Weather Tool Example

import { LuaTool } from 'lua-cli';
import { z } from 'zod';

export default class GetWeatherTool implements LuaTool {
  name = "get_weather";
  description = "Get current weather conditions for any city";
  
  inputSchema = z.object({
    city: z.string().describe("City name (e.g., 'London', 'Tokyo')")
  });

  async execute(input: z.infer<typeof this.inputSchema>) {
    // Step 1: Convert city name to coordinates
    const geoUrl = `https://geocoding-api.open-meteo.com/v1/search?name=${encodeURIComponent(input.city)}&count=1`;
    const geoRes = await fetch(geoUrl);
    const geoData = await geoRes.json();
    
    if (!geoData.results?.[0]) {
      throw new Error(`City not found: ${input.city}`);
    }
    
    const { latitude, longitude, name } = geoData.results[0];
    
    // Step 2: Get weather for coordinates
    const weatherUrl = `https://api.open-meteo.com/v1/forecast?latitude=${latitude}&longitude=${longitude}&current_weather=true`;
    const weatherRes = await fetch(weatherUrl);
    const weatherData = await weatherRes.json();
    
    return {
      city: name,
      temperature: weatherData.current_weather.temperature,
      windSpeed: weatherData.current_weather.windspeed,
      weatherCode: weatherData.current_weather.weathercode
    };
  }
}

// Step 1: City name → Coordinates
const geoData = await fetch(geocodingUrl);
const { latitude, longitude } = geoData.results[0];

// Step 2: Coordinates → Weather
const weatherData = await fetch(weatherUrl);

const geoUrl = `https://geocoding-api.open-meteo.com/v1/search?name=${encodeURIComponent(input.city)}&count=1`;

if (!geoData.results?.[0]) {
  throw new Error(`City not found: ${input.city}`);
}

return {
  city: name,              // Clean city name
  temperature: data.temp,  // Extract what's needed
  windSpeed: data.wind     // No extra data
};

lua test

inputSchema = z.object({
  city: z.string(),
  units: z.enum(['metric', 'imperial']).default('metric')
});

// In URL
const weatherUrl = `...&temperature_unit=${units === 'imperial' ? 'fahrenheit' : 'celsius'}`;

return {
  ...weatherData,
  recommendation: temperature < 10 
    ? "🧥 Bring a warm jacket"
    : temperature < 20
    ? "👕 Light jacket recommended"
    : "☀️ T-shirt weather!"
};

const forecastUrl = `...&forecast_days=7`;
const forecast = await fetch(forecastUrl);

return {
  current: {...},
  forecast: forecast.daily
};