Weather MCP Server

A Model Context Protocol (MCP) server that provides weather information and time utilities for AI assistants and applications.

Overview

This MCP server implements a simple weather service with two main tools:

• Weather Information: Get current weather data for any city
• Time Service: Retrieve the current timestamp

Built with TypeScript and the official MCP SDK, this server demonstrates how to create custom tools that can be used by Claude Desktop and other MCP-compatible clients.

Features

• 🌤️ Weather Data: Fetch weather information for any city worldwide
• ⏰ Time Service: Get current timestamp in ISO format
• 🔒 Input Validation: Robust parameter validation using Zod schemas
• 🚀 TypeScript: Full type safety and modern JavaScript features
• 📡 stdio Transport: Communicates via standard input/output for seamless integration

Installation

Prerequisites

• Node.js 18+
• npm or yarn package manager

Setup

1. Clone the repository

   git clone <repository-url>
   cd my-mcp-server
   

2. Install dependencies

   npm install
   

3. Build the project

   npm run build
   

Usage

Development

Run the server in development mode:

npm run dev

Production

Start the built server:

npm start

Integration with Claude Desktop

Add this server to your Claude Desktop configuration:

{
  "mcpServers": {
    "weather-server": {
      "command": "node",
      "args": ["/path/to/my-mcp-server/build/index.js"]
    }
  }
}

Available Tools

get_weather

Retrieves weather information for a specified city.

Parameters:

• city (string, required): The city to get weather for
• units (string, optional): Temperature units - "metric" or "imperial" (defaults to "metric")

Example Response:

Weather in London:
Temperature: 18°C
Conditions: Partly cloudy
Humidity: 65%

get_time

Returns the current timestamp in ISO 8601 format.

Parameters: None

Example Response:

Current time: 2025-01-08T14:30:25.123Z

Project Structure

my-mcp-server/
├── index.ts          # Main server implementation
├── package.json      # Project dependencies and scripts
├── tsconfig.json     # TypeScript configuration
├── build/           # Compiled JavaScript output
└── README.md        # This file

Technical Details

Dependencies

• @modelcontextprotocol/sdk: Official MCP SDK for server implementation
• axios: HTTP client for external API calls
• zod: Runtime type validation and parsing

Architecture

The server follows the MCP specification:

1. Tool Registration: Tools are registered via ListToolsRequestSchema handler
2. Tool Execution: Tool calls are handled via CallToolRequestSchema handler
3. Error Handling: Proper MCP error codes and validation
4. Transport: Uses stdio transport for communication

Weather Data

Currently returns mock weather data for demonstration purposes. To integrate with a real weather API:

1. Sign up for a weather service (e.g., OpenWeatherMap)
2. Replace the mock data generation in the get_weather case
3. Add proper API key handling and HTTP requests

Scripts

• npm run build - Compile TypeScript to JavaScript
• npm run dev - Build and run in development mode
• npm start - Run the compiled server

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Make your changes
4. Build and test (npm run build)
5. Commit your changes (git commit -m 'Add amazing feature')
6. Push to the branch (git push origin feature/amazing-feature)
7. Open a Pull Request

License

This project is open source and available under the MIT License.

Learn More

• Model Context Protocol Documentation
• MCP SDK Documentation
• Claude Desktop MCP Integration

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Built with ❤️ using TypeScript and the Model Context Protocol