GitLab Merge Request Review

Perform a code review on a GitLab merge request. Prefer glab MCP for fetching MR data; use glab CLI when MCP is unavailable.

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Repo and MR Resolution

Default repo

• Default: The GitLab project is assumed to be the same as the current project name (e.g. workspace or repo directory name).
• If the current directory is a Git repo with a GitLab remote, use that to infer namespace/project when possible.

When repo is missing or wrong

If any of these are true:

• Not in a Git repo, or
• No GitLab remote, or
• The MR to review is in a different project,

then ask the user for:

• Repo: GitLab project path (namespace/project or full path), or the repo URL.
• MR: Merge request IID (e.g. 42) or branch name, if not the current branch.

Do not guess the repo; ask once you know the default does not apply or cannot be determined.

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Workflow

1. Resolve repo
   • Use default (project name / current GitLab remote).
   • If not available or not the target repo, ask user for repo (and MR if needed).
2. Resolve MR
   • Prefer the merge request for the current branch.
   • If user specified an MR IID or branch, use that.
   • If none can be determined, ask for MR IID or branch.
3. Fetch MR data
   • MCP: Use glab MCP tools to get MR details and diff (e.g. view MR, get diff).
   • CLI: glab mr view [MR_IID] and glab mr diff [MR_IID] (omit MR_IID when one MR is in context for current branch).
   • Ensure you have the full diff and title/description before reviewing.
4. Perform the review
   • Analyze the diff for:
     • Correctness and logic
     • Security and data handling
     • Style, naming, and structure
     • Tests and edge cases
     • Docs and comments where relevant
   • Produce a concise review: summary, list of findings (with file/line or hunk context), and suggestions.
5. Optional: post as MR comment
   • Only after user confirmation. Do not post to GitLab until the user explicitly agrees.
   • MCP: Use the tool to add a comment (e.g. MR note) with the review text.
   • CLI: glab mr note [MR_IID] --message "..." with the review body (escape or quote appropriately).

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Getting MR data

• MCP: Use available glab MCP tools to:
  • List or get the current/specified MR
  • Retrieve the MR diff
• CLI (from repo with glab auth):
  • glab mr view - view MR for current branch (or glab mr view <IID>)
  • glab mr diff - diff for current branch MR (or glab mr diff <IID>)
  • If repo is different: glab mr view -R namespace/project <IID> and glab mr diff -R namespace/project <IID>

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Review output format

1. Summary: 2-4 sentences on what the MR does and overall assessment.
2. Findings: Group by severity or category (e.g. "Blocking", "Suggestions", "Nits").
   • For each item: file (and line/hunk if possible), issue, and suggested change or question.
3. Conclusion: Approve / approve with comments / request changes (or equivalent), and any follow-up steps.

Keep the review actionable: clear, specific, and tied to the diff.

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Checklist

• Repo resolved (default = project name; else asked user for repo)
• MR resolved (current branch or user-specified IID/branch)
• MR details and full diff fetched (MCP or CLI)
• Review written with summary, findings with context, and conclusion
• If posting comment: user confirmed; then used MCP or glab mr note