Weather MCP Server - Sample Implementation

Reference implementation for ASUS and OEM partners

A simple, production-ready MCP server demonstrating how to integrate external services with AI PCs using the Model Context Protocol.

🎯 Purpose

This sample MCP server demonstrates:

• ✅ How to create an MCP server from scratch

• ✅ How to expose tools (functions) to AI clients

• ✅ How to integrate external APIs (OpenWeather API)

• ✅ Production-ready error handling

• ✅ Clean, well-documented code

Perfect for: OEM partners building AI PC features, developers learning MCP, proof-of-concept projects

🌟 Features

Available Tools

1. get_current_weather - Get real-time weather for any city

   • Temperature, conditions, humidity, wind speed

   • Supports both Celsius and Fahrenheit

2. get_weather_forecast - Get 5-day forecast

   • Daily high/low temperatures

   • Weather conditions per day

🚀 Quick Start

Prerequisites

• Node.js >= 18.0.0

• OpenWeather API key (free tier available)

Installation

# Clone or download this repository
cd weather-mcp-server

# Install dependencies
npm install

# Configure API key
cp .env.example .env
# Edit .env and add your OpenWeather API key

Get API Key

1. Visit OpenWeather API

2. Sign up for free account

3. Generate API key

4. Add to .env file

Run the Server

# Start the server
npm start

# Or with auto-reload during development
npm run dev

📖 Usage Examples

Configure in Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "weather": {
      "command": "node",
      "args": ["/absolute/path/to/weather-mcp-server/index.js"],
      "env": {
        "OPENWEATHER_API_KEY": "your_api_key_here"
      }
    }
  }
}

Test with AI Client

Once configured, you can ask your AI assistant:

"What's the weather like in Taipei?"
"Give me a 5-day forecast for Tokyo"
"What's the temperature in New York in Fahrenheit?"

The AI will automatically call the appropriate MCP tools!

🏗️ Architecture

┌─────────────────┐
│   AI Client     │ (Claude, ChatGPT, etc.)
│  (Claude Desktop)│
└────────┬────────┘
         │ MCP Protocol (stdio)
         ↓
┌─────────────────┐
│  Weather MCP    │ ← This server
│     Server      │
└────────┬────────┘
         │ HTTPS
         ↓
┌─────────────────┐
│ OpenWeather API │
└─────────────────┘

Key Components

• index.js - Main server implementation

• @modelcontextprotocol/sdk - Official MCP SDK

• StdioServerTransport - Communicates via stdin/stdout

• OpenWeather API - External weather data source

📁 Project Structure

weather-mcp-server/
├── package.json          # Dependencies and scripts
├── index.js              # Main MCP server code
├── .env.example          # Environment variables template
├── .env                  # Your API keys (git-ignored)
├── README.md             # This file
├── README.zh-TW.md       # 繁體中文版
├── PARTNER-GUIDE.md      # Detailed guide for OEM partners
└── examples/
    └── client-example.js # Example client code

🛠️ Development

Code Structure

The server is organized into clear sections:

1. Configuration - API keys, URLs

2. WeatherServer Class - Main server logic

3. Tool Registration - Define available tools

4. Tool Handlers - Implement tool functionality

5. Error Handling - Robust error management

Adding New Tools

// 1. Add tool definition in setupToolHandlers()
{
  name: 'your_new_tool',
  description: 'What this tool does',
  inputSchema: {
    type: 'object',
    properties: {
      param1: { type: 'string', description: 'Parameter description' }
    },
    required: ['param1']
  }
}

// 2. Add handler in CallToolRequestSchema
case 'your_new_tool':
  return await this.yourNewTool(args.param1);

// 3. Implement the method
async yourNewTool(param1) {
  // Your logic here
  return {
    content: [{
      type: 'text',
      text: 'Result'
    }]
  };
}

🧪 Testing

Manual Testing

# Test the MCP server directly
npm test

Integration Testing

Use the included examples/client-example.js to test tool calls programmatically.

📝 API Reference

Tool: get_current_weather

Parameters:

• city (string, required) - City name (e.g., "Taipei", "Tokyo")

• units (string, optional) - "metric" (default) or "imperial"

Returns:

🌤️ Current Weather in Taipei, TW

Temperature: 25.3°C (feels like 26.1°C)
Condition: Clear - clear sky
Humidity: 65%
Wind Speed: 3.2 m/s
Pressure: 1013 hPa
Visibility: 10.0 km

Last updated: 11/14/2025, 10:30:00 AM

Tool: get_weather_forecast

Parameters:

• city (string, required) - City name

• units (string, optional) - "metric" (default) or "imperial"

Returns:

📅 5-Day Weather Forecast for Taipei, TW

11/14/2025:
  High: 26.5°C | Low: 22.1°C
  Condition: Clear

11/15/2025:
  High: 27.2°C | Low: 23.4°C
  Condition: Clouds

...

🔒 Security Best Practices

Implemented in this sample:

• ✅ API keys stored in environment variables (not in code)

• ✅ Input validation for all parameters

• ✅ Proper error handling (no sensitive data leakage)

• ✅ HTTPS for external API calls

• ✅ Minimal dependencies (reduces attack surface)

For production deployments:

• 🔐 Use secrets management system (AWS Secrets Manager, Azure Key Vault)

• 🔐 Implement rate limiting

• 🔐 Add request logging/monitoring

• 🔐 Use TLS for MCP communication if deployed remotely

🌐 Localization

This server supports multiple languages through the OpenWeather API:

// Add language parameter to API call
const url = `${API_BASE_URL}/weather?q=${city}&units=${units}&lang=zh_tw&appid=${API_KEY}`;

Supported languages: en, zh_tw, zh_cn, ja, ko, and 50+ more

🐛 Troubleshooting

Common Issues

"City not found"

• Check spelling of city name

• Try including country code: "Taipei,TW"

"Weather API error: Unauthorized"

• Verify your API key in .env

• Check API key is active at openweathermap.org

"Module not found"

• Run npm install

• Check Node.js version >= 18.0.0

MCP server not detected in Claude

• Verify claude_desktop_config.json path

• Restart Claude Desktop

• Check server logs for errors

📚 Learn More

MCP Resources

• MCP Specification

• MCP SDK Documentation

• Claude MCP Guide

Weather API

• OpenWeather API Docs

• API Response Examples

🤝 For OEM Partners

See :

• Detailed integration guide

• Deployment options

• Customization examples

• Production checklist

• Support information

Contact: partners@irisgo.ai

📄 License

MIT License - see LICENSE file

🙏 Credits

• Created by: IrisGo.AI Team

• MCP Protocol: Anthropic

• Weather Data: OpenWeather

• For: ASUS and AI PC OEM partners

📮 Support

• Issues: GitHub Issues

• Email: support@irisgo.ai

• Documentation: docs.irisgo.ai

Last Updated: 2025-11-14 Version: 1.0.0