Function Calling
A model selects and calls external functions based on user intent, then uses the result in its answer.
In plain language
Function calling lets models query databases, call APIs and operate software rather than only generate text. The model outputs structured arguments and the application executes the function. Key design points include validation, permissions, timeouts, retries and human confirmation.
Example
A user asks about an order; the model calls get_order(order_id) and answers from the result.
Recommended tools
Related terms
AI Agent
An AI system that perceives a goal, plans steps, calls tools and executes tasks.
Model Context Protocol
An open standard that lets AI applications connect to external tools and data sources.
Tool Use
A model using external tools such as search, code execution or APIs during reasoning.
Agent Memory
A mechanism for an agent to store and retrieve user preferences, past tasks and key facts across sessions.