GitLab Merge Request support for code-review plugin

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

The code-review plugin currently supports only GitHub pull requests via the gh CLI and mcp__github_inline_comment__create_inline_comment. I’d like to contribute support for GitLab merge requests.

Many teams use GitLab, both on gitlab.com and self-hosted instances. The plugin’s multi-agent review workflow is largely platform-agnostic in concept; the GitHub-specific logic is mostly limited to:

• fetching diffs

• checking MR/PR status

• posting review comments

Extending this to GitLab would make the plugin usable in a wider range of environments without changing its core design.

Proposed Solution

• Platform detection

Detect GitHub vs GitLab based on the git remote, using API probing to correctly handle self-hosted GitLab instances.

• GitLab CLI integration

Use glab (GitLab’s official CLI) for MR operations such as:

• glab mr view
• glab mr diff
• glab mr note

• Inline comments

Post position-based comments via glab api and the GitLab Discussions API, avoiding the need for a new MCP tool.

• Single command file

Keep a single code-review.md command that branches internally based on the detected platform.

• Link format

Use GitLab’s URL format for source links:

``
/-/blob/<sha>/<path>#L<line>
``

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

1. Is GitLab MR support something you’d be open to accepting, or do you prefer keeping the plugin GitHub-only?
2. Would you prefer extending the existing code-review command, or introducing a separate GitLab-specific command?
3. Are there any concerns about adding glab to the allowed tools alongside gh?

Happy to adjust the approach based on feedback before starting implementation.