LightRAG MCP Server

A Model Context Protocol (MCP) server that enables AI assistants to interact with LightRAG knowledge graphs. Query documents, manage entities, and build semantic relationships through a standardized tool interface. Optimized for Obsidian Vaults: The built-in smart upsert and document tracking capabilities make it perfect for agents that need to sync and reason over evolving Obsidian knowledge bases.

Features

• Smart Updates: Intelligent upsert logic that detects changes in documents, skipping redundant uploads and re-indexing only when necessary
• Knowledge Graph Queries: Perform semantic, keyword, or hybrid searches across your indexed documents
• Document Ingestion: Add text, files, or entire directories to your knowledge base
• Entity Management: Create, update, merge, and delete entities in the graph
• Relationship Handling: Define and modify connections between entities
• Robust Connectivity: Automatic retry with exponential backoff for reliable API communication
• Flexible Configuration: Set options via environment variables or command-line arguments

Installation

# Clone the repository
git clone https://github.com/enriquecatala/mcp-lightrag.git
cd mcp-lightrag

# Install dependencies
uv sync

Quick Start

1. Start your LightRAG server (must be running before the MCP server)

2. Launch the MCP server:

   uv run mcp-lightrag --host localhost --port 9621
   

3. Connect your AI assistant via the MCP protocol (stdio transport)

Configuration

Setting up as MCP Server

To integrate this server with an MCP client (such as Claude Desktop), add the following configuration to your mcp-server-config.json key in your settings file. This configuration uses uv to run the server from the source directory.

{
  "mcpServers": {
    "mcp-lightrag": {
      "command": "uv",
      "args": [
        "--directory",
        "/absolute/path/to/mcp-lightrag",
        "run",
        "mcp-lightrag",
        "--host",
        "localhost",
        "--port",
        "9621"
      ],
      "env": {
        "LIGHTRAG_API_KEY": "optional_api_key"
      }
    }
  }
}

Note: Replace /absolute/path/to/mcp-lightrag with the actual full path to where you cloned this repository.

Smart Document Handling