GitLab Code Reviewer support

[dennismeister93]

Summary

• Add GitLab platform support for the automated code review agent
• Implement GitLab OAuth callback, webhook handling, and merge request event processing
• Add GitLab adapter with full MR diffing, commenting, and status reporting
• Extend cloud_agent_code_reviews schema with platform and platform_project_id columns
• Support both OAuth and Project Access Token (PAT) authentication for GitLab
• Add automated GitLab webhook creation for merge request events
• Refactor code review UI and routers to be platform-agnostic (GitHub + GitLab)

Key Components

• gitlab/adapter.ts - GitLab platform adapter for code reviews (diff fetching, PR commenting, status updates)
• gitlab/webhook-handlers/merge-request-handler.ts - Handles GitLab MR webhooks to trigger reviews
• gitlab/webhook-schemas.ts + webhook-sync.ts - Webhook validation and automated webhook creation
• gitlab-service.ts - Extended GitLab integration service with OAuth and PAT support
• prepare-review-payload.ts - Refactored to support multi-platform review payloads
• platform-helpers.ts - Platform-agnostic prompt generation helpers
• ReviewConfigForm.tsx / RepositoryMultiSelect.tsx - Updated UI for platform selection
• cloud-agent / cloud-agent-next - Platform-aware session preparation and orchestration

Notes

• GitLab reviews use the same cloud-agent infrastructure as GitHub reviews
• DB migration adds platform column (default 'github') and platform_project_id to cloud_agent_code_reviews
• Cloud agent Dockerfiles updated to include latest glab CLI with OAuth support

Testing / Reproduce Steps for GitLab Code Review Support

Prerequisites

1. A GitLab account (gitlab.com works; self-hosted requires Enterprise).
2. A GitLab project where you have Maintainer role or higher (needed for Project Access Token creation and webhook auto-configuration).
3. The local dev server running at http://localhost:3000.
4. Database migrated

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1. Connect GitLab Integration

There are two connection methods (toggle in the UI at GitLabIntegrationDetails.tsx):

Option A: OAuth (gitlab.com)

1. Log in as a fake user → navigate to Settings → Integrations → GitLab.
2. Click "Connect GitLab" (OAuth button).
3. Authorize on gitlab.com → callback at /api/integrations/gitlab/callback.
4. Verify: integration appears as "Connected", repositories listed.

Option B: Personal Access Token (PAT)

1. On GitLab: User Settings → Access Tokens, create a token with api scope.
2. In the app, toggle to "Personal Access Token" tab.
3. Paste the PAT → automatic validation fires (debounced 500ms via validatePAT tRPC mutation).
4. Green checkmark + username should appear when valid.
5. Click "Connect GitLab with PAT".
6. Verify: integration appears as "Connected" with "Personal Access Token" badge.

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3. Webhook Configuration

Webhooks are auto-configured when you save the code review settings:

• syncWebhooksForRepositories() creates webhooks for selected repos.
• The webhook URL is {APP_URL}/api/webhooks/gitlab (see KILO_GITLAB_WEBHOOK_URL).
• The webhook secret is stored in integration metadata as webhook_secret.
• Requires Maintainer role — if you only have Developer role, you'll get a GitLabWebhookPermissionError.

Manual webhook setup (Has to be done for the smee setup):

1. Go to your GitLab project → Settings → Webhooks.
2. URL: smee url
3. Secret Token: copy from integration metadata webhook_secret.
4. Trigger: Merge request events.
5. Save.

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4. Trigger a Code Review

1. Open or update a Merge Request on a configured GitLab project (non-draft).
2. GitLab sends a webhook with X-Gitlab-Event: Merge Request Hook and action open/update/reopen.
3. The POST /api/webhooks/gitlab handler:
   • Verifies X-Gitlab-Token header against stored webhook_secret.
   • Parses payload via MergeRequestPayloadSchema.
   • Routes to handleMergeRequest().
4. The handler:
   • Skips draft/WIP MRs (line 51).
   • Checks getAgentConfigForOwner(owner, 'code_review', 'gitlab').
   • Creates a cloud_agent_code_reviews record with platform='gitlab' and platform_project_id set.
   • Gets/creates a Project Access Token (PrAT) via getOrCreateProjectAccessToken() — adds 👀 reaction to the MR.
   • Dispatches the review via tryDispatchPendingReviews().
5. Returns 202 Accepted.

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5. Review Payload Preparation

When the review is dispatched, prepareReviewPayload() runs:

• GitHub path: uses githubRepo (owner/repo) + githubToken (installation token).
• GitLab path: uses gitUrl (full HTTPS URL like https://gitlab.com/group/project.git) + gitToken (PrAT).
• Fetches existing review state (summary notes, inline comments, head SHA, diff refs) in parallel.
• Generates the review prompt with GitLab-specific diff context (baseSha/startSha/headSha).

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7. Local Testing with ngrok/Cloudflare Tunnel

Since GitLab needs to reach your Webhook its important that the webhook url needs to be manually adapted:

[dennismeister93]

@Sureshkumars @eshurakov @RSO I finally have a state which is working properly.

Can someone have a view and let me know if support is needed?

This PR supports Oauth or PAT integration with gitlab + code review configs with some "GitLab specialties" because they differ to GitHub Apps. Also this integration supports:

1. Personal
2. Organizations
3. Self Hosted GitLab

[vercel]

@dennismeister93 is attempting to deploy a commit to the emilie-6161's projects Team on Vercel.

A member of the Team first needs to authorize it.