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Home/Servers/Langchain

Langchain

I
by io.github.baixianger

LangChain/LangGraph/DeepAgents knowledge + LangGraph agent debugging (Polly-like)

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Local command
npx -y [email protected]
Provider
Claude Code
claude mcp add io.github.baixianger-langchain-mcp -- npx -y [email protected]

Run in a terminal.

Claude Desktop
{
  "mcpServers": {
    "io.github.baixianger-langchain-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "[email protected]"
      ]
    }
  }
}

claude_desktop_config.json

Step-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

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Questions

How do I install Langchain?
Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.
Does Langchain need an API key?
No required environment variable is listed on this record.
What transport does Langchain use?
Langchain runs locally over stdio.
When was Langchain last checked?
Last checked 2026-10-16. LangChain/LangGraph/DeepAgents knowledge + LangGraph agent debugging (Polly-like)

LangChain/LangGraph/DeepAgents knowledge + LangGraph agent debugging (Polly-like)

LangChain MCP

Give your AI assistant complete knowledge of LangChain, LangGraph & LangSmith

Website • Installation • Features • Documentation

Overview

LangChain MCP is a Model Context Protocol (MCP) server that provides semantic search across the entire LangChain ecosystem. Build AI applications faster with instant access to documentation and source code for LangChain, LangGraph, LangSmith, and DeepAgents.

Features

  • Semantic Search - Natural language queries across all LangChain ecosystem docs
  • Source Code Search - Find code examples in Python and JavaScript repositories
  • MCP Protocol - Works seamlessly with Claude Code, Claude Desktop, Cursor, and any MCP-compatible client
  • Production Ready - Scalable API with authentication and usage tracking
  • Fast & Accurate - Powered by ChromaDB and OpenRouter embeddings

Installation

Quick Start (Recommended)

# Install globally
npm install -g langchain-mcp

# Login with Google
langchain-mcp login

# Add to Claude Code
claude mcp add langchain-mcp -- npx langchain-mcp

Manual Configuration

Add the following configuration to your client's config file:

Claude Desktop

  • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
  • Windows: %APPDATA%\Claude\claude_desktop_config.json

Cursor

  • macOS/Linux: ~/.cursor/mcp.json
  • Windows: %USERPROFILE%\.cursor\mcp.json
{
  "mcpServers": {
    "langchain-mcp": {
      "command": "npx",
      "args": ["langchain-mcp"]
    }
  }
}

Usage

CLI Commands

langchain-mcp login      # Login via Google OAuth
langchain-mcp status     # Check usage and remaining credits
langchain-mcp logout     # Logout and clear credentials

Available MCP Tools

ToolDescriptionParameters
search_docsSearch documentation, references, and tutorialsquery, limit (default: 5)
search_langchain_codeSearch LangChain source codequery, language (py/js), limit
search_langgraph_codeSearch LangGraph source codequery, language (py/js), limit
search_deepagents_codeSearch DeepAgents source codequery, language (py/js), limit

Pricing

  • Free tier available for new users
  • Donation bonus for supporters

Documentation

Self-deploy

Project Structure
langchain-MCP/
├── packages/
│   ├── ingest/              # Python - Data ingestion (uv)
│   ├── api/                 # TypeScript - API server (Express)
│   ├── mcp-server/          # TypeScript - MCP client (npm package)
│   └── mcp-server-local/    # TypeScript - Local MCP server (dev)
├── config/
│   └── settings.json        # Shared configuration
└── deploy.sh                # Deployment script
Architecture
Setup Development Environment

1. Ingest Documentation & Source Code

cd packages/ingest
uv sync
uv run ingest --list     # List available repositories
uv run ingest docs       # Ingest documentation only
uv run ingest            # Ingest all (docs + code)

2. Run API Server

cd packages/api
npm install
npm run dev              # Development server on port 3000

3. Test Local MCP Server

cd packages/mcp-server-local
npm install
npm run dev
Configuration

All settings in config/settings.json:

{
  "embedding": {
    "provider": "openrouter",
    "model": "qwen/qwen3-embedding-8b"
  },
  "chromadb": {
    "path": "./data/chroma"
  },
  "chunking": {
    "docs": { "chunk_size": 2000, "chunk_overlap": 200 },
    "code": { "chunk_size": 4000, "chunk_overlap": 200 }
  },
  "repos": [
    {
      "name": "langchain",
      "url": "https://github.com/langchain-ai/langchain",
      "type": "code",
      "languages": ["python", "javascript"]
    }
  ]
}
Supported Embedding Providers
  • sentence-transformer (local)
  • openai
  • cohere
  • google
  • ollama
  • openrouter (default)

See ChromaDB Integrations for more options.

Deployment

The project includes automated deployment scripts for VPS hosting:

# Manual deployment
./deploy.sh

# GitHub Actions (production branch)
git push origin main:production

Deployment includes:

  • Code synchronization via rsync
  • Automatic npm installation and build
  • PM2 process management
  • Nginx static file serving
  • Environment variable management

Roadmap

  • Semantic search across docs and code
  • Google OAuth authentication
  • Usage tracking and credits system
  • MCP registry registration
  • Claude Code, Desktop, and Cursor support
  • Rate limiting (per user / per IP)
  • Additional embedding model options
  • Local mode (no API key required)
  • Browser extension for quick searches
  • VSCode extension integration

Contributing

Forking and contributions are welcome!

Support

  • Website: langchain-mcp.xyz
  • Issues: GitHub Issues
  • Donate: Support development at Ko-fi

License

MIT License - see the LICENSE file for details.

Built with ❤️ by baixianger

Website • GitHub • npm

How do I install Langchain?
Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.
Does Langchain need an API key?
No required environment variable is listed on this record.
What transport does Langchain use?
Langchain runs locally over stdio.
When was Langchain last checked?
Last checked 2026-10-16. LangChain/LangGraph/DeepAgents knowledge + LangGraph agent debugging (Polly-like)

No tool list yet. Remote servers get one after the first health check.

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