diff --git a/engine/Cargo.lock b/engine/Cargo.lock
index 3f8f27ad0..6dabfb12b 100644
--- a/engine/Cargo.lock
+++ b/engine/Cargo.lock
@@ -895,6 +895,7 @@ dependencies = [
  "serde",
  "serde_json",
  "tokio",
+ "tracing-subscriber",
 ]
 
 [[package]]
@@ -1060,6 +1061,7 @@ dependencies = [
  "serde",
  "serde_json",
  "tokio",
+ "tracing-subscriber",
 ]
 
 [[package]]
@@ -4010,6 +4012,7 @@ dependencies = [
  "serde_json",
  "serde_magnus",
  "tokio",
+ "tracing-subscriber",
 ]
 
 [[package]]
diff --git a/engine/language_client_python/Cargo.toml b/engine/language_client_python/Cargo.toml
index 0c2a13268..622f32b83 100644
--- a/engine/language_client_python/Cargo.toml
+++ b/engine/language_client_python/Cargo.toml
@@ -46,6 +46,7 @@ regex.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 tokio = { version = "1", features = ["full"] }
+tracing-subscriber = { version = "0.3.18", features = ["json", "env-filter","valuable"] }
 
 [build-dependencies]
 pyo3-build-config = "0.21.2"
diff --git a/engine/language_client_python/src/lib.rs b/engine/language_client_python/src/lib.rs
index 299b1e237..dbf693d47 100644
--- a/engine/language_client_python/src/lib.rs
+++ b/engine/language_client_python/src/lib.rs
@@ -5,6 +5,7 @@ mod types;
 
 use pyo3::prelude::{pyfunction, pymodule, PyAnyMethods, PyModule, PyResult};
 use pyo3::{wrap_pyfunction, Bound, Python};
+use tracing_subscriber::{self, EnvFilter};
 
 #[pyfunction]
 fn invoke_runtime_cli(py: Python) -> PyResult<()> {
@@ -21,14 +22,36 @@ fn invoke_runtime_cli(py: Python) -> PyResult<()> {
 
 #[pymodule]
 fn baml_py(m: Bound<'_, PyModule>) -> PyResult<()> {
-    if let Err(e) = env_logger::try_init_from_env(
-        env_logger::Env::new()
-            .filter("BAML_LOG")
-            .write_style("BAML_LOG_STYLE"),
-    ) {
-        eprintln!("Failed to initialize BAML logger: {:#}", e);
+    let use_json = match std::env::var("BAML_LOG_JSON") {
+        Ok(val) => val.trim().eq_ignore_ascii_case("true") || val.trim() == "1",
+        Err(_) => false,
     };
 
+    if use_json {
+        // JSON formatting
+        tracing_subscriber::fmt()
+            .with_target(false)
+            .with_file(false)
+            .with_line_number(false)
+            .json()
+            .with_env_filter(
+                EnvFilter::try_from_env("BAML_LOG").unwrap_or_else(|_| EnvFilter::new("info")),
+            )
+            .flatten_event(true)
+            .with_current_span(false)
+            .with_span_list(false)
+            .init();
+    } else {
+        // Regular formatting
+        if let Err(e) = env_logger::try_init_from_env(
+            env_logger::Env::new()
+                .filter("BAML_LOG")
+                .write_style("BAML_LOG_STYLE"),
+        ) {
+            eprintln!("Failed to initialize BAML logger: {:#}", e);
+        }
+    }
+
     m.add_class::<runtime::BamlRuntime>()?;
 
     m.add_class::<types::FunctionResult>()?;
diff --git a/engine/language_client_ruby/ext/ruby_ffi/Cargo.toml b/engine/language_client_ruby/ext/ruby_ffi/Cargo.toml
index 83a05013d..7899cfa80 100644
--- a/engine/language_client_ruby/ext/ruby_ffi/Cargo.toml
+++ b/engine/language_client_ruby/ext/ruby_ffi/Cargo.toml
@@ -31,6 +31,7 @@ serde.workspace = true
 serde_json.workspace = true
 serde_magnus = { git = "https://github.com/BoundaryML/serde-magnus.git", branch = "sam/magnus-0.7.1" }
 tokio = { version = "1", features = ["full"] }
+tracing-subscriber = { version = "0.3.18", features = ["json", "env-filter","valuable"] }
 
 [dev-dependencies.magnus]
 version = "0.7.1"
diff --git a/engine/language_client_ruby/ext/ruby_ffi/src/lib.rs b/engine/language_client_ruby/ext/ruby_ffi/src/lib.rs
index 3338fe7ea..7286a2487 100644
--- a/engine/language_client_ruby/ext/ruby_ffi/src/lib.rs
+++ b/engine/language_client_ruby/ext/ruby_ffi/src/lib.rs
@@ -4,6 +4,7 @@ use magnus::{class, function, method, prelude::*, Error, RHash, Ruby};
 use std::collections::HashMap;
 use std::path::PathBuf;
 use std::sync::Arc;
+use tracing_subscriber::EnvFilter;
 
 use function_result::FunctionResult;
 use function_result_stream::FunctionResultStream;
@@ -201,14 +202,36 @@ fn invoke_runtime_cli(ruby: &Ruby, argv0: String, argv: Vec<String>) -> Result<(
 
 #[magnus::init(name = "ruby_ffi")]
 fn init(ruby: &Ruby) -> Result<()> {
-    if let Err(e) = env_logger::try_init_from_env(
-        env_logger::Env::new()
-            .filter("BAML_LOG")
-            .write_style("BAML_LOG_STYLE"),
-    ) {
-        eprintln!("Failed to initialize BAML logger: {:#}", e);
+    let use_json = match std::env::var("BAML_LOG_JSON") {
+        Ok(val) => val.trim().eq_ignore_ascii_case("true") || val.trim() == "1",
+        Err(_) => false,
     };
 
+    if use_json {
+        // JSON formatting
+        tracing_subscriber::fmt()
+            .with_target(false)
+            .with_file(false)
+            .with_line_number(false)
+            .json()
+            .with_env_filter(
+                EnvFilter::try_from_env("BAML_LOG").unwrap_or_else(|_| EnvFilter::new("info")),
+            )
+            .flatten_event(true)
+            .with_current_span(false)
+            .with_span_list(false)
+            .init();
+    } else {
+        // Regular formatting
+        if let Err(e) = env_logger::try_init_from_env(
+            env_logger::Env::new()
+                .filter("BAML_LOG")
+                .write_style("BAML_LOG_STYLE"),
+        ) {
+            eprintln!("Failed to initialize BAML logger: {:#}", e);
+        }
+    }
+
     let module = ruby.define_module("Baml")?.define_module("Ffi")?;
 
     module.define_module_function("invoke_runtime_cli", function!(invoke_runtime_cli, 2))?;
diff --git a/engine/language_client_typescript/Cargo.toml b/engine/language_client_typescript/Cargo.toml
index 59172ff8b..39de4ab86 100644
--- a/engine/language_client_typescript/Cargo.toml
+++ b/engine/language_client_typescript/Cargo.toml
@@ -33,6 +33,7 @@ napi-derive = "2"
 serde.workspace = true
 serde_json.workspace = true
 tokio = { version = "1", features = ["full"] }
+tracing-subscriber = { version = "0.3.18", features = ["json", "env-filter","valuable"] }
 
 [build-dependencies]
 napi-build = "2.1.3"
diff --git a/engine/language_client_typescript/src/lib.rs b/engine/language_client_typescript/src/lib.rs
index f1388a4cf..5d5ab78c2 100644
--- a/engine/language_client_typescript/src/lib.rs
+++ b/engine/language_client_typescript/src/lib.rs
@@ -7,6 +7,7 @@ mod runtime;
 mod types;
 
 pub(crate) use runtime::BamlRuntime;
+use tracing_subscriber::{self, EnvFilter};
 
 #[napi(js_name = "invoke_runtime_cli")]
 pub fn run_cli(env: Env, params: Vec<String>) -> napi::Result<JsUndefined> {
@@ -21,11 +22,34 @@ pub fn run_cli(env: Env, params: Vec<String>) -> napi::Result<JsUndefined> {
 
 #[napi::module_init]
 fn module_init() {
-    if let Err(e) = env_logger::try_init_from_env(
-        env_logger::Env::new()
-            .filter("BAML_LOG")
-            .write_style("BAML_LOG_STYLE"),
-    ) {
-        eprintln!("Failed to initialize BAML logger: {:#}", e);
+    // Check if JSON logging is enabled
+    let use_json = match std::env::var("BAML_LOG_JSON") {
+        Ok(val) => val.trim().eq_ignore_ascii_case("true") || val.trim() == "1",
+        Err(_) => false,
     };
+
+    if use_json {
+        // JSON formatting
+        tracing_subscriber::fmt()
+            .with_target(false)
+            .with_file(false)
+            .with_line_number(false)
+            .json()
+            .with_env_filter(
+                EnvFilter::try_from_env("BAML_LOG").unwrap_or_else(|_| EnvFilter::new("info")),
+            )
+            .flatten_event(true)
+            .with_current_span(false)
+            .with_span_list(false)
+            .init();
+    } else {
+        // Regular formatting
+        if let Err(e) = env_logger::try_init_from_env(
+            env_logger::Env::new()
+                .filter("BAML_LOG")
+                .write_style("BAML_LOG_STYLE"),
+        ) {
+            eprintln!("Failed to initialize BAML logger: {:#}", e);
+        }
+    }
 }