# CodeRAG
> Lightning-fast semantic code search with AST chunking - RAG-ready for AI assistants
## Overview
CodeRAG is a high-performance code search library that combines TF-IDF keyword search with optional vector embeddings. It uses AST parsing to split code at semantic boundaries (functions, classes, etc.) for precise, chunk-level search results.
## Documentation
- Getting Started: /guide/getting-started
- Installation: /guide/installation
- Quick Start: /guide/quick-start
- How Search Works: /guide/how-search-works
- AST Chunking: /guide/ast-chunking
- TF-IDF & BM25: /guide/tfidf
- Vector Search: /guide/vector-search
- Hybrid Search: /guide/hybrid-search
- Persistent Storage: /guide/storage
- File Watching: /guide/file-watching
- Language Support: /guide/languages
- Performance: /guide/performance
## API Reference
- Overview: /api/overview
- CodebaseIndexer: /api/indexer
- PersistentStorage: /api/storage
- Search Functions: /api/search
- Embedding Providers: /api/embeddings
- AST Chunking: /api/chunking
- Types: /api/types
## MCP Server
- Overview: /mcp/overview
- Installation: /mcp/installation
- Configuration: /mcp/configuration
- Tools Reference: /mcp/tools
- IDE Integration: /mcp/ide-integration
## Key Concepts
### Chunk-Level Search
Unlike file-level search, CodeRAG returns semantic chunks (functions, classes, methods) with precise line numbers. This reduces token usage when feeding results to LLMs.
### Hybrid Search
Combines keyword search (BM25) with optional vector embeddings for best accuracy. Use vectorWeight parameter to balance precision vs semantic understanding.
### Persistent Storage
SQLite-based storage with instant startup (<100ms). Automatically handles incremental updates when files change.
### MCP Server
Model Context Protocol server for AI assistants (Claude, Cursor, VS Code). Provides codebase_search tool for semantic code search.
## Packages
- @sylphx/coderag - Core library (TF-IDF, storage, indexer)
- @sylphx/coderag-mcp - MCP server for AI assistants
## Quick Start
```typescript
import { CodebaseIndexer, PersistentStorage } from '@sylphx/coderag'
const storage = new PersistentStorage({ codebaseRoot: '.' })
const indexer = new CodebaseIndexer({ codebaseRoot: '.', storage })
await indexer.index()
const results = await indexer.search('authentication middleware')
```
## MCP Server Usage
```bash
npx @sylphx/coderag-mcp --root=/path/to/project
```
## Supported Languages
JavaScript, TypeScript, Python, Go, Rust, Java, C, C++, Ruby, PHP, Markdown, HTML, JSON, YAML, TOML, and more.
## Links
- GitHub: https://github.com/SylphxAI/coderag
- npm: https://www.npmjs.com/package/@sylphx/coderag
- Documentation: https://coderag.sylphx.com
