Simple MCP Client Using LangChain / TypeScript

This simple Model Context Protocol (MCP) client demonstrates MCP server invocations by LangChain ReAct Agent.

It leverages a utility function convertMcpToLangchainTools() from @h1deya/langchain-mcp-tools.
This function handles parallel initialization of specified multiple MCP servers and converts their available tools into a list of LangChain-compatible tools.

Anthropic's claude-3-5-haiku-latest is used as the LLM.
For convenience, code for OpenAI's gpt-4o-mini is also included and commented out.

Requirements

• Node.js 16+
• API key from Anthropic (or OpenAI)

Usage

1. Install dependencies:

   npm install

2. Setup API key:

   cp .env.template .env

   • Update .env as needed.
   • .gitignore is configured to ignore .env to prevent accidental commits of the credentials.

3. Run the app:

   npm start