CodeAst

MCP server for static code analysis — Returns structured data instead of raw files to reduce context window usage by 10x.

Built with Rust (analyzer) + TypeScript (MCP wrapper).

Why CodeAst?

When LLMs analyze code, they typically read entire files. CodeAst extracts only what matters:

| Without CodeAst | With CodeAst | |-----------------|--------------| | Read 500 lines to find functions | Get structured list of symbols | | Grep entire codebase for callers | Get precise caller locations | | Manual dependency tracing | Automatic cycle detection |

Installation

macOS / Linux:

claude mcp add codeast npx codeast

Windows:

npm install -g codeast
claude mcp add codeast codeast

The analyzer binary is downloaded automatically on first run.

Tools

| Tool | Description | |------|-------------| | get_symbols | List functions, classes, types in a file | | get_callers | Find all functions that call a function | | get_calls | Get all functions called by a function | | get_imports | Get imports (internal vs external) | | get_imported_by | Find files that import a file | | get_complexity | Get cyclomatic/cognitive complexity metrics | | get_cycles | Detect circular dependencies | | get_duplicates | Find duplicated code blocks | | get_file_info | Quick file overview | | search_files | Search files by glob pattern | | run_tests | Run tests (auto-detects npm/cargo/pytest) | | status | Check if analyzer is running |

Supported Languages

• JavaScript / TypeScript / JSX / TSX
• Python
• Rust
• Astro

Contributing

This project is open source and welcomes contributions! Whether you're fixing bugs, adding features, or improving documentation, your help is appreciated.

Getting Started

# Clone the repo
git clone https://github.com/YOUR_USERNAME/codeast.git
cd codeast

# Build the Rust analyzer
cd analyzer && cargo build --release

# Build and run MCP server
cd ../mcp && npm install && npm run build
node dist/mcp/server.js

The MCP auto-detects the local binary in dev mode.

Areas for Contribution

Bugs to Fix

| # | Bug | Impact | |---|-----|--------| | 1 | get_callers doesn't find without module prefix (fn vs module::fn) | Usability | | 2 | JS grammar doesn't detect exports (only TS works) | .js files |

Missing Features

| # | Feature | Description | |---|---------|-------------| | 1 | Function parameters | Extract params (name, type) from functions | | 2 | Return types | Extract return type from functions | | 3 | Class methods | get_symbols doesn't return methods | | 4 | Export default | export default function not detected | | 5 | Re-exports | export { foo } from './bar' not traced | | 6 | Decorators | @Controller, @Injectable (NestJS, Angular) | | 7 | JSDoc/TSDoc | Extract documentation comments | | 8 | Async detection | Mark if a function is async |

MCP Improvements

| # | Tool | Improvement | |---|------|-------------| | 1 | get_callers | Fuzzy match (without module prefix) | | 2 | get_callers | Add recursive: true param for call chain | | 3 | get_symbols | Add methods for classes | | 4 | get_complexity | Add maintainability index | | 5 | search_code | New tool for grep with context | | 6 | get_dependencies | Visualize dependency tree of a file |

Refactoring

| File | Complexity | Action | |------|------------|--------| | symbols.rs | 382 | Split into modules (js.rs, rust.rs, python.rs, astro.rs) | | analyzer.rs | 73 | Extract process_import logic | | handlers.ts | - | Factor out error handling |

New Language Support

Want to add support for a new language? Here's what you need:

1. Add tree-sitter grammar to analyzer/Cargo.toml
2. Create extraction functions in analyzer/src/symbols.rs
3. Add import parsing in analyzer/src/parser.rs
4. Add tests in analyzer/tests/

Languages we'd love to support:

• Go
• Java
• C/C++
• Ruby
• PHP

Project Structure

codeast/
├── analyzer/          # Rust - Core analysis engine
│   ├── src/
│   │   ├── main.rs        # CLI entry point
│   │   ├── analyzer.rs    # Orchestration
│   │   ├── symbols.rs     # AST symbol extraction
│   │   ├── parser.rs      # Import extraction
│   │   ├── complexity.rs  # Metrics calculation
│   │   ├── duplicates.rs  # Duplicate detection
│   │   └── graph.rs       # Dependency graph
│   └── Cargo.toml
│
├── mcp/               # TypeScript - MCP server wrapper
│   ├── src/
│   │   ├── mcp/
│   │   │   ├── server.ts      # MCP entry point
│   │   │   ├── tools.ts       # Tool definitions
│   │   │   └── handlers.ts    # Tool implementations
│   │   └── services/
│   │       ├── analyzer.ts    # Process management
│   │       └── queries.ts     # Query API
│   └── package.json
│
└── docs/              # Landing page

License

MIT

Found a bug? Have an idea? Open an issue or submit a PR!