MCP server for LangChain, LangGraph & DeepAgents knowledge + debug your LangGraph agents locally (Polly-like trace analysis)
npm install langchain-mcpGive Claude superpowers for LangChain development


---
langgraph dev server and:---
``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"
}
}
}
---
| 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 |
| 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 |
---
`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.
---
| Feature | Cost |
|---------|------|
| Doc/Code Search | $5 free credits (~2000 searches) |
| LangGraph Debugging | Free forever |
---
MIT