---

Features

$3

Search LangChain, LangGraph, LangSmith & DeepAgents documentation and source code instantly from Claude.

$3

Debug your LangGraph agents like Polly - connect to your local langgraph dev server and:
- List threads, runs, and traces
- Inspect agent state and checkpoints
- Ask "Why did this fail?" and get AI-powered analysis
- Get suggestions to improve your agent's prompts

---

Install

``bash
npm i -g langchain-mcp
langchain-mcp login
claude mcp add langchain-mcp -- langchain-mcp
`

Claude Desktop config

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

`json
{
"mcpServers": {
"langchain-mcp": {
"command": "langchain-mcp"
}
}
}
`

---

Tools

$3

| Tool | Description |
|------|-------------|
| search_docs | Search documentation and tutorials |
| search_langchain_code | Search LangChain source code |
| search_langgraph_code | Search LangGraph source code |
| search_deepagents_code | Search DeepAgents source code |

$3

| Tool | Description |
|------|-------------|
| langgraph_list_threads | List threads from local server |
| langgraph_get_thread | Get thread details |
| langgraph_get_thread_state | Get state/checkpoint |
| langgraph_list_runs | List runs for a thread |
| langgraph_get_run | Get run trace details |

---

Debug Your Agents

`bash


Start your LangGraph server


langgraph dev
`

Then ask Claude:
- "List my LangGraph threads"
- "What went wrong with thread abc123?"
- "Summarize the last run"
- "How can I improve this agent?"

Connects to localhost:2024` by default.

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Pricing

| Feature | Cost |
|---------|------|
| Doc/Code Search | $5 free credits (~2000 searches) |
| LangGraph Debugging | Free forever |

---

License

MIT