Example: Weather Tool

// tools/weather.ts
import type { Tool } from "@opendunes/agent-sdk";

interface WeatherResult {
  city: string;
  tempC: number;
  condition: string;
  humidity: number;
}

async function fetchWeather(city: string): Promise<WeatherResult> {
  const res = await fetch(
    `https://api.example-weather.com/current?city=${encodeURIComponent(city)}&key=${process.env.WEATHER_API_KEY}`
  );
  if (!res.ok) throw new Error(`Weather API error: ${res.status}`);
  return res.json();
}

export const weatherTool: Tool = {
  name: "get_weather",
  description:
    "Get the current weather for a city. Returns temperature in Celsius, condition summary, and humidity percentage.",
  parameters: {
    type: "object",
    properties: {
      city: {
        type: "string",
        description: "City name. Examples: Algiers, Oran, Constantine, Tlemcen.",
      },
    },
    required: ["city"],
  },
  execute: async ({ city }) => {
    const data = await fetchWeather(String(city));
    return `${data.city}: ${data.tempC}°C, ${data.condition}, ${data.humidity}% humidity.`;
  },
};

// agent.ts
import { OpenDunes } from "@opendunes/agent-sdk";
import { weatherTool } from "./tools/weather";

const client = new OpenDunes({
  apiKey: process.env.OPENDUNES_API_KEY!,
});

async function askWeather(question: string) {
  const result = await client.callModel({
    model: "google/gemini-2.5-pro",
    messages: [
      {
        role: "system",
        content:
          "You are a helpful weather assistant. Use the get_weather tool to answer questions about current conditions.",
      },
      { role: "user", content: question },
    ],
    tools: [weatherTool],
    stopConditions: [
      { type: "no_tool_calls" },
      { type: "max_turns", maxTurns: 5 },
    ],
    stream: true,
    onToken: (delta) => process.stdout.write(delta),
  });

  console.log("\n");
  const daCost = Number(result.usage.costMicroDA) / 1_000_000;
  console.log(`Tool calls: ${result.items.filter((i) => i.type === "tool_call").length}`);
  console.log(`Cost: ${daCost.toFixed(4)} DA`);
  console.log(`Balance remaining: ${Number(result.balance) / 1_000_000} DA`);
}

askWeather("What's the weather like in Algiers and Oran right now?");

Algiers is currently warm at 32°C with clear skies and 45% humidity. Oran is slightly
cooler at 29°C with a light sea breeze and some coastal haze, humidity at 62%.

Tool calls: 2
Cost: 0.0081 DA
Balance remaining: 142.3 DA