Getting an Auth0 Access Token in a Custom GPT

This article explains how to set up authentication in a GPT created in ChatGPT (Actions in GPTs).

• The basic OAuth configuration has been configured to point to the Auth0 tenant, but an opaque Access Token is sent to the API.

• Access Token
• ChatGPT
• Custom GPT
• OpenAI

OpenAI does not provide a way to send custom parameters like "audience" in login requests, so it will always receive an opaque Access Token.

A possible workaround is to set up Default Audience in tenant settings.

• This will ensure ChatGPT will always receive a JWT access token meant for that audience.
• When the API is called, it will be sent as a Bearer token in the Authorization header.