diff --git a/engine/Cargo.lock b/engine/Cargo.lock
index 9a14b2ad7..c9a9327ec 100644
--- a/engine/Cargo.lock
+++ b/engine/Cargo.lock
@@ -1119,6 +1119,26 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "bindgen"
+version = "0.69.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "271383c67ccabffb7381723dea0672a673f292304fcb45c01cc648c7a8d58088"
+dependencies = [
+ "bitflags 2.6.0",
+ "cexpr",
+ "clang-sys",
+ "itertools 0.10.5",
+ "lazy_static",
+ "lazycell",
+ "proc-macro2",
+ "quote",
+ "regex",
+ "rustc-hash",
+ "shlex",
+ "syn 2.0.87",
+]
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -1238,6 +1258,15 @@ version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "47de7e88bbbd467951ae7f5a6f34f70d1b4d9cfce53d5fd70f74ebe118b3db56"
 
+[[package]]
+name = "cexpr"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6fac387a98bb7c37292057cffc56d62ecb629900026402633ae9160df93a8766"
+dependencies = [
+ "nom",
+]
+
 [[package]]
 name = "cfb"
 version = "0.7.3"
@@ -1269,6 +1298,17 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[package]]
+name = "clang-sys"
+version = "1.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b023947811758c97c59bf9d1c188fd619ad4718dcaa767947df1cadb14f39f4"
+dependencies = [
+ "glob",
+ "libc",
+ "libloading",
+]
+
 [[package]]
 name = "clap"
 version = "4.5.9"
@@ -2856,6 +2896,12 @@ version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
+[[package]]
+name = "lazycell"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
+
 [[package]]
 name = "libc"
 version = "0.2.155"
@@ -2920,6 +2966,29 @@ dependencies = [
  "value-bag",
 ]
 
+[[package]]
+name = "magnus"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d87ae53030f3a22e83879e666cb94e58a7bdf31706878a0ba48752994146dab"
+dependencies = [
+ "magnus-macros",
+ "rb-sys",
+ "rb-sys-env",
+ "seq-macro",
+]
+
+[[package]]
+name = "magnus-macros"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5968c820e2960565f647819f5928a42d6e874551cab9d88d75e3e0660d7f71e3"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.87",
+]
+
 [[package]]
 name = "match_cfg"
 version = "0.1.0"
@@ -3792,6 +3861,36 @@ dependencies = [
  "crossbeam-utils",
 ]
 
+[[package]]
+name = "rb-sys"
+version = "0.9.103"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91dbe37ab6ac2fba187480fb6544b92445e41e5c6f553bf0c33743f3c450a1df"
+dependencies = [
+ "rb-sys-build",
+]
+
+[[package]]
+name = "rb-sys-build"
+version = "0.9.103"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4d56a49dcb646b70b758789c0d16c055a386a4f2a3346333abb69850fa860ce"
+dependencies = [
+ "bindgen",
+ "lazy_static",
+ "proc-macro2",
+ "quote",
+ "regex",
+ "shell-words",
+ "syn 2.0.87",
+]
+
+[[package]]
+name = "rb-sys-env"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a35802679f07360454b418a5d1735c89716bde01d35b1560fc953c1415a0b3bb"
+
 [[package]]
 name = "redox_syscall"
 version = "0.4.1"
@@ -3972,6 +4071,29 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "ruby_ffi"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "baml-cli",
+ "baml-runtime",
+ "baml-types",
+ "base64 0.22.1",
+ "env_logger",
+ "futures",
+ "indexmap 2.2.6",
+ "log",
+ "magnus",
+ "rb-sys",
+ "rb-sys-env",
+ "serde",
+ "serde_json",
+ "serde_magnus",
+ "tokio",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.24"
@@ -4199,6 +4321,12 @@ dependencies = [
  "futures-core",
 ]
 
+[[package]]
+name = "seq-macro"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3f0bf26fd526d2a95683cd0f87bf103b8539e2ca1ef48ce002d67aad59aa0b4"
+
 [[package]]
 name = "serde"
 version = "1.0.209"
@@ -4253,6 +4381,16 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_magnus"
+version = "0.9.0"
+source = "git+https://github.com/BoundaryML/serde-magnus.git?branch=sam/magnus-0.7.1#c547ef5ef475087ce57322b8e74c4a73ee2ab84b"
+dependencies = [
+ "magnus",
+ "serde",
+ "tap",
+]
+
 [[package]]
 name = "serde_path_to_error"
 version = "0.1.16"
@@ -4341,6 +4479,12 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
 [[package]]
 name = "signal-hook-registry"
 version = "1.4.2"
@@ -4548,6 +4692,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "tap"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
+
 [[package]]
 name = "target-lexicon"
 version = "0.12.15"
diff --git a/engine/Cargo.toml b/engine/Cargo.toml
index 3f7db103e..041a886f7 100644
--- a/engine/Cargo.toml
+++ b/engine/Cargo.toml
@@ -8,7 +8,7 @@ members = [
   "cli",
   "language_client_codegen",
   "language_client_python",
-  # "language_client_ruby/ext/ruby_ffi",
+  "language_client_ruby/ext/ruby_ffi",
   "language_client_typescript",
 ]
 default-members = [