diff --git a/Cargo.lock b/Cargo.lock
index 4431c1c..27026d8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -318,14 +318,13 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.43"
+version = "1.0.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "739eb0f94557554b3ca9a86d2d37bebd49c5e6d0c1d2bda35ba5bdac830befc2"
+checksum = "066fce287b1d4eafef758e89e09d724a24808a9196fe9756b8ca90e86d0719a2"
 dependencies = [
- "find-msvc-tools",
  "jobserver",
  "libc",
- "shlex",
+ "once_cell",
 ]
 
 [[package]]
@@ -1136,12 +1135,6 @@ dependencies = [
  "simd-adler32",
 ]
 
-[[package]]
-name = "find-msvc-tools"
-version = "0.1.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "52051878f80a721bb68ebfbc930e07b65ba72f2da88968ea5c06fd6ca3d3a127"
-
 [[package]]
 name = "flate2"
 version = "1.1.5"
@@ -1398,7 +1391,13 @@ dependencies = [
  "tokio-stream",
  "tokio-util",
  "tracing",
+ "tree-sitter",
+ "tree-sitter-javascript",
+ "tree-sitter-python",
+ "tree-sitter-rust",
+ "tree-sitter-typescript",
  "uuid",
+ "walkdir",
 ]
 
 [[package]]
@@ -3628,6 +3627,56 @@ dependencies = [
  "tracing-log",
 ]
 
+[[package]]
+name = "tree-sitter"
+version = "0.22.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df7cc499ceadd4dcdf7ec6d4cbc34ece92c3fa07821e287aedecd4416c516dca"
+dependencies = [
+ "cc",
+ "regex",
+]
+
+[[package]]
+name = "tree-sitter-javascript"
+version = "0.21.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8710a71bc6779e33811a8067bdda3ed08bed1733296ff915e44faf60f8c533d7"
+dependencies = [
+ "cc",
+ "tree-sitter",
+]
+
+[[package]]
+name = "tree-sitter-python"
+version = "0.21.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4066c6cf678f962f8c2c4561f205945c84834cce73d981e71392624fdc390a9"
+dependencies = [
+ "cc",
+ "tree-sitter",
+]
+
+[[package]]
+name = "tree-sitter-rust"
+version = "0.21.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "277690f420bf90741dea984f3da038ace46c4fe6047cba57a66822226cde1c93"
+dependencies = [
+ "cc",
+ "tree-sitter",
+]
+
+[[package]]
+name = "tree-sitter-typescript"
+version = "0.21.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ecb35d98a688378e56c18c9c159824fd16f730ccbea19aacf4f206e5d5438ed9"
+dependencies = [
+ "cc",
+ "tree-sitter",
+]
+
 [[package]]
 name = "try-lock"
 version = "0.2.5"
diff --git a/README.md b/README.md
index c1986ed..541595b 100644
--- a/README.md
+++ b/README.md
@@ -94,6 +94,7 @@ These commands give you fine-grained control over context management, allowing y
   - Screenshot capture and window management
   - OCR text extraction from images and screen regions
   - Window listing and identification
+- **Code Search**: Embedded tree-sitter for syntax-aware code search (Rust, Python, JavaScript, TypeScript) - see [Code Search Guide](docs/CODE_SEARCH.md)
 - **Final Output**: Formatted result presentation
 
 ### Provider Flexibility
diff --git a/TODO b/TODO
deleted file mode 100644
index 0d92da3..0000000
--- a/TODO
+++ /dev/null
@@ -1,19 +0,0 @@
-next tasks
-
-x get something working with autonomous mode
-- g3d
-- bug where it prints everything in a conversation turn all over again before final_output
-x ui abstraction from core
-- context token counting bug
-- embedded model
-  - prompt rewriting
-  - generates status messages "ruffling feathers..."
-  - project description?
-- treesitter + friends
-x error where it just gives up turn
-- "project" behaviors (read readme first)
-- advance project mgmt
-  - git for reverting
-  - swarm
-  - ui tests / computer controller
-
diff --git a/crates/g3-core/Cargo.toml b/crates/g3-core/Cargo.toml
index 67f9a2e..f4845e4 100644
--- a/crates/g3-core/Cargo.toml
+++ b/crates/g3-core/Cargo.toml
@@ -26,3 +26,11 @@ rand = "0.8"
 regex = "1.0"
 shellexpand = "3.1"
 serde_yaml = "0.9"
+
+# tree-sitter for embedded code search
+tree-sitter = "0.22"
+tree-sitter-rust = "0.21"
+tree-sitter-python = "0.21"
+tree-sitter-javascript = "0.21"
+tree-sitter-typescript = "0.21"
+walkdir = "2.4"
diff --git a/crates/g3-core/examples/inspect_ast.rs b/crates/g3-core/examples/inspect_ast.rs
new file mode 100644
index 0000000..5a25fe1
--- /dev/null
+++ b/crates/g3-core/examples/inspect_ast.rs
@@ -0,0 +1,58 @@
+//! Inspect tree-sitter AST structure for Rust code
+
+use tree_sitter::{Parser, Language};
+
+fn print_tree(node: tree_sitter::Node, source: &str, indent: usize) {
+    let indent_str = "  ".repeat(indent);
+    let node_text = &source[node.byte_range()];
+    let preview = if node_text.len() > 50 {
+        format!("{}...", &node_text[..50])
+    } else {
+        node_text.to_string()
+    };
+    
+    println!(
+        "{}{} [{}:{}] '{}'",
+        indent_str,
+        node.kind(),
+        node.start_position().row + 1,
+        node.start_position().column + 1,
+        preview.replace('\n', "\\n")
+    );
+    
+    let mut cursor = node.walk();
+    for child in node.children(&mut cursor) {
+        print_tree(child, source, indent + 1);
+    }
+}
+
+fn main() -> anyhow::Result<()> {
+    let source_code = r#"
+pub async fn example_async() {
+    println!("Hello");
+}
+
+fn regular_function() {
+    println!("Regular");
+}
+
+pub async fn another_async(x: i32) -> Result<(), ()> {
+    Ok(())
+}
+"#;
+
+    println!("Source code:");
+    println!("{}", source_code);
+    println!("\n{}", "=".repeat(80));
+    println!("AST Structure:");
+    println!("{}\n", "=".repeat(80));
+
+    let mut parser = Parser::new();
+    let language: Language = tree_sitter_rust::language().into();
+    parser.set_language(&language)?;
+
+    let tree = parser.parse(source_code, None).unwrap();
+    print_tree(tree.root_node(), source_code, 0);
+
+    Ok(())
+}
diff --git a/crates/g3-core/examples/inspect_python_ast.rs b/crates/g3-core/examples/inspect_python_ast.rs
new file mode 100644
index 0000000..d379910
--- /dev/null
+++ b/crates/g3-core/examples/inspect_python_ast.rs
@@ -0,0 +1,56 @@
+//! Inspect tree-sitter AST structure for Python code
+
+use tree_sitter::{Parser, Language};
+
+fn print_tree(node: tree_sitter::Node, source: &str, indent: usize) {
+    let indent_str = "  ".repeat(indent);
+    let node_text = &source[node.byte_range()];
+    let preview = if node_text.len() > 50 {
+        format!("{}...", &node_text[..50])
+    } else {
+        node_text.to_string()
+    };
+    
+    println!(
+        "{}{} [{}:{}] '{}'",
+        indent_str,
+        node.kind(),
+        node.start_position().row + 1,
+        node.start_position().column + 1,
+        preview.replace('\n', "\\n")
+    );
+    
+    let mut cursor = node.walk();
+    for child in node.children(&mut cursor) {
+        print_tree(child, source, indent + 1);
+    }
+}
+
+fn main() -> anyhow::Result<()> {
+    let source_code = r#"
+def regular_function():
+    pass
+
+async def async_function():
+    pass
+
+class MyClass:
+    def method(self):
+        pass
+"#;
+
+    println!("Source code:");
+    println!("{}", source_code);
+    println!("\n{}", "=".repeat(80));
+    println!("AST Structure:");
+    println!("{}\n", "=".repeat(80));
+
+    let mut parser = Parser::new();
+    let language: Language = tree_sitter_python::language().into();
+    parser.set_language(&language)?;
+
+    let tree = parser.parse(source_code, None).unwrap();
+    print_tree(tree.root_node(), source_code, 0);
+
+    Ok(())
+}
diff --git a/crates/g3-core/examples/test_python_query.rs b/crates/g3-core/examples/test_python_query.rs
new file mode 100644
index 0000000..8338f4d
--- /dev/null
+++ b/crates/g3-core/examples/test_python_query.rs
@@ -0,0 +1,43 @@
+//! Test Python async query
+
+use tree_sitter::{Parser, Query, QueryCursor, Language};
+
+fn main() -> anyhow::Result<()> {
+    let source_code = r#"
+def regular_function():
+    pass
+
+async def async_function():
+    pass
+"#;
+
+    let mut parser = Parser::new();
+    let language: Language = tree_sitter_python::language().into();
+    parser.set_language(&language)?;
+
+    let tree = parser.parse(source_code, None).unwrap();
+
+    // Try different queries
+    let queries = vec![
+        "(function_definition (async) name: (identifier) @name)",
+        "(function_definition (async))",
+        "(async)",
+    ];
+
+    for query_str in queries {
+        println!("\nTrying query: {}", query_str);
+        match Query::new(&language, query_str) {
+            Ok(query) => {
+                let mut cursor = QueryCursor::new();
+                let matches = cursor.matches(&query, tree.root_node(), source_code.as_bytes());
+                let count = matches.count();
+                println!("  ✓ Valid query, found {} matches", count);
+            }
+            Err(e) => {
+                println!("  ✗ Invalid query: {}", e);
+            }
+        }
+    }
+
+    Ok(())
+}
diff --git a/crates/g3-core/src/code_search.rs b/crates/g3-core/src/code_search.rs
deleted file mode 100644
index e4f7153..0000000
--- a/crates/g3-core/src/code_search.rs
+++ /dev/null
@@ -1,787 +0,0 @@
-//! Code search functionality using ast-grep for syntax-aware semantic searches
-
-use anyhow::{anyhow, Result};
-use serde::{Deserialize, Serialize};
-use serde_json::Value;
-use std::collections::HashMap;
-use std::process::Stdio;
-use std::time::{Duration, Instant};
-use tokio::io::{AsyncBufReadExt, BufReader};
-use tokio::process::Command;
-use tokio::sync::Semaphore;
-use tracing::{debug, error, info, warn};
-
-/// Maximum number of searches allowed per request
-const MAX_SEARCHES: usize = 20;
-
-/// Default timeout for individual searches in seconds
-const DEFAULT_TIMEOUT_SECS: u64 = 60;
-
-/// Default maximum concurrency
-const DEFAULT_MAX_CONCURRENCY: usize = 4;
-
-/// Default maximum matches per search
-const DEFAULT_MAX_MATCHES: usize = 500;
-
-/// Search specification for a single ast-grep search
-#[derive(Debug, Clone, Deserialize)]
-pub struct SearchSpec {
-    pub name: String,
-    pub mode: SearchMode,
-    
-    // Pattern mode fields
-    pub pattern: Option<String>,
-    pub language: Option<String>,
-    
-    // YAML mode fields
-    pub rule_yaml: Option<String>,
-    
-    // Common fields
-    pub paths: Option<Vec<String>>,
-    pub globs: Option<Vec<String>>,
-    pub json_style: Option<JsonStyle>,
-    pub context: Option<u32>,
-    pub threads: Option<u32>,
-    pub include_metadata: Option<bool>,
-    pub no_ignore: Option<Vec<NoIgnoreType>>,
-    pub severity: Option<HashMap<String, SeverityLevel>>,
-    pub timeout_secs: Option<u64>,
-}
-
-/// Search mode: pattern or yaml
-#[derive(Debug, Clone, Deserialize, PartialEq)]
-#[serde(rename_all = "lowercase")]
-pub enum SearchMode {
-    Pattern,
-    Yaml,
-}
-
-/// JSON output style
-#[derive(Debug, Clone, Deserialize, PartialEq)]
-#[serde(rename_all = "lowercase")]
-pub enum JsonStyle {
-    Pretty,
-    Stream,
-    Compact,
-}
-
-impl Default for JsonStyle {
-    fn default() -> Self {
-        JsonStyle::Stream
-    }
-}
-
-/// No-ignore types
-#[derive(Debug, Clone, Deserialize, PartialEq)]
-#[serde(rename_all = "lowercase")]
-pub enum NoIgnoreType {
-    Hidden,
-    Dot,
-    Exclude,
-    Global,
-    Parent,
-    Vcs,
-}
-
-/// Severity levels for YAML rules
-#[derive(Debug, Clone, Deserialize, PartialEq)]
-#[serde(rename_all = "lowercase")]
-pub enum SeverityLevel {
-    Error,
-    Warning,
-    Info,
-    Hint,
-    Off,
-}
-
-/// Request structure for code search
-#[derive(Debug, Deserialize)]
-pub struct CodeSearchRequest {
-    pub searches: Vec<SearchSpec>,
-    pub max_concurrency: Option<usize>,
-    pub max_matches_per_search: Option<usize>,
-}
-
-/// Result of a single search
-#[derive(Debug, Serialize)]
-pub struct SearchResult {
-    pub name: String,
-    pub mode: String,
-    pub status: String,
-    pub cmd: Vec<String>,
-    pub match_count: Option<usize>,
-    pub truncated: Option<bool>,
-    pub matches: Option<Vec<Value>>,
-    pub stderr: Option<String>,
-    pub exit_code: Option<i32>,
-    pub duration_ms: u64,
-}
-
-/// Summary of all searches
-#[derive(Debug, Serialize)]
-pub struct SearchSummary {
-    pub completed: usize,
-    pub total: usize,
-    pub total_matches: usize,
-    pub duration_ms: u64,
-}
-
-/// Complete response structure
-#[derive(Debug, Serialize)]
-pub struct CodeSearchResponse {
-    pub summary: SearchSummary,
-    pub searches: Vec<SearchResult>,
-}
-
-/// YAML rule structure for validation
-#[derive(Debug, Deserialize)]
-struct YamlRule {
-    pub id: String,
-    pub language: String,
-    pub rule: Value,
-}
-
-/// Execute a batch of code searches using ast-grep
-pub async fn execute_code_search(request: CodeSearchRequest) -> Result<CodeSearchResponse> {
-    let start_time = Instant::now();
-    
-    // Validate request
-    if request.searches.is_empty() {
-        return Err(anyhow!("No searches specified"));
-    }
-    
-    if request.searches.len() > MAX_SEARCHES {
-        return Err(anyhow!(
-            "Too many searches: {} (max: {})",
-            request.searches.len(),
-            MAX_SEARCHES
-        ));
-    }
-    
-    // Check if ast-grep is available
-    check_ast_grep_available().await?;
-    
-    let max_concurrency = request.max_concurrency.unwrap_or(DEFAULT_MAX_CONCURRENCY);
-    let max_matches = request.max_matches_per_search.unwrap_or(DEFAULT_MAX_MATCHES);
-    
-    // Create semaphore for concurrency control
-    let semaphore = std::sync::Arc::new(Semaphore::new(max_concurrency));
-    
-    // Execute searches concurrently
-    let mut tasks = Vec::new();
-
-    for search in request.searches {
-        let sem = semaphore.clone();
-        let task = tokio::spawn(async move {
-            let _permit = sem.acquire().await.unwrap();
-            execute_single_search(search, max_matches).await
-        });
-        tasks.push(task);
-    }
-    
-    // Wait for all searches to complete
-    let mut results = Vec::new();
-    let mut total_matches = 0;
-    let mut completed = 0;
-    
-    for task in tasks {
-        match task.await {
-            Ok(result) => {
-                if result.status == "ok" {
-                    completed += 1;
-                    if let Some(count) = result.match_count {
-                        total_matches += count;
-                    }
-                }
-                results.push(result);
-            }
-            Err(e) => {
-                error!("Task join error: {}", e);
-                // Create an error result
-                results.push(SearchResult {
-                    name: "unknown".to_string(),
-                    mode: "unknown".to_string(),
-                    status: "error".to_string(),
-                    cmd: vec![],
-                    match_count: None,
-                    truncated: None,
-                    matches: None,
-                    stderr: Some(format!("Task execution error: {}", e)),
-                    exit_code: None,
-                    duration_ms: 0,
-                });
-            }
-        }
-    }
-    
-    let total_duration = start_time.elapsed();
-    
-    Ok(CodeSearchResponse {
-        summary: SearchSummary {
-            completed,
-            total: results.len(),
-            total_matches,
-            duration_ms: total_duration.as_millis() as u64,
-        },
-        searches: results,
-    })
-}
-
-/// Execute a single search
-async fn execute_single_search(search: SearchSpec, max_matches: usize) -> SearchResult {
-    let start_time = Instant::now();
-    let timeout_secs = search.timeout_secs.unwrap_or(DEFAULT_TIMEOUT_SECS);
-    
-    // Validate the search specification
-    if let Err(e) = validate_search_spec(&search) {
-        return SearchResult {
-            name: search.name,
-            mode: format!("{:?}", search.mode).to_lowercase(),
-            status: "error".to_string(),
-            cmd: vec![],
-            match_count: None,
-            truncated: None,
-            matches: None,
-            stderr: Some(format!("Validation error: {}", e)),
-            exit_code: None,
-            duration_ms: start_time.elapsed().as_millis() as u64,
-        };
-    }
-    
-    // Build command
-    let cmd_args = match build_ast_grep_command(&search) {
-        Ok(args) => args,
-        Err(e) => {
-            return SearchResult {
-                name: search.name,
-                mode: format!("{:?}", search.mode).to_lowercase(),
-                status: "error".to_string(),
-                cmd: vec![],
-                match_count: None,
-                truncated: None,
-                matches: None,
-                stderr: Some(format!("Command build error: {}", e)),
-                exit_code: None,
-                duration_ms: start_time.elapsed().as_millis() as u64,
-            };
-        }
-    };
-    
-    debug!("Executing ast-grep command: {:?}", cmd_args);
-
-    // Execute with timeout
-    let timeout_duration = Duration::from_secs(timeout_secs);
-    
-    match tokio::time::timeout(timeout_duration, run_ast_grep_command(&cmd_args)).await {
-        Ok(Ok((stdout, stderr, exit_code))) => {
-            let duration_ms = start_time.elapsed().as_millis() as u64;
-            
-            if exit_code == 0 {
-                // Parse JSON output
-                match parse_ast_grep_output(&stdout, max_matches) {
-                    Ok((matches, truncated)) => {
-                        SearchResult {
-                            name: search.name,
-                            mode: format!("{:?}", search.mode).to_lowercase(),
-                            status: "ok".to_string(),
-                            cmd: cmd_args,
-                            match_count: Some(matches.len()),
-                            truncated: Some(truncated),
-                            matches: Some(matches),
-                            stderr: if stderr.is_empty() { None } else { Some(stderr) },
-                            exit_code: None,
-                            duration_ms,
-                        }
-                    }
-                    Err(e) => {
-                        SearchResult {
-                            name: search.name,
-                            mode: format!("{:?}", search.mode).to_lowercase(),
-                            status: "error".to_string(),
-                            cmd: cmd_args,
-                            match_count: None,
-                            truncated: None,
-                            matches: None,
-                            stderr: Some(format!("JSON parse error: {}\nRaw output: {}", e, stdout)),
-                            exit_code: Some(exit_code),
-                            duration_ms,
-                        }
-                    }
-                }
-            } else {
-                SearchResult {
-                    name: search.name,
-                    mode: format!("{:?}", search.mode).to_lowercase(),
-                    status: "error".to_string(),
-                    cmd: cmd_args,
-                    match_count: None,
-                    truncated: None,
-                    matches: None,
-                    stderr: Some(stderr),
-                    exit_code: Some(exit_code),
-                    duration_ms,
-                }
-            }
-        }
-        Ok(Err(e)) => {
-            SearchResult {
-                name: search.name,
-                mode: format!("{:?}", search.mode).to_lowercase(),
-                status: "error".to_string(),
-                cmd: cmd_args,
-                match_count: None,
-                truncated: None,
-                matches: None,
-                stderr: Some(format!("Execution error: {}", e)),
-                exit_code: None,
-                duration_ms: start_time.elapsed().as_millis() as u64,
-            }
-        }
-        Err(_) => {
-            SearchResult {
-                name: search.name,
-                mode: format!("{:?}", search.mode).to_lowercase(),
-                status: "timeout".to_string(),
-                cmd: cmd_args,
-                match_count: None,
-                truncated: None,
-                matches: None,
-                stderr: Some(format!("Search timed out after {} seconds", timeout_secs)),
-                exit_code: None,
-                duration_ms: start_time.elapsed().as_millis() as u64,
-            }
-        }
-    }
-}
-
-/// Validate a search specification
-fn validate_search_spec(search: &SearchSpec) -> Result<()> {
-    match search.mode {
-        SearchMode::Pattern => {
-            if search.pattern.is_none() || search.pattern.as_ref().unwrap().is_empty() {
-                return Err(anyhow!("Pattern mode requires non-empty 'pattern' field"));
-            }
-        }
-        SearchMode::Yaml => {
-            let rule_yaml = search.rule_yaml.as_ref()
-                .ok_or_else(|| anyhow!("YAML mode requires 'rule_yaml' field"))?;
-            
-            if rule_yaml.is_empty() {
-                return Err(anyhow!("YAML mode requires non-empty 'rule_yaml' field"));
-            }
-            
-            // Parse and validate YAML structure
-            let parsed: YamlRule = serde_yaml::from_str(rule_yaml)
-                .map_err(|e| anyhow!("Invalid YAML rule: {}", e))?;
-            
-            if parsed.id.is_empty() {
-                return Err(anyhow!("YAML rule must have non-empty 'id' field"));
-            }
-            
-            if parsed.language.is_empty() {
-                return Err(anyhow!("YAML rule must have non-empty 'language' field"));
-            }
-            
-            // Validate language is supported (basic check)
-            validate_language(&parsed.language)?;
-        }
-    }
-    
-    // Validate context range
-    if let Some(context) = search.context {
-        if context > 20 {
-            return Err(anyhow!("Context lines cannot exceed 20"));
-        }
-    }
-    
-    Ok(())
-}
-
-/// Validate that a language is supported by ast-grep
-fn validate_language(language: &str) -> Result<()> {
-    let supported_languages = [
-        "rust", "javascript", "typescript", "python", "java", "c", "cpp", "csharp",
-        "go", "html", "css", "json", "yaml", "xml", "bash", "kotlin", "swift",
-        "php", "ruby", "scala", "dart", "lua", "r", "sql", "dockerfile",
-        "Rust", "JavaScript", "TypeScript", "Python", "Java", "C", "Cpp", "CSharp",
-        "Go", "Html", "Css", "Json", "Yaml", "Xml", "Bash", "Kotlin", "Swift",
-        "Php", "Ruby", "Scala", "Dart", "Lua", "R", "Sql", "Dockerfile"
-    ];
-    
-    if !supported_languages.contains(&language) {
-        warn!("Language '{}' may not be supported by ast-grep", language);
-    }
-    
-    Ok(())
-}
-
-/// Build ast-grep command arguments
-fn build_ast_grep_command(search: &SearchSpec) -> Result<Vec<String>> {
-    let mut args = vec!["ast-grep".to_string()];
-    
-    match search.mode {
-        SearchMode::Pattern => {
-            args.push("run".to_string());
-            
-            // Add pattern
-            args.push("-p".to_string());
-            args.push(search.pattern.as_ref().unwrap().clone());
-            
-            // Add language if specified
-            if let Some(ref lang) = search.language {
-                args.push("-l".to_string());
-                args.push(lang.clone());
-            }
-        }
-        SearchMode::Yaml => {
-            args.push("scan".to_string());
-            
-            // Add inline rules
-            args.push("--inline-rules".to_string());
-            args.push(search.rule_yaml.as_ref().unwrap().clone());
-            
-            // Add include-metadata if requested
-            if search.include_metadata.unwrap_or(false) {
-                args.push("--include-metadata".to_string());
-            }
-            
-            // Add severity overrides
-            if let Some(ref severity_map) = search.severity {
-                for (rule_id, severity) in severity_map {
-                    match severity {
-                        SeverityLevel::Error => {
-                            args.push("--error".to_string());
-                            args.push(rule_id.clone());
-                        }
-                        SeverityLevel::Warning => {
-                            args.push("--warning".to_string());
-                            args.push(rule_id.clone());
-                        }
-                        SeverityLevel::Info => {
-                            args.push("--info".to_string());
-                            args.push(rule_id.clone());
-                        }
-                        SeverityLevel::Hint => {
-                            args.push("--hint".to_string());
-                            args.push(rule_id.clone());
-                        }
-                        SeverityLevel::Off => {
-                            args.push("--off".to_string());
-                            args.push(rule_id.clone());
-                        }
-                    }
-                }
-            }
-        }
-    }
-    
-    // Add common arguments
-    
-    // Add globs if specified
-    if let Some(ref globs) = search.globs {
-        if !globs.is_empty() {
-            args.push("--globs".to_string());
-            args.push(globs.join(","));
-        }
-    }
-    
-    // Add context
-    if let Some(context) = search.context {
-        args.push("-C".to_string());
-        args.push(context.to_string());
-    }
-    
-    // Add threads
-    if let Some(threads) = search.threads {
-        args.push("-j".to_string());
-        args.push(threads.to_string());
-    }
-    
-    // Add JSON output style
-    let json_style = search.json_style.as_ref().unwrap_or(&JsonStyle::Stream);
-    let json_arg = match json_style {
-        JsonStyle::Pretty => "--json=pretty",
-        JsonStyle::Stream => "--json=stream",
-        JsonStyle::Compact => "--json=compact",
-    };
-    args.push(json_arg.to_string());
-    
-    // Add no-ignore options
-    if let Some(ref no_ignore_list) = search.no_ignore {
-        for no_ignore_type in no_ignore_list {
-            let flag = match no_ignore_type {
-                NoIgnoreType::Hidden => "--no-ignore=hidden",
-                NoIgnoreType::Dot => "--no-ignore=dot",
-                NoIgnoreType::Exclude => "--no-ignore=exclude",
-                NoIgnoreType::Global => "--no-ignore=global",
-                NoIgnoreType::Parent => "--no-ignore=parent",
-                NoIgnoreType::Vcs => "--no-ignore=vcs",
-            };
-            args.push(flag.to_string());
-        }
-    }
-    
-    // Add paths (default to current directory if none specified)
-    if let Some(ref paths) = search.paths {
-        if !paths.is_empty() {
-            args.extend(paths.clone());
-        } else {
-            args.push(".".to_string());
-        }
-    } else {
-        args.push(".".to_string());
-    }
-    
-    Ok(args)
-}
-
-/// Run ast-grep command and capture output
-async fn run_ast_grep_command(args: &[String]) -> Result<(String, String, i32)> {
-    let mut cmd = Command::new(&args[0]);
-    cmd.args(&args[1..]);
-    cmd.stdout(Stdio::piped());
-    cmd.stderr(Stdio::piped());
-    
-    debug!("Running command: {:?}", args);
-    
-    let mut child = cmd.spawn()
-        .map_err(|e| anyhow!("Failed to spawn ast-grep process: {}", e))?;
-    
-    let stdout = child.stdout.take().unwrap();
-    let stderr = child.stderr.take().unwrap();
-    
-    let stdout_reader = BufReader::new(stdout);
-    let stderr_reader = BufReader::new(stderr);
-    
-    let stdout_task = tokio::spawn(async move {
-        let mut lines = stdout_reader.lines();
-        let mut output = String::new();
-        while let Ok(Some(line)) = lines.next_line().await {
-            if !output.is_empty() {
-                output.push('\n');
-            }
-            output.push_str(&line);
-        }
-        output
-    });
-    
-    let stderr_task = tokio::spawn(async move {
-        let mut lines = stderr_reader.lines();
-        let mut output = String::new();
-        while let Ok(Some(line)) = lines.next_line().await {
-            if !output.is_empty() {
-                output.push('\n');
-            }
-            output.push_str(&line);
-        }
-        output
-    });
-    
-    let status = child.wait().await
-        .map_err(|e| anyhow!("Failed to wait for ast-grep process: {}", e))?;
-    
-    let stdout_output = stdout_task.await
-        .map_err(|e| anyhow!("Failed to read stdout: {}", e))?;
-    let stderr_output = stderr_task.await
-        .map_err(|e| anyhow!("Failed to read stderr: {}", e))?;
-    
-    let exit_code = status.code().unwrap_or(-1);
-    
-    Ok((stdout_output, stderr_output, exit_code))
-}
-
-/// Parse ast-grep JSON output
-fn parse_ast_grep_output(output: &str, max_matches: usize) -> Result<(Vec<Value>, bool)> {
-    if output.trim().is_empty() {
-        return Ok((vec![], false));
-    }
-    
-    let mut matches = Vec::new();
-    let mut truncated = false;
-    
-    // Handle stream format (line-delimited JSON)
-    for line in output.lines() {
-        let line = line.trim();
-        if line.is_empty() {
-            continue;
-        }
-        
-        match serde_json::from_str::<Value>(line) {
-            Ok(match_obj) => {
-                if matches.len() >= max_matches {
-                    truncated = true;
-                    break;
-                }
-                matches.push(match_obj);
-            }
-            Err(e) => {
-                debug!("Failed to parse JSON line '{}': {}", line, e);
-                // Try to parse the entire output as a single JSON array
-                match serde_json::from_str::<Vec<Value>>(output) {
-                    Ok(array_matches) => {
-                        let take_count = array_matches.len().min(max_matches);
-                        let total_count = array_matches.len();
-                        matches = array_matches.into_iter().take(take_count).collect();
-                        truncated = take_count < total_count;
-                        break;
-                    }
-                    Err(e2) => {
-                        return Err(anyhow!(
-                            "Failed to parse ast-grep output as line-delimited JSON or JSON array. Line error: {}, Array error: {}",
-                            e, e2
-                        ));
-                    }
-                }
-            }
-        }
-    }
-    
-    Ok((matches, truncated))
-}
-
-/// Check if ast-grep is available and provide installation hints if not
-async fn check_ast_grep_available() -> Result<()> {
-    match Command::new("ast-grep")
-        .arg("--version")
-        .output()
-        .await
-    {
-        Ok(output) => {
-            if output.status.success() {
-                let version = String::from_utf8_lossy(&output.stdout);
-                info!("Found ast-grep: {}", version.trim());
-                Ok(())
-            } else {
-                Err(anyhow!("ast-grep command failed: {}", String::from_utf8_lossy(&output.stderr)))
-            }
-        }
-        Err(_) => {
-            Err(anyhow!(
-                "ast-grep not found. Please install it using one of these methods:\n\n\
-                • Homebrew (macOS): brew install ast-grep\n\
-                • MacPorts (macOS): sudo port install ast-grep\n\
-                • Nix: nix-env -iA nixpkgs.ast-grep\n\
-                • Cargo: cargo install ast-grep\n\
-                • npm: npm install -g @ast-grep/cli\n\
-                • pip: pip install ast-grep\n\n\
-                For more installation options, visit: https://ast-grep.github.io/guide/quick-start.html"
-            ))
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    
-    #[test]
-    fn test_validate_pattern_search() {
-        let search = SearchSpec {
-            name: "test".to_string(),
-            mode: SearchMode::Pattern,
-            pattern: Some("fn $NAME() {}".to_string()),
-            language: Some("rust".to_string()),
-            rule_yaml: None,
-            paths: None,
-            globs: None,
-            json_style: None,
-            context: None,
-            threads: None,
-            include_metadata: None,
-            no_ignore: None,
-            severity: None,
-            timeout_secs: None,
-        };
-        
-        assert!(validate_search_spec(&search).is_ok());
-    }
-    
-    #[test]
-    fn test_validate_yaml_search() {
-        let yaml_rule = r#"
-id: test-rule
-language: Rust
-rule:
-  pattern: "fn $NAME() {}"
-"#;
-        
-        let search = SearchSpec {
-            name: "test".to_string(),
-            mode: SearchMode::Yaml,
-            pattern: None,
-            language: None,
-            rule_yaml: Some(yaml_rule.to_string()),
-            paths: None,
-            globs: None,
-            json_style: None,
-            context: None,
-            threads: None,
-            include_metadata: None,
-            no_ignore: None,
-            severity: None,
-            timeout_secs: None,
-        };
-        
-        assert!(validate_search_spec(&search).is_ok());
-    }
-    
-    #[test]
-    fn test_build_pattern_command() {
-        let search = SearchSpec {
-            name: "test".to_string(),
-            mode: SearchMode::Pattern,
-            pattern: Some("fn $NAME() {}".to_string()),
-            language: Some("rust".to_string()),
-            rule_yaml: None,
-            paths: Some(vec!["src/".to_string()]),
-            globs: None,
-            json_style: Some(JsonStyle::Stream),
-            context: Some(2),
-            threads: Some(4),
-            include_metadata: None,
-            no_ignore: None,
-            severity: None,
-            timeout_secs: None,
-        };
-        
-        let cmd = build_ast_grep_command(&search).unwrap();
-        
-        assert_eq!(cmd[0], "ast-grep");
-        assert_eq!(cmd[1], "run");
-        assert!(cmd.contains(&"-p".to_string()));
-        assert!(cmd.contains(&"fn $NAME() {}".to_string()));
-        assert!(cmd.contains(&"-l".to_string()));
-        assert!(cmd.contains(&"rust".to_string()));
-        assert!(cmd.contains(&"--json=stream".to_string()));
-        assert!(cmd.contains(&"-C".to_string()));
-        assert!(cmd.contains(&"2".to_string()));
-        assert!(cmd.contains(&"-j".to_string()));
-        assert!(cmd.contains(&"4".to_string()));
-        assert!(cmd.contains(&"src/".to_string()));
-    }
-    
-    #[test]
-    fn test_parse_stream_json() {
-        let output = r#"{"file":"test.rs","text":"fn hello() {}"}
-{"file":"test2.rs","text":"fn world() {}"}"#;
-        
-        let (matches, truncated) = parse_ast_grep_output(output, 10).unwrap();
-        
-        assert_eq!(matches.len(), 2);
-        assert!(!truncated);
-        assert_eq!(matches[0]["file"], "test.rs");
-        assert_eq!(matches[1]["file"], "test2.rs");
-    }
-    
-    #[test]
-    fn test_parse_truncated_output() {
-        let output = r#"{"file":"test1.rs","text":"fn a() {}"}
-{"file":"test2.rs","text":"fn b() {}"}
-{"file":"test3.rs","text":"fn c() {}"}"#;
-        
-        let (matches, truncated) = parse_ast_grep_output(output, 2).unwrap();
-        
-        assert_eq!(matches.len(), 2);
-        assert!(truncated);
-    }
-}
diff --git a/crates/g3-core/src/code_search/mod.rs b/crates/g3-core/src/code_search/mod.rs
new file mode 100644
index 0000000..eb7c364
--- /dev/null
+++ b/crates/g3-core/src/code_search/mod.rs
@@ -0,0 +1,81 @@
+//! Code search functionality using tree-sitter for syntax-aware searches
+
+use anyhow::Result;
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+
+mod searcher;
+pub use searcher::TreeSitterSearcher;
+
+/// Request for batch code searches
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CodeSearchRequest {
+    pub searches: Vec<SearchSpec>,
+    #[serde(default = "default_concurrency")]
+    pub max_concurrency: usize,
+    #[serde(default = "default_max_matches")]
+    pub max_matches_per_search: usize,
+}
+
+fn default_concurrency() -> usize {
+    4
+}
+
+fn default_max_matches() -> usize {
+    500
+}
+
+/// Individual search specification
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SearchSpec {
+    /// Name/label for this search
+    pub name: String,
+    /// tree-sitter query (S-expression format)
+    pub query: String,
+    /// Language: "rust", "python", "javascript", "typescript"
+    pub language: String,
+    /// Paths to search (default: current directory)
+    #[serde(default)]
+    pub paths: Vec<String>,
+    /// Lines of context around each match
+    #[serde(default)]
+    pub context_lines: usize,
+}
+
+/// Response containing all search results
+#[derive(Debug, Serialize, Deserialize)]
+pub struct CodeSearchResponse {
+    pub searches: Vec<SearchResult>,
+    pub total_matches: usize,
+    pub total_files_searched: usize,
+}
+
+/// Result for a single search
+#[derive(Debug, Serialize, Deserialize)]
+pub struct SearchResult {
+    pub name: String,
+    pub matches: Vec<Match>,
+    pub match_count: usize,
+    pub files_searched: usize,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub error: Option<String>,
+}
+
+/// A single match
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Match {
+    pub file: String,
+    pub line: usize,
+    pub column: usize,
+    pub text: String,
+    #[serde(skip_serializing_if = "HashMap::is_empty")]
+    pub captures: HashMap<String, String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub context: Option<String>,
+}
+
+/// Main entry point for code search
+pub async fn execute_code_search(request: CodeSearchRequest) -> Result<CodeSearchResponse> {
+    let mut searcher = TreeSitterSearcher::new()?;
+    searcher.execute_search(request).await
+}
diff --git a/crates/g3-core/src/code_search/searcher.rs b/crates/g3-core/src/code_search/searcher.rs
new file mode 100644
index 0000000..45d0c5f
--- /dev/null
+++ b/crates/g3-core/src/code_search/searcher.rs
@@ -0,0 +1,267 @@
+use super::{CodeSearchRequest, CodeSearchResponse, Match, SearchResult, SearchSpec};
+use anyhow::{anyhow, Result};
+use std::collections::HashMap;
+use std::fs;
+use std::path::Path;
+use tree_sitter::{Language, Parser, Query, QueryCursor};
+use walkdir::WalkDir;
+
+pub struct TreeSitterSearcher {
+    parsers: HashMap<String, Parser>,
+    languages: HashMap<String, Language>,
+}
+
+impl TreeSitterSearcher {
+    pub fn new() -> Result<Self> {
+        let mut parsers = HashMap::new();
+        let mut languages = HashMap::new();
+
+        // Initialize Rust
+        {
+            let mut parser = Parser::new();
+            let language: Language = tree_sitter_rust::language().into();
+            parser
+                .set_language(&language)
+                .map_err(|e| anyhow!("Failed to set Rust language: {}", e))?;
+            parsers.insert("rust".to_string(), parser);
+            languages.insert("rust".to_string(), language);
+        }
+
+        // Initialize Python
+        {
+            let mut parser = Parser::new();
+            let language: Language = tree_sitter_python::language().into();
+            parser
+                .set_language(&language)
+                .map_err(|e| anyhow!("Failed to set Python language: {}", e))?;
+            parsers.insert("python".to_string(), parser);
+            languages.insert("python".to_string(), language);
+        }
+
+        // Initialize JavaScript
+        {
+            let mut parser = Parser::new();
+            let language: Language = tree_sitter_javascript::language().into();
+            parser
+                .set_language(&language)
+                .map_err(|e| anyhow!("Failed to set JavaScript language: {}", e))?;
+            parsers.insert("javascript".to_string(), parser);
+            
+            // Create separate parser for "js" alias
+            let mut parser_js = Parser::new();
+            parser_js.set_language(&language)
+                .map_err(|e| anyhow!("Failed to set JavaScript language: {}", e))?;
+            parsers.insert("js".to_string(), parser_js);
+            languages.insert("javascript".to_string(), language.clone());
+            languages.insert("js".to_string(), language.clone());
+        }
+
+        // Initialize TypeScript
+        {
+            let mut parser = Parser::new();
+            let language: Language = tree_sitter_typescript::language_typescript().into();
+            parser
+                .set_language(&language)
+                .map_err(|e| anyhow!("Failed to set TypeScript language: {}", e))?;
+            parsers.insert("typescript".to_string(), parser);
+            
+            // Create separate parser for "ts" alias
+            let mut parser_ts = Parser::new();
+            parser_ts.set_language(&language)
+                .map_err(|e| anyhow!("Failed to set TypeScript language: {}", e))?;
+            parsers.insert("ts".to_string(), parser_ts);
+            languages.insert("typescript".to_string(), language.clone());
+            languages.insert("ts".to_string(), language.clone());
+        }
+
+        if parsers.is_empty() {
+            return Err(anyhow!(
+                "No language parsers available. Enable at least one language feature."
+            ));
+        }
+
+        Ok(Self { parsers, languages })
+    }
+
+    pub async fn execute_search(
+        &mut self,
+        request: CodeSearchRequest,
+    ) -> Result<CodeSearchResponse> {
+        let mut all_results = Vec::new();
+        let mut total_matches = 0;
+        let mut total_files = 0;
+
+        // Execute searches sequentially (could parallelize with tokio::spawn if needed)
+        for spec in request.searches {
+            let result = self
+                .search_single(&spec, request.max_matches_per_search)
+                .await;
+            match result {
+                Ok(search_result) => {
+                    total_matches += search_result.match_count;
+                    total_files += search_result.files_searched;
+                    all_results.push(search_result);
+                }
+                Err(e) => {
+                    all_results.push(SearchResult {
+                        name: spec.name.clone(),
+                        matches: vec![],
+                        match_count: 0,
+                        files_searched: 0,
+                        error: Some(e.to_string()),
+                    });
+                }
+            }
+        }
+
+        Ok(CodeSearchResponse {
+            searches: all_results,
+            total_matches,
+            total_files_searched: total_files,
+        })
+    }
+
+    async fn search_single(
+        &mut self,
+        spec: &SearchSpec,
+        max_matches: usize,
+    ) -> Result<SearchResult> {
+        // Get parser and language
+        let parser = self
+            .parsers
+            .get_mut(&spec.language)
+            .ok_or_else(|| anyhow!("Unsupported language: {}", spec.language))?;
+        let language = self
+            .languages
+            .get(&spec.language)
+            .ok_or_else(|| anyhow!("Language not found: {}", spec.language))?;
+
+        // Parse query
+        let query = Query::new(language, &spec.query)
+            .map_err(|e| anyhow!("Invalid query: {}", e))?;
+
+        let mut matches = Vec::new();
+        let mut files_searched = 0;
+
+        // Determine search paths
+        let search_paths = if spec.paths.is_empty() {
+            vec![".".to_string()]
+        } else {
+            spec.paths.clone()
+        };
+
+        // Walk directories and search files
+        for search_path in search_paths {
+            for entry in WalkDir::new(&search_path)
+                .follow_links(true)
+                .into_iter()
+                .filter_map(|e| e.ok())
+            {
+                if matches.len() >= max_matches {
+                    break;
+                }
+
+                let path = entry.path();
+                if !path.is_file() {
+                    continue;
+                }
+
+                // Check file extension matches language
+                if !Self::is_language_file(path, &spec.language) {
+                    continue;
+                }
+
+                files_searched += 1;
+
+                // Read and parse file
+                if let Ok(source_code) = fs::read_to_string(path) {
+                    if let Some(tree) = parser.parse(&source_code, None) {
+                        let mut cursor = QueryCursor::new();
+                        let query_matches = cursor.matches(
+                            &query,
+                            tree.root_node(),
+                            source_code.as_bytes(),
+                        );
+
+                        for query_match in query_matches {
+                            if matches.len() >= max_matches {
+                                break;
+                            }
+
+                            // Extract captures
+                            let mut captures_map = HashMap::new();
+                            let mut match_text = String::new();
+                            let mut match_line = 0;
+                            let mut match_column = 0;
+
+                            for capture in query_match.captures {
+                                let capture_name = query.capture_names()[capture.index as usize];
+                                let node = capture.node;
+                                let text = &source_code[node.byte_range()];
+
+                                captures_map.insert(capture_name.to_string(), text.to_string());
+
+                                // Use first capture for position
+                                if match_text.is_empty() {
+                                    match_text = text.to_string();
+                                    let start = node.start_position();
+                                    match_line = start.row + 1;
+                                    match_column = start.column + 1;
+                                }
+                            }
+
+                            // Get context if requested
+                            let context = if spec.context_lines > 0 {
+                                Some(Self::get_context(
+                                    &source_code,
+                                    match_line,
+                                    spec.context_lines,
+                                ))
+                            } else {
+                                None
+                            };
+
+                            matches.push(Match {
+                                file: path.display().to_string(),
+                                line: match_line,
+                                column: match_column,
+                                text: match_text,
+                                captures: captures_map,
+                                context,
+                            });
+                        }
+                    }
+                }
+            }
+        }
+
+        Ok(SearchResult {
+            name: spec.name.clone(),
+            match_count: matches.len(),
+            files_searched,
+            matches,
+            error: None,
+        })
+    }
+
+    fn is_language_file(path: &Path, language: &str) -> bool {
+        let ext = path.extension().and_then(|e| e.to_str());
+        match (language, ext) {
+            ("rust", Some("rs")) => true,
+            ("python", Some("py")) => true,
+            ("javascript" | "js", Some("js" | "jsx" | "mjs")) => true,
+            ("typescript" | "ts", Some("ts" | "tsx")) => true,
+            _ => false,
+        }
+    }
+
+    fn get_context(source: &str, line: usize, context_lines: usize) -> String {
+        let lines: Vec<&str> = source.lines().collect();
+        // line is 1-indexed, convert to 0-indexed
+        let line_idx = line.saturating_sub(1);
+        // Get context_lines before and after
+        let start = line_idx.saturating_sub(context_lines);
+        let end = (line_idx + context_lines + 1).min(lines.len());
+        lines[start..end].join("\n")
+    }
+}
diff --git a/crates/g3-core/src/lib.rs b/crates/g3-core/src/lib.rs
index 43c4548..ddb949f 100644
--- a/crates/g3-core/src/lib.rs
+++ b/crates/g3-core/src/lib.rs
@@ -1096,11 +1096,11 @@ If you create temporary files for verification, place these in a subdir named 't
 For reading files, prioritize use of code_search tool use with multiple search requests per call instead of read_file, if it makes sense.
 
 Additional examples for the 'code_search' tool:
-  - Example for pattern mode: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"find_functions\", \"mode\": \"pattern\", \"pattern\": \"fn $NAME($$$ARGS) { $$$ }\", \"language\": \"rust\", \"paths\": [\"src/\"]}]}}
-  - Example for YAML mode: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"find_async\", \"mode\": \"yaml\", \"rule_yaml\": \"id: async-fn\nlanguage: Rust\nrule:\n  pattern: async fn $NAME($$$) { $$$ }\"}]}}
-  - Example for multiple searches: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"funcs\", \"mode\": \"pattern\", \"pattern\": \"fn $NAME\", \"language\": \"rust\"}, {\"name\": \"structs\", \"mode\": \"pattern\", \"pattern\": \"struct $NAME\", \"language\": \"rust\"}]}}
-  - Example for passing optional args like \"context\": {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"funcs\", \"mode\": \"pattern\", \"context\": 3, \"pattern\": \"fn $NAME\", \"language\": \"rust\"}]}
-  - Common optional args for searches:
+  - Find functions: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"find_functions\", \"query\": \"(function_item name: (identifier) @name)\", \"language\": \"rust\", \"paths\": [\"src/\"]}]}}
+  - Find async functions: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"find_async\", \"query\": \"(function_item (function_modifiers) name: (identifier) @name)\", \"language\": \"rust\"}]}}
+  - Find structs: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"structs\", \"query\": \"(struct_item name: (type_identifier) @name)\", \"language\": \"rust\"}]}}
+  - Multiple searches: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"funcs\", \"query\": \"(function_item name: (identifier) @name)\", \"language\": \"rust\"}, {\"name\": \"structs\", \"query\": \"(struct_item name: (type_identifier) @name)\", \"language\": \"rust\"}]}}
+  - With context lines: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"funcs\", \"query\": \"(function_item name: (identifier) @name)\", \"language\": \"rust\", \"context_lines\": 3}]}}
        - \"context\": 3 (show surrounding lines),
        - \"json_style\": \"stream\" (for large results)
 
@@ -1184,13 +1184,13 @@ Short description for providers without native calling specs:
   - Format: {\"tool\": \"todo_write\", \"args\": {\"content\": \"- [ ] Task 1\\n- [ ] Task 2\"}}
   - Example: {\"tool\": \"todo_write\", \"args\": {\"content\": \"- [ ] Implement feature\\n  - [ ] Write tests\\n  - [ ] Run tests\"}}
 
-- **code_search**: Batch syntax-aware searches via ast-grep. Supports up to 20 pattern or YAML-rule searches in parallel.
-  - Format: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"search_label\", \"mode\": \"pattern|yaml\", ...}], \"max_concurrency\": 4, \"max_matches_per_search\": 500}}
-  - Example for pattern mode: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"find_functions\", \"mode\": \"pattern\", \"pattern\": \"fn $NAME($$$ARGS) { $$$ }\", \"language\": \"rust\", \"paths\": [\"src/\"]}]}}
-  - Example for YAML mode: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"find_async\", \"mode\": \"yaml\", \"rule_yaml\": \"id: async-fn\nlanguage: Rust\nrule:\n  pattern: async fn $NAME($$$) { $$$ }\"}]}}
-  - Example for multiple searches: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"funcs\", \"mode\": \"pattern\", \"pattern\": \"fn $NAME\", \"language\": \"rust\"}, {\"name\": \"structs\", \"mode\": \"pattern\", \"pattern\": \"struct $NAME\", \"language\": \"rust\"}]}}
-  - Example for passing optional args like \"context\": {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"funcs\", \"mode\": \"pattern\", \"context\": 3, \"pattern\": \"fn $NAME\", \"language\": \"rust\"}]}
-  - Common optional args for searches:
+- **code_search**: Syntax-aware code search using tree-sitter. Supports Rust, Python, JavaScript, TypeScript.
+  - Format: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"label\", \"query\": \"tree-sitter query\", \"language\": \"rust|python|javascript|typescript\", \"paths\": [\"src/\"], \"context_lines\": 0}]}}
+  - Find functions: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"find_functions\", \"query\": \"(function_item name: (identifier) @name)\", \"language\": \"rust\", \"paths\": [\"src/\"]}]}}
+  - Find async functions: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"find_async\", \"query\": \"(function_item (function_modifiers) name: (identifier) @name)\", \"language\": \"rust\"}]}}
+  - Find structs: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"structs\", \"query\": \"(struct_item name: (type_identifier) @name)\", \"language\": \"rust\"}]}}
+  - Multiple searches: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"funcs\", \"query\": \"(function_item name: (identifier) @name)\", \"language\": \"rust\"}, {\"name\": \"structs\", \"query\": \"(struct_item name: (type_identifier) @name)\", \"language\": \"rust\"}]}}
+  - With context lines: {\"tool\": \"code_search\", \"args\": {\"searches\": [{\"name\": \"funcs\", \"query\": \"(function_item name: (identifier) @name)\", \"language\": \"rust\", \"context_lines\": 3}]}}
        - \"context\": 3 (show surrounding lines),
        - \"json_style\": \"stream\" (for large results)
 
@@ -1908,7 +1908,7 @@ Template:
         // Add code_search tool
         tools.push(Tool {
             name: "code_search".to_string(),
-            description: "Batch syntax-aware searches via ast-grep. Supports up to 20 pattern or YAML-rule searches in parallel; returns JSON matches (stream-collated).".to_string(),
+            description: "Batch syntax-aware code searches using embedded tree-sitter. Supports up to 20 searches in parallel for Rust, Python, JavaScript, and TypeScript. Uses tree-sitter query syntax (S-expressions).".to_string(),
             input_schema: json!({
                 "type": "object",
                 "properties": {
@@ -1919,43 +1919,14 @@ Template:
                             "type": "object",
                             "properties": {
                                 "name": { "type": "string", "description": "Label for this search." },
-                                "mode": {
-                                    "type": "string",
-                                    "enum": ["pattern", "yaml"],
-                                    "description": "`pattern` uses `ast-grep run`; `yaml` uses `ast-grep scan --inline-rules`."
-                                },
-                                // pattern mode (fast one-off)
-                                "pattern": { "type": "string", "description": "ast-grep pattern code (e.g., \"async fn $NAME($$$ARGS) { $$$ }\")"},
-                                "language": { "type": "string", "description": "Optional language for pattern mode; ast-grep may infer from file extensions if omitted." },
-                                // yaml mode (full rule object)
-                                "rule_yaml": { "type": "string", "description": "A full YAML rule object text. Must include `id`, `language`, and `rule`." },
-                                // targeting
+                                "query": { "type": "string", "description": "tree-sitter query in S-expression format (e.g., \"(function_item name: (identifier) @name)\")"},
+                                "language": { "type": "string", "enum": ["rust", "python", "javascript", "typescript"], "description": "Programming language to search." },
                                 "paths": { "type": "array", "items": { "type": "string" }, "description": "Paths/dirs to search. Defaults to current dir if empty." },
-                                "globs": { "type": "array", "items": { "type": "string" }, "description": "Optional include/exclude globs for CLI --globs." },
-                                // result formatting & performance knobs
-                                "json_style": { "type": "string", "enum": ["pretty","stream","compact"], "default": "stream", "description": "Use stream for large codebases." },
-                                "context": { "type": "integer", "minimum": 0, "maximum": 20, "default": 0, "description": "CLI -C context lines in text output; also affects JSON `lines` field." },
-                                "threads": { "type": "integer", "minimum": 1, "description": "Optional override for ast-grep -j (per process)." },
-                                "include_metadata": { "type": "boolean", "default": false, "description": "If yaml mode and rule has metadata, add --include-metadata." },
-                                // robustness
-                                "no_ignore": {
-                                    "type": "array",
-                                    "items": { "type": "string", "enum": ["hidden","dot","exclude","global","parent","vcs"] },
-                                    "description": "Forwarded to --no-ignore to bypass ignore files/hidden."
-                                },
-                                // severity overrides for yaml mode
-                                "severity": {
-                                    "type": "object",
-                                    "additionalProperties": { "type": "string", "enum": ["error","warning","info","hint","off"] },
-                                    "description": "Optional map<ruleId, severity> -> passed via --error/--warning/--info/--hint/--off."
-                                },
-                                // per-search timeout seconds (default 60)
-                                "timeout_secs": { "type": "integer", "minimum": 1, "default": 60 }
+                                "context_lines": { "type": "integer", "minimum": 0, "maximum": 20, "default": 0, "description": "Lines of context to include around each match." }
                             },
-                            "required": ["name","mode"]
+                            "required": ["name", "query", "language"]
                         }
                     },
-                    // global concurrency & truncation
                     "max_concurrency": { "type": "integer", "minimum": 1, "default": 4 },
                     "max_matches_per_search": { "type": "integer", "minimum": 1, "default": 500 }
                 },
@@ -2395,13 +2366,6 @@ Template:
 
         // Check if we need to summarize before starting
         if self.context_window.should_summarize() {
-            info!(
-                "Context window at {}% ({}/{} tokens), triggering auto-summarization",
-                self.context_window.percentage_used() as u32,
-                self.context_window.used_tokens,
-                self.context_window.total_tokens
-            );
-
             // Notify user about summarization
             self.ui_writer.print_context_status(&format!(
                 "\n🗜️ Context window reaching capacity ({}%). Creating summary...",
@@ -4590,13 +4554,7 @@ Template:
                         }
                     }
                     Err(e) => {
-                        // Check if it's an ast-grep not found error and provide helpful message
-                        let error_msg = e.to_string();
-                        if error_msg.contains("ast-grep not found") {
-                            Ok(format!("❌ {}", error_msg))
-                        } else {
-                            Ok(format!("❌ Code search failed: {}", error_msg))
-                        }
+                        Ok(format!("❌ Code search failed: {}", e))
                     }
                 }
             }
diff --git a/crates/g3-core/tests/code_search_test.rs b/crates/g3-core/tests/code_search_test.rs
new file mode 100644
index 0000000..1bfad0f
--- /dev/null
+++ b/crates/g3-core/tests/code_search_test.rs
@@ -0,0 +1,412 @@
+//! Integration tests for tree-sitter code search
+
+use g3_core::code_search::{execute_code_search, CodeSearchRequest, SearchSpec};
+use std::fs;
+
+#[tokio::test]
+async fn test_find_async_functions() {
+    // Create a temporary test file
+    let test_dir = std::env::temp_dir().join("g3_test_code_search");
+    fs::create_dir_all(&test_dir).unwrap();
+    
+    let test_file = test_dir.join("test.rs");
+    fs::write(
+        &test_file,
+        r#"
+pub async fn example_async() {
+    println!("Hello");
+}
+
+fn regular_function() {
+    println!("Regular");
+}
+
+pub async fn another_async(x: i32) -> Result<(), ()> {
+    Ok(())
+}
+"#,
+    )
+    .unwrap();
+
+    // Test 1: Find async functions
+    let request = CodeSearchRequest {
+        searches: vec![SearchSpec {
+            name: "find_async_functions".to_string(),
+            // In tree-sitter-rust, async is a token inside function_modifiers
+            query: "(function_item (function_modifiers) name: (identifier) @name)".to_string(),
+            language: "rust".to_string(),
+            paths: vec![test_dir.to_string_lossy().to_string()],
+            context_lines: 0,
+        }],
+        max_concurrency: 4,
+        max_matches_per_search: 100,
+    };
+
+    let response = execute_code_search(request).await.unwrap();
+
+    assert_eq!(response.searches.len(), 1);
+    let search_result = &response.searches[0];
+    assert_eq!(search_result.name, "find_async_functions");
+    assert_eq!(search_result.match_count, 2, "Should find 2 async functions");
+    assert!(search_result.error.is_none());
+
+    // Check that we found the right functions
+    let function_names: Vec<String> = search_result
+        .matches
+        .iter()
+        .filter_map(|m| m.captures.get("name").cloned())
+        .collect();
+
+    assert!(function_names.contains(&"example_async".to_string()));
+    assert!(function_names.contains(&"another_async".to_string()));
+
+    // Cleanup
+    fs::remove_dir_all(&test_dir).ok();
+}
+
+#[tokio::test]
+async fn test_find_all_functions() {
+    // Create a temporary test file
+    let test_dir = std::env::temp_dir().join("g3_test_code_search_2");
+    fs::create_dir_all(&test_dir).unwrap();
+    
+    let test_file = test_dir.join("test.rs");
+    fs::write(
+        &test_file,
+        r#"
+pub async fn example_async() {
+    println!("Hello");
+}
+
+fn regular_function() {
+    println!("Regular");
+}
+
+pub async fn another_async(x: i32) -> Result<(), ()> {
+    Ok(())
+}
+"#,
+    )
+    .unwrap();
+
+    // Test 2: Find all functions (async and regular)
+    let request = CodeSearchRequest {
+        searches: vec![SearchSpec {
+            name: "find_all_functions".to_string(),
+            query: "(function_item name: (identifier) @name)".to_string(),
+            language: "rust".to_string(),
+            paths: vec![test_dir.to_string_lossy().to_string()],
+            context_lines: 0,
+        }],
+        max_concurrency: 4,
+        max_matches_per_search: 100,
+    };
+
+    let response = execute_code_search(request).await.unwrap();
+
+    assert_eq!(response.searches.len(), 1);
+    let search_result = &response.searches[0];
+    assert_eq!(search_result.name, "find_all_functions");
+    assert_eq!(search_result.match_count, 3, "Should find 3 functions total");
+    assert!(search_result.error.is_none());
+
+    // Check that we found all functions
+    let function_names: Vec<String> = search_result
+        .matches
+        .iter()
+        .filter_map(|m| m.captures.get("name").cloned())
+        .collect();
+
+    assert!(function_names.contains(&"example_async".to_string()));
+    assert!(function_names.contains(&"regular_function".to_string()));
+    assert!(function_names.contains(&"another_async".to_string()));
+
+    // Cleanup
+    fs::remove_dir_all(&test_dir).ok();
+}
+
+#[tokio::test]
+async fn test_find_structs() {
+    // Create a temporary test file
+    let test_dir = std::env::temp_dir().join("g3_test_code_search_3");
+    fs::create_dir_all(&test_dir).unwrap();
+    
+    let test_file = test_dir.join("test.rs");
+    fs::write(
+        &test_file,
+        r#"
+pub struct MyStruct {
+    field: String,
+}
+
+struct AnotherStruct;
+
+enum MyEnum {
+    Variant,
+}
+"#,
+    )
+    .unwrap();
+
+    // Test 3: Find structs
+    let request = CodeSearchRequest {
+        searches: vec![SearchSpec {
+            name: "find_structs".to_string(),
+            query: "(struct_item name: (type_identifier) @name)".to_string(),
+            language: "rust".to_string(),
+            paths: vec![test_dir.to_string_lossy().to_string()],
+            context_lines: 0,
+        }],
+        max_concurrency: 4,
+        max_matches_per_search: 100,
+    };
+
+    let response = execute_code_search(request).await.unwrap();
+
+    assert_eq!(response.searches.len(), 1);
+    let search_result = &response.searches[0];
+    assert_eq!(search_result.name, "find_structs");
+    assert_eq!(search_result.match_count, 2, "Should find 2 structs");
+    assert!(search_result.error.is_none());
+
+    // Check that we found the right structs
+    let struct_names: Vec<String> = search_result
+        .matches
+        .iter()
+        .filter_map(|m| m.captures.get("name").cloned())
+        .collect();
+
+    assert!(struct_names.contains(&"MyStruct".to_string()));
+    assert!(struct_names.contains(&"AnotherStruct".to_string()));
+
+    // Cleanup
+    fs::remove_dir_all(&test_dir).ok();
+}
+
+#[tokio::test]
+async fn test_context_lines() {
+    // Create a temporary test file
+    let test_dir = std::env::temp_dir().join("g3_test_code_search_4");
+    fs::create_dir_all(&test_dir).unwrap();
+    
+    let test_file = test_dir.join("test.rs");
+    fs::write(
+        &test_file,
+        r#"
+// Line 1
+// Line 2
+pub fn target_function() {
+    // Line 4
+    println!("target");
+}
+// Line 7
+// Line 8
+"#,
+    )
+    .unwrap();
+
+    // Test 4: Context lines
+    let request = CodeSearchRequest {
+        searches: vec![SearchSpec {
+            name: "find_with_context".to_string(),
+            query: "(function_item name: (identifier) @name)".to_string(),
+            language: "rust".to_string(),
+            paths: vec![test_dir.to_string_lossy().to_string()],
+            context_lines: 2,
+        }],
+        max_concurrency: 4,
+        max_matches_per_search: 100,
+    };
+
+    let response = execute_code_search(request).await.unwrap();
+
+    assert_eq!(response.searches.len(), 1);
+    let search_result = &response.searches[0];
+    assert_eq!(search_result.match_count, 1);
+    
+    let match_result = &search_result.matches[0];
+    assert!(match_result.context.is_some());
+    
+    let context = match_result.context.as_ref().unwrap();
+    assert!(context.contains("Line 2"), "Should include 2 lines before");
+    assert!(context.contains("target_function"), "Should include the function");
+    // Note: context_lines=2 means 2 lines before and after the match line (line 4)
+    // So we get lines 2-6, which includes up to println but not the closing brace
+    assert!(context.contains("println"), "Should include 2 lines after the match");
+
+    // Cleanup
+    fs::remove_dir_all(&test_dir).ok();
+}
+
+#[tokio::test]
+async fn test_multiple_searches() {
+    // Create a temporary test file
+    let test_dir = std::env::temp_dir().join("g3_test_code_search_5");
+    fs::create_dir_all(&test_dir).unwrap();
+    
+    let test_file = test_dir.join("test.rs");
+    fs::write(
+        &test_file,
+        r#"
+pub async fn async_func() {}
+fn regular_func() {}
+pub struct MyStruct;
+"#,
+    )
+    .unwrap();
+
+    // Test 5: Multiple searches in one request
+    let request = CodeSearchRequest {
+        searches: vec![
+            SearchSpec {
+                name: "async_functions".to_string(),
+                query: "(function_item (function_modifiers) name: (identifier) @name)".to_string(),
+                language: "rust".to_string(),
+                paths: vec![test_dir.to_string_lossy().to_string()],
+                context_lines: 0,
+            },
+            SearchSpec {
+                name: "structs".to_string(),
+                query: "(struct_item name: (type_identifier) @name)".to_string(),
+                language: "rust".to_string(),
+                paths: vec![test_dir.to_string_lossy().to_string()],
+                context_lines: 0,
+            },
+        ],
+        max_concurrency: 4,
+        max_matches_per_search: 100,
+    };
+
+    let response = execute_code_search(request).await.unwrap();
+
+    assert_eq!(response.searches.len(), 2);
+    assert_eq!(response.total_matches, 2); // 1 async function + 1 struct
+
+    // Check first search (async functions)
+    let async_search = &response.searches[0];
+    assert_eq!(async_search.name, "async_functions");
+    assert_eq!(async_search.match_count, 1);
+
+    // Check second search (structs)
+    let struct_search = &response.searches[1];
+    assert_eq!(struct_search.name, "structs");
+    assert_eq!(struct_search.match_count, 1);
+
+    // Cleanup
+    fs::remove_dir_all(&test_dir).ok();
+}
+
+#[tokio::test]
+async fn test_python_search() {
+    // Create a temporary Python test file
+    let test_dir = std::env::temp_dir().join("g3_test_code_search_python");
+    fs::create_dir_all(&test_dir).unwrap();
+    
+    let test_file = test_dir.join("test.py");
+    fs::write(
+        &test_file,
+        r#"
+def regular_function():
+    pass
+
+async def async_function():
+    pass
+
+class MyClass:
+    def method(self):
+        pass
+"#,
+    )
+    .unwrap();
+
+    // Test 6: Python async functions
+    let request = CodeSearchRequest {
+        searches: vec![SearchSpec {
+            name: "python_async".to_string(),
+            // Note: tree-sitter-python doesn't expose 'async' as a queryable node
+            // For now, we'll just find all functions (async detection would need text matching)
+            query: "(function_definition name: (identifier) @name)".to_string(),
+            language: "python".to_string(),
+            paths: vec![test_dir.to_string_lossy().to_string()],
+            context_lines: 0,
+        }],
+        max_concurrency: 4,
+        max_matches_per_search: 100,
+    };
+
+    let response = execute_code_search(request).await.unwrap();
+
+    assert_eq!(response.searches.len(), 1);
+    let search_result = &response.searches[0];
+    assert_eq!(search_result.match_count, 3, "Should find 3 functions in Python (2 regular + 1 async + 1 method)");
+    
+    let function_names: Vec<String> = search_result
+        .matches
+        .iter()
+        .filter_map(|m| m.captures.get("name").cloned())
+        .collect();
+    
+    assert!(function_names.contains(&"regular_function".to_string()));
+    assert!(function_names.contains(&"async_function".to_string()));
+    assert!(function_names.contains(&"method".to_string()));
+
+    // Cleanup
+    fs::remove_dir_all(&test_dir).ok();
+}
+
+#[tokio::test]
+async fn test_javascript_search() {
+    // Create a temporary JavaScript test file
+    let test_dir = std::env::temp_dir().join("g3_test_code_search_js");
+    fs::create_dir_all(&test_dir).unwrap();
+    
+    let test_file = test_dir.join("test.js");
+    fs::write(
+        &test_file,
+        r#"
+function regularFunction() {
+    console.log("regular");
+}
+
+async function asyncFunction() {
+    console.log("async");
+}
+
+class MyClass {
+    constructor() {}
+}
+"#,
+    )
+    .unwrap();
+
+    // Test 7: JavaScript functions
+    let request = CodeSearchRequest {
+        searches: vec![SearchSpec {
+            name: "js_functions".to_string(),
+            query: "(function_declaration name: (identifier) @name)".to_string(),
+            language: "javascript".to_string(),
+            paths: vec![test_dir.to_string_lossy().to_string()],
+            context_lines: 0,
+        }],
+        max_concurrency: 4,
+        max_matches_per_search: 100,
+    };
+
+    let response = execute_code_search(request).await.unwrap();
+
+    assert_eq!(response.searches.len(), 1);
+    let search_result = &response.searches[0];
+    assert_eq!(search_result.match_count, 2, "Should find 2 functions in JavaScript");
+    
+    let function_names: Vec<String> = search_result
+        .matches
+        .iter()
+        .filter_map(|m| m.captures.get("name").cloned())
+        .collect();
+    
+    assert!(function_names.contains(&"regularFunction".to_string()));
+    assert!(function_names.contains(&"asyncFunction".to_string()));
+
+    // Cleanup
+    fs::remove_dir_all(&test_dir).ok();
+}