Meteo_MCP_server_tuto

🚀 Tutorial: Use FastMCP with GitHub Copilot in VS Code

A minimal weather tool demo using MCP over STDIO

This repo shows how to:

• Build an MCP server using fastmcp
• Run it locally via uv and the STDIO protocol
• Use GitHub Copilot Chat in VS Code to call your tools without any glue code
• Debug using MCP Inspector

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📦 Setup

git clone <your-repo-url>
cd <repo>
uv pip install -r requirements.txt

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🧠 What tools are exposed?

Defined in meteo_mcp.py:

Tool	Description
get_coords(city: str)	Returns (lat, lon)
get_current_weather(lat: float, lon: float)	Returns current temperature and wind
get_forecast(lat: float, lon: float, days: int = 3)	Returns a weather forecast for up to 3 days

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🛠️ Add MCP Server in VS Code (STDIO)

1. Open Command Palette: Ctrl/⌘ + Shift + P → MCP: Add Server

2. Choose:

   • Transport: Command (stdio)
   • Command: uv
   • Arguments: ["run", "meteo_mcp.py"]

3. The config will be saved (or added to) under:

// .vscode/mcp.json
{
  "servers": {
    "my-mcp-server-f963fb24": {
      "type": "stdio",
      "command": "uv",
      "args": ["run", "meteo_mcp.py"]
    }
  }
}

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🧠 Use GitHub Copilot Chat (as a Tool-Calling Agent)

1. Open GitHub Copilot Chat panel

2. Click 3-dot menu (⋮) → Enable Agent Mode

3. Ask:

What’s the 3-day forecast for Paris?

Copilot will:

• Call get_coords("Paris")
• Then call get_forecast(lat, lon, 3)

✅ No glue code or prompt engineering needed — tools are invoked automatically via MCP!

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🧪 Test with MCP Inspector

1. Install Inspector CLI (requires Node.js v18 or later):

npm install -g @modelcontextprotocol/inspector

2. Launch the MCP Inspector in STDIO mode:

uv run mcp dev meteo_mcp.py

This starts both:

• A web UI at http://localhost:6274
• An MCP proxy for debugging requests/responses

3. In the UI:

   • Select a tool (get_coords, get_forecast, etc.)
   • Provide JSON input (e.g. { "city": "Berlin" })
   • Run and inspect results

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🌐 External APIs Used

API	Purpose
https://geocoding-api.open-meteo.com/v1/search	Geocoding
https://api.open-meteo.com/v1/forecast	Weather forecast

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Let me know if you want a template version of this for new MCP tool projects or want to integrate logging or unit tests.