LangChain MCP Tools

How to Set Up and Use LangChain MCP Tools

langchain-mcp-tools-ts (published as @h1deya/langchain-mcp-tools) is a TypeScript utility library that converts MCP server tools into LangChain-compatible tool objects, enabling LangChain agents to call any MCP server's capabilities as native tools. It handles parallel initialization of multiple MCP servers, performs provider-specific schema transformations to prevent compatibility issues with OpenAI, Google Gemini, Anthropic, and xAI, and exposes a simple cleanup lifecycle for resource management. Developers building LangChain agents who want to leverage the growing ecosystem of MCP servers can drop this utility in without writing manual adapter code.

npm i @h1deya/langchain-mcp-tools

const mcpServers = {
  filesystem: {
    command: "npx",
    args: ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"]
  },
  fetch: {
    command: "uvx",
    args: ["mcp-server-fetch"]
  }
};

import { convertMcpToLangchainTools } from "@h1deya/langchain-mcp-tools";

const { tools, cleanup } = await convertMcpToLangchainTools(
  mcpServers,
  { llmProvider: "anthropic" }
);

import { createReactAgent } from "@langchain/langgraph/prebuilt";
import Anthropic from "@anthropic-ai/sdk";

const agent = createReactAgent({ model, tools });
const result = await agent.invoke({ messages: [{ role: "user", content: "List files in /tmp" }] });

await cleanup();

{
  "dependencies": {
    "@h1deya/langchain-mcp-tools": "latest",
    "@langchain/anthropic": "latest",
    "@langchain/langgraph": "latest"
  }
}

- "List all files in the /tmp directory using the filesystem server"
- "Fetch the content of https://example.com and summarize it"
- "Search my notes vault for mentions of 'project deadline'"
- "What tools are available from the connected MCP servers?"
- "Use the GitHub MCP server to list open pull requests in my repository"