Function Calling
Also called: tool calling
The mechanism by which a model asks your code to run a specific function with specific arguments.
You describe your functions and their parameters; the model returns a structured request naming one and supplying arguments. Critically, the model does not execute anything — your application does, which is where validation and authorisation belong. It is the plumbing under almost every agent product.
In practice: The model emits get_order_status(order_id=‘A-4471’); your backend decides whether to run it.