dspy-mcp-tool-integration

DSPy MCP Tool Integration

Goal

Connect an MCP server with the MCP Python client, convert its tools to dspy.Tool, and use them in an async DSPy agent.

Install

pip install -U "dspy[mcp]>=3.2.1,<3.3"

DSPy converts tools but does not manage MCP connections. Keep the ClientSession alive for as long as the DSPy tools are in use.

Streamable HTTP Server

import asyncio
import dspy
from mcp import ClientSession
from mcp.client.streamable_http import streamablehttp_client

async def main():
    async with streamablehttp_client("http://localhost:8000/mcp") as (read, write):
        async with ClientSession(read, write) as session:
            await session.initialize()
            response = await session.list_tools()
            tools = [dspy.Tool.from_mcp_tool(session, tool) for tool in response.tools]

            agent = dspy.ReAct("task -> result", tools=tools, max_iters=5)
            output = await agent.acall(task="Check the weather in Tokyo")
            print(output.result)

asyncio.run(main())

Local Stdio Server

import asyncio
import dspy
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client

async def main():
    params = StdioServerParameters(
        command="python3",
        args=["path/to/server.py"],
        env=None,
    )

    async with stdio_client(params) as (read, write):
        async with ClientSession(read, write) as session:
            await session.initialize()
            response = await session.list_tools()
            tools = [dspy.Tool.from_mcp_tool(session, tool) for tool in response.tools]
            agent = dspy.ReAct("question -> answer", tools=tools, max_iters=5)
            print((await agent.acall(question="What is 25 + 17?")).answer)

asyncio.run(main())

Best Practices

1. Use acall() because MCP tools are asynchronous.
2. Initialize the session before listing tools.
3. Keep tool descriptions precise at the MCP server boundary.
4. Apply authentication and authorization before exposing sensitive tools.
5. Set a modest max_iters and trace tool use in production.