WeatherAPI MCP Server

Instructions

Implementation Reference

• src/index.ts:286-295 (handler)

  The handler for 'get_forecast' extracts arguments from the request and calls 'weatherRequest'.

  case "get_forecast": {
    const { q, days = 3, alerts = "no", aqi = "no" } = args as {
      q: string;
      days?: number;
      alerts?: string;
      aqi?: string;
    };
    result = await weatherRequest("/forecast.json", { q, days, alerts, aqi });
    break;
  }

• src/index.ts:80-95 (schema)

  Registration of the 'get_forecast' tool with its description and input schema.

  name: "get_forecast",
  description:
    "Get weather forecast for 1 to 14 days. Returns daily summaries (max/min/avg temp, rain chance, UV, wind) and hourly breakdowns. Also returns current conditions, astronomy data (sunrise/sunset/moon phase), and optionally weather alerts and air quality.",
  inputSchema: {
    type: "object",
    properties: {
      q: {
        type: "string",
        description: "Location query — city name, lat/lon, zip, postcode, IATA, or IP.",
      },
      days: {
        type: "number",
        description: "Number of forecast days (1–14). Default: 3.",
      },
      alerts: {
        type: "string",

• src/index.ts:22-38 (helper)

  The 'weatherRequest' helper function that executes the actual API call for all weather tools.

  async function weatherRequest(
    endpoint: string,
    params: Record<string, string | number>
  ): Promise<unknown> {
    const searchParams = new URLSearchParams({ key: API_KEY! });
    for (const [k, v] of Object.entries(params)) {
      searchParams.set(k, String(v));
    }
    const url = `${BASE_URL}${endpoint}?${searchParams.toString()}`;
    const res = await fetch(url);
    const data = await res.json();
    if (!res.ok) {
      const err = data as { error?: { code: number; message: string } };
      throw new McpError(
        ErrorCode.InternalError,
        `WeatherAPI error ${err.error?.code}: ${err.error?.message ?? res.statusText}`
      );