# Node MCP Server
Small example MCP (Model Context Protocol) server that exposes a weather tool using the `@modelcontextprotocol/sdk`.
## Overview
- Provides a minimal Express-based HTTP server that connects an `McpServer` to a Streamable HTTP transport.
- Exposes endpoints: `/mcp` (MCP transport), `/health`, `/status`, and `/`.
## Requirements
- Node.js 18+ recommended
- npm
## Install
```bash
npm install
```
## Run
```bash
npm start
```
Server listens on port `3000` by default.
## Endpoints
- `GET /health` — returns `OK`.
- `GET /status` — returns a JSON status object.
- `POST /mcp` — Streamable HTTP MCP transport endpoint. The server expects clients to POST JSON-RPC messages.
Important: the Streamable HTTP transport expects clients to include the following headers for POSTs:
- `Content-Type: application/json`
- `Accept: application/json, text/event-stream`
Example curl (initialize):
```bash
curl --location 'http://localhost:3000/mcp' \
--header 'Content-Type: application/json' \
--header 'Accept: application/json, text/event-stream' \
--data '{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "getWeather_Tool",
"arguments": {
"location":"New York"
}
}
}'
```
## Notes
- The project uses `@modelcontextprotocol/sdk` (see `package.json`) and returns structured tool results. Tool callbacks must return objects matching the SDK's expected schema (not plain strings).
- If you see errors about Accept headers or tool result shapes, verify headers and that tool callbacks return an object with a `content` array.
## License
MIT
