diff --git a/.cargo/config.toml b/.cargo/config.toml
index e0e3f5b..4036f31 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -4,5 +4,9 @@ test_details = ["test", "--target", "aarch64-apple-darwin"]
 [build]
 target = "wasm32-wasip1"
 
+[env]
+CC_wasm32_wasip1 = { value = "/Users/christian/.wasi-sdk/bin/clang", force = true }
+CFLAGS_wasm32_wasip1 = { value = "--sysroot=/Users/christian/.wasi-sdk/share/wasi-sysroot", force = true }
+
 [target.'cfg(all(target_arch = "wasm32"))']
 runner = "viceroy run -C ../../fastly.toml -- "
diff --git a/Cargo.lock b/Cargo.lock
index 1a2227d..cb44e36 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1989,6 +1989,7 @@ version = "1.0.145"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "402a6f66d8c709116cf22f558eab210f5a50187f702eb4d7e5ef38d9a7f1c79c"
 dependencies = [
+ "indexmap",
  "itoa",
  "memchr",
  "ryu",
@@ -2123,6 +2124,12 @@ version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ce2be8dc25455e1f91df71bfa12ad37d7af1092ae736f3a6cd0e37bc7810596"
 
+[[package]]
+name = "streaming-iterator"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b2231b7c3057d5e4ad0156fb3dc807d900806020c5ffa3ee6ff2c8c76fb8520"
+
 [[package]]
 name = "strsim"
 version = "0.11.1"
@@ -2352,6 +2359,36 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "df8b2b54733674ad286d16267dcfc7a71ed5c776e4ac7aa3c3e2561f7c637bf2"
 
+[[package]]
+name = "tree-sitter"
+version = "0.26.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2135256a14d38ef69702cf6afdb6a36805d8914523de06eb4e2756cee08736f2"
+dependencies = [
+ "cc",
+ "regex",
+ "regex-syntax",
+ "serde_json",
+ "streaming-iterator",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-javascript"
+version = "0.25.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68204f2abc0627a90bdf06e605f5c470aa26fdcb2081ea553a04bdad756693f5"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-language"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ae62f7eae5eb549c71b76658648b72cc6111f2d87d24a1e31fa907f4943e3ce"
+
 [[package]]
 name = "trusted-server-common"
 version = "0.1.0"
@@ -2390,6 +2427,8 @@ dependencies = [
  "tokio",
  "tokio-test",
  "toml",
+ "tree-sitter",
+ "tree-sitter-javascript",
  "trusted-server-js",
  "url",
  "urlencoding",
diff --git a/Cargo.toml b/Cargo.toml
index 9545c84..566d46c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -56,3 +56,6 @@ urlencoding = "2.1"
 uuid = { version = "1.18", features = ["v4"] }
 validator = { version = "0.20", features = ["derive"] }
 which = "8"
+tree-sitter = { version = "0.26.2" }
+tree-sitter-javascript = { version = "0.25.0" }
+
diff --git a/README.md b/README.md
index 49f1dc8..bd5457c 100644
--- a/README.md
+++ b/README.md
@@ -112,6 +112,26 @@ See https://asdf-vm.com/guide/getting-started.html#_2-configure-asdf
 git clone git@github.com:IABTechLab/trusted-server.git
 ```
 
+### WASI SDK (Required for Tree-sitter)
+
+This project uses tree-sitter for JavaScript parsing, which requires the WASI SDK to compile C code for WebAssembly.
+
+#### Download and Install WASI SDK
+
+```sh
+cd /tmp
+curl -LO https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-24/wasi-sdk-24.0-arm64-macos.tar.gz
+tar -xzf wasi-sdk-24.0-arm64-macos.tar.gz
+mv wasi-sdk-24.0-arm64-macos ~/.wasi-sdk
+```
+
+:warning: For Linux or x86_64 macOS, download the appropriate release from [WASI SDK releases](https://github.com/WebAssembly/wasi-sdk/releases/tag/wasi-sdk-24):
+- Linux x86_64: `wasi-sdk-24.0-x86_64-linux.tar.gz`
+- Linux arm64: `wasi-sdk-24.0-arm64-linux.tar.gz`
+- macOS x86_64: `wasi-sdk-24.0-x86_64-macos.tar.gz`
+
+The WASI SDK paths are already configured in `.cargo/config.toml` and will be used automatically during build.
+
 ### Configure
 
 #### Edit configuration files
diff --git a/crates/common/Cargo.toml b/crates/common/Cargo.toml
index bbb8a2a..d1537ab 100644
--- a/crates/common/Cargo.toml
+++ b/crates/common/Cargo.toml
@@ -45,6 +45,8 @@ uuid = { workspace = true }
 validator = { workspace = true }
 ed25519-dalek = { workspace = true }
 once_cell = { workspace = true }
+tree-sitter = { workspace = true }
+tree-sitter-javascript = { workspace = true }
 
 [build-dependencies]
 config = { workspace = true }
diff --git a/crates/common/src/lib.rs b/crates/common/src/lib.rs
index fc0b888..7e5ba7b 100644
--- a/crates/common/src/lib.rs
+++ b/crates/common/src/lib.rs
@@ -43,4 +43,5 @@ pub mod streaming_processor;
 pub mod streaming_replacer;
 pub mod synthetic;
 pub mod test_support;
+pub mod tree_sitter_test;
 pub mod tsjs;
diff --git a/crates/common/src/tree_sitter_test.rs b/crates/common/src/tree_sitter_test.rs
new file mode 100644
index 0000000..6d72e2a
--- /dev/null
+++ b/crates/common/src/tree_sitter_test.rs
@@ -0,0 +1,108 @@
+use tree_sitter::{Parser, Tree};
+
+/// Initialize a tree-sitter parser with JavaScript language support
+pub fn create_js_parser() -> Parser {
+    let mut parser = Parser::new();
+    let language = tree_sitter_javascript::LANGUAGE.into();
+    parser
+        .set_language(&language)
+        .expect("Failed to set JavaScript language");
+    parser
+}
+
+/// Parse JavaScript source code and return the syntax tree
+pub fn parse_js(source: &str) -> Option<Tree> {
+    let mut parser = create_js_parser();
+    parser.parse(source, None)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parser_creation() {
+        let parser = create_js_parser();
+        // Parser should be created successfully with JavaScript language
+        assert!(parser.language().is_some());
+    }
+
+    #[test]
+    fn test_parse_simple_function() {
+        let source = "function add(a, b) { return a + b; }";
+        let tree = parse_js(source).expect("Failed to parse JavaScript");
+
+        let root_node = tree.root_node();
+        assert_eq!(root_node.kind(), "program");
+        assert_eq!(root_node.child_count(), 1);
+
+        // First child should be a function declaration
+        let function_node = root_node.child(0).expect("Should have a child");
+        assert_eq!(function_node.kind(), "function_declaration");
+    }
+
+    #[test]
+    fn test_parse_variable_declaration() {
+        let source = "const x = 42;";
+        let tree = parse_js(source).expect("Failed to parse JavaScript");
+
+        let root_node = tree.root_node();
+        assert_eq!(root_node.kind(), "program");
+
+        // First child should be a lexical declaration
+        let declaration = root_node.child(0).expect("Should have a child");
+        assert_eq!(declaration.kind(), "lexical_declaration");
+    }
+
+    #[test]
+    fn test_parse_complex_code() {
+        let source = r#"
+            class Calculator {
+                constructor() {
+                    this.result = 0;
+                }
+                
+                add(x, y) {
+                    return x + y;
+                }
+            }
+            
+            const calc = new Calculator();
+            console.log(calc.add(5, 3));
+        "#;
+
+        let tree = parse_js(source).expect("Failed to parse JavaScript");
+        let root_node = tree.root_node();
+
+        assert_eq!(root_node.kind(), "program");
+        // Should have at least 3 children: class, const declaration, expression statement
+        assert!(root_node.child_count() >= 3);
+
+        // Verify the class declaration
+        let class_node = root_node.child(0).expect("Should have first child");
+        assert_eq!(class_node.kind(), "class_declaration");
+    }
+
+    #[test]
+    fn test_parse_arrow_function() {
+        let source = "const multiply = (a, b) => a * b;";
+        let tree = parse_js(source).expect("Failed to parse JavaScript");
+
+        let root_node = tree.root_node();
+        assert_eq!(root_node.kind(), "program");
+
+        let declaration = root_node.child(0).expect("Should have a child");
+        assert_eq!(declaration.kind(), "lexical_declaration");
+    }
+
+    #[test]
+    fn test_parse_with_syntax_error() {
+        // This should still produce a tree, but with error nodes
+        let source = "function broken( { return x; }";
+        let tree = parse_js(source);
+
+        assert!(tree.is_some());
+        let tree = tree.unwrap();
+        assert!(tree.root_node().has_error());
+    }
+}