Tool calling

import os, json
from openai import OpenAI

client = OpenAI(
    base_url="https://api.opper.ai/v3/compat",
    api_key=os.environ["OPPER_API_KEY"],
)

# 1. Declare the tool
tools = [{
    "type": "function",
    "function": {
        "name": "get_weather",
        "description": "Get the current weather for a city.",
        "parameters": {
            "type": "object",
            "properties": {
                "city": {"type": "string", "description": "City name, e.g. 'Stockholm'"}
            },
            "required": ["city"],
        },
    },
}]

# 2. Your local implementation
def get_weather(city: str) -> str:
    return f"Sunny, 22°C in {city}"

# 3. First call. Model decides to use the tool.
messages = [{"role": "user", "content": "What's the weather in Stockholm?"}]
r = client.chat.completions.create(
    model="openai/gpt-5-mini",
    messages=messages,
    tools=tools,
)
msg = r.choices[0].message
messages.append(msg)

# 4. Run the tool, append the result
for call in (msg.tool_calls or []):
    args = json.loads(call.function.arguments)
    result = get_weather(**args)
    messages.append({
        "role": "tool",
        "tool_call_id": call.id,
        "content": result,
    })

# 5. Second call. Model uses the result to answer.
r = client.chat.completions.create(
    model="openai/gpt-5-mini",
    messages=messages,
    tools=tools,
)
print(r.choices[0].message.content)

import OpenAI from "openai";

const client = new OpenAI({
    baseURL: "https://api.opper.ai/v3/compat",
    apiKey: process.env.OPPER_API_KEY!,
});

const tools = [{
    type: "function" as const,
    function: {
        name: "get_weather",
        description: "Get the current weather for a city.",
        parameters: {
            type: "object",
            properties: {
                city: { type: "string", description: "City name, e.g. 'Stockholm'" },
            },
            required: ["city"],
        },
    },
}];

function getWeather(city: string) {
    return `Sunny, 22°C in ${city}`;
}

const messages: any[] = [{ role: "user", content: "What's the weather in Stockholm?" }];

let r = await client.chat.completions.create({
    model: "openai/gpt-5-mini",
    messages,
    tools,
});
const msg = r.choices[0].message;
messages.push(msg);

for (const call of msg.tool_calls ?? []) {
    const args = JSON.parse(call.function.arguments);
    const result = getWeather(args.city);
    messages.push({
        role: "tool",
        tool_call_id: call.id,
        content: result,
    });
}

r = await client.chat.completions.create({
    model: "openai/gpt-5-mini",
    messages,
    tools,
});
console.log(r.choices[0].message.content);