fi_weather_forecast

Instructions

Implementation Reference

• src/servers/finnish-weather.js:155-200 (handler)

  The handler for the 'fi_weather_forecast' tool. It fetches location coordinates, prepares Open-Meteo API parameters, and processes the response into a formatted string.

  async ({ location, days, mode }) => {
    try {
      const loc = await getLocation(location);
      const forecastDays = days || 3;
      const isHourly = mode === "hourly";
  
      const params = { latitude: loc.lat, longitude: loc.lon, forecast_days: forecastDays };
      if (isHourly) {
        params.hourly = "temperature_2m,apparent_temperature,precipitation,snowfall,weather_code,wind_speed_10m,wind_gusts_10m,cloud_cover";
      } else {
        params.daily = "weather_code,temperature_2m_max,temperature_2m_min,apparent_temperature_max,apparent_temperature_min,sunrise,sunset,precipitation_sum,snowfall_sum,wind_speed_10m_max,wind_gusts_10m_max,wind_direction_10m_dominant";
      }
  
      const data = await openMeteoFetch(params);
      const lines = [`## ${loc.name} — ${forecastDays}-Day Forecast\n`];
  
      if (isHourly) {
        const h = data.hourly;
        for (let i = 0; i < h.time.length; i++) {
          const t = new Date(h.time[i]);
          const time = t.toLocaleString("fi-FI", { timeZone: "Europe/Helsinki", weekday: "short", day: "numeric", month: "short", hour: "2-digit", minute: "2-digit" });
          const wx = WMO_CODES[h.weather_code[i]] || "";
          const snow = h.snowfall[i] > 0 ? `, snow ${h.snowfall[i]} cm` : "";
          lines.push(`**${time}:** ${h.temperature_2m[i]}°C (feels ${h.apparent_temperature[i]}°C), ${wx}, wind ${h.wind_speed_10m[i]} km/h, precip ${h.precipitation[i]} mm${snow}`);
        }
      } else {
        const d = data.daily;
        for (let i = 0; i < d.time.length; i++) {
          const date = new Date(d.time[i]);
          const day = date.toLocaleDateString("fi-FI", { timeZone: "Europe/Helsinki", weekday: "long", day: "numeric", month: "long" });
          const wx = WMO_CODES[d.weather_code[i]] || "";
          const sunrise = d.sunrise[i]?.split("T")[1] || "";
          const sunset = d.sunset[i]?.split("T")[1] || "";
          const snow = d.snowfall_sum[i] > 0 ? `\nSnowfall: ${d.snowfall_sum[i]} cm` : "";
          lines.push(`### ${day}`);
          lines.push(`${wx} | ${d.temperature_2m_min[i]}°C to ${d.temperature_2m_max[i]}°C (feels ${d.apparent_temperature_min[i]}° to ${d.apparent_temperature_max[i]}°)`);
          lines.push(`Wind: up to ${d.wind_speed_10m_max[i]} km/h (gusts ${d.wind_gusts_10m_max[i]} km/h) from ${d.wind_direction_10m_dominant[i]}°`);
          lines.push(`Precipitation: ${d.precipitation_sum[i]} mm${snow} | ☀️ ${sunrise} — ${sunset}\n`);
        }
      }
  
      lines.push(`*Open-Meteo forecast (Europe/Helsinki)*`);
      return { content: [{ type: "text", text: lines.join("\n") }] };
    } catch (err) {
      return { content: [{ type: "text", text: `Error: ${err.message}` }], isError: true };
    }

• src/servers/finnish-weather.js:147-154 (registration)

  Registration of the 'fi_weather_forecast' tool, including input schema validation using Zod.

  server.tool(
    "fi_weather_forecast",
    "Get hourly or daily weather forecast for a location in Finland. Up to 16 days ahead.",
    {
      location: z.string().describe("Finnish city name or lat,lon coordinates"),
      days: z.number().min(1).max(16).optional().describe("Forecast days (default 3, max 16)"),
      mode: z.enum(["hourly", "daily"]).optional().describe("Hourly detail or daily summary (default: daily)"),
    },