Concept
aka tool calling
Function Calling
Structured-output mode where a model emits JSON describing which tool/function to invoke.
Definition
Function calling lets a model return a structured JSON payload that an application can execute, instead of free-form text. Modern APIs accept a schema of available functions; the model picks one, fills its arguments, and the orchestrator runs the call. It is the backbone of agentic workflows.
Common use cases
- Agents
- API orchestration
- Database queries
Related models
gpt
claude
gemini