MCP Node SSE Reference Implementation

A simple Model Context Protocol (MCP) server implementation using bare Node.js.

Overview

This project implements an MCP server using native Node.js HTTP capabilities. We chose Node.js over frameworks like Fastify, Express, or Bun.js because they have less straightforward support for Server-Sent Events (SSE).

All MCP-specific components are located in the mcp folder, following the protocol specification.

Try adding tools. Haven't tested it on resources and prompts yet.

Running the Server

npm install
npm run dev

Testing with MCP Inspector

You can use the MCP Inspector to test this implementation:

npx @modelcontextprotocol/inspector node server.js

This will:

1. Start your MCP server
2. Open a debugging UI (default port 5173)
3. Create a proxy server (default port 3000)

MCP Example Screenshots

!MCP Inspector Interface MCP Inspector interface showing available tools like echo and calculator

!Calculator Tool in Action Using the calculator tool to solve addition problems

!MCP Server Configuration *MCP Servers Cursor config

Authentication

The sdk requires credential headers to be passed even if they are empty. Authentication headers are handled by the CORS setup (see src/utils/cors.ts).

Zod

The SDK seems to require zod for validating tool schema

SDK Integration

This implementation uses the MCP TypeScript SDK

License

MIT