Create Function Calling

POST

/v1/responses

• Register callable functions with the model via tools (Function calling)
• Compatible with the OpenAI Responses API create response endpoint
• Some models (e.g. o3-pro, codex-mini-latest) only support the Response format
• Official docs: Create a model response

Authorizations

bearer

Type

HTTP (bearer)

Request Body

application/json

object

ID of the model to use. See the model endpoint compatibility table for which models work with the Responses API.

object[]

Required

Text, image, and other inputs for the model to generate a response.

Controls whether the model calls a function, e.g. auto, none, or a specific function name.

object[]

List of tools the model may call; currently supports tools with type function.

Optional metadata, such as custom fields like model_id.