Web IDE OAuth callback URL

Overview

Access to the Web IDE application requires that the DNS domain of the OAuth callback URL matches the domain of the GitLab environment. In environments which have multiple different domains or aliases, you can add multiple callback URLs.

Description

Attempting to access the Web IDE results in a Cannot open Web IDE error page with this message:

The URL you're using to access the Web IDE and the configured OAuth callback URL do not match. This issue often occurs when you're using a proxy.

This may be persistent, or intermittent and unpredictable.

Impacted offerings:

  • GitLab Self-Managed

Impacted versions:

GitLab 18.0, or older GitLab with the vscode_web_ide feature flag enabled.

Resolution

Update the OAuth callback URL to match the URL used to access the GitLab instance:

  1. On the left sidebar, at the bottom, select Admin.
  2. Select Applications.
  3. For GitLab Web IDE, select Edit.
  4. Enter the OAuth callback URL.

Example:

In cases where your GitLab can be reached by multiple URLs, you can enter multiple URLs into the OAuth callback URL field, separated by newlines:

https://gitlab.example.com/-/ide/oauth_redirect
https://gitlab.example.org/-/ide/oauth_redirect
http://server.infra/-/ide/oauth_redirect

Cause

The Web IDE uses an instance-wide OAuth application for authentication. If the OAuth callback URL is misconfigured, the Web IDE application cannot authenticate to GitLab.

Symptom 

The Web IDE cannot be opened, and visitors see the Cannot open Web IDE error page.

Root Cause 

Accessing the Web IDE through a GitLab URL that is not included in the OAuth callback URL list.

Related Links

Web IDE troubleshooting

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