get-forecast-by-lat-long

Instructions

Implementation Reference

• src/tools/forecast-by-lat-long.ts:32-53 (handler)

  The MCP handler function for the get-forecast-by-lat-long tool. It calls the AirNow API helper and returns the result as text content or an error.

  async (params) => {
    const result = await airnowApi.fetchForecastByLatLong(params);
    if (result === null) {
      return {
        content: [
          {
            type: "text",
            text: "Failed to fetch forecast data from AirNow API.",
          },
        ],
        isError: true,
      };
    }
    return {
      content: [
        {
          type: "text",
          text: result,
        },
      ],
    };
  }

• src/tools/forecast-by-lat-long.ts:9-32 (schema)

  Zod schema defining the input parameters for the tool: latitude, longitude, optional date, format, and distance.

  {
    latitude: z
      .string()
      .describe("Latitude in decimal degrees. Example: 38.33"),
    longitude: z
      .string()
      .describe("Longitude in decimal degrees. Example: -122.28"),
    date: z
      .string()
      .optional()
      .describe("Date of forecast. Format: YYYY-MM-DD. Example: 2012-02-01"),
    format: z
      .enum(["text/csv", "application/json", "application/xml"])
      .describe(
        "Format of the payload file returned. Example: application/json"
      ),
    distance: z
      .string()
      .optional()
      .describe(
        "Return a forecast from a nearby reporting area within this distance (in miles). Example: 150"
      ),
  },
  async (params) => {

• src/tools/forecast-by-lat-long.ts:5-55 (registration)

  The registration function that calls server.tool() to register the get-forecast-by-lat-long tool with MCP server, including name, description, schema, and handler.

  export const registerForecastByLatLong = (server: McpServer): void => {
    server.tool(
      "get-forecast-by-lat-long",
      "Get current or historical forecasted AQI values and categories for a reporting area by latitude and longitude.",
      {
        latitude: z
          .string()
          .describe("Latitude in decimal degrees. Example: 38.33"),
        longitude: z
          .string()
          .describe("Longitude in decimal degrees. Example: -122.28"),
        date: z
          .string()
          .optional()
          .describe("Date of forecast. Format: YYYY-MM-DD. Example: 2012-02-01"),
        format: z
          .enum(["text/csv", "application/json", "application/xml"])
          .describe(
            "Format of the payload file returned. Example: application/json"
          ),
        distance: z
          .string()
          .optional()
          .describe(
            "Return a forecast from a nearby reporting area within this distance (in miles). Example: 150"
          ),
      },
      async (params) => {
        const result = await airnowApi.fetchForecastByLatLong(params);
        if (result === null) {
          return {
            content: [
              {
                type: "text",
                text: "Failed to fetch forecast data from AirNow API.",
              },
            ],
            isError: true,
          };
        }
        return {
          content: [
            {
              type: "text",
              text: result,
            },
          ],
        };
      }
    );
  };

• src/tools/index.ts:19-19 (registration)

  Invocation of the tool registration function within the main registerTools function.

  registerForecastByLatLong(server);

• src/airnow-api.ts:30-40 (helper)

  Core helper function implementing the API call to AirNow for fetching forecast by latitude and longitude, constructing query params and using shared airnowGet fetcher.

  export async function fetchForecastByLatLong(params: Record<string, string>): Promise<string | null> {
    const endpoint = 'aq/forecast/latlong/';
    const queryParams = new URLSearchParams();
    queryParams.append('latitude', params.latitude);
    queryParams.append('longitude', params.longitude);
    queryParams.append('format', params.format);
    if (params.date) queryParams.append('date', params.date);
    if (params.distance) queryParams.append('distance', params.distance);
  
    return airnowGet(endpoint, queryParams);
  }