Function Calling

What it means

A structured mechanism through which an AI model requests a specific function with the required arguments.

Code example

const tools = [{
  type: "function",
  function: {
    name: "get_weather",
    description: "Get current weather for a city",
    parameters: {
      type: "object",
      properties: { city: { type: "string" } },
      required: ["city"],
    },
  },
}];
const res = await openai.chat.completions.create({
  model: "gpt-4o",
  messages: [{ role: "user", content: "Weather in London?" }],
  tools,
});

Why it matters

It connects AI models to application logic in a controlled and predictable way.