weather_service MCP server

April 6, 2025 · View on GitHub

天気予報をする MCPサーバ

reference

setup

Claude Desktopをインストールしておく
OpenWeather APIのキーが必要。無料プランでいい

uv sync
source .venv/bin/activate

curlで APIの確認

環境変数 OPENWEATHER_API_KEY をセット。

curl -s "https://api.openweathermap.org/data/2.5/weather?q=Tokyo&units=metric&appid=${OPENWEATHER_API_KEY}"

{"coord":{"lon":139.6917,"lat":35.6895},"weather":[{"id":803,"main":"Clouds","description":"broken clouds","icon":"04d"}],"base":"stations","main":{"temp":15.73,"feels_like":14.61,"temp_min":14.75,"temp_max":16.95,"pressure":1019,"humidity":48,"sea_level":1019,"grnd_level":1017},"visibility":10000,"wind":{"speed":5.14,"deg":170},"clouds":{"all":75},"dt":1743831370,"sys":{"type":2,"id":268395,"country":"JP","sunrise":1743798144,"sunset":1743843915},"timezone":32400,"id":1850144,"name":"Tokyo","cod":200}

How to Use MCP Server on Claude Desktop

edit $(HOME)/Library/Application\ Support/Claude/claude_desktop_config.json (macOS)

{
  "mcpServers": {
    "weather_service": {
      "command": "uv",
      "args": [
        "--directory",
        "*****LOCATION_OF_THIS_PROJECT*****",
        "run",
        "weather-service"
      ],
      "env": {
        "OPENWEATHER_API_KEY": "*****YOUR_API_KEY*****"
      }
    }
  }
}

How to Use MCP Server on VSCode(1.99)

create a new workspace
create .vscode/.mcp.json file

{
  "servers": {
    "my-mcp-server-9874c5e4": {
      "type": "stdio",
      "command": "uv",
      "args": [
        "--directory",
        "*****LOCATION_OF_THIS_PROJECT*****",
        "run",
        "weather-service"
      ],
      "env": {
        "OPENWEATHER_API_KEY": "*****YOUR_API_KEY*****"
      }
    }
  }
}

create .vscode/settings.json file

{
  "chat.agent.enabled": true
}

After that, select Agent Mode in Copilot Chat and ask a question like ‘What is the weather like in Tokyo today?’.

server.pyの構造

提供する機能

リソースとしての天気 API。
- weather://{city}/current のようなスキーマを宣言。
ツールとしての天気 API。
- get_forecast ツールを宣言。

アノテーション

@app.list_resources() ... リソースのリストをクライアントに提供する
@app.read_resource() ... リソース取得の実行
@app.list_tools() ... ツールのリストをクライアントに提供する
@app.call_tool() ... ツールの実行