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Dictionary

Function Calling

The API mechanism that lets a model request a tool call.

1 min readupdated 2026-07-04

/ quick answer

Function calling exposes typed function signatures to the model; the model returns a structured call the runtime executes. The primitive underlying every agent framework. The API mechanism that lets a model request a tool call.

The API mechanism that lets a model request a tool call. Function calling exposes typed function signatures to the model; the model returns a structured call the runtime executes. The primitive underlying every agent framework. In practice: Passing tools: [{ name: 'get_weather', parameters: { city: 'string' } }] to the API. This dictionary node is part of the Onexial knowledge graph and links to related concepts, workflows and tools below.
Definition
Function calling exposes typed function signatures to the model; the model returns a structured call the runtime executes. The primitive underlying every agent framework.
Example
Passing tools: [{ name: 'get_weather', parameters: { city: 'string' } }] to the API.
Related Tool Stacks
/ frequently asked

What is Function Calling?

Function calling exposes typed function signatures to the model; the model returns a structured call the runtime executes. The primitive underlying every agent framework.

What is an example of Function Calling?

Passing tools: [{ name: 'get_weather', parameters: { city: 'string' } }] to the API.

Why does Function Calling matter for AI and automation?

The API mechanism that lets a model request a tool call. It connects to the workflows, prompts and tool stacks linked on this page, so you can move from definition to execution without leaving Onexial.

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