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import asyncio
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from mcp.server import Server
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from mcp.server.stdio import stdio_server
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# Create Server instance
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server = Server("my-first-mcp-server")
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@server.tool()
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async def get_current_time() -> str:
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    """Get the current system time"""
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    from datetime import datetime
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    return datetime.now().strftime("%Y-%m-%d %H:%M:%S")
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async def main():
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    async with stdio_server() as (read_stream, write_stream):
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        await server.run(
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            read_stream,
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            write_stream,
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            server.create_initialization_options()
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        )
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if __name__ == "__main__":
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    asyncio.run(main())

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// macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
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{
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  "mcpServers": {
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    "my-first-server": {
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      "command": "python3",
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      "args": ["/path/to/my-mcp-server/server.py"]
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    }
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  }
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}

1
import asyncio
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import httpx
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from typing import Optional
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from mcp.server import Server
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from mcp.server.stdio import stdio_server
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from mcp.types import Tool, TextContent
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server = Server("weather-mcp-server")
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# Simulated weather data (replace with real API calls in actual projects)
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WEATHER_DATA = {
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    "Beijing": {"temp": 32, "humidity": 65, "condition": "Sunny"},
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    "Shanghai": {"temp": 35, "humidity": 70, "condition": "Cloudy"},
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    "Shenzhen": {"temp": 30, "humidity": 80, "condition": "Thunderstorms"},
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    "Tokyo": {"temp": 28, "humidity": 60, "condition": "Overcast"},
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}
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@server.tool()
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async def get_weather(city: str, unit: Optional[str] = "celsius") -> str:
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    """Query weather information for a specified city.
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    Args:
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        city: City name, such as "Beijing", "Shanghai", "Shenzhen"
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        unit: Temperature unit, celsius or fahrenheit
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    """
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    data = WEATHER_DATA.get(city)
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    if not data:
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        return f"No weather data for “{city}”. Supported cities: {', '.join(WEATHER_DATA.keys())}"
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    temp = data["temp"]
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    if unit == "fahrenheit":
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        temp = temp * 9 / 5 + 32
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        unit_str = "°F"
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    else:
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        unit_str = "°C"
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    return (
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        f"🌍 Weather report for {city}\n"
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        f"━━━━━━━━━━━━━━\n"
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        f"🌡️  Temperature: {temp:.1f}{unit_str}\n"
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        f"💧 Humidity: {data['humidity']}%\n"
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        f"☁️  Weather: {data['condition']}\n"
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    )
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@server.tool()
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async def compare_weather(city_a: str, city_b: str) -> str:
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    """Compare the weather conditions of two cities.
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    Args:
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        city_a: Name of the first city
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        city_b: Name of the second city
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    """
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    data_a = WEATHER_DATA.get(city_a)
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    data_b = WEATHER_DATA.get(city_b)
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    if not data_a or not data_b:
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        missing = city_a if not data_a else city_b
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        return f"No weather data for “{missing}”"
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    comparison = f"📊 Weather comparison: {city_a} vs {city_b}\n"
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    comparison += f"━━━━━━━━━━━━━━━━━━━━\n"
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    comparison += f"🌡️   {city_a}: {data_a['temp']}°C  |  {city_b}: {data_b['temp']}°C\n"
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    comparison += f"💧 {city_a}: {data_a['humidity']}%  |  {city_b}: {data_b['humidity']}%\n"
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    comparison += f"☁️  {city_a}: {data_a['condition']}  |  {city_b}: {data_b['condition']}\n"
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    cooler = city_a if data_a['temp'] < data_b['temp'] else city_b
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    comparison += f"\n💡 {cooler} is cooler, great for going out!"
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    return comparison
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72

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async def main():
74
    async with stdio_server() as (read_stream, write_stream):
75
        await server.run(
76
            read_stream,
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            write_stream,
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            server.create_initialization_options()
79
        )
80

81
if __name__ == "__main__":
82
    asyncio.run(main())