Repo Lens MCP Server

Cross-repository code intelligence for developers.

Search functions, classes, and API routes across all your local repositories without switching context.

Why Use This?

The problem: You're working in your frontend repo and need to find a backend API endpoint. Or you're debugging and need to find where a function is defined across your monorepo. With Claude Code, you can search the current repository, but what about your other local projects?

The solution: Repo Lens lets you register multiple local repositories and search across all of them simultaneously using AST-based structural search. Find the exact function signature, class definition, or API route you need without leaving your current context.

Use Cases

• Frontend + Backend development: Search backend API routes while working in your frontend repo
• Microservices architecture: Find function definitions across multiple services
• Monorepo navigation: Search across packages without switching directories
• Code exploration: Understand how different projects in your ecosystem connect

Quickstart

npx repo-lens-mcp

Key Features

AST-Based Intelligence

Unlike grep-style text search, Repo Lens uses ast-grep (written in Rust) to parse code into Abstract Syntax Trees:

• Structural accuracy: Distinguish between class User and const User
• Export awareness: Find only exported functions, or include private ones
• Signature extraction: Get full function signatures, not just names

Multi-Repository Search

Register any number of local git repositories and search them all at once:

• Instant registration (< 1 second per repo)
• Filter by repository, tags, or search all
• Results include repository context

API Route Discovery

Map all API endpoints across Express, NestJS, Fastify, and Laravel projects. Find that /users/:id endpoint in seconds.

Roadmap

• Phase 1 (Current): Stability, Multi-repo, Basic AST
• Phase 2 (Q1 2026): Cross-file references, Smart Context Summaries
• Phase 2.5 (Q1 2026): Python support (symbol search + Flask/Django routes)
• Phase 3 (Q2 2026): Semantic Search (Local Embeddings)
• Phase 3.5 (Q2 2026): Go & Rust support
• Phase 4.5 (Q3 2026): Java & C# support

Check the full ROADMAP.md | Language Expansion Plan

Installation

Claude Desktop / VS Code (Recommended)

Add this to your claude_desktop_config.json (or VS Code MCP settings):

{
  "mcpServers": {
    "repo-lens": {
      "command": "npx",
      "args": ["-y", "repo-lens-mcp"]
    }
  }
}

Restart Claude, and you're ready to go.

Local Development

git clone https://github.com/YohannHommet/repo-lens-mcp.git
cd repo-lens-mcp
npm install
npm run build
npm run dev

Capabilities

Repository Management (2 tools)

Manage which repositories are available for cross-repo search:

| Tool | Description | |:---|:---| | register_repository | Add or update a git repository (force: true to update existing) | | repositories | List, view, or remove repositories |

repositories usage patterns:

• repositories() → List all repos
• repositories({ identifier: 'my-api' }) → Get details of one repo
• repositories({ identifier: 'my-api', remove: true }) → Remove that repo
• repositories({ tags: ['frontend'] }) → List repos filtered by tags

Symbol Search (3 tools)

AST-based structural search powered by ast-grep:

| Tool | Description | |:---|:---| | find_functions | Find function/method definitions (supports wildcards like handle*) | | find_classes | Find class definitions | | find_types | Find TypeScript interfaces and type aliases |

API Route Discovery (1 tool)

| Tool | Description | |:---|:---| | find_api_routes | Map API endpoints across Express, NestJS, Fastify, Laravel |

Usage Examples

1. Register Your Projects

"Register the backend at /path/to/backend-api"

register_repository(path: "/path/to/backend-api", alias: "backend")

2. Find an API Endpoint

"Find the Express route that handles POST requests to /login"

find_api_routes(framework: "express", method: "POST", pathPattern: "/login")

3. Search Functions Across Repos

"Find all functions starting with 'handle' across all my registered repos"

find_functions(name: "handle*")

4. Find a Specific Class

"Where is the UserService class defined?"

find_classes(name: "UserService")

Configuration

Minimal configuration via environment variables:

| Variable | Default | Description | |:---|:---|:---| | MCP_LOG_LEVEL | info | Log level: debug, info, warn, error | | MCP_REPO_SEARCH_CONFIG_DIR | ~/.config/mcp-repo-search | Config directory for repository data |

Example:

{
  "env": {
    "MCP_LOG_LEVEL": "debug"
  }
}

What About Text Search / File Operations?

Repo Lens focuses on multi-repository AST-based search. For text search and file operations within your current repository, use Claude Code's built-in tools (Grep, Read, Glob) which are optimized for single-repo use.

This separation keeps Repo Lens fast and focused on what it does best: cross-repository structural code intelligence.

License

AGPL-3.0

This software is free to use. If you modify and distribute it (or run it as a network service), you must share your source code under the same license.