GitLab SSH deploy key auth broken for 400+ sites — first deploy succeeds, redeploy fails

ERROR: Please provide a private_token or auth_token for user

ENVIRONMENT
We have 400+ active production sites on Netlify, all connected to a single GitLab repository via the Netlify API. This setup has been stable in production for over 5 years with no changes on our end. All sites began failing today simultaneously.

OUR INTEGRATION FLOW

  1. Generate a deploy key via Netlify API (POST /api/v1/deploy_keys)
  2. Add the returned public key to our GitLab repository
  3. Pass the deploy_key_id in the site repo payload when creating the site via API

CRITICAL BEHAVIOUR TO NOTE:
The initial deploy succeeds. When a site is first created and deployed through our flow, it completes successfully. However, any subsequent redeploy — whether triggered manually from the Netlify UI or via the API — fails immediately with the auth error above.

This behaviour is consistent across all 400+ sites and started today without any changes to our configuration or codebase.

WORKAROUND ATTEMPTED
We also tried using GitLab project-level deploy keys as an alternative:

  1. Generated a new Netlify deploy key
  2. Added it directly to the GitLab project via the GitLab API
  3. Confirmed successful key registration (200/201 response from GitLab)

Redeployments still fail with the identical error. The issue persists both through our API integration and when triggering manually from the Netlify dashboard.

WHAT WE’RE ASKING FOR
→ Confirmation of any incident or change on Netlify’s side today affecting GitLab SSH / deploy key authentication on redeployment
→ An immediate fix or workaround to restore redeploy functionality across our 400+ sites
→ Clarification on why the first deploy succeeds but subsequent deploys fail — this pattern suggests the issue is in how credentials are persisted or re-validated after initial site creation

Contact: Muhammad Haziq — m.haziq.frt@gmail.com

Hi,

I have the same issue. Could you already find a solution to the problem, or did the support contact you?

Manually reconnecting the gitlab repo in the Netlify UI solved the issue for me, but as I have 1000+ sites thats not a possible solution.