LEANN/packages/leann-mcp/README.md

🔥 LEANN Claude Code Integration

Transform your development workflow with intelligent code assistance using LEANN's semantic search directly in Claude Code.

Prerequisites

Step 1: First, complete the basic LEANN installation following the 📦 Installation guide in the root README:

uv venv
source .venv/bin/activate
uv pip install leann

Step 2: Install LEANN globally for MCP integration:

uv tool install leann-core

This makes the leann command available system-wide, which leann_mcp requires.

🚀 Quick Setup

Add the LEANN MCP server to Claude Code:

claude mcp add leann-server -- leann_mcp

🛠️ Available Tools

Once connected, you'll have access to these powerful semantic search tools in Claude Code:

• leann_list - List all available indexes across your projects
• leann_search - Perform semantic searches across code and documents
• leann_ask - Ask natural language questions and get AI-powered answers from your codebase

🎯 Quick Start Example

# Build an index for your project (change to your actual path)
leann build my-project --docs ./

# Start Claude Code
claude

Try this in Claude Code:

Help me understand this codebase. List available indexes and search for authentication patterns.

🧠 How It Works

The integration consists of three key components working seamlessly together:

• leann - Core CLI tool for indexing and searching (installed globally via uv tool install)
• leann_mcp - MCP server that wraps leann commands for Claude Code integration
• Claude Code - Calls leann_mcp, which executes leann commands and returns intelligent results

📁 File Support

LEANN understands 30+ file types including:

• Programming: Python, JavaScript, TypeScript, Java, Go, Rust, C++, C#
• Data: SQL, YAML, JSON, CSV, XML
• Documentation: Markdown, TXT, PDF
• And many more!

💾 Storage & Organization

• Project indexes: Stored in .leann/ directory (just like .git)
• Global registry: Project tracking at ~/.leann/projects.json
• Multi-project support: Switch between different codebases seamlessly
• Portable: Transfer indexes between machines with minimal overhead

🗑️ Uninstalling

To remove the LEANN MCP server from Claude Code:

claude mcp remove leann-server

To remove LEANN

uv pip uninstall leann leann-backend-hnsw leann-core