LangChain MCP

pip install langchain-mcp langchain-core
# For the Groq demo model:
pip install langchain-groq

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

server_params = StdioServerParameters(
    command="npx",
    args=["-y", "@modelcontextprotocol/server-filesystem", "/tmp"]
)

async with stdio_client(server_params) as (read, write):
    async with ClientSession(read, write) as session:
        await session.initialize()
        # pass session to MCPToolkit below

import langchain_mcp

toolkit = langchain_mcp.MCPToolkit(session)
await toolkit.initialize()
tools = toolkit.get_tools()

from langchain_groq import ChatGroq
from langchain.agents import create_tool_calling_agent, AgentExecutor
from langchain_core.prompts import ChatPromptTemplate

llm = ChatGroq(model="llama-3.1-8b-instant")
prompt = ChatPromptTemplate.from_messages([("system", "You are a helpful assistant."), ("placeholder", "{agent_scratchpad}"), ("human", "{input}")])
agent = create_tool_calling_agent(llm, tools, prompt)
executor = AgentExecutor(agent=agent, tools=tools)
result = await executor.ainvoke({"input": "Read and summarize the file ./LICENSE"})