ChatGPT GitLab Connector – Invalid Redirect URI Error

Summary: When attempting to connect GitLab to ChatGPT through Settings → Connected Apps → GitLab, the OAuth process fails with the following error from GitLab:

“The redirect URI included is not valid.”

Steps to Reproduce:

1. Open ChatGPT (https://chatgpt.com).

2. Go to Settings → Connected Apps → GitLab.

3. Click Connect GitLab.

4. The browser redirects to a GitLab OAuth authorization page such as:

   https://gitlab.com/oauth/authorize?response_type=code&client_id=xxxxxxxxxxxxx&
   redirect_uri=https%3A%2F%2Fchatgpt.com%2Fconnector_platform_oauth_redirect&
   state=oauth_s_xxxxxxxx&
   scope=openid+email+read_user+read_api+profile

5. GitLab responds with an error page: “The redirect URI included is not valid.”

Expected Result: GitLab should display the “Grant access to ChatGPT” authorization page and complete the OAuth connection.

Actual Result: GitLab immediately blocks the authorization with the redirect URI validation error.

Notes:

• The issue appears to stem from the OpenAI GitLab OAuth app registration.
• The redirect_uri=https://chatgpt.com/connector_platform_oauth_redirect likely needs to be added to the allowed redirect URIs for that client ID.
• Multiple users have reported the same issue as of October 2025.

Impact: ChatGPT → GitLab integration is completely nonfunctional (OAuth connection cannot complete).