MCP Weather Server

A lightweight, self‑hosted Model Context Protocol (MCP) server that exposes your weather‑forecast API as MCP tools.
This allows LLMs and agent frameworks to call your weather data directly through a standardized interface.

Clients run this server inside their own environment and connect it to their preferred MCP‑compatible LLM (e.g., Claude Desktop, Cursor, etc.).

🚀 Features

• MCP‑compatible WebSocket server

• Tools for:

  • Current weather by latitude/longitude

  • Multi‑day forecast

• JSON Schema–validated tool inputs

• Simple configuration via environment variables

• No external dependencies required to run the server (beyond Node.js)

• Ready for Docker, CI, and cloud deployment

🛠️ Requirements

• Node.js 20+

• A valid API key for your weather service

• Access to your weather API base URL

⚙️ Configuration

Copy the example environment file:

bash cp .env.example .env

Then edit `.env`:

WEATHER_API_KEY=your_api_key_here WEATHER_API_URL=https://api.yourweather.com PORT=3001 LOG_LEVEL=info

▶️ Running the Server

Development mode

bash npm run dev

Build & run

bash npm run build npm start

The server will start on: ws://localhost:3001

🌤️ Available MCP Tools

`getCurrentWeather`

Retrieve current weather conditions for a specific latitude/longitude.

Input:

json { "lat": 38.9, "lon": -77.0 }

Output (example):

json { "summary": "Current weather at (38.9, -77)", "data": { ... } }

`getForecast`

Retrieve a multi‑day forecast for a location.

Input:

json { "lat": 38.9, "lon": -77.0, "days": 5 }

Output (example):

json { "summary": "5‑day forecast for (38.9, -77)", "data": { ... } }

🧪 Testing

bash npm test

🐳 Docker (Optional)

A Dockerfile is included.

Build: bash docker build -t mcp-weather-server .

Run: bash docker run -p 3001:3001 -e WEATHER_API_KEY=your_api_key -e WEATHER_API_URL=https://api.yourweather.com mcp-weather-server

🔒 Security Notes

• Host this server inside your network or VPC

• Protect access with firewall rules or mTLS if exposing externally

• Rotate API keys regularly

• Avoid exposing your weather API key in logs or client‑side code

📄 License

MIT License.
Feel free to fork, modify, and integrate into your own systems.

🤝 Contributing

Pull requests and issues are welcome.
If you extend the toolset or add new weather endpoints, feel free to contribute back.