diff --git a/Cargo.lock b/Cargo.lock
index 32a9921..e2f13db 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4017,6 +4017,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 
+[[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"
@@ -4074,6 +4080,10 @@ dependencies = [
  "tonic",
  "tracing",
  "tracing-subscriber",
+ "tree-sitter",
+ "tree-sitter-python",
+ "tree-sitter-rust",
+ "tree-sitter-typescript",
  "tui-markdown",
 ]
 
@@ -4654,6 +4664,55 @@ dependencies = [
  "tracing-log",
 ]
 
+[[package]]
+name = "tree-sitter"
+version = "0.24.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a5387dffa7ffc7d2dae12b50c6f7aab8ff79d6210147c6613561fc3d474c6f75"
+dependencies = [
+ "cc",
+ "regex",
+ "regex-syntax",
+ "streaming-iterator",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-language"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "009994f150cc0cd50ff54917d5bc8bffe8cad10ca10d81c34da2ec421ae61782"
+
+[[package]]
+name = "tree-sitter-python"
+version = "0.23.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d065aaa27f3aaceaf60c1f0e0ac09e1cb9eb8ed28e7bcdaa52129cffc7f4b04"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-rust"
+version = "0.23.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca8ccb3e3a3495c8a943f6c3fd24c3804c471fd7f4f16087623c7fa4c0068e8a"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
+[[package]]
+name = "tree-sitter-typescript"
+version = "0.23.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c5f76ed8d947a75cc446d5fccd8b602ebf0cde64ccf2ffa434d873d7a575eff"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
 [[package]]
 name = "try-lock"
 version = "0.2.5"
diff --git a/sunbeam-proto/proto/code.proto b/sunbeam-proto/proto/code.proto
index 580bdc5..8f33a74 100644
--- a/sunbeam-proto/proto/code.proto
+++ b/sunbeam-proto/proto/code.proto
@@ -16,9 +16,28 @@ message ClientMessage {
     ToolResult tool_result = 3;
     ToolApproval approval = 4;
     EndSession end = 5;
+    IndexSymbols index_symbols = 6;
   }
 }
 
+message IndexSymbols {
+  string project_name = 1;
+  string branch = 2;
+  repeated SymbolEntry symbols = 3;
+}
+
+message SymbolEntry {
+  string file_path = 1;
+  string name = 2;
+  string kind = 3;
+  string signature = 4;
+  string docstring = 5;
+  int32 start_line = 6;
+  int32 end_line = 7;
+  string language = 8;
+  string content = 9;
+}
+
 message StartSession {
   string project_path = 1;
   string prompt_md = 2;
diff --git a/sunbeam/Cargo.toml b/sunbeam/Cargo.toml
index e76b1fe..5ec6b9b 100644
--- a/sunbeam/Cargo.toml
+++ b/sunbeam/Cargo.toml
@@ -29,6 +29,10 @@ futures = "0.3"
 crossbeam-channel = "0.5"
 textwrap = "0.16"
 tui-markdown = "=0.3.6"
+tree-sitter = "0.24"
+tree-sitter-rust = "0.23"
+tree-sitter-typescript = "0.23"
+tree-sitter-python = "0.23"
 
 [dev-dependencies]
 tokio-stream = { version = "0.1", features = ["net"] }
diff --git a/sunbeam/src/code/client.rs b/sunbeam/src/code/client.rs
index f52f818..be4f7da 100644
--- a/sunbeam/src/code/client.rs
+++ b/sunbeam/src/code/client.rs
@@ -104,6 +104,38 @@ pub async fn connect(
         }
     };
 
+    // Extract and send symbols for code index (fire-and-forget)
+    let symbols = super::symbols::extract_project_symbols(&project.path);
+    if !symbols.is_empty() {
+        let branch = project.git_branch.clone().unwrap_or_else(|| "mainline".into());
+        let proto_symbols: Vec<_> = symbols
+            .iter()
+            .map(|s| SymbolEntry {
+                file_path: s.file_path.clone(),
+                name: s.name.clone(),
+                kind: s.kind.clone(),
+                signature: s.signature.clone(),
+                docstring: s.docstring.clone(),
+                start_line: s.start_line as i32,
+                end_line: s.end_line as i32,
+                language: s.language.clone(),
+                content: s.content.clone(),
+            })
+            .collect();
+
+        let project_name = project.path.split('/').last().unwrap_or("unknown").to_string();
+        let _ = tx
+            .send(ClientMessage {
+                payload: Some(client_message::Payload::IndexSymbols(IndexSymbols {
+                    project_name,
+                    branch,
+                    symbols: proto_symbols,
+                })),
+            })
+            .await;
+        info!(count = symbols.len(), "Sent project symbols for indexing");
+    }
+
     let history = ready
         .history
         .into_iter()
diff --git a/sunbeam/src/code/mod.rs b/sunbeam/src/code/mod.rs
index 8632036..f944b55 100644
--- a/sunbeam/src/code/mod.rs
+++ b/sunbeam/src/code/mod.rs
@@ -2,6 +2,7 @@ pub mod agent;
 pub mod client;
 pub mod config;
 pub mod project;
+pub mod symbols;
 pub mod tools;
 pub mod tui;
 
diff --git a/sunbeam/src/code/symbols.rs b/sunbeam/src/code/symbols.rs
new file mode 100644
index 0000000..7171f22
--- /dev/null
+++ b/sunbeam/src/code/symbols.rs
@@ -0,0 +1,659 @@
+//! Symbol extraction from source code using tree-sitter.
+//!
+//! Extracts function signatures, struct/enum/trait definitions, and
+//! docstrings from Rust, TypeScript, and Python files. These symbols
+//! are sent to Sol for indexing in the code search index.
+
+use std::path::Path;
+use tracing::debug;
+
+/// An extracted code symbol with file context.
+#[derive(Debug, Clone)]
+pub struct ProjectSymbol {
+    pub file_path: String, // relative to project root
+    pub name: String,
+    pub kind: String,
+    pub signature: String,
+    pub docstring: String,
+    pub start_line: u32,
+    pub end_line: u32,
+    pub language: String,
+    pub content: String,
+}
+
+/// Extract symbols from all source files in a project.
+pub fn extract_project_symbols(project_root: &str) -> Vec<ProjectSymbol> {
+    let root = Path::new(project_root);
+    let mut symbols = Vec::new();
+
+    walk_directory(root, root, &mut symbols);
+    debug!(count = symbols.len(), "Extracted project symbols");
+    symbols
+}
+
+fn walk_directory(dir: &Path, root: &Path, symbols: &mut Vec<ProjectSymbol>) {
+    let Ok(entries) = std::fs::read_dir(dir) else { return };
+
+    for entry in entries.flatten() {
+        let path = entry.path();
+        let name = entry.file_name().to_string_lossy().to_string();
+
+        // Skip hidden, vendor, target, node_modules, etc.
+        if name.starts_with('.') || name == "target" || name == "vendor"
+            || name == "node_modules" || name == "dist" || name == "build"
+            || name == "__pycache__" || name == ".git"
+        {
+            continue;
+        }
+
+        if path.is_dir() {
+            walk_directory(&path, root, symbols);
+        } else if path.is_file() {
+            let path_str = path.to_string_lossy().to_string();
+            if detect_language(&path_str).is_some() {
+                // Read file (skip large files)
+                if let Ok(content) = std::fs::read_to_string(&path) {
+                    if content.len() > 100_000 { continue; } // skip >100KB
+
+                    let rel_path = path.strip_prefix(root)
+                        .map(|p| p.to_string_lossy().to_string())
+                        .unwrap_or(path_str.clone());
+
+                    for sym in extract_symbols(&path_str, &content) {
+                        // Build content: signature + body up to 500 chars
+                        let body_start = content.lines()
+                            .take(sym.start_line as usize - 1)
+                            .map(|l| l.len() + 1)
+                            .sum::<usize>();
+                        let body_end = content.lines()
+                            .take(sym.end_line as usize)
+                            .map(|l| l.len() + 1)
+                            .sum::<usize>()
+                            .min(content.len());
+                        let body = &content[body_start..body_end];
+                        let truncated = if body.len() > 500 {
+                            format!("{}…", &body[..497])
+                        } else {
+                            body.to_string()
+                        };
+
+                        symbols.push(ProjectSymbol {
+                            file_path: rel_path.clone(),
+                            name: sym.name,
+                            kind: sym.kind,
+                            signature: sym.signature,
+                            docstring: sym.docstring,
+                            start_line: sym.start_line,
+                            end_line: sym.end_line,
+                            language: sym.language,
+                            content: truncated,
+                        });
+                    }
+                }
+            }
+        }
+    }
+}
+
+/// An extracted code symbol.
+#[derive(Debug, Clone)]
+pub struct CodeSymbol {
+    pub name: String,
+    pub kind: String,       // "function", "struct", "enum", "trait", "class", "interface", "method"
+    pub signature: String,  // full signature line
+    pub docstring: String,  // doc comment / docstring
+    pub start_line: u32,    // 1-based
+    pub end_line: u32,      // 1-based
+    pub language: String,
+}
+
+/// Detect language from file extension.
+pub fn detect_language(path: &str) -> Option<&'static str> {
+    let ext = Path::new(path).extension()?.to_str()?;
+    match ext {
+        "rs" => Some("rust"),
+        "ts" | "tsx" => Some("typescript"),
+        "js" | "jsx" => Some("javascript"),
+        "py" => Some("python"),
+        _ => None,
+    }
+}
+
+/// Extract symbols from a source file's content.
+pub fn extract_symbols(path: &str, content: &str) -> Vec<CodeSymbol> {
+    let Some(lang) = detect_language(path) else {
+        return Vec::new();
+    };
+
+    match lang {
+        "rust" => extract_rust_symbols(content),
+        "typescript" | "javascript" => extract_ts_symbols(content),
+        "python" => extract_python_symbols(content),
+        _ => Vec::new(),
+    }
+}
+
+// ── Rust ────────────────────────────────────────────────────────────────
+
+fn extract_rust_symbols(content: &str) -> Vec<CodeSymbol> {
+    let mut parser = tree_sitter::Parser::new();
+    parser.set_language(&tree_sitter_rust::LANGUAGE.into()).ok();
+
+    let Some(tree) = parser.parse(content, None) else {
+        return Vec::new();
+    };
+
+    let mut symbols = Vec::new();
+    let root = tree.root_node();
+    let bytes = content.as_bytes();
+
+    walk_rust_node(root, bytes, content, &mut symbols);
+    symbols
+}
+
+fn walk_rust_node(
+    node: tree_sitter::Node,
+    bytes: &[u8],
+    source: &str,
+    symbols: &mut Vec<CodeSymbol>,
+) {
+    match node.kind() {
+        "function_item" | "function_signature_item" => {
+            if let Some(sym) = extract_rust_function(node, bytes, source) {
+                symbols.push(sym);
+            }
+        }
+        "struct_item" => {
+            if let Some(sym) = extract_rust_type(node, bytes, source, "struct") {
+                symbols.push(sym);
+            }
+        }
+        "enum_item" => {
+            if let Some(sym) = extract_rust_type(node, bytes, source, "enum") {
+                symbols.push(sym);
+            }
+        }
+        "trait_item" => {
+            if let Some(sym) = extract_rust_type(node, bytes, source, "trait") {
+                symbols.push(sym);
+            }
+        }
+        "impl_item" => {
+            // Walk impl methods
+            for i in 0..node.child_count() {
+                if let Some(child) = node.child(i) {
+                    if child.kind() == "declaration_list" {
+                        walk_rust_node(child, bytes, source, symbols);
+                    }
+                }
+            }
+        }
+        _ => {
+            for i in 0..node.child_count() {
+                if let Some(child) = node.child(i) {
+                    walk_rust_node(child, bytes, source, symbols);
+                }
+            }
+        }
+    }
+}
+
+fn extract_rust_function(node: tree_sitter::Node, bytes: &[u8], source: &str) -> Option<CodeSymbol> {
+    let name = node.child_by_field_name("name")?;
+    let name_str = name.utf8_text(bytes).ok()?.to_string();
+
+    // Build signature: everything from start to the opening brace (or end if no body)
+    let start_byte = node.start_byte();
+    let sig_end = find_rust_sig_end(node, source);
+    let signature = source[start_byte..sig_end].trim().to_string();
+
+    // Extract doc comment (line comments starting with /// before the function)
+    let docstring = extract_rust_doc_comment(node, source);
+
+    Some(CodeSymbol {
+        name: name_str,
+        kind: "function".into(),
+        signature,
+        docstring,
+        start_line: node.start_position().row as u32 + 1,
+        end_line: node.end_position().row as u32 + 1,
+        language: "rust".into(),
+    })
+}
+
+fn extract_rust_type(node: tree_sitter::Node, bytes: &[u8], source: &str, kind: &str) -> Option<CodeSymbol> {
+    let name = node.child_by_field_name("name")?;
+    let name_str = name.utf8_text(bytes).ok()?.to_string();
+
+    // Signature: first line of the definition
+    let start = node.start_byte();
+    let first_line_end = source[start..].find('\n').map(|i| start + i).unwrap_or(node.end_byte());
+    let signature = source[start..first_line_end].trim().to_string();
+
+    let docstring = extract_rust_doc_comment(node, source);
+
+    Some(CodeSymbol {
+        name: name_str,
+        kind: kind.into(),
+        signature,
+        docstring,
+        start_line: node.start_position().row as u32 + 1,
+        end_line: node.end_position().row as u32 + 1,
+        language: "rust".into(),
+    })
+}
+
+fn find_rust_sig_end(node: tree_sitter::Node, source: &str) -> usize {
+    // Find the opening brace
+    for i in 0..node.child_count() {
+        if let Some(child) = node.child(i) {
+            if child.kind() == "block" || child.kind() == "field_declaration_list"
+                || child.kind() == "enum_variant_list" || child.kind() == "declaration_list"
+            {
+                return child.start_byte();
+            }
+        }
+    }
+    // No body (e.g., trait method signature)
+    node.end_byte().min(source.len())
+}
+
+fn extract_rust_doc_comment(node: tree_sitter::Node, source: &str) -> String {
+    let start_line = node.start_position().row;
+    if start_line == 0 {
+        return String::new();
+    }
+
+    let lines: Vec<&str> = source.lines().collect();
+    let mut doc_lines = Vec::new();
+
+    // Walk backwards from the line before the node
+    let mut line_idx = start_line.saturating_sub(1);
+    loop {
+        if line_idx >= lines.len() {
+            break;
+        }
+        let line = lines[line_idx].trim();
+        if line.starts_with("///") {
+            doc_lines.push(line.trim_start_matches("///").trim());
+        } else if line.starts_with("#[") || line.is_empty() {
+            // Skip attributes and blank lines between doc and function
+            if line.is_empty() && !doc_lines.is_empty() {
+                break; // blank line after doc block = stop
+            }
+        } else {
+            break;
+        }
+        if line_idx == 0 {
+            break;
+        }
+        line_idx -= 1;
+    }
+
+    doc_lines.reverse();
+    doc_lines.join("\n")
+}
+
+// ── TypeScript / JavaScript ─────────────────────────────────────────────
+
+fn extract_ts_symbols(content: &str) -> Vec<CodeSymbol> {
+    let mut parser = tree_sitter::Parser::new();
+    parser.set_language(&tree_sitter_typescript::LANGUAGE_TYPESCRIPT.into()).ok();
+
+    let Some(tree) = parser.parse(content, None) else {
+        return Vec::new();
+    };
+
+    let mut symbols = Vec::new();
+    walk_ts_node(tree.root_node(), content.as_bytes(), content, &mut symbols);
+    symbols
+}
+
+fn walk_ts_node(
+    node: tree_sitter::Node,
+    bytes: &[u8],
+    source: &str,
+    symbols: &mut Vec<CodeSymbol>,
+) {
+    match node.kind() {
+        "function_declaration" | "method_definition" | "arrow_function" => {
+            if let Some(name) = node.child_by_field_name("name") {
+                let name_str = name.utf8_text(bytes).unwrap_or("").to_string();
+                if !name_str.is_empty() {
+                    let start = node.start_byte();
+                    let first_line_end = source[start..].find('\n').map(|i| start + i).unwrap_or(node.end_byte());
+                    symbols.push(CodeSymbol {
+                        name: name_str,
+                        kind: "function".into(),
+                        signature: source[start..first_line_end].trim().to_string(),
+                        docstring: String::new(), // TODO: JSDoc extraction
+                        start_line: node.start_position().row as u32 + 1,
+                        end_line: node.end_position().row as u32 + 1,
+                        language: "typescript".into(),
+                    });
+                }
+            }
+        }
+        "class_declaration" | "interface_declaration" | "type_alias_declaration" | "enum_declaration" => {
+            if let Some(name) = node.child_by_field_name("name") {
+                let name_str = name.utf8_text(bytes).unwrap_or("").to_string();
+                let kind = match node.kind() {
+                    "class_declaration" => "class",
+                    "interface_declaration" => "interface",
+                    "enum_declaration" => "enum",
+                    _ => "type",
+                };
+                let start = node.start_byte();
+                let first_line_end = source[start..].find('\n').map(|i| start + i).unwrap_or(node.end_byte());
+                symbols.push(CodeSymbol {
+                    name: name_str,
+                    kind: kind.into(),
+                    signature: source[start..first_line_end].trim().to_string(),
+                    docstring: String::new(),
+                    start_line: node.start_position().row as u32 + 1,
+                    end_line: node.end_position().row as u32 + 1,
+                    language: "typescript".into(),
+                });
+            }
+        }
+        _ => {}
+    }
+
+    for i in 0..node.child_count() {
+        if let Some(child) = node.child(i) {
+            walk_ts_node(child, bytes, source, symbols);
+        }
+    }
+}
+
+// ── Python ──────────────────────────────────────────────────────────────
+
+fn extract_python_symbols(content: &str) -> Vec<CodeSymbol> {
+    let mut parser = tree_sitter::Parser::new();
+    parser.set_language(&tree_sitter_python::LANGUAGE.into()).ok();
+
+    let Some(tree) = parser.parse(content, None) else {
+        return Vec::new();
+    };
+
+    let mut symbols = Vec::new();
+    walk_python_node(tree.root_node(), content.as_bytes(), content, &mut symbols);
+    symbols
+}
+
+fn walk_python_node(
+    node: tree_sitter::Node,
+    bytes: &[u8],
+    source: &str,
+    symbols: &mut Vec<CodeSymbol>,
+) {
+    match node.kind() {
+        "function_definition" => {
+            if let Some(name) = node.child_by_field_name("name") {
+                let name_str = name.utf8_text(bytes).unwrap_or("").to_string();
+                let start = node.start_byte();
+                let first_line_end = source[start..].find('\n').map(|i| start + i).unwrap_or(node.end_byte());
+                let docstring = extract_python_docstring(node, bytes);
+                symbols.push(CodeSymbol {
+                    name: name_str,
+                    kind: "function".into(),
+                    signature: source[start..first_line_end].trim().to_string(),
+                    docstring,
+                    start_line: node.start_position().row as u32 + 1,
+                    end_line: node.end_position().row as u32 + 1,
+                    language: "python".into(),
+                });
+            }
+        }
+        "class_definition" => {
+            if let Some(name) = node.child_by_field_name("name") {
+                let name_str = name.utf8_text(bytes).unwrap_or("").to_string();
+                let start = node.start_byte();
+                let first_line_end = source[start..].find('\n').map(|i| start + i).unwrap_or(node.end_byte());
+                let docstring = extract_python_docstring(node, bytes);
+                symbols.push(CodeSymbol {
+                    name: name_str,
+                    kind: "class".into(),
+                    signature: source[start..first_line_end].trim().to_string(),
+                    docstring,
+                    start_line: node.start_position().row as u32 + 1,
+                    end_line: node.end_position().row as u32 + 1,
+                    language: "python".into(),
+                });
+            }
+        }
+        _ => {}
+    }
+
+    for i in 0..node.child_count() {
+        if let Some(child) = node.child(i) {
+            walk_python_node(child, bytes, source, symbols);
+        }
+    }
+}
+
+fn extract_python_docstring(node: tree_sitter::Node, bytes: &[u8]) -> String {
+    // Python docstrings are the first expression_statement in the body
+    if let Some(body) = node.child_by_field_name("body") {
+        if let Some(first_stmt) = body.child(0) {
+            if first_stmt.kind() == "expression_statement" {
+                if let Some(expr) = first_stmt.child(0) {
+                    if expr.kind() == "string" {
+                        let text = expr.utf8_text(bytes).unwrap_or("");
+                        // Strip triple quotes
+                        let trimmed = text
+                            .trim_start_matches("\"\"\"")
+                            .trim_start_matches("'''")
+                            .trim_end_matches("\"\"\"")
+                            .trim_end_matches("'''")
+                            .trim();
+                        return trimmed.to_string();
+                    }
+                }
+            }
+        }
+    }
+    String::new()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_detect_language() {
+        assert_eq!(detect_language("src/main.rs"), Some("rust"));
+        assert_eq!(detect_language("app.ts"), Some("typescript"));
+        assert_eq!(detect_language("app.tsx"), Some("typescript"));
+        assert_eq!(detect_language("script.py"), Some("python"));
+        assert_eq!(detect_language("script.js"), Some("javascript"));
+        assert_eq!(detect_language("data.json"), None);
+        assert_eq!(detect_language("README.md"), None);
+    }
+
+    #[test]
+    fn test_extract_rust_function() {
+        let source = r#"
+/// Generate a response.
+pub async fn generate(&self, req: &GenerateRequest) -> Option<String> {
+    self.run_and_emit(req).await
+}
+"#;
+        let symbols = extract_rust_symbols(source);
+        assert!(!symbols.is_empty(), "Should extract at least one symbol");
+
+        let func = &symbols[0];
+        assert_eq!(func.name, "generate");
+        assert_eq!(func.kind, "function");
+        assert!(func.signature.contains("pub async fn generate"));
+        assert!(func.docstring.contains("Generate a response"));
+        assert_eq!(func.language, "rust");
+    }
+
+    #[test]
+    fn test_extract_rust_struct() {
+        let source = r#"
+/// A request to generate.
+pub struct GenerateRequest {
+    pub text: String,
+    pub user_id: String,
+}
+"#;
+        let symbols = extract_rust_symbols(source);
+        let structs: Vec<_> = symbols.iter().filter(|s| s.kind == "struct").collect();
+        assert!(!structs.is_empty());
+        assert_eq!(structs[0].name, "GenerateRequest");
+        assert!(structs[0].docstring.contains("request to generate"));
+    }
+
+    #[test]
+    fn test_extract_rust_enum() {
+        let source = r#"
+/// Whether server or client.
+pub enum ToolSide {
+    Server,
+    Client,
+}
+"#;
+        let symbols = extract_rust_symbols(source);
+        let enums: Vec<_> = symbols.iter().filter(|s| s.kind == "enum").collect();
+        assert!(!enums.is_empty());
+        assert_eq!(enums[0].name, "ToolSide");
+    }
+
+    #[test]
+    fn test_extract_rust_trait() {
+        let source = r#"
+pub trait Executor {
+    fn execute(&self, args: &str) -> String;
+}
+"#;
+        let symbols = extract_rust_symbols(source);
+        let traits: Vec<_> = symbols.iter().filter(|s| s.kind == "trait").collect();
+        assert!(!traits.is_empty());
+        assert_eq!(traits[0].name, "Executor");
+    }
+
+    #[test]
+    fn test_extract_rust_impl_methods() {
+        let source = r#"
+impl Orchestrator {
+    /// Create new.
+    pub fn new(config: Config) -> Self {
+        Self { config }
+    }
+
+    /// Subscribe to events.
+    pub fn subscribe(&self) -> Receiver {
+        self.tx.subscribe()
+    }
+}
+"#;
+        let symbols = extract_rust_symbols(source);
+        let fns: Vec<_> = symbols.iter().filter(|s| s.kind == "function").collect();
+        assert!(fns.len() >= 2, "Should find impl methods, got {}", fns.len());
+        let names: Vec<&str> = fns.iter().map(|s| s.name.as_str()).collect();
+        assert!(names.contains(&"new"));
+        assert!(names.contains(&"subscribe"));
+    }
+
+    #[test]
+    fn test_extract_ts_function() {
+        let source = r#"
+function greet(name: string): string {
+    return `Hello, ${name}`;
+}
+"#;
+        let symbols = extract_ts_symbols(source);
+        assert!(!symbols.is_empty());
+        assert_eq!(symbols[0].name, "greet");
+        assert_eq!(symbols[0].kind, "function");
+    }
+
+    #[test]
+    fn test_extract_ts_class() {
+        let source = r#"
+class UserService {
+    constructor(private db: Database) {}
+
+    async getUser(id: string): Promise<User> {
+        return this.db.find(id);
+    }
+}
+"#;
+        let symbols = extract_ts_symbols(source);
+        let classes: Vec<_> = symbols.iter().filter(|s| s.kind == "class").collect();
+        assert!(!classes.is_empty());
+        assert_eq!(classes[0].name, "UserService");
+    }
+
+    #[test]
+    fn test_extract_ts_interface() {
+        let source = r#"
+interface User {
+    id: string;
+    name: string;
+    email?: string;
+}
+"#;
+        let symbols = extract_ts_symbols(source);
+        let ifaces: Vec<_> = symbols.iter().filter(|s| s.kind == "interface").collect();
+        assert!(!ifaces.is_empty());
+        assert_eq!(ifaces[0].name, "User");
+    }
+
+    #[test]
+    fn test_extract_python_function() {
+        let source = r#"
+def process_data(items: list[str]) -> dict:
+    """Process a list of items into a dictionary."""
+    return {item: len(item) for item in items}
+"#;
+        let symbols = extract_python_symbols(source);
+        assert!(!symbols.is_empty());
+        assert_eq!(symbols[0].name, "process_data");
+        assert_eq!(symbols[0].kind, "function");
+        assert!(symbols[0].docstring.contains("Process a list"));
+    }
+
+    #[test]
+    fn test_extract_python_class() {
+        let source = r#"
+class DataProcessor:
+    """Processes data from various sources."""
+
+    def __init__(self, config):
+        self.config = config
+
+    def run(self):
+        pass
+"#;
+        let symbols = extract_python_symbols(source);
+        let classes: Vec<_> = symbols.iter().filter(|s| s.kind == "class").collect();
+        assert!(!classes.is_empty());
+        assert_eq!(classes[0].name, "DataProcessor");
+        assert!(classes[0].docstring.contains("Processes data"));
+    }
+
+    #[test]
+    fn test_extract_symbols_unknown_language() {
+        let symbols = extract_symbols("data.json", "{}");
+        assert!(symbols.is_empty());
+    }
+
+    #[test]
+    fn test_extract_symbols_empty_file() {
+        let symbols = extract_symbols("empty.rs", "");
+        assert!(symbols.is_empty());
+    }
+
+    #[test]
+    fn test_line_numbers_are_1_based() {
+        let source = "fn first() {}\nfn second() {}\nfn third() {}";
+        let symbols = extract_rust_symbols(source);
+        assert!(symbols.len() >= 3);
+        assert_eq!(symbols[0].start_line, 1);
+        assert_eq!(symbols[1].start_line, 2);
+        assert_eq!(symbols[2].start_line, 3);
+    }
+}