Codex App: create GitLab merge requests from desktop Git controls

What variant of Codex are you using?

App (Codex desktop)

What feature would you like to see?

Add native GitLab merge request creation to the desktop app's Git workflow, equivalent to the existing GitHub Create pull request action.

I use GitLab rather than GitHub. After working on a local GitLab repository in Codex, I want to create a merge request directly from the desktop app without switching to a browser or asking the agent to run a separate CLI workflow.

The desired flow is:

• Recognize a GitLab remote and offer Create merge request.
• Let me choose the target branch and review the MR title and description.
• Push the source branch if needed and create the MR with my GitLab credentials.
• Open or display a link to the resulting MR.

Please support GitLab.com and allow configuration for self-managed GitLab hosts.

Additional information

Related: #26963 requests displaying links to existing GitLab MRs in the sidebar. This request focuses on creating MRs from the desktop Git controls.

The current GitLab integration documentation explicitly excludes desktop repository controls such as Create pull request from the cloud integration beta: https://learn.chatgpt.com/docs/third-party/gitlab

Using GitLab through a CLI, skill, or MCP tool can provide a workaround, but native desktop controls would make the workflow consistent for GitLab users.

I would also be interested in contributing an implementation if there is a supported contribution path or extension point for desktop repository providers.

Begin by locating the existing desktop GitHub Create pull request control and the repository-provider extension point mentioned in the issue. Trace how remotes, branch selection, credentials, pushing, and resulting links are handled; done means equivalent GitLab.com and configurable self-managed host support.