwrap()
+                    .extract()
+                    .await
+            });
+        }
+        let (responses, transcode_status): (Vec<_>, Vec<_>) = stream_set
+            .join_all()
+            .await
+            .into_iter()
+            .map(|(status, headers, body)| {
+                ((status, body), headers.typed_get::<TranscodeHeader>().unwrap().0)
+            })
+            .unzip();
+        (responses, transcode_status.into_iter().sorted().collect())
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_stream(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+        #[values(filesystem::Type::Local, filesystem::Type::S3)] ty: filesystem::Type,
+    ) {
+        mock.add_music_folder().ty(ty).call().await;
+        let mut music_folder = mock.music_folder(0).await;
+        music_folder.add_audio_filesystem::<&str>().format(audio::Format::Flac).call().await;
+
+        let user_id = mock.user_id(0).await;
+        let song_id = music_folder.song_id_filesystem(0).await;
+        let format = format::Transcode::Opus;
+        let bitrate = 32;
+
+        let transcoded = {
+            let path = music_folder.absolute_path(0);
+            let input = music_folder.to_impl().transcode_input(path.to_path()).await.unwrap();
+            let config = &mock.config.transcode;
+            transcode::Transcoder::spawn_collect(&input, config, format, bitrate, 0).await
+        };
+
+        let request = Request {
+            id: song_id,
+            max_bit_rate: Some(bitrate),
+            format: Some(format.into()),
+            time_offset: None,
+        };
+
+        let (responses, transcode_status) = spawn_stream(&mock, 2, user_id, request).await;
+        for (status, body) in responses {
+            assert_eq!(status, StatusCode::OK);
+            assert_eq!(transcoded, body);
+        }
+        assert_eq!(transcode_status, &[TranscodeStatus::NoCache, TranscodeStatus::WithCache]);
+
+        let (responses, transcode_status) = spawn_stream(&mock, 2, user_id, request).await;
+        for (status, body) in responses {
+            assert_eq!(status, StatusCode::OK);
+            assert_eq!(transcoded, body);
+        }
+        assert_eq!(
+            transcode_status,
+            &[TranscodeStatus::ServeCachedOutput, TranscodeStatus::ServeCachedOutput]
+        );
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_stream_time_offset(
+        #[future(awt)]
+        #[with(1, 0)]
+        mock: Mock,
+        #[values(filesystem::Type::Local, filesystem::Type::S3)] ty: filesystem::Type,
+    ) {
+        mock.add_music_folder().ty(ty).call().await;
+        let mut music_folder = mock.music_folder(0).await;
+        music_folder.add_audio_filesystem::<&str>().format(audio::Format::Flac).call().await;
+
+        let user_id = mock.user_id(0).await;
+        let song_id = music_folder.song_id_filesystem(0).await;
+        let format = format::Transcode::Opus;
+        let bitrate = 32;
+        let time_offset = 10;
+
+        let transcoded = {
+            let path = music_folder.absolute_path(0);
+            let input = music_folder.to_impl().transcode_input(path.to_path()).await.unwrap();
+            let config = &mock.config.transcode;
+            transcode::Transcoder::spawn_collect(&input, config, format, bitrate, time_offset).await
+        };
+
+        let request = Request {
+            id: song_id,
+            max_bit_rate: Some(bitrate),
+            format: Some(format.into()),
+            time_offset: Some(time_offset),
+        };
+
+        let (responses, transcode_status) = spawn_stream(&mock, 2, user_id, request).await;
+        for (status, body) in responses {
+            assert_eq!(status, StatusCode::OK);
+            assert_eq!(transcoded, body);
+        }
+        assert_eq!(transcode_status, &[TranscodeStatus::NoCache, TranscodeStatus::NoCache]);
+
+        let transcode_status =
+            spawn_stream(&mock, 1, user_id, Request { time_offset: None, ..request }).await.1;
+        assert_eq!(transcode_status, &[TranscodeStatus::WithCache]);
+
+        // We don't test the response body here because it does not take the same input as above.
+        // However, we want to make sure that the transcode status is equal to `UseCachedOutput`.
+        let (responses, transcode_status) = spawn_stream(&mock, 2, user_id, request).await;
+        for (status, _) in responses {
+            assert_eq!(status, StatusCode::OK);
+        }
+        assert_eq!(
+            transcode_status,
+            &[TranscodeStatus::UseCachedOutput, TranscodeStatus::UseCachedOutput]
+        );
+    }
+}
diff --git a/nghe-backend/src/route/mod.rs b/nghe-backend/src/route/mod.rs
new file mode 100644
index 000000000..84e4dcd06
--- /dev/null
+++ b/nghe-backend/src/route/mod.rs
@@ -0,0 +1,10 @@
+pub mod browsing;
+pub mod lists;
+pub mod media_annotation;
+pub mod media_retrieval;
+pub mod music_folder;
+pub mod permission;
+pub mod scan;
+pub mod search;
+pub mod system;
+pub mod user;
diff --git a/nghe-backend/src/route/music_folder/add.rs b/nghe-backend/src/route/music_folder/add.rs
new file mode 100644
index 000000000..5df7985e4
--- /dev/null
+++ b/nghe-backend/src/route/music_folder/add.rs
@@ -0,0 +1,62 @@
+use diesel_async::RunQueryDsl;
+pub use nghe_api::music_folder::add::{Request, Response};
+use nghe_proc_macro::handler;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::error::Error;
+use crate::filesystem::{self, Filesystem, Trait as _};
+use crate::orm::music_folders;
+use crate::route::permission;
+
+async fn handler_impl(
+    database: &Database,
+    filesystem: filesystem::Impl<'_>,
+    request: Request,
+) -> Result<Response, Error> {
+    filesystem.check_folder(request.path.as_str().into()).await?;
+
+    let music_folder_id = diesel::insert_into(music_folders::table)
+        .values(music_folders::Upsert::from(&request))
+        .returning(music_folders::id)
+        .get_result::<Uuid>(&mut database.get().await?)
+        .await?;
+
+    if request.allow {
+        permission::add::handler(
+            database,
+            permission::add::Request { user_id: None, music_folder_id: Some(music_folder_id) },
+        )
+        .await?;
+    }
+
+    Ok(Response { music_folder_id })
+}
+
+#[handler(role = admin)]
+pub async fn handler(
+    database: &Database,
+    filesystem: &Filesystem,
+    request: Request,
+) -> Result<Response, Error> {
+    handler_impl(database, filesystem.to_impl(request.ty)?, request).await
+}
+
+#[cfg(test)]
+mod tests {
+    use nghe_api::common::filesystem;
+    use rstest::rstest;
+
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_add(
+        #[future(awt)]
+        #[with(0, 0)]
+        mock: Mock,
+        #[values(filesystem::Type::Local, filesystem::Type::S3)] ty: filesystem::Type,
+    ) {
+        mock.add_music_folder().ty(ty).call().await;
+    }
+}
diff --git a/nghe-backend/src/route/music_folder/mod.rs b/nghe-backend/src/route/music_folder/mod.rs
new file mode 100644
index 000000000..0876564ab
--- /dev/null
+++ b/nghe-backend/src/route/music_folder/mod.rs
@@ -0,0 +1,6 @@
+pub mod add;
+
+nghe_proc_macro::build_router! {
+    modules = [add],
+    filesystem = true,
+}
diff --git a/nghe-backend/src/route/permission/add.rs b/nghe-backend/src/route/permission/add.rs
new file mode 100644
index 000000000..f9d77ec65
--- /dev/null
+++ b/nghe-backend/src/route/permission/add.rs
@@ -0,0 +1,101 @@
+use diesel::{sql_types, IntoSql, JoinOnDsl, QueryDsl};
+use diesel_async::RunQueryDsl;
+pub use nghe_api::permission::add::{Request, Response};
+use nghe_proc_macro::handler;
+
+use crate::database::Database;
+use crate::orm::{music_folders, user_music_folder_permissions, users};
+use crate::Error;
+
+#[handler(role = admin)]
+pub async fn handler(database: &Database, request: Request) -> Result<Response, Error> {
+    let Request { user_id, music_folder_id } = request;
+
+    if let Some(user_id) = user_id {
+        if let Some(music_folder_id) = music_folder_id {
+            let new = user_music_folder_permissions::New { user_id, music_folder_id };
+
+            diesel::insert_into(user_music_folder_permissions::table)
+                .values(new)
+                .on_conflict_do_nothing()
+                .execute(&mut database.get().await?)
+                .await?;
+        } else {
+            let new = music_folders::table
+                .select((user_id.into_sql::<sql_types::Uuid>(), music_folders::id));
+
+            diesel::insert_into(user_music_folder_permissions::table)
+                .values(new)
+                .into_columns((
+                    user_music_folder_permissions::user_id,
+                    user_music_folder_permissions::music_folder_id,
+                ))
+                .on_conflict_do_nothing()
+                .execute(&mut database.get().await?)
+                .await?;
+        }
+    } else if let Some(music_folder_id) = music_folder_id {
+        let new = users::table.select((users::id, music_folder_id.into_sql::<sql_types::Uuid>()));
+
+        diesel::insert_into(user_music_folder_permissions::table)
+            .values(new)
+            .into_columns((
+                user_music_folder_permissions::user_id,
+                user_music_folder_permissions::music_folder_id,
+            ))
+            .on_conflict_do_nothing()
+            .execute(&mut database.get().await?)
+            .await?;
+    } else if cfg!(test) {
+        let new = users::table
+            .inner_join(music_folders::table.on(true.into_sql::<sql_types::Bool>()))
+            .select((users::id, music_folders::id));
+
+        diesel::insert_into(user_music_folder_permissions::table)
+            .values(new)
+            .into_columns((
+                user_music_folder_permissions::user_id,
+                user_music_folder_permissions::music_folder_id,
+            ))
+            .on_conflict_do_nothing()
+            .execute(&mut database.get().await?)
+            .await?;
+    } else {
+        return Err(Error::InvalidParameter(
+            "The fields `user_id` and `music_folder_id` can not be both empty",
+        ));
+    }
+
+    Ok(Response)
+}
+
+#[cfg(test)]
+mod tests {
+    use rstest::rstest;
+
+    use super::*;
+    use crate::test::route::permission::{count, reset};
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[case(true, true, 1)]
+    #[case(true, false, 3)]
+    #[case(false, true, 2)]
+    #[case(false, false, 6)]
+    #[tokio::test]
+    async fn test_add(
+        #[future(awt)]
+        #[with(2, 3)]
+        mock: Mock,
+        #[case] with_user: bool,
+        #[case] with_music_folder: bool,
+        #[case] permission_count: usize,
+    ) {
+        reset(&mock).await;
+        let user_id = if with_user { Some(mock.user_id(0).await) } else { None };
+        let music_folder_id =
+            if with_music_folder { Some(mock.music_folder_id(0).await) } else { None };
+        assert!(handler(mock.database(), Request { user_id, music_folder_id }).await.is_ok());
+        assert_eq!(count(&mock).await, permission_count);
+    }
+}
diff --git a/nghe-backend/src/route/permission/mod.rs b/nghe-backend/src/route/permission/mod.rs
new file mode 100644
index 000000000..1ea12c8ef
--- /dev/null
+++ b/nghe-backend/src/route/permission/mod.rs
@@ -0,0 +1,5 @@
+pub mod add;
+
+nghe_proc_macro::build_router! {
+    modules = [add],
+}
diff --git a/nghe-backend/src/route/scan/mod.rs b/nghe-backend/src/route/scan/mod.rs
new file mode 100644
index 000000000..5e2dfb1d6
--- /dev/null
+++ b/nghe-backend/src/route/scan/mod.rs
@@ -0,0 +1,9 @@
+mod start;
+
+use crate::scan::scanner;
+
+nghe_proc_macro::build_router! {
+    modules = [start],
+    filesystem = true,
+    extensions = [scanner::Config],
+}
diff --git a/nghe-backend/src/route/scan/start.rs b/nghe-backend/src/route/scan/start.rs
new file mode 100644
index 000000000..8ec2daeaa
--- /dev/null
+++ b/nghe-backend/src/route/scan/start.rs
@@ -0,0 +1,24 @@
+pub use nghe_api::scan::start::{Request, Response};
+use nghe_proc_macro::handler;
+use tracing::Instrument;
+
+use crate::database::Database;
+use crate::filesystem::Filesystem;
+use crate::scan::scanner;
+use crate::Error;
+
+#[handler(role = admin)]
+pub async fn handler(
+    database: &Database,
+    filesystem: &Filesystem,
+    config: scanner::Config,
+    request: Request,
+) -> Result<Response, Error> {
+    let scanner = scanner::Scanner::new(database, filesystem, config, request.music_folder_id)
+        .await?
+        .into_owned();
+
+    let span = tracing::Span::current();
+    tokio::task::spawn(async move { scanner.run().await }.instrument(span));
+    Ok(Response)
+}
diff --git a/nghe-backend/src/route/search/mod.rs b/nghe-backend/src/route/search/mod.rs
new file mode 100644
index 000000000..a1daa66f3
--- /dev/null
+++ b/nghe-backend/src/route/search/mod.rs
@@ -0,0 +1,5 @@
+mod search3;
+
+nghe_proc_macro::build_router! {
+    modules = [search3],
+}
diff --git a/nghe-backend/src/route/search/search3.rs b/nghe-backend/src/route/search/search3.rs
new file mode 100644
index 000000000..7438d8058
--- /dev/null
+++ b/nghe-backend/src/route/search/search3.rs
@@ -0,0 +1,133 @@
+use diesel::{ExpressionMethods, QueryDsl};
+use diesel_async::RunQueryDsl;
+use diesel_full_text_search::configuration::TsConfigurationByName;
+use diesel_full_text_search::{
+    ts_rank_cd, websearch_to_tsquery_with_search_config, TsVectorExtensions,
+};
+use nghe_api::search::search3::SearchResult3;
+pub use nghe_api::search::search3::{Request, Response};
+use nghe_proc_macro::{check_music_folder, handler};
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::orm::{albums, artists, id3, songs};
+use crate::Error;
+
+const USIMPLE_TS_CONFIGURATION: TsConfigurationByName = TsConfigurationByName("usimple");
+
+#[handler]
+pub async fn handler(
+    database: &Database,
+    user_id: Uuid,
+    request: Request,
+) -> Result<Response, Error> {
+    let search_query = &request.query;
+    let sync = search_query.is_empty() || search_query == "\"\"";
+
+    #[check_music_folder]
+    {
+        let count = request.artist_count.unwrap_or(20).into();
+        let artist = if count > 0 {
+            let offset = request.artist_offset.unwrap_or(0).into();
+            let query = id3::artist::query::with_user_id(user_id).limit(count).offset(offset);
+            if sync {
+                query
+                    .order_by((artists::name, artists::mbz_id))
+                    .get_results(&mut database.get().await?)
+                    .await?
+            } else {
+                query
+                    .filter(artists::ts.matches(websearch_to_tsquery_with_search_config(
+                        USIMPLE_TS_CONFIGURATION,
+                        search_query,
+                    )))
+                    .order_by(
+                        ts_rank_cd(
+                            artists::ts,
+                            websearch_to_tsquery_with_search_config(
+                                USIMPLE_TS_CONFIGURATION,
+                                search_query,
+                            ),
+                        )
+                        .desc(),
+                    )
+                    .get_results(&mut database.get().await?)
+                    .await?
+            }
+        } else {
+            vec![]
+        };
+
+        let count = request.album_count.unwrap_or(20).into();
+        let album = if count > 0 {
+            let offset = request.album_offset.unwrap_or(0).into();
+            let query = id3::album::short::query::with_user_id(user_id).limit(count).offset(offset);
+            if sync {
+                query
+                    .order_by((albums::name, albums::mbz_id))
+                    .get_results(&mut database.get().await?)
+                    .await?
+            } else {
+                query
+                    .filter(albums::ts.matches(websearch_to_tsquery_with_search_config(
+                        USIMPLE_TS_CONFIGURATION,
+                        search_query,
+                    )))
+                    .order_by(
+                        ts_rank_cd(
+                            albums::ts,
+                            websearch_to_tsquery_with_search_config(
+                                USIMPLE_TS_CONFIGURATION,
+                                search_query,
+                            ),
+                        )
+                        .desc(),
+                    )
+                    .get_results(&mut database.get().await?)
+                    .await?
+            }
+        } else {
+            vec![]
+        };
+
+        let count = request.song_count.unwrap_or(20).into();
+        let song = if count > 0 {
+            let offset = request.song_offset.unwrap_or(0).into();
+            let query = id3::song::query::with_user_id(user_id).limit(count).offset(offset);
+            if sync {
+                query
+                    .order_by((songs::title, songs::mbz_id))
+                    .get_results(&mut database.get().await?)
+                    .await?
+            } else {
+                query
+                    .filter(songs::ts.matches(websearch_to_tsquery_with_search_config(
+                        USIMPLE_TS_CONFIGURATION,
+                        search_query,
+                    )))
+                    .order_by(
+                        ts_rank_cd(
+                            songs::ts,
+                            websearch_to_tsquery_with_search_config(
+                                USIMPLE_TS_CONFIGURATION,
+                                search_query,
+                            ),
+                        )
+                        .desc(),
+                    )
+                    .get_results(&mut database.get().await?)
+                    .await?
+            }
+        } else {
+            vec![]
+        };
+
+        Ok(Response {
+            search_result3: SearchResult3 {
+                artist: artist.into_iter().map(id3::artist::Artist::try_into).try_collect()?,
+                album: album.into_iter().map(id3::album::short::Short::try_into).try_collect()?,
+                song: song.into_iter().map(id3::song::Song::try_into).try_collect()?,
+            },
+        })
+    }
+}
diff --git a/nghe-backend/src/route/system/get_open_subsonic_extensions.rs b/nghe-backend/src/route/system/get_open_subsonic_extensions.rs
new file mode 100644
index 000000000..07a323e56
--- /dev/null
+++ b/nghe-backend/src/route/system/get_open_subsonic_extensions.rs
@@ -0,0 +1,17 @@
+use nghe_api::system::get_open_subsonic_extensions::Extension;
+pub use nghe_api::system::get_open_subsonic_extensions::{Request, Response};
+use nghe_proc_macro::handler;
+
+use crate::database::Database;
+use crate::Error;
+
+static EXTENSIONS: &[Extension] = &[
+    Extension { name: "transcodeOffset", versions: &[1] },
+    Extension { name: "songLyrics", versions: &[1] },
+    Extension { name: "formPost", versions: &[1] },
+];
+
+#[handler(need_auth = false, binary = false)]
+pub async fn handler(_database: &Database, request: Request) -> Result<Response, Error> {
+    Ok(Response { open_subsonic_extensions: EXTENSIONS })
+}
diff --git a/nghe-backend/src/route/system/mod.rs b/nghe-backend/src/route/system/mod.rs
new file mode 100644
index 000000000..90f8bd1d9
--- /dev/null
+++ b/nghe-backend/src/route/system/mod.rs
@@ -0,0 +1,6 @@
+mod get_open_subsonic_extensions;
+mod ping;
+
+nghe_proc_macro::build_router! {
+    modules = [get_open_subsonic_extensions { binary: false }, ping],
+}
diff --git a/nghe-backend/src/route/system/ping.rs b/nghe-backend/src/route/system/ping.rs
new file mode 100644
index 000000000..3a193e80b
--- /dev/null
+++ b/nghe-backend/src/route/system/ping.rs
@@ -0,0 +1,10 @@
+pub use nghe_api::system::ping::{Request, Response};
+use nghe_proc_macro::handler;
+
+use crate::database::Database;
+use crate::Error;
+
+#[handler]
+pub async fn handler(_database: &Database, request: Request) -> Result<Response, Error> {
+    Ok(Response)
+}
diff --git a/nghe-backend/src/route/user/create.rs b/nghe-backend/src/route/user/create.rs
new file mode 100644
index 000000000..9b7d4e541
--- /dev/null
+++ b/nghe-backend/src/route/user/create.rs
@@ -0,0 +1,54 @@
+use diesel_async::RunQueryDsl;
+pub use nghe_api::user::create::{Request, Response};
+use nghe_proc_macro::handler;
+
+use crate::database::Database;
+use crate::orm::users;
+use crate::route::permission;
+use crate::Error;
+
+#[handler(role = admin)]
+pub async fn handler(database: &Database, request: Request) -> Result<Response, Error> {
+    let Request { username, password, email, role, allow } = request;
+    let password = database.encrypt(password);
+
+    let user_id = diesel::insert_into(users::table)
+        .values(users::Data {
+            username: username.into(),
+            password: password.into(),
+            email: email.into(),
+            role: role.into(),
+        })
+        .returning(users::id)
+        .get_result(&mut database.get().await?)
+        .await?;
+
+    if allow {
+        permission::add::handler(
+            database,
+            permission::add::Request { user_id: Some(user_id), music_folder_id: None },
+        )
+        .await?;
+    }
+    Ok(Response { user_id })
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_create_user(
+        #[future(awt)]
+        #[with(0, 0)]
+        mock: Mock,
+    ) {
+        let user_id = handler(mock.database(), Faker.fake()).await.unwrap().user_id;
+        assert_eq!(mock.user_id(0).await, user_id);
+    }
+}
diff --git a/nghe-backend/src/route/user/mod.rs b/nghe-backend/src/route/user/mod.rs
new file mode 100644
index 000000000..74f053ef5
--- /dev/null
+++ b/nghe-backend/src/route/user/mod.rs
@@ -0,0 +1,6 @@
+pub mod create;
+mod setup;
+
+nghe_proc_macro::build_router! {
+    modules = [create, setup],
+}
diff --git a/nghe-backend/src/route/user/setup.rs b/nghe-backend/src/route/user/setup.rs
new file mode 100644
index 000000000..0aa89b8b2
--- /dev/null
+++ b/nghe-backend/src/route/user/setup.rs
@@ -0,0 +1,51 @@
+use diesel::QueryDsl;
+use diesel_async::RunQueryDsl;
+pub use nghe_api::user::setup::{Request, Response};
+use nghe_api::user::Role;
+use nghe_proc_macro::handler;
+
+use super::create;
+use crate::database::Database;
+use crate::orm::users;
+use crate::Error;
+
+#[handler(need_auth = false)]
+pub async fn handler(database: &Database, request: Request) -> Result<Response, Error> {
+    if users::table.count().first::<i64>(&mut database.get().await?).await? > 0 {
+        Err(Error::Unauthorized("Could not access setup endpoint when there is already one user"))
+    } else {
+        let Request { username, password, email } = request;
+        create::handler(
+            database,
+            create::Request {
+                username,
+                password,
+                email,
+                role: Role { admin: true, stream: true, download: true, share: true },
+                allow: false,
+            },
+        )
+        .await?;
+        Ok(Response)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+    use rstest::rstest;
+
+    use super::*;
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_setup(
+        #[future(awt)]
+        #[with(0, 0)]
+        mock: Mock,
+    ) {
+        assert!(handler(mock.database(), Faker.fake()).await.is_ok());
+        assert!(handler(mock.database(), Faker.fake()).await.is_err());
+    }
+}
diff --git a/nghe-backend/src/scan/mod.rs b/nghe-backend/src/scan/mod.rs
new file mode 100644
index 000000000..a8df477f0
--- /dev/null
+++ b/nghe-backend/src/scan/mod.rs
@@ -0,0 +1 @@
+pub mod scanner;
diff --git a/nghe-backend/src/scan/scanner.rs b/nghe-backend/src/scan/scanner.rs
new file mode 100644
index 000000000..d7e97645e
--- /dev/null
+++ b/nghe-backend/src/scan/scanner.rs
@@ -0,0 +1,416 @@
+use std::borrow::Cow;
+use std::sync::Arc;
+
+use diesel::{ExpressionMethods, NullableExpressionMethods, OptionalExtension, QueryDsl};
+use diesel_async::RunQueryDsl;
+use lofty::config::ParseOptions;
+use loole::Receiver;
+use tokio::sync::Semaphore;
+use tokio::task::JoinHandle;
+use tracing::{instrument, Instrument};
+use typed_path::Utf8TypedPath;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::file::{self, audio, picture, File};
+use crate::filesystem::{self, entry, Entry, Filesystem, Trait};
+use crate::orm::{albums, music_folders, songs};
+use crate::{config, Error};
+
+#[derive(Debug, Clone)]
+pub struct Config {
+    pub lofty: ParseOptions,
+    pub scan: config::filesystem::Scan,
+    pub parsing: config::Parsing,
+    pub index: config::Index,
+    pub cover_art: config::CoverArt,
+}
+
+#[derive(Clone)]
+pub struct Scanner<'db, 'fs, 'mf> {
+    pub database: Cow<'db, Database>,
+    pub filesystem: filesystem::Impl<'fs>,
+    pub config: Config,
+    pub music_folder: music_folders::MusicFolder<'mf>,
+}
+
+impl<'db, 'fs, 'mf> Scanner<'db, 'fs, 'mf> {
+    pub async fn new(
+        database: &'db Database,
+        filesystem: &'fs Filesystem,
+        config: Config,
+        music_folder_id: Uuid,
+    ) -> Result<Self, Error> {
+        Self::new_orm(
+            database,
+            filesystem,
+            config,
+            music_folders::MusicFolder::query(database, music_folder_id).await?,
+        )
+    }
+
+    pub fn new_orm(
+        database: &'db Database,
+        filesystem: &'fs Filesystem,
+        config: Config,
+        music_folder: music_folders::MusicFolder<'mf>,
+    ) -> Result<Self, Error> {
+        let filesystem = filesystem.to_impl(music_folder.data.ty.into())?;
+        Ok(Self { database: Cow::Borrowed(database), filesystem, config, music_folder })
+    }
+
+    pub fn into_owned(self) -> Scanner<'static, 'static, 'static> {
+        Scanner {
+            database: Cow::Owned(self.database.into_owned()),
+            filesystem: self.filesystem.into_owned(),
+            music_folder: self.music_folder.into_owned(),
+            ..self
+        }
+    }
+
+    fn path(&self) -> Utf8TypedPath {
+        self.filesystem.path().from_str(&self.music_folder.data.path)
+    }
+
+    fn relative_path<'entry>(&self, entry: &'entry Entry) -> Result<Utf8TypedPath<'entry>, Error> {
+        entry.path.strip_prefix(&self.music_folder.data.path).map_err(Error::from)
+    }
+
+    fn init(&self) -> (JoinHandle<Result<(), Error>>, Arc<Semaphore>, Receiver<Entry>) {
+        let config = self.config.scan;
+        let (tx, rx) = crate::sync::channel(config.channel_size);
+        let filesystem = self.filesystem.clone().into_owned();
+        let sender = entry::Sender { tx, minimum_size: config.minimum_size };
+        let prefix = self.path().to_path_buf();
+        (
+            tokio::spawn(async move { filesystem.scan_folder(sender, prefix.to_path()).await }),
+            Arc::new(Semaphore::const_new(config.pool_size)),
+            rx,
+        )
+    }
+
+    async fn set_scanned_at(
+        &self,
+        entry: &Entry,
+    ) -> Result<Option<(Uuid, time::OffsetDateTime)>, Error> {
+        let song_path = diesel::alias!(songs as song_path);
+        diesel::update(songs::table)
+            .filter(
+                songs::id.nullable().eq(song_path
+                    .inner_join(albums::table)
+                    .filter(albums::music_folder_id.eq(self.music_folder.id))
+                    .filter(
+                        song_path
+                            .field(songs::relative_path)
+                            .eq(entry.relative_path(&self.music_folder.data.path)?.as_str()),
+                    )
+                    .select(song_path.field(songs::id))
+                    .single_value()),
+            )
+            .set(songs::scanned_at.eq(time::OffsetDateTime::now_utc()))
+            .returning((songs::id, songs::updated_at))
+            .get_result(&mut self.database.get().await?)
+            .await
+            .optional()
+            .map_err(Error::from)
+    }
+
+    async fn query_hash_size(
+        &self,
+        property: &file::Property<audio::Format>,
+    ) -> Result<Option<(Uuid, String)>, Error> {
+        songs::table
+            .inner_join(albums::table)
+            .filter(albums::music_folder_id.eq(self.music_folder.id))
+            .filter(songs::file_hash.eq(property.hash.cast_signed()))
+            .filter(songs::file_size.eq(property.size.cast_signed()))
+            .select((songs::id, songs::relative_path))
+            .get_result(&mut self.database.get().await?)
+            .await
+            .optional()
+            .map_err(Error::from)
+    }
+
+    #[instrument(skip(self, started_at), ret(level = "debug"), err)]
+    async fn one(&self, entry: &Entry, started_at: time::OffsetDateTime) -> Result<(), Error> {
+        let database = &self.database;
+
+        // Query the database to see if we have any song within this music folder that has the same
+        // relative path. If yes, update its scanned at to the current time.
+        let song_id = if let Some((song_id, updated_at)) = self.set_scanned_at(entry).await? {
+            if entry.last_modified.is_some_and(|last_modified| last_modified < updated_at) {
+                // If its filesystem's last modified is sooner than its database's updated at, it
+                // means that we have the latest data, we can return the function.
+                return Ok(());
+            }
+            Some(song_id)
+        } else {
+            None
+        };
+
+        let file = File::new(entry.format, self.filesystem.read(entry.path.to_path()).await?)?;
+        let dir_picture_id = picture::Picture::scan(
+            &self.database,
+            &self.filesystem,
+            &self.config.cover_art,
+            entry.path.parent().ok_or_else(|| Error::AbsoluteFilePathDoesNotHaveParentDirectory)?,
+        )
+        .await?;
+
+        let relative_path = self.relative_path(entry)?;
+        let relative_path = relative_path.as_str();
+        if let Some((database_song_id, database_relative_path)) =
+            self.query_hash_size(&file.property).await?
+        {
+            if let Some(song_id) = song_id {
+                if song_id == database_song_id && relative_path == database_relative_path {
+                    // Everything is the same but the song's last modified for some reason, update
+                    // its updated at and return the function.
+                    diesel::update(songs::table)
+                        .filter(songs::id.eq(song_id))
+                        .set(songs::updated_at.eq(time::OffsetDateTime::now_utc()))
+                        .execute(&mut database.get().await?)
+                        .await?;
+                    return Ok(());
+                }
+                // Since `song_id` is queried only by music folder and relative path and there is a
+                // constraint `songs_album_id_file_hash_file_size_key`, other cases should be
+                // unreachable.
+                return Err(Error::DatabaseScanQueryInconsistent);
+            }
+            // We have one entry that is in the same music folder, same hash and size but
+            // different relative path (since song_id is none). We only need to update the relative
+            // path, set scanned at and return the function.
+            let album_id: Uuid = diesel::update(songs::table)
+                .filter(songs::id.eq(database_song_id))
+                .set((
+                    songs::relative_path.eq(relative_path),
+                    songs::scanned_at.eq(time::OffsetDateTime::now_utc()),
+                ))
+                .returning(songs::album_id)
+                .get_result(&mut database.get().await?)
+                .await?;
+            // We also need to set album cover_art_id since it might be added or removed after the
+            // previous scan.
+            diesel::update(albums::table)
+                .filter(albums::id.eq(album_id))
+                .set(albums::cover_art_id.eq(dir_picture_id))
+                .execute(&mut database.get().await?)
+                .await?;
+
+            tracing::warn!(
+                old = ?database_relative_path, new = ?relative_path, "renamed duplication"
+            );
+            return Ok(());
+        }
+
+        let audio = file.audio(self.config.lofty)?;
+        let information = audio.extract(&self.config.parsing)?;
+
+        let song_id = information
+            .upsert(
+                database,
+                &self.config,
+                albums::Foreign {
+                    music_folder_id: self.music_folder.id,
+                    cover_art_id: dir_picture_id,
+                },
+                relative_path,
+                song_id,
+            )
+            .await?;
+        audio::Information::cleanup_one(database, started_at, song_id).await?;
+
+        Ok(())
+    }
+
+    #[instrument(
+        skip(self), fields(music_folder_data = ?self.music_folder.data, started_at), ret, err
+    )]
+    pub async fn run(&self) -> Result<(), Error> {
+        let span = tracing::Span::current();
+        let started_at = crate::time::now().await;
+        span.record("started_at", tracing::field::display(&started_at));
+
+        let (scan_handle, permit, rx) = self.init();
+        let mut join_set = tokio::task::JoinSet::new();
+
+        while let Ok(entry) = rx.recv_async().await {
+            let permit = permit.clone().acquire_owned().await?;
+            let scan = self.clone().into_owned();
+            join_set.spawn(
+                async move {
+                    let _guard = permit;
+                    scan.one(&entry, started_at).await
+                }
+                .instrument(span.clone()),
+            );
+        }
+
+        while let Some(result) = join_set.join_next().await {
+            result??;
+        }
+        scan_handle.await??;
+
+        audio::Information::cleanup(&self.database, started_at).await?;
+
+        self.database.upsert_config(&self.config.index).await?;
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use fake::Fake;
+    use rstest::rstest;
+
+    use crate::test::{mock, Mock};
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_simple_scan(#[future(awt)] mock: Mock, #[values(0, 10, 50)] n_song: usize) {
+        let mut music_folder = mock.music_folder(0).await;
+        music_folder.add_audio_filesystem::<&str>().n_song(n_song).call().await;
+
+        let database_audio = music_folder.query_filesystem().await;
+        assert_eq!(database_audio, music_folder.filesystem);
+    }
+
+    // TODO: Make multiple scans work
+    #[allow(dead_code)]
+    async fn test_multiple_scan(mock: Mock) {
+        let mut music_folder = mock.music_folder(0).await;
+        music_folder.add_audio_filesystem::<&str>().n_song(20).scan(false).call().await;
+
+        let mut join_set = tokio::task::JoinSet::new();
+        for _ in 0..5 {
+            let scanner = music_folder.scan().into_owned();
+            join_set.spawn(async move { scanner.run().await.unwrap() });
+        }
+        join_set.join_all().await;
+
+        let database_audio = music_folder.query_filesystem().await;
+        assert_eq!(database_audio, music_folder.filesystem);
+    }
+
+    mod filesystem {
+        use super::*;
+
+        #[rstest]
+        #[tokio::test]
+        async fn test_overwrite(#[future(awt)] mock: Mock) {
+            let mut music_folder = mock.music_folder(0).await;
+
+            music_folder.add_audio_filesystem().path("test").call().await;
+            let database_audio = music_folder.query_filesystem().await;
+            assert_eq!(database_audio, music_folder.filesystem);
+
+            music_folder.add_audio_filesystem().path("test").call().await;
+            let database_audio = music_folder.query_filesystem().await;
+            assert_eq!(database_audio, music_folder.filesystem);
+        }
+
+        #[rstest]
+        #[tokio::test]
+        async fn test_remove(#[future(awt)] mock: Mock, #[values(true, false)] same_dir: bool) {
+            let mut music_folder = mock.music_folder(0).await;
+            music_folder
+                .add_audio_filesystem::<&str>()
+                .n_song(10)
+                .depth(if same_dir { 0 } else { (1..3).fake() })
+                .call()
+                .await;
+            music_folder.remove_audio_filesystem::<&str>().call().await;
+
+            let database_audio = music_folder.query_filesystem().await;
+            assert_eq!(database_audio, music_folder.filesystem);
+        }
+
+        #[rstest]
+        #[tokio::test]
+        async fn test_duplicate(#[future(awt)] mock: Mock, #[values(true, false)] same_dir: bool) {
+            let mut music_folder = mock.music_folder(0).await;
+            music_folder.add_audio_filesystem::<&str>().depth(0).call().await;
+            let audio = music_folder.filesystem[0].clone();
+
+            music_folder
+                .add_audio_filesystem::<&str>()
+                .metadata(audio.information.metadata.clone())
+                .format(audio.information.file.format)
+                .depth(if same_dir { 0 } else { (1..3).fake() })
+                .call()
+                .await;
+
+            let mut database_audio = music_folder.query_filesystem().await;
+            assert_eq!(database_audio.len(), 1);
+            let (database_path, database_audio) = database_audio.shift_remove_index(0).unwrap();
+
+            let (path, audio) = music_folder
+                .filesystem
+                .shift_remove_index(usize::from(
+                    audio.relative_path != database_audio.relative_path,
+                ))
+                .unwrap();
+            assert_eq!(database_path, path);
+
+            let (database_audio, audio) = if same_dir {
+                (database_audio, audio)
+            } else {
+                (database_audio.with_dir_picture(None), audio.with_dir_picture(None))
+            };
+            assert_eq!(database_audio, audio);
+        }
+
+        #[rstest]
+        #[tokio::test]
+        async fn test_move(#[future(awt)] mock: Mock) {
+            let mut music_folder = mock.music_folder(0).await;
+            music_folder.add_audio_filesystem::<&str>().call().await;
+            let audio = music_folder.filesystem[0].clone();
+            music_folder.remove_audio_filesystem::<&str>().index(0).call().await;
+
+            music_folder
+                .add_audio_filesystem::<&str>()
+                .metadata(audio.information.metadata.clone())
+                .format(audio.information.file.format)
+                .call()
+                .await;
+
+            let database_audio = music_folder.query_filesystem().await;
+            assert_eq!(database_audio, music_folder.filesystem);
+        }
+    }
+
+    #[rstest]
+    #[tokio::test]
+    async fn test_scan_dir_picture(#[future(awt)] mock: Mock) {
+        let mut music_folder = mock.music_folder(0).await;
+        music_folder
+            .add_audio_filesystem::<&str>()
+            .n_song(10)
+            .depth(0)
+            .recompute_dir_picture(false)
+            .call()
+            .await;
+
+        // All pictures are the same. However, the picture will only be the same from the first
+        // file that has a picture so we have to filter out none before checking.
+        let dir_pictures: Vec<_> = music_folder
+            .filesystem
+            .values()
+            .filter_map(|information| information.dir_picture.clone())
+            .collect();
+        assert!(dir_pictures.windows(2).all(|window| window[0] == window[1]));
+
+        // On the other hand, data queried from database should have all the same picture
+        // regardless if the very first file have a picture or not. So we use `map` instead of
+        // `filter_map` here.
+        let database_dir_pictures: Vec<_> = music_folder
+            .query_filesystem()
+            .await
+            .values()
+            .map(|information| information.dir_picture.clone())
+            .collect();
+        assert!(database_dir_pictures.windows(2).all(|window| window[0] == window[1]));
+    }
+}
diff --git a/nghe-backend/src/schema.rs b/nghe-backend/src/schema.rs
new file mode 100644
index 000000000..3b4c71af4
--- /dev/null
+++ b/nghe-backend/src/schema.rs
@@ -0,0 +1,332 @@
+// @generated automatically by Diesel CLI.
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    albums (id) {
+        id -> Uuid,
+        name -> Text,
+        created_at -> Timestamptz,
+        updated_at -> Timestamptz,
+        scanned_at -> Timestamptz,
+        year -> Nullable<Int2>,
+        month -> Nullable<Int2>,
+        day -> Nullable<Int2>,
+        release_year -> Nullable<Int2>,
+        release_month -> Nullable<Int2>,
+        release_day -> Nullable<Int2>,
+        original_release_year -> Nullable<Int2>,
+        original_release_month -> Nullable<Int2>,
+        original_release_day -> Nullable<Int2>,
+        mbz_id -> Nullable<Uuid>,
+        ts -> Tsvector,
+        music_folder_id -> Uuid,
+        cover_art_id -> Nullable<Uuid>,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    artists (id) {
+        id -> Uuid,
+        name -> Text,
+        index -> Text,
+        created_at -> Timestamptz,
+        updated_at -> Timestamptz,
+        scanned_at -> Timestamptz,
+        mbz_id -> Nullable<Uuid>,
+        ts -> Tsvector,
+        lastfm_url -> Nullable<Text>,
+        lastfm_mbz_id -> Nullable<Uuid>,
+        lastfm_biography -> Nullable<Text>,
+        cover_art_id -> Nullable<Uuid>,
+        spotify_id -> Nullable<Text>,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    configs (key) {
+        key -> Text,
+        text -> Nullable<Text>,
+        byte -> Nullable<Bytea>,
+        updated_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    cover_arts (id) {
+        id -> Uuid,
+        format -> Text,
+        file_hash -> Int8,
+        file_size -> Int4,
+        source -> Nullable<Text>,
+        updated_at -> Timestamptz,
+        scanned_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    genres (id) {
+        id -> Uuid,
+        value -> Text,
+        upserted_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    lyrics (song_id, description, language, external) {
+        song_id -> Uuid,
+        description -> Text,
+        language -> Text,
+        line_values -> Array<Nullable<Text>>,
+        line_starts -> Nullable<Array<Nullable<Int4>>>,
+        lyric_hash -> Int8,
+        lyric_size -> Int4,
+        external -> Bool,
+        updated_at -> Timestamptz,
+        scanned_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    music_folders (id) {
+        id -> Uuid,
+        path -> Text,
+        scanned_at -> Timestamptz,
+        name -> Text,
+        updated_at -> Timestamptz,
+        fs_type -> Int2,
+        created_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    playbacks (user_id, song_id) {
+        user_id -> Uuid,
+        song_id -> Uuid,
+        count -> Int4,
+        updated_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    playlists (id) {
+        id -> Uuid,
+        name -> Text,
+        comment -> Nullable<Text>,
+        public -> Bool,
+        created_at -> Timestamptz,
+        updated_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    playlists_songs (playlist_id, song_id) {
+        playlist_id -> Uuid,
+        song_id -> Uuid,
+        created_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    playlists_users (playlist_id, user_id) {
+        playlist_id -> Uuid,
+        user_id -> Uuid,
+        access_level -> Int2,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    scans (started_at, music_folder_id) {
+        started_at -> Timestamptz,
+        is_scanning -> Bool,
+        finished_at -> Nullable<Timestamptz>,
+        music_folder_id -> Uuid,
+        scanned_song_count -> Int8,
+        upserted_song_count -> Int8,
+        deleted_song_count -> Int8,
+        deleted_album_count -> Int8,
+        deleted_artist_count -> Int8,
+        deleted_genre_count -> Int8,
+        scan_error_count -> Int8,
+        unrecoverable -> Nullable<Bool>,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    songs (id) {
+        id -> Uuid,
+        title -> Text,
+        album_id -> Uuid,
+        track_number -> Nullable<Int4>,
+        track_total -> Nullable<Int4>,
+        disc_number -> Nullable<Int4>,
+        disc_total -> Nullable<Int4>,
+        year -> Nullable<Int2>,
+        month -> Nullable<Int2>,
+        day -> Nullable<Int2>,
+        release_year -> Nullable<Int2>,
+        release_month -> Nullable<Int2>,
+        release_day -> Nullable<Int2>,
+        original_release_year -> Nullable<Int2>,
+        original_release_month -> Nullable<Int2>,
+        original_release_day -> Nullable<Int2>,
+        languages -> Array<Nullable<Text>>,
+        format -> Text,
+        duration -> Float4,
+        bitrate -> Int4,
+        sample_rate -> Int4,
+        channel_count -> Int2,
+        relative_path -> Text,
+        file_hash -> Int8,
+        file_size -> Int4,
+        created_at -> Timestamptz,
+        updated_at -> Timestamptz,
+        scanned_at -> Timestamptz,
+        cover_art_id -> Nullable<Uuid>,
+        mbz_id -> Nullable<Uuid>,
+        ts -> Tsvector,
+        bit_depth -> Nullable<Int2>,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    songs_album_artists (song_id, album_artist_id) {
+        song_id -> Uuid,
+        album_artist_id -> Uuid,
+        upserted_at -> Timestamptz,
+        compilation -> Bool,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    songs_artists (song_id, artist_id) {
+        song_id -> Uuid,
+        artist_id -> Uuid,
+        upserted_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    songs_genres (song_id, genre_id) {
+        song_id -> Uuid,
+        genre_id -> Uuid,
+        upserted_at -> Timestamptz,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    user_music_folder_permissions (user_id, music_folder_id) {
+        user_id -> Uuid,
+        music_folder_id -> Uuid,
+    }
+}
+
+diesel::table! {
+    use diesel::sql_types::*;
+    use diesel_full_text_search::*;
+
+    users (id) {
+        id -> Uuid,
+        username -> Text,
+        password -> Bytea,
+        email -> Text,
+        admin_role -> Bool,
+        stream_role -> Bool,
+        download_role -> Bool,
+        share_role -> Bool,
+        created_at -> Timestamptz,
+        updated_at -> Timestamptz,
+    }
+}
+
+diesel::joinable!(albums -> cover_arts (cover_art_id));
+diesel::joinable!(albums -> music_folders (music_folder_id));
+diesel::joinable!(artists -> cover_arts (cover_art_id));
+diesel::joinable!(lyrics -> songs (song_id));
+diesel::joinable!(playbacks -> songs (song_id));
+diesel::joinable!(playbacks -> users (user_id));
+diesel::joinable!(playlists_songs -> playlists (playlist_id));
+diesel::joinable!(playlists_songs -> songs (song_id));
+diesel::joinable!(playlists_users -> playlists (playlist_id));
+diesel::joinable!(playlists_users -> users (user_id));
+diesel::joinable!(scans -> music_folders (music_folder_id));
+diesel::joinable!(songs -> albums (album_id));
+diesel::joinable!(songs -> cover_arts (cover_art_id));
+diesel::joinable!(songs_album_artists -> artists (album_artist_id));
+diesel::joinable!(songs_album_artists -> songs (song_id));
+diesel::joinable!(songs_artists -> artists (artist_id));
+diesel::joinable!(songs_artists -> songs (song_id));
+diesel::joinable!(songs_genres -> genres (genre_id));
+diesel::joinable!(songs_genres -> songs (song_id));
+diesel::joinable!(user_music_folder_permissions -> music_folders (music_folder_id));
+diesel::joinable!(user_music_folder_permissions -> users (user_id));
+
+diesel::allow_tables_to_appear_in_same_query!(
+    albums,
+    artists,
+    configs,
+    cover_arts,
+    genres,
+    lyrics,
+    music_folders,
+    playbacks,
+    playlists,
+    playlists_songs,
+    playlists_users,
+    scans,
+    songs,
+    songs_album_artists,
+    songs_artists,
+    songs_genres,
+    user_music_folder_permissions,
+    users,
+);
diff --git a/nghe-backend/src/sync.rs b/nghe-backend/src/sync.rs
new file mode 100644
index 000000000..e43bc37ec
--- /dev/null
+++ b/nghe-backend/src/sync.rs
@@ -0,0 +1,5 @@
+use loole::{Receiver, Sender};
+
+pub fn channel<T>(size: Option<usize>) -> (Sender<T>, Receiver<T>) {
+    if let Some(size) = size { loole::bounded(size) } else { loole::unbounded() }
+}
diff --git a/nghe-backend/src/test/assets/mod.rs b/nghe-backend/src/test/assets/mod.rs
new file mode 100644
index 000000000..cca346fe0
--- /dev/null
+++ b/nghe-backend/src/test/assets/mod.rs
@@ -0,0 +1,12 @@
+use typed_path::Utf8TypedPathBuf;
+
+use crate::file::audio;
+use crate::filesystem::path;
+
+pub fn dir() -> Utf8TypedPathBuf {
+    path::Local::from_str(&env!("CARGO_MANIFEST_DIR")).parent().unwrap().join("assets").join("test")
+}
+
+pub fn path(format: audio::Format) -> Utf8TypedPathBuf {
+    dir().join("sample").with_extension(format.as_ref())
+}
diff --git a/nghe-backend/src/test/database/mod.rs b/nghe-backend/src/test/database/mod.rs
new file mode 100644
index 000000000..61a9740b9
--- /dev/null
+++ b/nghe-backend/src/test/database/mod.rs
@@ -0,0 +1,70 @@
+use concat_string::concat_string;
+use diesel_async::{AsyncConnection, AsyncPgConnection};
+use url::Url;
+use uuid::Uuid;
+
+use crate::database::Database;
+use crate::{config, migration};
+
+pub struct Mock {
+    name: String,
+    url: String,
+    database: Database,
+}
+
+impl Mock {
+    pub async fn new() -> Self {
+        let url = std::env::var("DATABASE_URL").unwrap();
+
+        let _ = tracing_subscriber::fmt()
+            .with_env_filter(
+                tracing_subscriber::EnvFilter::try_from_default_env()
+                    .unwrap_or_else(|_| "info".into()),
+            )
+            .with_test_writer()
+            .try_init();
+
+        let name = Uuid::new_v4().to_string();
+        let mut mock_url = Url::parse(&url).unwrap();
+        mock_url.set_path(&name);
+
+        let mut root_conn = AsyncPgConnection::establish(&url).await.unwrap();
+        diesel_async::RunQueryDsl::execute(
+            diesel::sql_query(concat_string!("CREATE DATABASE \"", name, "\";")),
+            &mut root_conn,
+        )
+        .await
+        .unwrap();
+
+        let mock_url = mock_url.to_string();
+        migration::run(&mock_url).await;
+
+        Self {
+            name,
+            url,
+            database: Database::new(&config::Database { url: mock_url, key: rand::random() }),
+        }
+    }
+
+    pub fn database(&self) -> &Database {
+        &self.database
+    }
+}
+
+#[cfg(not(any(target_env = "musl", all(target_arch = "aarch64", target_os = "linux"))))]
+impl Drop for Mock {
+    fn drop(&mut self) {
+        use diesel::pg::PgConnection;
+        use diesel::Connection;
+
+        let raw_statement =
+            concat_string!("DROP DATABASE IF EXISTS \"", &self.name, "\" WITH (FORCE);");
+        if let Err::<_, color_eyre::Report>(e) = try {
+            let mut conn = PgConnection::establish(&self.url)?;
+            diesel::RunQueryDsl::execute(diesel::sql_query(&raw_statement), &mut conn)?;
+        } {
+            println!("Could not drop temporary database because of {:?}", &e);
+            println!("Please drop the database manually with '{}'", &raw_statement);
+        }
+    }
+}
diff --git a/nghe-backend/src/test/file/audio/dump/flac.rs b/nghe-backend/src/test/file/audio/dump/flac.rs
new file mode 100644
index 000000000..76021f0ad
--- /dev/null
+++ b/nghe-backend/src/test/file/audio/dump/flac.rs
@@ -0,0 +1,50 @@
+use lofty::flac::FlacFile;
+use lofty::ogg::OggPictureStorage as _;
+
+use super::Metadata;
+use crate::config;
+use crate::file::audio::{Album, Artists, Genres, NameDateMbz, TrackDisc};
+use crate::file::picture::Picture;
+
+impl Metadata for FlacFile {
+    fn dump_song(&mut self, config: &config::Parsing, song: NameDateMbz<'_>) -> &mut Self {
+        self.vorbis_comments_mut().unwrap().dump_song(config, song);
+        self
+    }
+
+    fn dump_album(&mut self, config: &config::Parsing, album: Album<'_>) -> &mut Self {
+        self.vorbis_comments_mut().unwrap().dump_album(config, album);
+        self
+    }
+
+    fn dump_artists(&mut self, config: &config::Parsing, artists: Artists<'_>) -> &mut Self {
+        self.vorbis_comments_mut().unwrap().dump_artists(config, artists);
+        self
+    }
+
+    fn dump_track_disc(&mut self, config: &config::Parsing, track_disc: TrackDisc) -> &mut Self {
+        self.vorbis_comments_mut().unwrap().dump_track_disc(config, track_disc);
+        self
+    }
+
+    fn dump_languages(
+        &mut self,
+        config: &config::Parsing,
+        languages: Vec<isolang::Language>,
+    ) -> &mut Self {
+        self.vorbis_comments_mut().unwrap().dump_languages(config, languages);
+        self
+    }
+
+    fn dump_genres(&mut self, config: &config::Parsing, genres: Genres<'_>) -> &mut Self {
+        self.vorbis_comments_mut().unwrap().dump_genres(config, genres);
+        self
+    }
+
+    fn dump_picture(&mut self, picture: Option<Picture<'_, '_>>) -> &mut Self {
+        if let Some(picture) = picture {
+            self.insert_picture(picture.into(), None).unwrap();
+        }
+        self
+    }
+}
diff --git a/nghe-backend/src/test/file/audio/dump/mod.rs b/nghe-backend/src/test/file/audio/dump/mod.rs
new file mode 100644
index 000000000..d8a1f895d
--- /dev/null
+++ b/nghe-backend/src/test/file/audio/dump/mod.rs
@@ -0,0 +1,99 @@
+mod flac;
+mod tag;
+
+use isolang::Language;
+
+use crate::config;
+use crate::file::audio::{self, Album, Artists, File, Genres, NameDateMbz, TrackDisc};
+use crate::file::picture::Picture;
+
+pub trait Metadata {
+    fn dump_song(&mut self, config: &config::Parsing, song: NameDateMbz<'_>) -> &mut Self;
+    fn dump_album(&mut self, config: &config::Parsing, album: Album<'_>) -> &mut Self;
+    fn dump_artists(&mut self, config: &config::Parsing, artists: Artists<'_>) -> &mut Self;
+    fn dump_track_disc(&mut self, config: &config::Parsing, track_disc: TrackDisc) -> &mut Self;
+    fn dump_languages(&mut self, config: &config::Parsing, languages: Vec<Language>) -> &mut Self;
+    fn dump_genres(&mut self, config: &config::Parsing, genres: Genres<'_>) -> &mut Self;
+    fn dump_picture(&mut self, picture: Option<Picture<'_, '_>>) -> &mut Self;
+
+    fn dump_metadata(
+        &mut self,
+        config: &config::Parsing,
+        metadata: audio::Metadata<'_>,
+    ) -> &mut Self {
+        let audio::Metadata { song, album, artists, genres, picture } = metadata;
+        let audio::Song { main, track_disc, languages } = song;
+        self.dump_song(config, main)
+            .dump_album(config, album)
+            .dump_artists(config, artists)
+            .dump_track_disc(config, track_disc)
+            .dump_languages(config, languages)
+            .dump_genres(config, genres)
+            .dump_picture(picture)
+    }
+}
+
+impl Metadata for File {
+    fn dump_song(&mut self, config: &config::Parsing, song: NameDateMbz<'_>) -> &mut Self {
+        match self {
+            File::Flac { audio, .. } => {
+                audio.dump_song(config, song);
+            }
+        }
+        self
+    }
+
+    fn dump_album(&mut self, config: &config::Parsing, album: Album<'_>) -> &mut Self {
+        match self {
+            File::Flac { audio, .. } => {
+                audio.dump_album(config, album);
+            }
+        }
+        self
+    }
+
+    fn dump_artists(&mut self, config: &config::Parsing, artists: Artists<'_>) -> &mut Self {
+        match self {
+            File::Flac { audio, .. } => {
+                audio.dump_artists(config, artists);
+            }
+        }
+        self
+    }
+
+    fn dump_track_disc(&mut self, config: &config::Parsing, track_disc: TrackDisc) -> &mut Self {
+        match self {
+            File::Flac { audio, .. } => {
+                audio.dump_track_disc(config, track_disc);
+            }
+        }
+        self
+    }
+
+    fn dump_languages(&mut self, config: &config::Parsing, languages: Vec<Language>) -> &mut Self {
+        match self {
+            File::Flac { audio, .. } => {
+                audio.dump_languages(config, languages);
+            }
+        }
+        self
+    }
+
+    fn dump_genres(&mut self, config: &config::Parsing, genres: Genres<'_>) -> &mut Self {
+        match self {
+            File::Flac { audio, .. } => {
+                audio.dump_genres(config, genres);
+            }
+        }
+        self
+    }
+
+    fn dump_picture(&mut self, picture: Option<Picture<'_, '_>>) -> &mut Self {
+        match self {
+            File::Flac { audio, .. } => {
+                audio.dump_picture(picture);
+            }
+        }
+        self
+    }
+}
diff --git a/nghe-backend/src/test/file/audio/dump/tag/mod.rs b/nghe-backend/src/test/file/audio/dump/tag/mod.rs
new file mode 100644
index 000000000..f425370c6
--- /dev/null
+++ b/nghe-backend/src/test/file/audio/dump/tag/mod.rs
@@ -0,0 +1 @@
+mod vorbis_comments;
diff --git a/nghe-backend/src/test/file/audio/dump/tag/vorbis_comments.rs b/nghe-backend/src/test/file/audio/dump/tag/vorbis_comments.rs
new file mode 100644
index 000000000..8d0a6d154
--- /dev/null
+++ b/nghe-backend/src/test/file/audio/dump/tag/vorbis_comments.rs
@@ -0,0 +1,117 @@
+use indexmap::IndexSet;
+use isolang::Language;
+use lofty::ogg::{OggPictureStorage, VorbisComments};
+use uuid::Uuid;
+
+use crate::config;
+use crate::file::audio::position::Position;
+use crate::file::audio::{Album, Artist, Artists, Date, Genres, NameDateMbz, TrackDisc};
+use crate::file::picture::Picture;
+use crate::test::file::audio::dump;
+
+impl Date {
+    fn dump_vorbis_comments(self, tag: &mut VorbisComments, key: Option<&str>) {
+        if let Some(key) = key
+            && self.is_some()
+        {
+            tag.push(key.to_string(), self.to_string());
+        }
+    }
+}
+
+impl NameDateMbz<'_> {
+    fn dump_vorbis_comments(
+        self,
+        tag: &mut VorbisComments,
+        config: &config::parsing::vorbis_comments::Common,
+    ) {
+        let Self { name, date, release_date, original_release_date, mbz_id } = self;
+        tag.push(config.name.clone(), name.into_owned());
+        date.dump_vorbis_comments(tag, config.date.as_deref());
+        release_date.dump_vorbis_comments(tag, config.release_date.as_deref());
+        original_release_date.dump_vorbis_comments(tag, config.original_release_date.as_deref());
+        if let Some(mbz_id) = mbz_id {
+            tag.push(config.mbz_id.clone(), mbz_id.to_string());
+        }
+    }
+}
+
+impl Artist<'_> {
+    fn dump_vorbis_comments(
+        artists: IndexSet<Self>,
+        tag: &mut VorbisComments,
+        config: &config::parsing::vorbis_comments::Artist,
+    ) {
+        for artist in artists {
+            tag.push(config.name.clone(), artist.name.into_owned());
+            tag.push(config.mbz_id.clone(), artist.mbz_id.unwrap_or(Uuid::nil()).to_string());
+        }
+    }
+}
+
+impl Position {
+    fn dump_vorbis_comments(self, tag: &mut VorbisComments, number_key: &str, total_key: &str) {
+        if let Some(number) = self.number {
+            tag.push(number_key.to_owned(), number.to_string());
+        }
+        if let Some(total) = self.total {
+            tag.push(total_key.to_owned(), total.to_string());
+        }
+    }
+}
+
+impl dump::Metadata for VorbisComments {
+    fn dump_song(&mut self, config: &config::Parsing, song: NameDateMbz<'_>) -> &mut Self {
+        song.dump_vorbis_comments(self, &config.vorbis_comments.song);
+        self
+    }
+
+    fn dump_album(&mut self, config: &config::Parsing, album: Album<'_>) -> &mut Self {
+        album.dump_vorbis_comments(self, &config.vorbis_comments.album);
+        self
+    }
+
+    fn dump_artists(&mut self, config: &config::Parsing, artists: Artists<'_>) -> &mut Self {
+        Artist::dump_vorbis_comments(artists.song, self, &config.vorbis_comments.artists.song);
+        Artist::dump_vorbis_comments(artists.album, self, &config.vorbis_comments.artists.album);
+        if artists.compilation {
+            self.push(config.vorbis_comments.compilation.clone(), "1".to_string());
+        }
+        self
+    }
+
+    fn dump_track_disc(&mut self, config: &config::Parsing, track_disc: TrackDisc) -> &mut Self {
+        track_disc.track.dump_vorbis_comments(
+            self,
+            &config.vorbis_comments.track_disc.track_number,
+            &config.vorbis_comments.track_disc.track_total,
+        );
+        track_disc.disc.dump_vorbis_comments(
+            self,
+            &config.vorbis_comments.track_disc.disc_number,
+            &config.vorbis_comments.track_disc.disc_total,
+        );
+        self
+    }
+
+    fn dump_languages(&mut self, config: &config::Parsing, languages: Vec<Language>) -> &mut Self {
+        for language in languages {
+            self.push(config.vorbis_comments.languages.clone(), language.to_string());
+        }
+        self
+    }
+
+    fn dump_genres(&mut self, config: &config::Parsing, genres: Genres<'_>) -> &mut Self {
+        for genre in genres.value {
+            self.push(config.vorbis_comments.genres.clone(), genre.value.into_owned());
+        }
+        self
+    }
+
+    fn dump_picture(&mut self, picture: Option<Picture<'_, '_>>) -> &mut Self {
+        if let Some(picture) = picture {
+            self.insert_picture(picture.into(), None).unwrap();
+        }
+        self
+    }
+}
diff --git a/nghe-backend/src/test/file/audio/mod.rs b/nghe-backend/src/test/file/audio/mod.rs
new file mode 100644
index 000000000..88f425104
--- /dev/null
+++ b/nghe-backend/src/test/file/audio/mod.rs
@@ -0,0 +1 @@
+pub mod dump;
diff --git a/nghe-backend/src/test/file/mod.rs b/nghe-backend/src/test/file/mod.rs
new file mode 100644
index 000000000..fa3e4e468
--- /dev/null
+++ b/nghe-backend/src/test/file/mod.rs
@@ -0,0 +1 @@
+pub mod audio;
diff --git a/nghe-backend/src/test/filesystem/common.rs b/nghe-backend/src/test/filesystem/common.rs
new file mode 100644
index 000000000..71cc7acd6
--- /dev/null
+++ b/nghe-backend/src/test/filesystem/common.rs
@@ -0,0 +1,125 @@
+use typed_path::{Utf8TypedPath, Utf8TypedPathBuf};
+
+use crate::file::{self, audio};
+use crate::http::binary;
+use crate::{filesystem, Error};
+
+#[derive(Debug)]
+pub enum Impl<'fs> {
+    Local(&'fs super::local::Mock),
+    S3(&'fs super::s3::Mock),
+}
+
+impl Impl<'_> {
+    pub fn path(&self) -> filesystem::path::Builder {
+        self.main().path()
+    }
+
+    pub fn fake_path(&self, depth: usize) -> Utf8TypedPathBuf {
+        fake::vec![String; depth + 1]
+            .into_iter()
+            .fold(self.path().empty(), |path, component| path.join(component))
+    }
+}
+
+pub trait Trait: filesystem::Trait {
+    fn prefix(&self) -> Utf8TypedPath<'_>;
+    fn main(&self) -> filesystem::Impl<'_>;
+
+    fn absolutize(&self, path: Utf8TypedPath<'_>) -> Utf8TypedPathBuf {
+        if path.is_absolute() { path.to_path_buf() } else { self.prefix().join(path) }
+    }
+
+    async fn create_dir(&self, path: Utf8TypedPath<'_>) -> Utf8TypedPathBuf;
+    async fn write(&self, path: Utf8TypedPath<'_>, data: &[u8]);
+    async fn delete(&self, path: Utf8TypedPath<'_>);
+}
+
+impl filesystem::Trait for Impl<'_> {
+    async fn check_folder(&self, path: Utf8TypedPath<'_>) -> Result<(), Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.check_folder(path).await,
+            Impl::S3(filesystem) => filesystem.check_folder(path).await,
+        }
+    }
+
+    async fn scan_folder(
+        &self,
+        sender: filesystem::entry::Sender,
+        prefix: Utf8TypedPath<'_>,
+    ) -> Result<(), Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.scan_folder(sender, prefix).await,
+            Impl::S3(filesystem) => filesystem.scan_folder(sender, prefix).await,
+        }
+    }
+
+    async fn exists(&self, path: Utf8TypedPath<'_>) -> Result<bool, Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.exists(path).await,
+            Impl::S3(filesystem) => filesystem.exists(path).await,
+        }
+    }
+
+    async fn read(&self, path: Utf8TypedPath<'_>) -> Result<Vec<u8>, Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.read(path).await,
+            Impl::S3(filesystem) => filesystem.read(path).await,
+        }
+    }
+
+    async fn read_to_binary(
+        &self,
+        source: &binary::Source<file::Property<audio::Format>>,
+        offset: Option<u64>,
+    ) -> Result<binary::Response, Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.read_to_binary(source, offset).await,
+            Impl::S3(filesystem) => filesystem.read_to_binary(source, offset).await,
+        }
+    }
+
+    async fn transcode_input(&self, path: Utf8TypedPath<'_>) -> Result<String, Error> {
+        match self {
+            Impl::Local(filesystem) => filesystem.transcode_input(path).await,
+            Impl::S3(filesystem) => filesystem.transcode_input(path).await,
+        }
+    }
+}
+
+impl Trait for Impl<'_> {
+    fn prefix(&self) -> Utf8TypedPath<'_> {
+        match self {
+            Impl::Local(filesystem) => filesystem.prefix(),
+            Impl::S3(filesystem) => filesystem.prefix(),
+        }
+    }
+
+    fn main(&self) -> filesystem::Impl<'_> {
+        match self {
+            Impl::Local(filesystem) => filesystem.main(),
+            Impl::S3(filesystem) => filesystem.main(),
+        }
+    }
+
+    async fn create_dir(&self, path: Utf8TypedPath<'_>) -> Utf8TypedPathBuf {
+        match self {
+            Impl::Local(filesystem) => filesystem.create_dir(path).await,
+            Impl::S3(filesystem) => filesystem.create_dir(path).await,
+        }
+    }
+
+    async fn write(&self, path: Utf8TypedPath<'_>, data: &[u8]) {
+        match self {
+            Impl::Local(filesystem) => filesystem.write(path, data).await,
+            Impl::S3(filesystem) => filesystem.write(path, data).await,
+        }
+    }
+
+    async fn delete(&self, path: Utf8TypedPath<'_>) {
+        match self {
+            Impl::Local(filesystem) => filesystem.delete(path).await,
+            Impl::S3(filesystem) => filesystem.delete(path).await,
+        }
+    }
+}
diff --git a/nghe-backend/src/test/filesystem/local.rs b/nghe-backend/src/test/filesystem/local.rs
new file mode 100644
index 000000000..f340b77ad
--- /dev/null
+++ b/nghe-backend/src/test/filesystem/local.rs
@@ -0,0 +1,89 @@
+use std::borrow::Cow;
+
+use nghe_api::constant;
+use tempfile::{Builder, TempDir};
+use typed_path::{Utf8TypedPath, Utf8TypedPathBuf};
+
+use crate::file::{self, audio};
+use crate::filesystem::{self, local};
+use crate::http::binary;
+use crate::Error;
+
+#[derive(Debug)]
+pub struct Mock {
+    root: TempDir,
+    filesystem: local::Filesystem,
+}
+
+impl Mock {
+    pub fn new(filesystem: local::Filesystem) -> Self {
+        Self {
+            root: Builder::new()
+                .prefix(&const_format::concatc!(constant::SERVER_NAME, "."))
+                .tempdir()
+                .unwrap(),
+            filesystem,
+        }
+    }
+}
+
+impl filesystem::Trait for Mock {
+    async fn check_folder(&self, path: Utf8TypedPath<'_>) -> Result<(), Error> {
+        self.filesystem.check_folder(path).await
+    }
+
+    async fn scan_folder(
+        &self,
+        sender: filesystem::entry::Sender,
+        prefix: Utf8TypedPath<'_>,
+    ) -> Result<(), Error> {
+        self.filesystem.scan_folder(sender, prefix).await
+    }
+
+    async fn exists(&self, path: Utf8TypedPath<'_>) -> Result<bool, Error> {
+        self.filesystem.exists(path).await
+    }
+
+    async fn read(&self, path: Utf8TypedPath<'_>) -> Result<Vec<u8>, Error> {
+        self.filesystem.read(path).await
+    }
+
+    async fn read_to_binary(
+        &self,
+        source: &binary::Source<file::Property<audio::Format>>,
+        offset: Option<u64>,
+    ) -> Result<binary::Response, Error> {
+        self.filesystem.read_to_binary(source, offset).await
+    }
+
+    async fn transcode_input(&self, path: Utf8TypedPath<'_>) -> Result<String, Error> {
+        self.filesystem.transcode_input(path).await
+    }
+}
+
+impl super::Trait for Mock {
+    fn prefix(&self) -> Utf8TypedPath<'_> {
+        self.root.path().to_str().unwrap().into()
+    }
+
+    fn main(&self) -> filesystem::Impl<'_> {
+        filesystem::Impl::Local(Cow::Borrowed(&self.filesystem))
+    }
+
+    async fn create_dir(&self, path: Utf8TypedPath<'_>) -> Utf8TypedPathBuf {
+        let path = self.absolutize(path);
+        tokio::fs::create_dir_all(path.as_str()).await.unwrap();
+        path
+    }
+
+    async fn write(&self, path: Utf8TypedPath<'_>, data: &[u8]) {
+        let path = self.absolutize(path);
+        self.create_dir(path.parent().unwrap()).await;
+        tokio::fs::write(path.as_str(), data).await.unwrap();
+    }
+
+    async fn delete(&self, path: Utf8TypedPath<'_>) {
+        let path = self.absolutize(path);
+        tokio::fs::remove_file(path.as_str()).await.unwrap();
+    }
+}
diff --git a/nghe-backend/src/test/filesystem/mod.rs b/nghe-backend/src/test/filesystem/mod.rs
new file mode 100644
index 000000000..e53522c07
--- /dev/null
+++ b/nghe-backend/src/test/filesystem/mod.rs
@@ -0,0 +1,42 @@
+mod common;
+mod local;
+mod s3;
+
+pub use common::{Impl, Trait};
+use nghe_api::common::filesystem;
+use typed_path::{TryAsRef as _, Utf8NativePath, Utf8NativePathBuf};
+
+use crate::filesystem::Filesystem;
+
+pub struct Mock {
+    filesystem: Filesystem,
+    local: local::Mock,
+    s3: s3::Mock,
+}
+
+impl Mock {
+    pub async fn new(prefix: Option<&str>, config: &super::Config) -> Self {
+        let filesystem = Filesystem::new(&config.filesystem.tls, &config.filesystem.s3).await;
+        let local = local::Mock::new(filesystem.local());
+        let s3 = s3::Mock::new(prefix, filesystem.s3()).await;
+
+        Self { filesystem, local, s3 }
+    }
+
+    pub fn filesystem(&self) -> &Filesystem {
+        &self.filesystem
+    }
+
+    pub fn to_impl(&self, ty: filesystem::Type) -> Impl<'_> {
+        match ty {
+            filesystem::Type::Local => Impl::Local(&self.local),
+            filesystem::Type::S3 => Impl::S3(&self.s3),
+        }
+    }
+
+    pub fn prefix(&self) -> Utf8NativePathBuf {
+        let prefix = self.local.prefix();
+        let prefix: &Utf8NativePath = prefix.try_as_ref().unwrap();
+        prefix.into()
+    }
+}
diff --git a/nghe-backend/src/test/filesystem/s3.rs b/nghe-backend/src/test/filesystem/s3.rs
new file mode 100644
index 000000000..4f4559b44
--- /dev/null
+++ b/nghe-backend/src/test/filesystem/s3.rs
@@ -0,0 +1,112 @@
+use std::borrow::Cow;
+
+use aws_sdk_s3::error::SdkError;
+use aws_sdk_s3::operation::create_bucket::CreateBucketError;
+use aws_sdk_s3::Client;
+use concat_string::concat_string;
+use fake::{Fake, Faker};
+use typed_path::{Utf8TypedPath, Utf8TypedPathBuf};
+
+use crate::file::{self, audio};
+use crate::filesystem::{self, path, s3};
+use crate::http::binary;
+use crate::Error;
+
+#[derive(Debug)]
+pub struct Mock {
+    bucket: Utf8TypedPathBuf,
+    filesystem: s3::Filesystem,
+}
+
+impl Mock {
+    pub async fn new(prefix: Option<&str>, filesystem: s3::Filesystem) -> Self {
+        let bucket =
+            prefix.map_or_else(|| Faker.fake::<String>().to_lowercase().into(), Cow::Borrowed);
+
+        let result = filesystem.client().create_bucket().bucket(bucket.clone()).send().await;
+        if result.is_err() {
+            if let Err(SdkError::ServiceError(err)) =
+                filesystem.client().create_bucket().bucket(bucket.clone()).send().await
+                && let CreateBucketError::BucketAlreadyOwnedByYou(_) = err.into_err()
+            {
+            } else {
+                panic!("Could not create bucket {bucket}")
+            }
+        }
+
+        let bucket = path::S3::from_string(concat_string!("/", bucket));
+        assert!(bucket.is_absolute());
+        Self { bucket, filesystem }
+    }
+
+    pub fn client(&self) -> &Client {
+        self.filesystem.client()
+    }
+}
+
+impl filesystem::Trait for Mock {
+    async fn check_folder(&self, path: Utf8TypedPath<'_>) -> Result<(), Error> {
+        self.filesystem.check_folder(path).await
+    }
+
+    async fn scan_folder(
+        &self,
+        sender: filesystem::entry::Sender,
+        prefix: Utf8TypedPath<'_>,
+    ) -> Result<(), Error> {
+        self.filesystem.scan_folder(sender, prefix).await
+    }
+
+    async fn exists(&self, path: Utf8TypedPath<'_>) -> Result<bool, Error> {
+        self.filesystem.exists(path).await
+    }
+
+    async fn read(&self, path: Utf8TypedPath<'_>) -> Result<Vec<u8>, Error> {
+        self.filesystem.read(path).await
+    }
+
+    async fn read_to_binary(
+        &self,
+        source: &binary::Source<file::Property<audio::Format>>,
+        offset: Option<u64>,
+    ) -> Result<binary::Response, Error> {
+        self.filesystem.read_to_binary(source, offset).await
+    }
+
+    async fn transcode_input(&self, path: Utf8TypedPath<'_>) -> Result<String, Error> {
+        self.filesystem.transcode_input(path).await
+    }
+}
+
+impl super::Trait for Mock {
+    fn prefix(&self) -> Utf8TypedPath<'_> {
+        self.bucket.to_path()
+    }
+
+    fn main(&self) -> filesystem::Impl<'_> {
+        filesystem::Impl::S3(Cow::Borrowed(&self.filesystem))
+    }
+
+    async fn create_dir(&self, path: Utf8TypedPath<'_>) -> Utf8TypedPathBuf {
+        self.prefix().join(path)
+    }
+
+    async fn write(&self, path: Utf8TypedPath<'_>, data: &[u8]) {
+        let path = self.absolutize(path);
+        let s3::Path { bucket, key } = s3::Filesystem::split(path.to_path()).unwrap();
+        self.client()
+            .put_object()
+            .bucket(bucket)
+            .key(key)
+            .body(aws_sdk_s3::primitives::ByteStream::from(data.to_vec()))
+            .send()
+            .await
+            .unwrap();
+    }
+
+    async fn delete(&self, path: Utf8TypedPath<'_>) {
+        let path = self.absolutize(path);
+        let s3::Path { bucket, key } = s3::Filesystem::split(path.to_path()).unwrap();
+        self.client().delete_object().bucket(bucket).key(key).send().await.unwrap();
+    }
+}
diff --git a/nghe-backend/src/test/mock_impl/information.rs b/nghe-backend/src/test/mock_impl/information.rs
new file mode 100644
index 000000000..2023d6e3a
--- /dev/null
+++ b/nghe-backend/src/test/mock_impl/information.rs
@@ -0,0 +1,200 @@
+use std::borrow::Cow;
+use std::io::{Cursor, Write};
+
+use diesel::{ExpressionMethods, QueryDsl, SelectableHelper};
+use diesel_async::RunQueryDsl;
+use fake::{Fake, Faker};
+use uuid::Uuid;
+
+use super::music_folder;
+use crate::file::{self, audio, picture};
+use crate::orm::{albums, songs};
+use crate::test::assets;
+use crate::test::file::audio::dump::Metadata as _;
+use crate::test::filesystem::Trait as _;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Mock<'info, 'path> {
+    pub information: audio::Information<'info>,
+    pub dir_picture: Option<picture::Picture<'static, 'static>>,
+    pub relative_path: Cow<'path, str>,
+}
+
+#[bon::bon]
+impl Mock<'static, 'static> {
+    pub async fn query_upsert(mock: &super::Mock, id: Uuid) -> songs::Upsert<'static> {
+        songs::table
+            .filter(songs::id.eq(id))
+            .select(songs::Upsert::as_select())
+            .get_result(&mut mock.get().await)
+            .await
+            .unwrap()
+    }
+
+    pub async fn query_data(mock: &super::Mock, id: Uuid) -> songs::Data<'static> {
+        Self::query_upsert(mock, id).await.data
+    }
+
+    pub async fn query(mock: &super::Mock, id: Uuid) -> Self {
+        let upsert = Self::query_upsert(mock, id).await;
+        let album_id = upsert.foreign.album_id;
+        let album = audio::Album::query_upsert(mock, upsert.foreign.album_id).await;
+        let artists = audio::Artists::query(mock, id).await;
+        let genres = audio::Genres::query(mock, id).await;
+        let picture = picture::Picture::query_song(mock, id).await;
+
+        let dir_picture = picture::Picture::query_album(mock, album_id).await;
+
+        Self {
+            information: audio::Information {
+                metadata: audio::Metadata {
+                    song: upsert.data.song.try_into().unwrap(),
+                    album: album.data.try_into().unwrap(),
+                    artists,
+                    genres,
+                    picture,
+                },
+                property: upsert.data.property.try_into().unwrap(),
+                file: upsert.data.file.into(),
+            },
+            dir_picture,
+            relative_path: upsert.relative_path,
+        }
+    }
+
+    #[builder(
+        builder_type(name = "Builder", vis = "pub"),
+        state_mod(name = "builder", vis = "pub"),
+        derive(Clone)
+    )]
+    pub fn builder(
+        metadata: Option<audio::Metadata<'static>>,
+        song: Option<audio::Song<'static>>,
+        album: Option<audio::Album<'static>>,
+        artists: Option<audio::Artists<'static>>,
+        genres: Option<audio::Genres<'static>>,
+        picture: Option<Option<picture::Picture<'static, 'static>>>,
+        format: Option<audio::Format>,
+        property: Option<audio::Property>,
+        dir_picture: Option<Option<picture::Picture<'static, 'static>>>,
+        relative_path: Option<Cow<'static, str>>,
+    ) -> Self {
+        let metadata = metadata.unwrap_or_else(|| audio::Metadata {
+            song: song.unwrap_or_else(|| Faker.fake()),
+            album: album.unwrap_or_else(|| Faker.fake()),
+            artists: artists.unwrap_or_else(|| Faker.fake()),
+            genres: genres.unwrap_or_else(|| Faker.fake()),
+            picture: picture.unwrap_or_else(|| Faker.fake()),
+        });
+        let file =
+            file::Property { format: format.unwrap_or_else(|| Faker.fake()), ..Faker.fake() };
+        let property = property.unwrap_or_else(|| audio::Property::default(file.format));
+
+        let dir_picture = dir_picture.unwrap_or_else(|| Faker.fake());
+        let relative_path =
+            relative_path.map_or_else(|| Faker.fake::<String>().into(), std::convert::Into::into);
+
+        Self {
+            information: audio::Information { metadata, property, file },
+            dir_picture,
+            relative_path,
+        }
+    }
+}
+
+impl Mock<'_, '_> {
+    pub async fn upsert(
+        &self,
+        music_folder: &music_folder::Mock<'_>,
+        song_id: impl Into<Option<Uuid>>,
+    ) -> Uuid {
+        let database = music_folder.database();
+        let dir_picture_id = if let Some(ref dir) = music_folder.config.cover_art.dir
+            && let Some(ref picture) = self.dir_picture
+        {
+            Some(picture.upsert(database, dir).await.unwrap())
+        } else {
+            None
+        };
+
+        self.information
+            .upsert(
+                database,
+                &music_folder.config,
+                albums::Foreign {
+                    music_folder_id: music_folder.id(),
+                    cover_art_id: dir_picture_id,
+                },
+                self.relative_path.as_str(),
+                song_id,
+            )
+            .await
+            .unwrap()
+    }
+
+    pub async fn upsert_mock(
+        &self,
+        mock: &super::Mock,
+        index: usize,
+        song_id: impl Into<Option<Uuid>>,
+    ) -> Uuid {
+        let music_folder = mock.music_folder(index).await;
+        self.upsert(&music_folder, song_id).await
+    }
+
+    pub async fn dump(self, music_folder: &music_folder::Mock<'_>) -> Self {
+        let path = music_folder.path().join(&self.relative_path);
+        let path = path.to_path();
+
+        let format = self.information.file.format;
+        let data = tokio::fs::read(assets::path(format).as_str()).await.unwrap();
+        let mut asset = Cursor::new(data.clone());
+        let mut file =
+            file::File::new(format, data).unwrap().audio(music_folder.config.lofty).unwrap();
+        asset.set_position(0);
+
+        file.clear()
+            .dump_metadata(&music_folder.config.parsing, self.information.metadata.clone())
+            .save_to(&mut asset, music_folder.write_options());
+
+        asset.flush().unwrap();
+        asset.set_position(0);
+        let data = asset.into_inner();
+
+        let filesystem = &music_folder.to_impl();
+        filesystem.write(path, &data).await;
+
+        let cover_art_config = &music_folder.config.cover_art;
+        let parent = path.parent().unwrap();
+        let dir_picture = if let Some(picture) =
+            picture::Picture::scan_filesystem(filesystem, cover_art_config, parent).await
+        {
+            Some(picture)
+        } else if let Some(picture) = self.dir_picture {
+            let path = parent.join(picture.property.format.name());
+            filesystem.write(path.to_path(), &picture.data).await;
+            Some(picture::Picture { source: Some(path.into_string().into()), ..picture })
+        } else {
+            None
+        };
+
+        Self {
+            information: audio::Information {
+                file: file::Property::new(format, &data).unwrap(),
+                ..self.information
+            },
+            dir_picture,
+            ..self
+        }
+    }
+
+    pub fn with_dir_picture(self, dir_picture: Option<picture::Picture<'static, 'static>>) -> Self {
+        Self { dir_picture, ..self }
+    }
+}
+
+impl<'path> Mock<'_, 'path> {
+    pub fn with_relative_path(self, relative_path: Cow<'path, str>) -> Self {
+        Self { relative_path, ..self }
+    }
+}
diff --git a/nghe-backend/src/test/mock_impl/mod.rs b/nghe-backend/src/test/mock_impl/mod.rs
new file mode 100644
index 000000000..d9395fd7c
--- /dev/null
+++ b/nghe-backend/src/test/mock_impl/mod.rs
@@ -0,0 +1,190 @@
+#![allow(clippy::option_option)]
+
+mod information;
+mod music_folder;
+mod user;
+
+use diesel_async::pooled_connection::deadpool;
+use diesel_async::AsyncPgConnection;
+use educe::Educe;
+use fake::{Fake, Faker};
+pub use information::Mock as Information;
+use lofty::config::{ParseOptions, WriteOptions};
+use nghe_api::common;
+use rstest::fixture;
+use typed_path::Utf8NativePath;
+use uuid::Uuid;
+
+use super::filesystem::Trait;
+use super::{database, filesystem};
+use crate::database::Database;
+use crate::file::audio;
+use crate::filesystem::Filesystem;
+use crate::orm::users;
+use crate::scan::scanner;
+use crate::{config, route};
+
+#[derive(Debug, Educe)]
+#[educe(Default)]
+pub struct Config {
+    #[educe(Default(expression = config::filesystem::Filesystem::test()))]
+    pub filesystem: config::filesystem::Filesystem,
+    #[educe(Default(expression = config::Parsing::test()))]
+    pub parsing: config::Parsing,
+    pub index: config::Index,
+    pub transcode: config::Transcode,
+    pub cover_art: config::CoverArt,
+
+    pub lofty_parse: ParseOptions,
+    pub lofty_write: WriteOptions,
+}
+
+pub struct Mock {
+    pub config: Config,
+
+    pub database: database::Mock,
+    pub filesystem: filesystem::Mock,
+}
+
+impl Config {
+    fn with_prefix(self, prefix: impl AsRef<Utf8NativePath> + Copy) -> Self {
+        Self {
+            transcode: self.transcode.with_prefix(prefix),
+            cover_art: self.cover_art.with_prefix(prefix),
+            ..self
+        }
+    }
+
+    pub fn scanner(&self) -> scanner::Config {
+        scanner::Config {
+            lofty: self.lofty_parse,
+            scan: self.filesystem.scan,
+            parsing: self.parsing.clone(),
+            index: self.index.clone(),
+            cover_art: self.cover_art.clone(),
+        }
+    }
+}
+
+#[bon::bon]
+impl Mock {
+    async fn new(prefix: Option<&str>, config: Config) -> Self {
+        let database = database::Mock::new().await;
+        let filesystem = filesystem::Mock::new(prefix, &config).await;
+        let config = config.with_prefix(&filesystem.prefix());
+
+        Self { config, database, filesystem }
+    }
+
+    pub fn state(&self) -> &Database {
+        self.database()
+    }
+
+    pub fn database(&self) -> &Database {
+        self.database.database()
+    }
+
+    pub async fn get(&self) -> deadpool::Object<AsyncPgConnection> {
+        self.database().get().await.unwrap()
+    }
+
+    #[builder]
+    pub async fn add_user(
+        &self,
+        #[builder(default = users::Role {
+            admin: false,
+            stream: true,
+            download: true,
+            share: false
+        })]
+        role: users::Role,
+        #[builder(default = true)] allow: bool,
+    ) -> &Self {
+        route::user::create::handler(
+            self.database(),
+            route::user::create::Request { role: role.into(), allow, ..Faker.fake() },
+        )
+        .await
+        .unwrap();
+        self
+    }
+
+    pub async fn user(&self, index: usize) -> user::Mock<'_> {
+        user::Mock::new(self, index).await
+    }
+
+    pub async fn user_id(&self, index: usize) -> Uuid {
+        self.user(index).await.id()
+    }
+
+    pub fn filesystem(&self) -> &Filesystem {
+        self.filesystem.filesystem()
+    }
+
+    pub fn to_impl(&self, ty: common::filesystem::Type) -> filesystem::Impl<'_> {
+        self.filesystem.to_impl(ty)
+    }
+
+    #[builder]
+    pub async fn add_music_folder(
+        &self,
+        #[builder(default = Faker.fake::<common::filesystem::Type>())] ty: common::filesystem::Type,
+        #[builder(default = true)] allow: bool,
+    ) -> Uuid {
+        let filesystem = self.to_impl(ty);
+        route::music_folder::add::handler(
+            self.database(),
+            self.filesystem(),
+            route::music_folder::add::Request {
+                ty,
+                allow,
+                path: filesystem
+                    .create_dir(Faker.fake::<String>().as_str().into())
+                    .await
+                    .into_string(),
+                ..Faker.fake()
+            },
+        )
+        .await
+        .unwrap()
+        .music_folder_id
+    }
+
+    pub async fn music_folder(&self, index: usize) -> music_folder::Mock<'_> {
+        music_folder::Mock::new(self, index).await
+    }
+
+    pub async fn music_folder_id(&self, index: usize) -> Uuid {
+        self.music_folder(index).await.id()
+    }
+
+    pub async fn add_audio_artist(
+        &self,
+        index: usize,
+        songs: impl IntoIterator<Item = audio::Artist<'static>>,
+        albums: impl IntoIterator<Item = audio::Artist<'static>>,
+        compilation: bool,
+        n_song: usize,
+    ) {
+        self.music_folder(index).await.add_audio_artist(songs, albums, compilation, n_song).await;
+    }
+}
+
+#[fixture]
+pub async fn mock(
+    #[default(1)] n_user: usize,
+    #[default(1)] n_music_folder: usize,
+    #[default(None)] prefix: Option<&str>,
+    #[default(Config::default())] config: Config,
+) -> Mock {
+    let mock = Mock::new(prefix, config).await;
+    for _ in 0..n_user {
+        mock.add_user().call().await;
+    }
+    for _ in 0..n_music_folder {
+        mock.add_music_folder().ty(Faker.fake::<common::filesystem::Type>()).call().await;
+    }
+    mock.database().upsert_config(&mock.config.index).await.unwrap();
+
+    mock
+}
diff --git a/nghe-backend/src/test/mock_impl/music_folder.rs b/nghe-backend/src/test/mock_impl/music_folder.rs
new file mode 100644
index 000000000..0032e1c65
--- /dev/null
+++ b/nghe-backend/src/test/mock_impl/music_folder.rs
@@ -0,0 +1,319 @@
+#![allow(clippy::struct_field_names)]
+
+use diesel::{ExpressionMethods, OptionalExtension, QueryDsl, SelectableHelper};
+use diesel_async::RunQueryDsl;
+use fake::{Fake, Faker};
+use futures_lite::{stream, StreamExt};
+use indexmap::IndexMap;
+use itertools::Itertools;
+use typed_path::{Utf8TypedPath, Utf8TypedPathBuf};
+use uuid::Uuid;
+
+use super::Information;
+use crate::database::Database;
+use crate::file::{audio, picture, File};
+use crate::filesystem::Trait as _;
+use crate::orm::{albums, music_folders, songs};
+use crate::scan::scanner;
+use crate::test::filesystem::{self, Trait as _};
+
+pub struct Mock<'a> {
+    mock: &'a super::Mock,
+    music_folder: music_folders::MusicFolder<'static>,
+    pub filesystem: IndexMap<Utf8TypedPathBuf, Information<'static, 'static>>,
+    pub database: IndexMap<Uuid, Information<'static, 'static>>,
+    pub config: scanner::Config,
+}
+
+#[bon::bon]
+impl<'a> Mock<'a> {
+    pub async fn new(mock: &'a super::Mock, index: usize) -> Self {
+        Self {
+            mock,
+            music_folder: music_folders::table
+                .select(music_folders::MusicFolder::as_select())
+                .order_by(music_folders::created_at)
+                .offset(index.try_into().unwrap())
+                .first(&mut mock.get().await)
+                .await
+                .unwrap(),
+            filesystem: IndexMap::new(),
+            database: IndexMap::new(),
+            config: mock.config.scanner(),
+        }
+    }
+
+    pub fn database(&self) -> &Database {
+        self.mock.database()
+    }
+
+    pub fn write_options(&self) -> lofty::config::WriteOptions {
+        self.mock.config.lofty_write
+    }
+
+    pub fn id(&self) -> Uuid {
+        self.music_folder.id
+    }
+
+    pub fn path(&self) -> Utf8TypedPath<'_> {
+        self.path_str(&self.music_folder.data.path)
+    }
+
+    pub fn path_str<'path>(&self, value: &'path (impl AsRef<str> + Sized)) -> Utf8TypedPath<'path> {
+        self.to_impl().path().from_str(value)
+    }
+
+    pub fn path_string(&self, value: impl Into<String>) -> Utf8TypedPathBuf {
+        self.to_impl().path().from_string(value)
+    }
+
+    pub fn absolute_path(&self, index: usize) -> Utf8TypedPathBuf {
+        self.path().join(self.filesystem.get_index(index).unwrap().0)
+    }
+
+    pub fn absolutize(&self, path: impl AsRef<str>) -> Utf8TypedPathBuf {
+        let path = self.path_str(&path);
+        let music_folder_path = self.path();
+
+        if path.is_absolute() {
+            if path.starts_with(music_folder_path) {
+                path.to_path_buf()
+            } else {
+                panic!("Path {path} does not start with music folder path {music_folder_path}")
+            }
+        } else {
+            music_folder_path.join(path)
+        }
+    }
+
+    pub fn relativize<'b>(&self, path: &'b Utf8TypedPath<'b>) -> Utf8TypedPath<'b> {
+        if path.is_absolute() { path.strip_prefix(self.path()).unwrap() } else { *path }
+    }
+
+    pub fn to_impl(&self) -> filesystem::Impl<'_> {
+        self.mock.to_impl(self.music_folder.data.ty.into())
+    }
+
+    #[builder]
+    pub async fn add_audio(
+        &mut self,
+        metadata: Option<audio::Metadata<'static>>,
+        song: Option<audio::Song<'static>>,
+        album: Option<audio::Album<'static>>,
+        artists: Option<audio::Artists<'static>>,
+        genres: Option<audio::Genres<'static>>,
+        picture: Option<Option<picture::Picture<'static, 'static>>>,
+        dir_picture: Option<Option<picture::Picture<'static, 'static>>>,
+        #[builder(default = 1)] n_song: usize,
+    ) -> &mut Self {
+        let builder = Information::builder()
+            .maybe_metadata(metadata)
+            .maybe_song(song)
+            .maybe_album(album)
+            .maybe_artists(artists)
+            .maybe_genres(genres)
+            .maybe_picture(picture)
+            .maybe_dir_picture(dir_picture);
+
+        for _ in 0..n_song {
+            let information = builder.clone().build();
+            let song_id = information.upsert(self, None).await;
+            self.database.insert(song_id, information);
+        }
+
+        self
+    }
+
+    #[builder]
+    pub async fn add_audio_filesystem(
+        &mut self,
+        path: Option<impl AsRef<str>>,
+        #[builder(default = (0..3).fake::<usize>())] depth: usize,
+        #[builder(default = Faker.fake::<audio::Format>())] format: audio::Format,
+        metadata: Option<audio::Metadata<'static>>,
+        song: Option<audio::Song<'static>>,
+        album: Option<audio::Album<'static>>,
+        artists: Option<audio::Artists<'static>>,
+        genres: Option<audio::Genres<'static>>,
+        picture: Option<Option<picture::Picture<'static, 'static>>>,
+        dir_picture: Option<Option<picture::Picture<'static, 'static>>>,
+        #[builder(default = 1)] n_song: usize,
+        #[builder(default = true)] scan: bool,
+        #[builder(default = true)] recompute_dir_picture: bool,
+    ) -> &mut Self {
+        let builder = Information::builder()
+            .maybe_metadata(metadata)
+            .maybe_song(song)
+            .maybe_album(album)
+            .maybe_artists(artists)
+            .maybe_genres(genres)
+            .maybe_picture(picture)
+            .maybe_dir_picture(dir_picture);
+
+        for _ in 0..n_song {
+            let relative_path = if let Some(ref path) = path {
+                assert_eq!(n_song, 1, "The same path is supplied for multiple audio");
+                self.relativize(&self.path_str(path)).to_path_buf()
+            } else {
+                self.to_impl().fake_path(depth)
+            }
+            .with_extension(format.as_ref());
+
+            let information = builder
+                .clone()
+                .format(format)
+                .relative_path(relative_path.to_string().into())
+                .build();
+            let information = information.dump(self).await;
+
+            self.filesystem.shift_remove(&relative_path);
+            self.filesystem.insert(relative_path.clone(), information);
+        }
+
+        if scan {
+            self.scan().run().await.unwrap();
+        }
+
+        if recompute_dir_picture {
+            let group = self
+                .filesystem
+                .clone()
+                .into_iter()
+                .into_group_map_by(|value| value.0.parent().unwrap().to_path_buf());
+            for (parent, files) in group {
+                let dir_picture = picture::Picture::scan_filesystem(
+                    &self.to_impl(),
+                    &self.config.cover_art,
+                    self.path().join(parent).to_path(),
+                )
+                .await;
+                for (path, information) in files {
+                    let information =
+                        Information { dir_picture: dir_picture.clone(), ..information };
+                    self.filesystem.insert(path, information);
+                }
+            }
+        }
+
+        self
+    }
+
+    pub async fn add_audio_artist(
+        &mut self,
+        songs: impl IntoIterator<Item = audio::Artist<'static>>,
+        albums: impl IntoIterator<Item = audio::Artist<'static>>,
+        compilation: bool,
+        n_song: usize,
+    ) {
+        self.add_audio()
+            .artists(audio::Artists {
+                song: songs.into_iter().collect(),
+                album: albums.into_iter().collect(),
+                compilation,
+            })
+            .n_song(n_song)
+            .call()
+            .await;
+    }
+
+    #[builder]
+    pub async fn remove_audio_filesystem(
+        &mut self,
+        path: Option<impl AsRef<str>>,
+        #[builder(default = 0)] index: usize,
+        #[builder(default = true)] scan: bool,
+    ) -> &mut Self {
+        if let Some(path) = path {
+            let absolute_path = self.absolutize(path);
+            let absolute_path = absolute_path.to_path();
+            let relative_path = self.relativize(&absolute_path).to_path_buf();
+            self.to_impl().delete(absolute_path).await;
+            self.filesystem.shift_remove(&relative_path);
+        } else if let Some((relative_path, _)) = self.filesystem.shift_remove_index(index) {
+            self.to_impl().delete(self.absolutize(relative_path).to_path()).await;
+        }
+
+        if scan {
+            self.scan().run().await.unwrap();
+        }
+
+        self
+    }
+
+    pub async fn file(&self, path: Utf8TypedPath<'_>, format: audio::Format) -> audio::File {
+        let path = self.absolutize(path).with_extension(format.as_ref());
+        File::new(format, self.to_impl().read(path.to_path()).await.unwrap())
+            .unwrap()
+            .audio(self.config.lofty)
+            .unwrap()
+    }
+
+    pub fn scan(&self) -> scanner::Scanner<'_, '_, '_> {
+        scanner::Scanner::new_orm(
+            self.mock.database(),
+            self.mock.filesystem(),
+            self.config.clone(),
+            music_folders::MusicFolder {
+                id: self.music_folder.id,
+                data: music_folders::Data {
+                    path: self.music_folder.data.path.as_str().into(),
+                    ty: self.music_folder.data.ty,
+                },
+            },
+        )
+        .unwrap()
+    }
+
+    async fn optional_song_id_filesystem(&self, index: usize) -> Option<Uuid> {
+        let path = self.filesystem.get_index(index).unwrap().0.as_str();
+        albums::table
+            .inner_join(songs::table)
+            .filter(albums::music_folder_id.eq(self.music_folder.id))
+            .filter(songs::relative_path.eq(path))
+            .select(songs::id)
+            .get_result(&mut self.mock.get().await)
+            .await
+            .optional()
+            .unwrap()
+    }
+
+    pub fn song_id(&self, index: usize) -> Uuid {
+        *self.database.get_index(index).unwrap().0
+    }
+
+    pub async fn song_id_filesystem(&self, index: usize) -> Uuid {
+        self.optional_song_id_filesystem(index).await.unwrap()
+    }
+
+    pub async fn query_filesystem(
+        &self,
+    ) -> IndexMap<Utf8TypedPathBuf, Information<'static, 'static>> {
+        let song_ids: Vec<_> = stream::iter(0..self.filesystem.len())
+            .then(async |index| self.optional_song_id_filesystem(index).await)
+            .filter_map(std::convert::identity)
+            .collect()
+            .await;
+        stream::iter(song_ids)
+            .then(async |id| {
+                let mock = Information::query(self.mock, id).await;
+                (self.path_str(&mock.relative_path).to_path_buf(), mock)
+            })
+            .collect()
+            .await
+    }
+}
+
+mod duration {
+    use super::*;
+    use crate::orm::id3::duration::Trait;
+    use crate::Error;
+
+    impl Trait for IndexMap<Uuid, Information<'static, 'static>> {
+        fn duration(&self) -> Result<u32, Error> {
+            self.values()
+                .map(|information| information.information.property.duration)
+                .sum::<f32>()
+                .duration()
+        }
+    }
+}
diff --git a/nghe-backend/src/test/mock_impl/user.rs b/nghe-backend/src/test/mock_impl/user.rs
new file mode 100644
index 000000000..fc550f802
--- /dev/null
+++ b/nghe-backend/src/test/mock_impl/user.rs
@@ -0,0 +1,50 @@
+use diesel::{QueryDsl, SelectableHelper};
+use diesel_async::RunQueryDsl;
+use fake::{Fake, Faker};
+use nghe_api::auth;
+use o2o::o2o;
+use uuid::Uuid;
+
+use crate::orm::users;
+
+// TODO: remove this after https://github.com/SoftbearStudios/bitcode/issues/27
+#[derive(o2o)]
+#[ref_into(auth::Auth<'u, 's>)]
+pub struct Auth {
+    #[into(~.as_str())]
+    pub username: String,
+    #[into(~.as_str())]
+    pub salt: String,
+    pub token: auth::Token,
+}
+
+pub struct Mock<'a> {
+    mock: &'a super::Mock,
+    pub user: users::User<'static>,
+}
+
+impl<'a> Mock<'a> {
+    pub async fn new(mock: &'a super::Mock, index: usize) -> Self {
+        Self {
+            mock,
+            user: users::table
+                .select(users::User::as_select())
+                .order_by(users::created_at)
+                .offset(index.try_into().unwrap())
+                .first(&mut mock.get().await)
+                .await
+                .unwrap(),
+        }
+    }
+
+    pub fn id(&self) -> Uuid {
+        self.user.id
+    }
+
+    pub fn auth(&self) -> Auth {
+        let users::Data { username, password, .. } = &self.user.data;
+        let salt: String = Faker.fake();
+        let token = auth::Auth::tokenize(self.mock.database().decrypt(password).unwrap(), &salt);
+        Auth { username: username.to_string(), salt, token }
+    }
+}
diff --git a/nghe-backend/src/test/mod.rs b/nghe-backend/src/test/mod.rs
new file mode 100644
index 000000000..e5b84dc9f
--- /dev/null
+++ b/nghe-backend/src/test/mod.rs
@@ -0,0 +1,9 @@
+pub mod assets;
+mod database;
+pub mod file;
+pub mod filesystem;
+mod mock_impl;
+pub mod route;
+pub mod transcode;
+
+pub use mock_impl::{mock, Config, Information, Mock};
diff --git a/nghe-backend/src/test/route/mod.rs b/nghe-backend/src/test/route/mod.rs
new file mode 100644
index 000000000..bcb4e6449
--- /dev/null
+++ b/nghe-backend/src/test/route/mod.rs
@@ -0,0 +1 @@
+pub mod permission;
diff --git a/nghe-backend/src/test/route/permission.rs b/nghe-backend/src/test/route/permission.rs
new file mode 100644
index 000000000..03b094cec
--- /dev/null
+++ b/nghe-backend/src/test/route/permission.rs
@@ -0,0 +1,22 @@
+use diesel::QueryDsl;
+use diesel_async::RunQueryDsl;
+
+use crate::orm::user_music_folder_permissions;
+use crate::test::Mock;
+
+pub async fn reset(mock: &Mock) {
+    diesel::delete(user_music_folder_permissions::table)
+        .execute(&mut mock.get().await)
+        .await
+        .unwrap();
+}
+
+pub async fn count(mock: &Mock) -> usize {
+    user_music_folder_permissions::table
+        .count()
+        .get_result::<i64>(&mut mock.get().await)
+        .await
+        .unwrap()
+        .try_into()
+        .unwrap()
+}
diff --git a/nghe-backend/src/test/transcode.rs b/nghe-backend/src/test/transcode.rs
new file mode 100644
index 000000000..1e239b8e4
--- /dev/null
+++ b/nghe-backend/src/test/transcode.rs
@@ -0,0 +1,42 @@
+use axum::http::{HeaderName, HeaderValue};
+use axum_extra::headers;
+use strum::{EnumString, IntoStaticStr};
+
+static TRANSCODE_STATUS: HeaderName = HeaderName::from_static("x-transcode-status");
+
+#[derive(Debug, Clone, Copy, EnumString, IntoStaticStr, PartialEq, Eq, PartialOrd, Ord)]
+#[strum(serialize_all = "lowercase")]
+pub enum Status {
+    NoCache,
+    WithCache,
+    ServeCachedOutput,
+    UseCachedOutput,
+}
+
+pub struct Header(pub Status);
+
+impl headers::Header for Header {
+    fn name() -> &'static HeaderName {
+        &TRANSCODE_STATUS
+    }
+
+    fn decode<'i, I>(values: &mut I) -> Result<Self, headers::Error>
+    where
+        Self: Sized,
+        I: Iterator<Item = &'i HeaderValue>,
+    {
+        Ok(Self(
+            values
+                .next()
+                .ok_or_else(headers::Error::invalid)?
+                .to_str()
+                .map_err(|_| headers::Error::invalid())?
+                .parse()
+                .map_err(|_| headers::Error::invalid())?,
+        ))
+    }
+
+    fn encode<E: Extend<HeaderValue>>(&self, values: &mut E) {
+        values.extend(std::iter::once(HeaderValue::from_static(self.0.into())));
+    }
+}
diff --git a/nghe-backend/src/time/mod.rs b/nghe-backend/src/time/mod.rs
new file mode 100644
index 000000000..22d490cd9
--- /dev/null
+++ b/nghe-backend/src/time/mod.rs
@@ -0,0 +1,8 @@
+use std::time::Duration;
+
+pub async fn now() -> time::OffsetDateTime {
+    let now = time::OffsetDateTime::now_utc();
+    // Sleep one microsecond because that is the highest time precision postgresql can store.
+    tokio::time::sleep(Duration::from_micros(1)).await;
+    now
+}
diff --git a/nghe-backend/src/transcode/format.rs b/nghe-backend/src/transcode/format.rs
new file mode 100644
index 000000000..366b0fda9
--- /dev/null
+++ b/nghe-backend/src/transcode/format.rs
@@ -0,0 +1,25 @@
+use axum_extra::headers::{CacheControl, ETag};
+use nghe_api::common::format;
+
+use crate::http::binary;
+use crate::Error;
+
+impl binary::property::Trait for format::Transcode {
+    const SEEKABLE: bool = false;
+
+    fn mime(&self) -> &'static str {
+        format::Trait::mime(self)
+    }
+
+    fn size(&self) -> Option<u64> {
+        None
+    }
+
+    fn etag(&self) -> Result<Option<ETag>, Error> {
+        Ok(None)
+    }
+
+    fn cache_control() -> CacheControl {
+        CacheControl::new().with_no_cache()
+    }
+}
diff --git a/nghe-backend/src/transcode/mod.rs b/nghe-backend/src/transcode/mod.rs
new file mode 100644
index 000000000..74edc36f1
--- /dev/null
+++ b/nghe-backend/src/transcode/mod.rs
@@ -0,0 +1,6 @@
+mod format;
+mod sink;
+mod transcoder;
+
+pub use sink::Sink;
+pub use transcoder::Transcoder;
diff --git a/nghe-backend/src/transcode/sink.rs b/nghe-backend/src/transcode/sink.rs
new file mode 100644
index 000000000..670b41caf
--- /dev/null
+++ b/nghe-backend/src/transcode/sink.rs
@@ -0,0 +1,125 @@
+use std::ffi::CStr;
+use std::fmt::Debug;
+use std::io::Write;
+
+use educe::Educe;
+use fs4::fs_std::FileExt;
+use loole::{Receiver, Sender};
+use nghe_api::common::format;
+use rsmpeg::avformat::{AVIOContextContainer, AVIOContextCustom};
+use rsmpeg::avutil::AVMem;
+use rsmpeg::ffi;
+use tracing::instrument;
+use typed_path::Utf8NativePath;
+
+use crate::{config, Error};
+
+#[derive(Educe)]
+#[educe(Debug)]
+pub struct Sink {
+    #[educe(Debug(ignore))]
+    tx: Sender<Vec<u8>>,
+    buffer_size: usize,
+    format: format::Transcode,
+    file: Option<std::fs::File>,
+}
+
+impl Sink {
+    pub async fn new(
+        config: &config::Transcode,
+        format: format::Transcode,
+        output: Option<impl AsRef<Utf8NativePath> + Debug + Send + 'static>,
+    ) -> Result<(Self, Receiver<Vec<u8>>), Error> {
+        let (tx, rx) = crate::sync::channel(config.channel_size);
+        // It will fail in two cases:
+        //  - The file already exists because of `create_new`.
+        //  - The lock can not be acquired. In this case, another process is already writing to this
+        //    file.
+        // In both cases, we could start transcoding without writing to a file.
+        let span = tracing::Span::current();
+        let file = tokio::task::spawn_blocking(move || {
+            let _entered = span.enter();
+            output.map(Self::lock_write).transpose().ok().flatten()
+        })
+        .await?;
+        Ok((Self { tx, buffer_size: config.buffer_size, format, file }, rx))
+    }
+
+    pub fn format(&self) -> &'static CStr {
+        // TODO: Use ffmpeg format code after https://github.com/larksuite/rsmpeg/pull/196
+        match self.format {
+            format::Transcode::Aac => c"output.aac",
+            format::Transcode::Flac => c"output.flac",
+            format::Transcode::Mp3 => c"output.mp3",
+            format::Transcode::Opus => c"output.opus",
+            format::Transcode::Wav => c"output.wav",
+            format::Transcode::Wma => c"output.wma",
+        }
+    }
+
+    #[instrument(err(level = "debug"))]
+    pub fn lock_write(path: impl AsRef<Utf8NativePath> + Debug) -> Result<std::fs::File, Error> {
+        let file = std::fs::OpenOptions::new().write(true).create_new(true).open(path.as_ref())?;
+        file.try_lock_exclusive()?;
+        Ok(file)
+    }
+
+    #[instrument(err(level = "debug"))]
+    pub fn lock_read(path: impl AsRef<Utf8NativePath> + Debug) -> Result<std::fs::File, Error> {
+        let file = if cfg!(windows) {
+            // On Windows, the file must be open with write permissions to lock it.
+            std::fs::OpenOptions::new().read(true).write(true).open(path.as_ref())?
+        } else {
+            std::fs::OpenOptions::new().read(true).open(path.as_ref())?
+        };
+        FileExt::try_lock_shared(&file)?;
+        Ok(file)
+    }
+
+    fn write(&mut self, data: &[u8]) -> i32 {
+        let write_len = data.len().try_into().unwrap_or(ffi::AVERROR_BUG2);
+
+        let send_result = self.tx.send(data.to_vec());
+        let write_result = self.file.as_mut().map(|file| file.write_all(data));
+
+        tracing::trace!(?write_len, ?send_result, ?write_result);
+
+        // We will keep continue writing in one of two cases below:
+        //  - We can still send data to the receiver. We don't care if we can write or not
+        //    (including the case where the file is none).
+        //  - We can write to the file (this means the file must not be none).
+        if send_result.is_ok() || write_result.is_some_and(|result| result.is_ok()) {
+            write_len
+        } else {
+            ffi::AVERROR_OUTPUT_CHANGED
+        }
+    }
+}
+
+impl From<Sink> for AVIOContextContainer {
+    fn from(mut sink: Sink) -> Self {
+        AVIOContextContainer::Custom(AVIOContextCustom::alloc_context(
+            AVMem::new(sink.buffer_size),
+            true,
+            Vec::default(),
+            None,
+            Some(Box::new(move |_, data| sink.write(data))),
+            None,
+        ))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::test::transcode::Status;
+
+    impl Sink {
+        pub fn status(&self, status: Status) -> Status {
+            match status {
+                Status::WithCache if self.file.is_none() => Status::NoCache,
+                _ => status,
+            }
+        }
+    }
+}
diff --git a/nghe-backend/src/transcode/transcoder.rs b/nghe-backend/src/transcode/transcoder.rs
new file mode 100644
index 000000000..7b23d1ef1
--- /dev/null
+++ b/nghe-backend/src/transcode/transcoder.rs
@@ -0,0 +1,341 @@
+use std::borrow::Cow;
+use std::ffi::{CStr, CString};
+use std::fmt::Debug;
+
+use concat_string::concat_string;
+use rsmpeg::avcodec::{AVCodec, AVCodecContext};
+use rsmpeg::avfilter::{AVFilter, AVFilterContextMut, AVFilterGraph, AVFilterInOut};
+use rsmpeg::avformat::{AVFormatContextInput, AVFormatContextOutput};
+use rsmpeg::avutil::AVFrame;
+use rsmpeg::error::RsmpegError;
+use rsmpeg::{avutil, ffi, UnsafeDerefMut};
+use tracing::instrument;
+
+use super::Sink;
+use crate::Error;
+
+struct Input {
+    context: AVFormatContextInput,
+    decoder: AVCodecContext,
+    index: i32,
+}
+
+struct Output {
+    context: AVFormatContextOutput,
+    encoder: AVCodecContext,
+}
+
+struct Graph {
+    filter: AVFilterGraph,
+    spec: Cow<'static, CStr>,
+}
+
+struct Filter<'a> {
+    source: AVFilterContextMut<'a>,
+    sink: AVFilterContextMut<'a>,
+}
+
+pub struct Transcoder {
+    input: Input,
+    output: Output,
+    graph: Graph,
+}
+
+impl Input {
+    fn new(input: &CStr) -> Result<Self, Error> {
+        let context = AVFormatContextInput::open(input, None, &mut None)?;
+        let (index, codec) = context
+            .find_best_stream(ffi::AVMEDIA_TYPE_AUDIO)?
+            .ok_or_else(|| Error::MediaAudioTrackMissing)?;
+        let stream = &context.streams()[index];
+
+        let mut decoder = AVCodecContext::new(&codec);
+        decoder.apply_codecpar(&stream.codecpar())?;
+        decoder.open(None)?;
+        decoder.set_pkt_timebase(stream.time_base);
+        decoder.set_bit_rate(context.bit_rate);
+
+        Ok(Self { context, decoder, index: index.try_into()? })
+    }
+}
+
+impl Output {
+    fn new(sink: Sink, bitrate: u32, decoder: &AVCodecContext) -> Result<Self, Error> {
+        let mut context = AVFormatContextOutput::create(sink.format(), Some(sink.into()))?;
+
+        if cfg!(test) {
+            // Set bitexact for deterministic transcoding output.
+            unsafe {
+                context.deref_mut().flags |= ffi::AVFMT_FLAG_BITEXACT as i32;
+            }
+        }
+
+        let codec = AVCodec::find_encoder(context.oformat().audio_codec)
+            .ok_or_else(|| Error::TranscodeOutputFormatNotSupported)?;
+
+        // bit to kbit
+        let bitrate = bitrate * 1000;
+        // Opus sample rate will always be 48000Hz.
+        let sample_rate =
+            if codec.id == ffi::AV_CODEC_ID_OPUS { 48000 } else { decoder.sample_rate };
+
+        let mut encoder = AVCodecContext::new(&codec);
+        encoder.set_ch_layout(decoder.ch_layout);
+        encoder.set_sample_fmt(
+            codec.sample_fmts().ok_or_else(|| Error::TranscodeEncoderSampleFmtsMissing)?[0],
+        );
+        encoder.set_sample_rate(sample_rate);
+        encoder.set_bit_rate(bitrate.into());
+        encoder.set_time_base(avutil::ra(1, sample_rate));
+
+        // Some formats want stream headers to be separate.
+        if context.oformat().flags & ffi::AVFMT_GLOBALHEADER as i32 != 0 {
+            encoder.set_flags(encoder.flags | ffi::AV_CODEC_FLAG_GLOBAL_HEADER as i32);
+        }
+
+        encoder.open(None)?;
+        {
+            let mut stream = context.new_stream();
+            stream.set_codecpar(encoder.extract_codecpar());
+            stream.set_time_base(encoder.time_base);
+        }
+        context.write_header(&mut None)?;
+
+        Ok(Self { context, encoder })
+    }
+
+    fn encode(&mut self, frame: Option<&AVFrame>) -> Result<(), Error> {
+        self.encoder.send_frame(frame)?;
+
+        loop {
+            let mut packet = match self.encoder.receive_packet() {
+                Err(RsmpegError::EncoderDrainError | RsmpegError::EncoderFlushedError) => {
+                    return Ok(());
+                }
+                result => result?,
+            };
+
+            packet.set_stream_index(0);
+            packet.rescale_ts(self.encoder.time_base, self.context.streams()[0].time_base);
+            self.context.interleaved_write_frame(&mut packet)?;
+        }
+    }
+
+    fn flush(&mut self) -> Result<(), Error> {
+        if self.encoder.codec().capabilities & ffi::AV_CODEC_CAP_DELAY as i32 != 0 {
+            self.encode(None)
+        } else {
+            Ok(())
+        }
+    }
+}
+
+impl Graph {
+    fn new(decoder: &AVCodecContext, encoder: &AVCodecContext, offset: u32) -> Result<Self, Error> {
+        let mut specs: Vec<Cow<'static, str>> = vec![];
+        if offset > 0 {
+            specs.push(concat_string!("atrim=start=", offset.to_string()).into());
+        }
+        if decoder.sample_rate != encoder.sample_rate {
+            specs.push("aresample=resampler=soxr".into());
+        }
+        if encoder.frame_size > 0 {
+            specs.push(
+                concat_string!("asetnsamples=n=", encoder.frame_size.to_string(), ":p=0").into(),
+            );
+        }
+
+        let spec =
+            if specs.is_empty() { c"anull".into() } else { CString::new(specs.join(","))?.into() };
+
+        Ok(Self { filter: AVFilterGraph::new(), spec })
+    }
+}
+
+impl<'graph> Filter<'graph> {
+    pub fn new(
+        graph: &'graph Graph,
+        decoder: &AVCodecContext,
+        encoder: &AVCodecContext,
+    ) -> Result<Self, Error> {
+        let source_ref = AVFilter::get_by_name(c"abuffer")
+            .ok_or_else(|| Error::TranscodeAVFilterMissing("abuffer"))?;
+        let sink_ref = AVFilter::get_by_name(c"abuffersink")
+            .ok_or_else(|| Error::TranscodeAVFilterMissing("abuffersink"))?;
+
+        let source_arg = concat_string!(
+            "time_base=",
+            decoder.pkt_timebase.num.to_string(),
+            "/",
+            decoder.pkt_timebase.den.to_string(),
+            ":sample_rate=",
+            decoder.sample_rate.to_string(),
+            ":sample_fmt=",
+            avutil::get_sample_fmt_name(decoder.sample_fmt)
+                .ok_or_else(|| Error::TranscodeSampleFmtNameMissing(decoder.sample_fmt))?
+                .to_str()?,
+            ":channel_layout=",
+            decoder.ch_layout().describe()?.to_str()?
+        );
+        let source_arg = CString::new(source_arg)?;
+        let mut source =
+            graph.filter.create_filter_context(&source_ref, c"in", Some(&source_arg))?;
+
+        let mut sink = graph.filter.create_filter_context(&sink_ref, c"out", None)?;
+        sink.opt_set_bin(c"sample_rates", &encoder.sample_rate)?;
+        sink.opt_set_bin(c"sample_fmts", &encoder.sample_fmt)?;
+        sink.opt_set(c"ch_layouts", &encoder.ch_layout().describe()?)?;
+
+        // Yes. The output name is in.
+        let outputs = AVFilterInOut::new(c"in", &mut source, 0);
+        let inputs = AVFilterInOut::new(c"out", &mut sink, 0);
+        graph.filter.parse_ptr(&graph.spec, Some(inputs), Some(outputs))?;
+
+        graph.filter.config()?;
+
+        Ok(Self { source, sink })
+    }
+
+    fn filter_and_encode(
+        &mut self,
+        output: &mut Output,
+        frame: Option<AVFrame>,
+    ) -> Result<(), Error> {
+        self.source.buffersrc_add_frame(frame, None)?;
+
+        loop {
+            let frame = match self.sink.buffersink_get_frame(None) {
+                Err(RsmpegError::BufferSinkDrainError | RsmpegError::BufferSinkEofError) => {
+                    break Ok(());
+                }
+                result => result?,
+            };
+            output.encode(Some(&frame))?;
+        }
+    }
+}
+
+impl Transcoder {
+    #[instrument(err)]
+    pub fn spawn(
+        input: impl Into<String> + Debug,
+        sink: Sink,
+        bitrate: u32,
+        offset: u32,
+    ) -> Result<tokio::task::JoinHandle<Result<(), Error>>, Error> {
+        let mut transcoder = Self::new(&CString::new(input.into())?, sink, bitrate, offset)?;
+
+        let span = tracing::Span::current();
+        Ok(tokio::task::spawn_blocking(move || {
+            let _entered = span.enter();
+            transcoder.transcode()
+        }))
+    }
+
+    fn new(input: &CStr, sink: Sink, bitrate: u32, offset: u32) -> Result<Self, Error> {
+        let input = Input::new(input)?;
+        let output = Output::new(sink, bitrate, &input.decoder)?;
+        let graph = Graph::new(&input.decoder, &output.encoder, offset)?;
+        Ok(Self { input, output, graph })
+    }
+
+    #[instrument(skip_all, ret(level = "debug"), err(level = "debug"))]
+    pub fn transcode(&mut self) -> Result<(), Error> {
+        let mut filter = Filter::new(&self.graph, &self.input.decoder, &self.output.encoder)?;
+
+        loop {
+            let packet = self.input.context.read_packet()?;
+
+            // Ignore non audio stream packets.
+            if packet.as_ref().is_some_and(|p| p.stream_index != self.input.index) {
+                continue;
+            }
+
+            self.input.decoder.send_packet(packet.as_ref())?;
+
+            // If packet is none, we are at input EOF.
+            // The decoder is flushed by passing a none packet as above.
+            if packet.is_none() {
+                break;
+            }
+
+            loop {
+                let frame = match self.input.decoder.receive_frame() {
+                    Err(RsmpegError::DecoderDrainError | RsmpegError::DecoderFlushedError) => {
+                        break;
+                    }
+                    result => result?,
+                };
+                filter.filter_and_encode(&mut self.output, Some(frame))?;
+            }
+        }
+
+        // Flush the filter graph by pushing none packet to its source.
+        filter.filter_and_encode(&mut self.output, None)?;
+
+        self.output.flush()?;
+        self.output.context.write_trailer()?;
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use futures_lite::{stream, StreamExt};
+    use nghe_api::common::format;
+    use typed_path::Utf8NativePathBuf;
+
+    use super::*;
+    use crate::config;
+
+    impl Transcoder {
+        pub async fn spawn_collect(
+            input: impl Into<String> + Debug,
+            config: &config::Transcode,
+            format: format::Transcode,
+            bitrate: u32,
+            offset: u32,
+        ) -> Vec<u8> {
+            let (sink, rx) = Sink::new(config, format, None::<Utf8NativePathBuf>).await.unwrap();
+            let handle = Transcoder::spawn(input, sink, bitrate, offset).unwrap();
+            let data = rx.into_stream().map(stream::iter).flatten().collect().await;
+            handle.await.unwrap().unwrap();
+            data
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use nghe_api::common::format;
+    use rstest::rstest;
+    use typed_path::Utf8NativePath;
+
+    use super::*;
+    use crate::config;
+
+    #[cfg(hearing_test)]
+    #[rstest]
+    #[case(format::Transcode::Opus, 64)]
+    #[case(format::Transcode::Mp3, 320)]
+    #[tokio::test]
+    async fn test_hearing(
+        #[case] format: format::Transcode,
+        #[case] bitrate: u32,
+        #[values(0, 10)] offset: u32,
+    ) {
+        let input = env!("NGHE_HEARING_TEST_INPUT");
+        let config = config::Transcode::default();
+        let data = Transcoder::spawn_collect(input, &config, format, bitrate, offset).await;
+
+        tokio::fs::write(
+            Utf8NativePath::new(env!("NGHE_HEARING_TEST_OUTPUT"))
+                .join(concat_string!(bitrate.to_string(), "-", offset.to_string()))
+                .with_extension(format.as_ref()),
+            &data,
+        )
+        .await
+        .unwrap();
+    }
+}
diff --git a/nghe-proc-macro/Cargo.toml b/nghe-proc-macro/Cargo.toml
new file mode 100644
index 000000000..df69fe818
--- /dev/null
+++ b/nghe-proc-macro/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+name = "nghe_proc_macro"
+version = { workspace = true }
+edition = { workspace = true }
+
+[lints]
+workspace = true
+
+[lib]
+proc-macro = true
+
+[dependencies]
+bon = { workspace = true }
+concat-string = { workspace = true }
+convert_case = { workspace = true }
+
+deluxe = { version = "0.5.0" }
+proc-macro2 = { version = "1.0.86" }
+quote = { version = "1.0.36" }
+syn = { version = "2.0.68", features = ["fold", "full"] }
diff --git a/nghe-proc-macro/src/api.rs b/nghe-proc-macro/src/api.rs
new file mode 100644
index 000000000..6bba7d150
--- /dev/null
+++ b/nghe-proc-macro/src/api.rs
@@ -0,0 +1,210 @@
+use concat_string::concat_string;
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote};
+use syn::{parse_quote, parse_str, Error};
+
+#[derive(Debug, deluxe::ExtractAttributes)]
+#[deluxe(attributes(endpoint))]
+struct Endpoint {
+    path: String,
+    #[deluxe(default = true)]
+    json: bool,
+    #[deluxe(default = true)]
+    binary: bool,
+    #[deluxe(default = false)]
+    url_only: bool,
+    #[deluxe(default = true)]
+    same_crate: bool,
+}
+
+#[derive(Debug, deluxe::ParseMetaItem)]
+struct Derive {
+    #[deluxe(default = false)]
+    request: bool,
+    #[deluxe(default = false)]
+    response: bool,
+    #[deluxe(default = false)]
+    endpoint: bool,
+    #[deluxe(default = true)]
+    debug: bool,
+    #[deluxe(default = true)]
+    json: bool,
+    #[deluxe(default = true)]
+    binary: bool,
+    #[deluxe(default = true)]
+    fake: bool,
+    #[deluxe(default = true)]
+    copy: bool,
+    #[deluxe(default = true)]
+    eq: bool,
+    #[deluxe(default = true)]
+    ord: bool,
+    #[deluxe(default = true)]
+    test_only: bool,
+}
+
+pub fn derive_endpoint(item: TokenStream) -> Result<TokenStream, Error> {
+    let mut input: syn::DeriveInput = syn::parse2(item)?;
+    let Endpoint { path, json, binary, url_only, same_crate } =
+        deluxe::extract_attributes(&mut input)?;
+
+    let ident = &input.ident;
+    if ident != "Request" {
+        return Err(syn::Error::new(
+            ident.span(),
+            "Struct derived with `Endpoint` should be named `Request`",
+        ));
+    }
+
+    let crate_path = if same_crate { format_ident!("crate") } else { format_ident!("nghe_api") };
+
+    let impl_json = if json {
+        let url = concat_string!("/rest/", &path);
+        let url_view = concat_string!("/rest/", &path, ".view");
+
+        let impl_endpoint = if url_only {
+            quote! {}
+        } else {
+            quote! {
+                impl #crate_path::common::JsonEndpoint for #ident {
+                    type Response = Response;
+                }
+            }
+        };
+
+        quote! {
+            impl #crate_path::common::JsonURL for #ident {
+                const URL: &'static str = #url;
+                const URL_VIEW: &'static str = #url_view;
+            }
+
+            #impl_endpoint
+        }
+    } else {
+        quote! {}
+    };
+
+    let impl_binary = if binary {
+        let url_binary = concat_string!("/rest/", &path, ".bin");
+
+        let impl_endpoint = if url_only {
+            quote! {}
+        } else {
+            quote! {
+                impl #crate_path::common::BinaryEndpoint for #ident {
+                    type Response = Response;
+                }
+            }
+        };
+
+        quote! {
+            impl #crate_path::common::BinaryURL for #ident {
+                const URL_BINARY: &'static str = #url_binary;
+            }
+
+            #impl_endpoint
+        }
+    } else {
+        quote! {}
+    };
+
+    Ok(quote! {
+        #impl_json
+        #impl_binary
+    })
+}
+
+pub fn derive(args: TokenStream, item: TokenStream) -> Result<TokenStream, Error> {
+    let args: Derive = deluxe::parse2(args)?;
+    let input: syn::DeriveInput = syn::parse2(item)?;
+
+    let ident = input.ident.to_string();
+    let is_request_struct = ident == "Request";
+    let is_request = args.request || ident.ends_with("Request");
+    let is_response = args.response || ident.ends_with("Response");
+
+    let is_enum = matches!(input.data, syn::Data::Enum(_));
+
+    let mut derives: Vec<syn::Expr> = vec![];
+    let mut attributes: Vec<syn::Attribute> = vec![];
+
+    if args.json {
+        if is_request {
+            derives.push(parse_str("::serde::Deserialize")?);
+        }
+        if is_response {
+            derives.push(parse_str("::serde::Serialize")?);
+        }
+    }
+
+    if args.debug {
+        derives.push(parse_str("Debug")?);
+    }
+    if args.binary {
+        derives.push(parse_str("bitcode::Encode")?);
+        derives.push(parse_str("bitcode::Decode")?);
+    }
+    if args.endpoint || is_request_struct {
+        derives.push(parse_str("nghe_proc_macro::Endpoint")?);
+        if !args.json {
+            attributes.push(parse_quote!(#[endpoint(json = false)]));
+        }
+        if !args.binary {
+            attributes.push(parse_quote!(#[endpoint(binary = false)]));
+        }
+    }
+
+    if args.json {
+        if is_enum {
+            attributes.push(parse_quote!(#[serde(rename_all_fields = "camelCase")]));
+        }
+        attributes.push(parse_quote!(#[serde(rename_all = "camelCase")]));
+    };
+
+    if is_request && args.fake {
+        attributes
+            .push(parse_quote!(#[cfg_attr(any(test, feature = "fake"), derive(fake::Dummy))]));
+    }
+
+    if is_enum {
+        derives.extend_from_slice(
+            &["Clone", "PartialEq", "Eq", "PartialOrd", "Ord"]
+                .into_iter()
+                .map(parse_str)
+                .try_collect::<Vec<_>>()?,
+        );
+        if args.copy {
+            derives.push(parse_str("Copy")?);
+        }
+    }
+
+    if !is_enum && args.eq {
+        if args.test_only {
+            attributes.push(
+                parse_quote!(#[cfg_attr(any(test, feature = "test"), derive(PartialEq, Eq))]),
+            );
+        } else {
+            derives.extend_from_slice(
+                &["PartialEq", "Eq"].into_iter().map(parse_str).try_collect::<Vec<_>>()?,
+            );
+        }
+    }
+
+    if !is_enum && args.ord {
+        if args.test_only {
+            attributes.push(
+                parse_quote!(#[cfg_attr(any(test, feature = "test"), derive(PartialOrd, Ord))]),
+            );
+        } else {
+            derives.extend_from_slice(
+                &["PartialOrd", "Ord"].into_iter().map(parse_str).try_collect::<Vec<_>>()?,
+            );
+        }
+    }
+
+    Ok(quote! {
+        #[derive(#(#derives),*)]
+        #( #attributes )*
+        #input
+    })
+}
diff --git a/nghe-proc-macro/src/backend.rs b/nghe-proc-macro/src/backend.rs
new file mode 100644
index 000000000..7c2514d5a
--- /dev/null
+++ b/nghe-proc-macro/src/backend.rs
@@ -0,0 +1,378 @@
+#![allow(clippy::too_many_lines)]
+
+use convert_case::{Case, Casing};
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote};
+use syn::spanned::Spanned;
+use syn::{parse_quote, Error};
+
+#[derive(Debug, deluxe::ParseMetaItem)]
+struct Handler {
+    #[deluxe(default = "trace".into())]
+    ret_level: String,
+    role: Option<syn::Ident>,
+    #[deluxe(default = true)]
+    json: bool,
+    #[deluxe(default = true)]
+    binary: bool,
+    #[deluxe(default = vec![])]
+    headers: Vec<syn::Ident>,
+    #[deluxe(default = true)]
+    need_auth: bool,
+}
+
+#[derive(Debug, deluxe::ParseMetaItem)]
+struct BuildRouter {
+    modules: Vec<syn::Expr>,
+    #[deluxe(default = false)]
+    filesystem: bool,
+    #[deluxe(default = vec![])]
+    extensions: Vec<syn::Path>,
+}
+
+#[derive(Debug, bon::Builder)]
+struct ModuleConfig {
+    pub ident: syn::Ident,
+    #[builder(default = true)]
+    pub json: bool,
+    #[builder(default = true)]
+    pub binary: bool,
+}
+
+impl TryFrom<syn::Expr> for ModuleConfig {
+    type Error = Error;
+
+    fn try_from(value: syn::Expr) -> Result<Self, Self::Error> {
+        let span = value.span();
+        match value {
+            syn::Expr::Path(syn::ExprPath { path, .. }) => {
+                let ident = path
+                    .get_ident()
+                    .ok_or_else(|| Error::new(span, "Only `Path` with one segment is supported"))?
+                    .to_owned();
+                Ok(Self::builder().ident(ident).build())
+            }
+            syn::Expr::Struct(syn::ExprStruct { path, fields, .. }) => {
+                let ident = path
+                    .get_ident()
+                    .ok_or_else(|| {
+                        Error::new(span, "Only `Struct` path with one segment is supported")
+                    })?
+                    .to_owned();
+
+                let extract_bool = |key: &'static str| -> Option<bool> {
+                    fields.iter().find_map(|value| {
+                        if let syn::Member::Named(ref ident) = value.member
+                            && ident == key
+                            && let syn::Expr::Lit(syn::ExprLit { ref lit, .. }) = value.expr
+                            && let syn::Lit::Bool(syn::LitBool { value, .. }) = lit
+                        {
+                            Some(*value)
+                        } else {
+                            None
+                        }
+                    })
+                };
+
+                Ok(Self::builder()
+                    .ident(ident)
+                    .maybe_json(extract_bool("json"))
+                    .maybe_binary(extract_bool("binary"))
+                    .build())
+            }
+            _ => Err(Error::new(span, "Only `Path` and `Struct` expressions are supported")),
+        }
+    }
+}
+
+pub fn handler(attr: TokenStream, item: TokenStream) -> Result<TokenStream, Error> {
+    let input: syn::ItemFn = syn::parse2(item)?;
+    let Handler { ret_level, role, json, binary, headers, need_auth } = deluxe::parse2(attr)?;
+
+    let ident = &input.sig.ident;
+    if ident != "handler" {
+        return Err(syn::Error::new(
+            ident.span(),
+            "Function derived with `handler` should be named `handler`",
+        ));
+    }
+
+    let mut skip_debugs: Vec<&syn::Ident> = vec![];
+    let mut common_args: Vec<syn::FnArg> = vec![];
+    let mut pass_args: Vec<syn::Expr> = vec![];
+
+    for fn_arg in &input.sig.inputs {
+        if let syn::FnArg::Typed(arg) = fn_arg
+            && let syn::Pat::Ident(pat) = arg.pat.as_ref()
+            && pat.ident != "request"
+        {
+            match pat.ident.to_string().as_str() {
+                "database" | "_database" => {
+                    skip_debugs.push(&pat.ident);
+                    common_args.push(parse_quote! {
+                        extract::State(database): extract::State<crate::database::Database>
+                    });
+                    pass_args.push(parse_quote!(&database));
+                }
+                "user_id" => {
+                    pass_args.push(parse_quote!(user.id));
+                }
+                _ => match arg.ty.as_ref() {
+                    syn::Type::Path(ty) => {
+                        if headers.contains(&pat.ident) {
+                            if let Some(segment) = ty.path.segments.last()
+                                && segment.ident == "Option"
+                                && let syn::PathArguments::AngleBracketed(angle) =
+                                    &segment.arguments
+                                && let Some(syn::GenericArgument::Type(syn::Type::Path(ty))) =
+                                    angle.args.first()
+                            {
+                                common_args
+                                    .push(parse_quote!(#pat: Option<axum_extra::TypedHeader<#ty>>));
+                                pass_args.push(parse_quote!(#pat.map(|header| header.0)));
+                            }
+                        } else {
+                            if pat.ident == "config" {
+                                skip_debugs.push(&pat.ident);
+                            }
+                            common_args.push(
+                                parse_quote!(extract::Extension(#pat): extract::Extension<#ty>),
+                            );
+                            pass_args.push(parse_quote!(#pat));
+                        }
+                    }
+                    syn::Type::Reference(ty) => {
+                        if pat.ident == "filesystem" || pat.ident == "config" {
+                            skip_debugs.push(&pat.ident);
+                        }
+                        let ty = ty.elem.as_ref();
+                        common_args
+                            .push(parse_quote!(extract::Extension(#pat): extract::Extension<#ty>));
+                        pass_args.push(parse_quote!(&#pat));
+                    }
+                    _ => {
+                        return Err(syn::Error::new(
+                            arg.ty.span(),
+                            "Only path type and reference type are supported for handler function",
+                        ));
+                    }
+                },
+            }
+        }
+    }
+
+    let (authorize_fn, missing_role) = if let Some(role) = role {
+        if role == "admin" {
+            (quote! { role.admin }, role.to_string())
+        } else {
+            (quote! { role.admin || role.#role }, role.to_string())
+        }
+    } else {
+        (quote! { true }, String::default())
+    };
+
+    let is_binary_respone = if let syn::ReturnType::Type(_, ty) = &input.sig.output
+        && let syn::Type::Path(ty) = ty.as_ref()
+        && let Some(segment) = ty.path.segments.last()
+        && segment.ident == "Result"
+        && let syn::PathArguments::AngleBracketed(angle) = &segment.arguments
+        && let Some(syn::GenericArgument::Type(syn::Type::Path(ty))) = angle.args.first()
+        && let Some(segment) = ty.path.segments.first()
+        && segment.ident == "binary"
+        && let Some(segment) = ty.path.segments.last()
+        && segment.ident == "Response"
+    {
+        true
+    } else {
+        false
+    };
+
+    pass_args.push(parse_quote!(user.request));
+
+    let json_handler = if json {
+        let json_get_args =
+            [common_args.as_slice(), [parse_quote!(user: GetUser<Request, #need_auth>)].as_slice()]
+                .concat();
+        let json_post_args =
+            [common_args.as_slice(), [parse_quote!(user: PostUser<Request>)].as_slice()].concat();
+
+        if is_binary_respone {
+            quote! {
+                #[axum::debug_handler]
+                pub async fn json_get_handler(
+                    #( #json_get_args ),*
+                ) -> Result<crate::http::binary::Response, Error> {
+                    #ident(#( #pass_args ),*).await
+                }
+
+                #[axum::debug_handler]
+                pub async fn json_post_handler(
+                    #( #json_post_args ),*
+                ) -> Result<crate::http::binary::Response, Error> {
+                    #ident(#( #pass_args ),*).await
+                }
+            }
+        } else {
+            quote! {
+                #[axum::debug_handler]
+                pub async fn json_get_handler(
+                    #( #json_get_args ),*
+                ) -> Result<
+                        axum::Json<SubsonicResponse<<Request as JsonEndpoint>::Response>
+                    >, Error> {
+                    let response = #ident(#( #pass_args ),*).await?;
+                    Ok(axum::Json(SubsonicResponse::new(response)))
+                }
+
+                #[axum::debug_handler]
+                pub async fn json_post_handler(
+                    #( #json_post_args ),*
+                ) -> Result<
+                        axum::Json<SubsonicResponse<<Request as JsonEndpoint>::Response>
+                    >, Error> {
+                    let response = #ident(#( #pass_args ),*).await?;
+                    Ok(axum::Json(SubsonicResponse::new(response)))
+                }
+            }
+        }
+    } else {
+        quote! {}
+    };
+
+    let binary_handler = if binary {
+        let binary_args = [
+            common_args.as_slice(),
+            [parse_quote!(user: BinaryUser<Request, #need_auth>)].as_slice(),
+        ]
+        .concat();
+
+        if is_binary_respone {
+            quote! {
+                #[axum::debug_handler]
+                pub async fn binary_handler(
+                    #( #binary_args ),*
+                ) -> Result<crate::http::binary::Response, Error> {
+                    #ident(#( #pass_args ),*).await
+                }
+            }
+        } else {
+            quote! {
+                #[axum::debug_handler]
+                pub async fn binary_handler(
+                    #( #binary_args ),*
+                ) -> Result<Vec<u8>, Error> {
+                    let response = #ident(#( #pass_args ),*).await?;
+                    Ok(bitcode::encode(&response))
+                }
+            }
+        }
+    } else {
+        quote! {}
+    };
+
+    Ok(quote! {
+        #[tracing::instrument(skip(#( #skip_debugs ),*), ret(level = #ret_level), err)]
+        #input
+
+        use axum::extract;
+        use nghe_api::common::{JsonEndpoint, SubsonicResponse};
+
+        use crate::auth::{Authorize, BinaryUser, GetUser, PostUser};
+
+        impl Authorize for Request {
+            fn authorize(role: crate::orm::users::Role) -> Result<(), Error> {
+                if #authorize_fn {
+                    Ok(())
+                } else {
+                    Err(Error::MissingRole(#missing_role))
+                }
+            }
+        }
+
+        #json_handler
+        #binary_handler
+    })
+}
+
+pub fn build_router(item: TokenStream) -> Result<TokenStream, Error> {
+    let input = deluxe::parse2::<BuildRouter>(item)?;
+    let endpoints: Vec<_> = input
+        .modules
+        .into_iter()
+        .map(|module| {
+            let config: ModuleConfig = module.try_into()?;
+            let module = config.ident;
+
+            let json_get_handler = quote! { #module::json_get_handler };
+            let json_post_handler = quote! { #module::json_post_handler };
+            let binary_handler = quote! { #module::binary_handler };
+
+            let mut routers = vec![];
+
+            if config.json {
+                let request = quote! { <#module::Request as nghe_api::common::JsonURL> };
+
+                routers.push(quote! {
+                    route(
+                        #request::URL,
+                        axum::routing::get(#json_get_handler).post(#json_post_handler)
+                    )
+                });
+                routers.push(quote! {
+                    route(
+                        #request::URL_VIEW,
+                        axum::routing::get(#json_get_handler).post(#json_post_handler)
+                    )
+                });
+            }
+
+            if config.binary {
+                let request = quote! { <#module::Request as nghe_api::common::BinaryURL> };
+
+                routers.push(quote! {
+                    route(
+                        #request::URL_BINARY,
+                        axum::routing::post(#binary_handler)
+                    )
+                });
+            }
+
+            Ok::<_, Error>(routers)
+        })
+        .try_collect::<Vec<_>>()?
+        .into_iter()
+        .flatten()
+        .collect();
+
+    let mut router_args: Vec<syn::FnArg> = vec![];
+    let mut router_layers: Vec<syn::Expr> = vec![];
+
+    if input.filesystem {
+        router_args.push(parse_quote!(filesystem: crate::filesystem::Filesystem));
+        router_layers.push(parse_quote!(layer(axum::Extension(filesystem))));
+    }
+
+    for extension in input.extensions {
+        let arg = extension
+            .segments
+            .iter()
+            .map(|segment| segment.ident.to_string().to_case(Case::Snake))
+            .collect::<Vec<_>>()
+            .join("_");
+        let arg = format_ident!("{arg}");
+        router_args.push(parse_quote!(#arg: #extension));
+        router_layers.push(parse_quote!(layer(axum::Extension(#arg))));
+    }
+
+    let router_body: syn::Expr = if router_layers.is_empty() {
+        parse_quote!(axum::Router::new().#( #endpoints ).*)
+    } else {
+        parse_quote!(axum::Router::new().#( #endpoints ).*.#( #router_layers ).*)
+    };
+
+    Ok(quote! {
+        pub fn router(#( #router_args ),*) -> axum::Router<crate::database::Database> {
+            #router_body
+        }
+    })
+}
diff --git a/nghe-proc-macro/src/lib.rs b/nghe-proc-macro/src/lib.rs
new file mode 100644
index 000000000..c3d3f5858
--- /dev/null
+++ b/nghe-proc-macro/src/lib.rs
@@ -0,0 +1,46 @@
+#![feature(iterator_try_collect)]
+#![feature(let_chains)]
+
+use proc_macro::TokenStream;
+
+mod api;
+mod backend;
+mod orm;
+
+trait IntoTokenStream {
+    fn into_token_stream(self) -> TokenStream;
+}
+
+impl IntoTokenStream for Result<proc_macro2::TokenStream, syn::Error> {
+    fn into_token_stream(self) -> TokenStream {
+        match self {
+            Ok(r) => r.into(),
+            Err(e) => e.to_compile_error().into(),
+        }
+    }
+}
+
+#[proc_macro_derive(Endpoint, attributes(endpoint))]
+pub fn derive_endpoint(item: TokenStream) -> TokenStream {
+    api::derive_endpoint(item.into()).into_token_stream()
+}
+
+#[proc_macro_attribute]
+pub fn api_derive(attr: TokenStream, item: TokenStream) -> TokenStream {
+    api::derive(attr.into(), item.into()).into_token_stream()
+}
+
+#[proc_macro_attribute]
+pub fn handler(attr: TokenStream, item: TokenStream) -> TokenStream {
+    backend::handler(attr.into(), item.into()).into_token_stream()
+}
+
+#[proc_macro]
+pub fn build_router(item: TokenStream) -> TokenStream {
+    backend::build_router(item.into()).into_token_stream()
+}
+
+#[proc_macro_attribute]
+pub fn check_music_folder(attr: TokenStream, item: TokenStream) -> TokenStream {
+    orm::check_music_folder(attr.into(), item.into()).into_token_stream()
+}
diff --git a/nghe-proc-macro/src/orm.rs b/nghe-proc-macro/src/orm.rs
new file mode 100644
index 000000000..7ced573ed
--- /dev/null
+++ b/nghe-proc-macro/src/orm.rs
@@ -0,0 +1,52 @@
+use proc_macro2::TokenStream;
+use quote::quote;
+use syn::fold::Fold;
+use syn::{parse_quote, Error};
+
+#[derive(Debug, deluxe::ParseMetaItem)]
+struct CheckMusicFolder {
+    #[deluxe(default = parse_quote!(request.music_folder_ids.as_ref()))]
+    input: syn::Expr,
+    #[deluxe(default = parse_quote!(with_user_id))]
+    user_id: syn::Ident,
+    #[deluxe(default = parse_quote!(with_music_folder))]
+    music_folder: syn::Ident,
+}
+
+impl Fold for CheckMusicFolder {
+    fn fold_expr_call(&mut self, expr: syn::ExprCall) -> syn::ExprCall {
+        if let syn::Expr::Path(syn::ExprPath { path, .. }) = expr.func.as_ref()
+            && let Some(segment) = path.segments.last()
+            && segment.ident == self.user_id
+            && expr.args.len() == 1
+            && let Some(syn::Expr::Path(arg)) = expr.args.last()
+            && let Some(arg) = arg.path.get_ident()
+            && arg == "user_id"
+        {
+            let mut with_music_folder_path = path.clone();
+            with_music_folder_path.segments.pop();
+            with_music_folder_path.segments.push(syn::PathSegment {
+                ident: self.music_folder.clone(),
+                arguments: syn::PathArguments::None,
+            });
+            parse_quote! { #with_music_folder_path(user_id, music_folder_ids) }
+        } else {
+            expr
+        }
+    }
+}
+
+pub fn check_music_folder(args: TokenStream, item: TokenStream) -> Result<TokenStream, Error> {
+    let check_user_id: syn::Expr = syn::parse2(item)?;
+    let mut args: CheckMusicFolder = deluxe::parse2(args)?;
+    let check_music_folder: syn::Expr = args.fold_expr(check_user_id.clone());
+
+    let input = args.input;
+    Ok(quote! {
+        if let Some(music_folder_ids) = #input {
+            #check_music_folder
+        } else {
+            #check_user_id
+        }
+    })
+}
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index a1ba14f8f..6cfccbde4 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,2 +1,2 @@
 [toolchain]
-channel = "nightly-2024-10-22"
+channel = "nightly-2024-11-22"