LangGraph Integration

async agentstr.mcp.langgraph.to_langgraph_tools(nostr_mcp_client: NostrMCPClient) → list[BaseTool]

Convert tools from the MCP client to LangGraph tools.

Parameters:

nostr_mcp_client – An instance of NostrMCPClient to fetch tools from.

Returns:

A list of LangGraph BaseTool objects that wrap the MCP tools.

This module provides integration with LangGraph tools, enabling conversion between MCP tools and LangGraph’s tool format.

Usage Example

from dotenv import load_dotenv

load_dotenv()

import os

from langchain_openai import ChatOpenAI
from langgraph.prebuilt import create_react_agent

from agentstr import NostrAgentServer, NostrMCPClient, ChatInput
from agentstr.mcp.langgraph import to_langgraph_tools

# Create Nostr MCP client
nostr_mcp_client = NostrMCPClient(relays=os.getenv("NOSTR_RELAYS").split(","),
                                  private_key=os.getenv("EXAMPLE_LANGGRAPH_AGENT_NSEC"),
                                  mcp_pubkey=os.getenv("EXAMPLE_MCP_SERVER_PUBKEY"),
                                  nwc_str=os.getenv("MCP_CLIENT_NWC_CONN_STR"))

async def agent_server():
    # Convert tools to LangGraph tools
    langgraph_tools = await to_langgraph_tools(nostr_mcp_client)

    for tool in langgraph_tools:
        print(f'Found {tool.name}: {tool.description}')

    # Create react agent
    agent = create_react_agent(
        model=ChatOpenAI(temperature=0,
                         base_url=os.getenv("LLM_BASE_URL"),
                         api_key=os.getenv("LLM_API_KEY"),
                         model_name=os.getenv("LLM_MODEL_NAME")),
        tools=langgraph_tools,
        prompt="You are a helpful assistant",
    )

    # Define agent callable
    async def agent_callable(input: ChatInput) -> str:
        result = await agent.ainvoke(
            {"messages": [{"role": "user", "content": input.messages[-1]}]},
        )
        return result["messages"][-1].content

    # Create Nostr Agent Server
    server = NostrAgentServer(nostr_mcp_client=nostr_mcp_client,
                              agent_callable=agent_callable)

    # Start server
    await server.start()


if __name__ == "__main__":
    import asyncio
    asyncio.run(agent_server())