Multi-MCPs

Instructions

Implementation Reference

• src/apis/weather/openweather.ts:91-100 (handler)

  The async handler function that implements the get_weather_forecast tool. It validates the API key and location, fetches the forecast data using client.forecastByCity, and optionally slices the list based on the 'days' parameter.

  async get_weather_forecast(args: Record<string, unknown>) {
    if (!cfg.openWeatherApiKey) throw new Error("OPENWEATHER_API_KEY is not configured");
    const location = String(args.location || "");
    const days = args.days ? Number(args.days) : undefined;
    if (!location) throw new Error("location is required");
    const data: any = await client.forecastByCity(location);
    if (!days) return data;
    const count = Math.max(1, Math.min(5, days));
    const list = (data as any).list || [];
    return { ...(data as object), list: list.slice(0, count * 8) } as any;

• src/apis/weather/openweather.ts:63-70 (schema)

  The inputSchema for the get_weather_forecast tool, defining 'location' as required string and optional 'days' number.

  inputSchema: {
    type: "object",
    properties: {
      location: { type: "string" },
      days: { type: "number", description: "Days to include (1-5)" },
    },
    required: ["location"],
  },

• src/tools/register.ts:23-23 (registration)

  The call to registerOpenWeather() within the registerAllTools function, which includes the get_weather_forecast tool in the overall tool registrations for the MCP server.

  registerOpenWeather(),

• src/apis/weather/openweather.ts:18-22 (helper)

  The forecastByCity method in OpenWeatherClient that makes the API request to retrieve the raw forecast data used by the handler.

  async forecastByCity(location: string) {
    return this.request("/data/2.5/forecast", {
      query: { q: location, appid: this.apiKey, units: "metric" },
    });
  }

• src/apis/weather/openweather.ts:43-110 (registration)

  The registerOpenWeather function that defines and returns the ToolRegistration object containing the tool schema and handler for get_weather_forecast.

  export function registerOpenWeather(): ToolRegistration {
    const cfg = loadConfig();
    const client = new OpenWeatherClient(cfg.openWeatherApiKey || "");
  
    return {
      tools: [
        {
          name: "get_current_weather",
          description: "Get current weather by city name",
          inputSchema: {
            type: "object",
            properties: {
              location: { type: "string", description: "City name, e.g., London" },
            },
            required: ["location"],
          },
        },
        {
          name: "get_weather_forecast",
          description: "Get 5-day/3-hour forecast by city name",
          inputSchema: {
            type: "object",
            properties: {
              location: { type: "string" },
              days: { type: "number", description: "Days to include (1-5)" },
            },
            required: ["location"],
          },
        },
        {
          name: "get_weather_alerts",
          description: "Get weather alerts for a location (requires One Call support)",
          inputSchema: {
            type: "object",
            properties: {
              location: { type: "string" },
            },
            required: ["location"],
          },
        },
      ],
      handlers: {
        async get_current_weather(args: Record<string, unknown>) {
          if (!cfg.openWeatherApiKey) throw new Error("OPENWEATHER_API_KEY is not configured");
          const location = String(args.location || "");
          if (!location) throw new Error("location is required");
          return client.currentWeatherByCity(location);
        },
        async get_weather_forecast(args: Record<string, unknown>) {
          if (!cfg.openWeatherApiKey) throw new Error("OPENWEATHER_API_KEY is not configured");
          const location = String(args.location || "");
          const days = args.days ? Number(args.days) : undefined;
          if (!location) throw new Error("location is required");
          const data: any = await client.forecastByCity(location);
          if (!days) return data;
          const count = Math.max(1, Math.min(5, days));
          const list = (data as any).list || [];
          return { ...(data as object), list: list.slice(0, count * 8) } as any;
        },
        async get_weather_alerts(args: Record<string, unknown>) {
          if (!cfg.openWeatherApiKey) throw new Error("OPENWEATHER_API_KEY is not configured");
          const location = String(args.location || "");
          if (!location) throw new Error("location is required");
          return client.alertsByLocation(location);
        },
      },
    };
  }