Reference · Glossary
Function calling
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When an LLM **returns a structured request** to run a function (API, database, calculator) instead of answering directly — the app executes and may send results back.
#When to use
Weather lookups, booking, CRM updates, code execution, anything that needs live data or actions.
#When not to
Pure Q&A over static text — RAG or prompt alone may suffice without tools.
#Example
User: "What's the weather in Dubai?"
Model returns: `get_weather(city="Dubai")` → your code calls the API → model summarizes the result.