JMA Data MCP

Instructions

Implementation Reference

• jma_data_mcp/server.py:153-180 (handler)

  Handler function for the get_weather_by_location tool. It finds the nearest AMeDAS station to the given coordinates and fetches current weather data from it. The @mcp.tool() decorator registers the tool.

  @mcp.tool()
  async def get_weather_by_location(
      lat: float,
      lon: float,
  ) -> dict:
      """Get current weather from the nearest AMeDAS station to given coordinates.
  
      Args:
          lat: Latitude in decimal degrees
          lon: Longitude in decimal degrees
  
      Returns:
          Weather data from the nearest station
      """
      nearby = search_stations_by_location(lat, lon, radius_km=100)
      if not nearby:
          return {"error": "No stations found within 100km of the specified location"}
  
      nearest = nearby[0]
      station_code = nearest["code"]
      weather_data = await fetch_amedas_data(station_code)
  
      return {
          "observation_time": weather_data["observation_time"],
          "observation_time_jst": weather_data["observation_time_jst"],
          "station": nearest,
          "weather": weather_data["stations"].get(station_code, {}),
      }

• jma_data_mcp/server.py:153-153 (registration)

  The @mcp.tool() decorator registers the get_weather_by_location function as an MCP tool.

  @mcp.tool()