Architecture

Function Calling / Tool Use

Letting the AI ask your software to do things, like search, read a file, or run a command, and use the results.

Definition

The ability of a model to invoke external functions or tools during generation. The model outputs structured parameters that the client executes, returning results back into the context. Enables agentic workflows.

Example

The model returns {"name": "get_weather", "input": {"city": "Oslo"}}; your code calls the weather API and sends the result back.