Integration
Function Calling
Function calling is the mechanism by which a language model returns a structured request to invoke a developer-defined function rather than a free-form text response. It is the lowest-level primitive for tool use and the building block of agents.
Related terms
- Tool Use — Tool use is the capability of an AI model to call external functions — search APIs, databases, code interpreters, file systems, web browsers — as part of generating its response.
- AI Agent — An AI agent is a software system that takes a goal, plans a sequence of steps to reach it, executes those steps using tools (APIs, databases, browsers, code), and adapts when steps fail.