Deprecation and removal of Code Suggestions v2 and v3 AI Gateway API endpoints

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Deprecation Summary

The Code Suggestions v2 and v3 AI Gateway API endpoints are deprecated. As part of consolidating the Duo Code Suggestions API endpoints onto version 4, support for v2 and v3 callers in the AI Gateway will be removed.

GitLab.com-managed traffic is migrated automatically with no noticeable change for customers. The breaking event is the eventual removal of the legacy endpoints for any remaining callers that still depend on them directly, primarily GitLab Self-Managed and GitLab Dedicated customers using the GitLab-provisioned AI Gateway on GitLab 19.0 or earlier.

https://docs.gitlab.com/api/code_suggestions/

Migration guidelines

  • GitLab.com: Traffic is migrated automatically to v4; no customer action is required.
  • Self-Managed and Dedicated: Upgrade GitLab within the two-major-version compatibility window to a version that calls the v4 endpoints. Customers who upgrade within this window experience no disruption.
  • The AI Gateway endpoints are used internally only, so no further action is required other than upgrading GitLab within the specified time window if you are using the GitLab AI Gateway.

Background

This deprecation is part of the larger effort to consolidate the Duo Code Suggestions API endpoints onto version 4. Maintaining the legacy v2 and v3 endpoints alongside v4 adds ongoing complexity. Removal is explicitly gated on the AI Gateway two-major-version compatibility policy and on observed traffic dropping to a negligible level.

Breaking Change?

Does this deprecation contain a breaking change? Yes

Instructions for users: Self-Managed and Dedicated customers on GitLab 19.0 or earlier must upgrade to a supported GitLab version (which uses the v4 endpoints) before the removal milestone.

Affected Customers

Who is affected by this deprecation:

  • GitLab.com
  • Self-managed
  • Dedicated

What pricing tiers are impacted?

  • GitLab Free
  • GitLab Premium
  • GitLab Ultimate

Deprecation Milestone

This deprecation is being announced in milestone: 19.5

Planned Removal Milestone

The feature / functionality will be removed in milestone: 21.0

Rollout Plan

Proposed sequence:

  1. Migrate GitLab-controlled traffic to v4 first, with no noticeable change for customers. This has already been completed.
  2. Public deprecation announcement in GitLab 19.5.
  3. Continued migration and monitoring during 19.x and 20.x using the Code Suggestions telemetry dashboard to track remaining v2/v3 usage.
  4. Do not remove legacy routes before the two-major-version compatibility window and traffic thresholds are met.
  5. Remove legacy v2/v3 endpoints in GitLab 21.0.

Communication Plan

Since the breaking change wil

Internal Communication Plan

External Communication Plan

  • Customer announcement plan
    • Document the migration plan for users, clearly outlining the actions they need to take to mitigate the impact of the breaking change.
    • A deprecation announcement entry has been created so the deprecation will appear in release posts and on the general deprecation page. Add link to the relevant merge request.
    • Documentation has been updated to mark the feature as deprecated. Add link to the relevant merge request.
  • On the major milestone (21.0):
    • The deprecated item has been removed. Add link to the relevant merge request.
    • The removal MR is labeled breaking change.

Edited by Mike Wronski