Express MCP Server

What is Express MCP Server?

Express MCP Server is a stateless Model Context Protocol (MCP) server built with Express and TypeScript. It implements modern Streamable HTTP transport and provides an echo endpoint with resource, tool, and prompt components.

How to use Express MCP Server?

Clone the repository, install dependencies with npm install, build the TypeScript code with npm run build, then run in development mode with npm run dev. Send POST requests to the /mcp endpoint with JSON-RPC payloads to initialize the server and call the echo tool.

Key features of Express MCP Server

• Stateless MCP implementation with Streamable HTTP transport
• TypeScript for type safety
• Express.js for HTTP handling
• Echo resource, tool, and prompt components
• Simple JSON-RPC API
• Node.js 18+ required

Use cases of Express MCP Server

• Testing MCP client integration with a minimal server
• Demonstrating MCP resource, tool, and prompt patterns
• Prototyping or learning the Model Context Protocol

FAQ from Express MCP Server

What is the Model Context Protocol (MCP)?

MCP is a standardized way for LLMs to interact with external data and functionality. This server exposes a stateless API endpoint responding to JSON-RPC requests.

What are the runtime requirements?

Node.js 18+ and npm or yarn are required.

How do I install and run the server?

Clone the repository, run npm install, then npm run build and npm run dev (development mode). Use npm test when tests are added.

What functionality does this server provide?

It implements an echo endpoint: a resource at echo://{message}, a tool echo, and a prompt echo that all return or create the provided message.

How do I call the echo tool?

Send a POST request to /mcp with a JSON-RPC payload containing "method": "tools/call", "params": {"name": "echo", "arguments": {"message": "Hello, World!"}}.