Weather Server

Instructions

Implementation Reference

• weather.py:230-290 (handler)

  The handler function for the 'get_current_conditions' tool. It validates coordinates, fetches weather points from NWS API, retrieves the nearest observation station, gets latest observations, and formats current conditions including temperature, humidity, wind, etc.
  @mcp.tool() async def get_current_conditions(latitude: float, longitude: float) -> str: """Get current weather conditions for a location. Args: latitude: Latitude of the location (-90 to 90) longitude: Longitude of the location (-180 to 180) """ if not validate_coordinates(latitude, longitude): return "Error: Invalid coordinates. Latitude must be between -90 and 90, longitude between -180 and 180." points_url = f"{NWS_API_BASE}/points/{latitude},{longitude}" points_data = await make_nws_request(points_url) if not points_data or "properties" not in points_data: return f"Unable to fetch weather data for coordinates ({latitude}, {longitude})." observation_url = points_data["properties"].get("observationStations") if not observation_url: return "No observation stations available for this location." # Get the nearest observation station stations_data = await make_nws_request(observation_url) if not stations_data or not stations_data.get("features"): return "No observation stations found for this location." station_id = stations_data["features"][0]["properties"]["stationIdentifier"] observations_url = f"{NWS_API_BASE}/stations/{station_id}/observations/latest" observations_data = await make_nws_request(observations_url) if not observations_data or "properties" not in observations_data: return "Unable to fetch current observations." props = observations_data["properties"] location_info = points_data["properties"].get("relativeLocation", {}) location_str = f"{location_info.get('properties', {}).get('city', 'Unknown')}, {location_info.get('properties', {}).get('state', 'Unknown')}" temp = props.get("temperature", {}).get("value") temp_unit = "°C" if temp is not None: temp_f = (temp * 9/5) + 32 temp_unit = f"°F ({temp:.1f}°C)" dewpoint = props.get("dewpoint", {}).get("value") humidity = props.get("relativeHumidity", {}).get("value") wind_speed = props.get("windSpeed", {}).get("value") wind_direction = props.get("windDirection", {}).get("value") pressure = props.get("barometricPressure", {}).get("value") visibility = props.get("visibility", {}).get("value") text_description = props.get("textDescription", "N/A") result = f"Current Conditions for {location_str}:\n\n" result += f"Temperature: {temp_f:.1f}{temp_unit}\n" if temp is not None else "Temperature: N/A\n" result += f"Conditions: {text_description}\n" result += f"Humidity: {humidity:.1f}%\n" if humidity is not None else "" result += f"Dewpoint: {dewpoint * 9/5 + 32:.1f}°F\n" if dewpoint is not None else "" result += f"Wind: {wind_speed * 2.237:.1f} mph from {wind_direction}°\n" if wind_speed is not None and wind_direction is not None else "" result += f"Pressure: {pressure / 100:.2f} hPa\n" if pressure is not None else "" result += f"Visibility: {visibility / 1609.34:.2f} miles\n" if visibility is not None else "" return result
• weather.py:230-230 (registration)

  The @mcp.tool() decorator registers the get_current_conditions function as an MCP tool.
  @mcp.tool()
• weather.py:28-31 (helper)

  Helper function to validate input coordinates used by get_current_conditions.
  def validate_coordinates(latitude: float, longitude: float) -> bool: """Validate that coordinates are within valid ranges.""" return -90 <= latitude <= 90 and -180 <= longitude <= 180
• weather.py:73-92 (helper)

  Helper function to make HTTP requests to NWS API endpoints, used multiple times in get_current_conditions.
  async def make_nws_request(url: str) -> dict[str, Any] | None: """Make a request to the NWS API with proper error handling.""" headers = { "User-Agent": USER_AGENT, "Accept": "application/geo+json" } async with httpx.AsyncClient() as client: try: response = await client.get(url, headers=headers, timeout=30.0) response.raise_for_status() return response.json() except httpx.HTTPStatusError as e: if e.response.status_code == 404: return None return None except (httpx.RequestError, httpx.TimeoutException): return None except Exception: return None
• weather.py:232-237 (schema)

  Docstring providing input schema description for the tool parameters.
  """Get current weather conditions for a location. Args: latitude: Latitude of the location (-90 to 90) longitude: Longitude of the location (-180 to 180) """