← Glossary
Function Calling / Tool Use
A model's ability to call external functions or APIs as part of generating a response.
Rather than only producing text, models with function-calling support can output a structured request to call a specific tool (e.g. 'look up this order status'), receive the result, and incorporate it into their response. This is the mechanism that lets AI agents actually take actions instead of just describing what to do.
Related terms
Where this shows up in practice
Have a project in mind?
Tell us what you're trying to automate or build — we'll reply with next steps, not a sales pitch.