Disruption with Copilot for access to some models

Final update

On August 10, 2026, between 19:48 UTC and 20:49 UTC, GitHub Copilot users saw an incomplete list of available models. During this window, the service could return as few as one model instead of the full catalog. Requests that tried to use a model missing from that shortened list failed with a "model not found" error. Copilot requests that used an available model were not affected. This did not affect customers on data-residency (Proxima) environments. The issue was caused by a change to how model data was published, which our systems could not read back correctly and fell back to a limited default list. We mitigated the incident by 20:49 UTC and deployed a fix to prevent immediate recurrence by 21:50 UTC. We are adding validation and retry safeguards so that model data is verified before it is served. We apologize for the disruption.

1. Resolved · Aug 10, 21:50 UTC
   On August 10, 2026, between 19:48 UTC and 20:49 UTC, GitHub Copilot users saw an incomplete list of available models. During this window, the service could return as few as one model instead of the full catalog. Requests that tried to use a model missing from that shortened list failed with a "model not found" error. Copilot requests that used an available model were not affected. This did not affect customers on data-residency (Proxima) environments. The issue was caused by a change to how model data was published, which our systems could not read back correctly and fell back to a limited default list. We mitigated the incident by 20:49 UTC and deployed a fix to prevent immediate recurrence by 21:50 UTC. We are adding validation and retry safeguards so that model data is verified before it is served. We apologize for the disruption.
2. Monitoring · Aug 10, 21:50 UTC
   We have deployed and validated the fix to prevent immediate reoccurrence. We will be performing additional work to limit these kinds of failures in the future.
3. Monitoring · Aug 10, 21:19 UTC
   The issue has been mitigated across all affected environments. We are currently deploying on a fix to prevent reoccurrence. We will provide another update once the fix has been deployed.
4. Monitoring · Aug 10, 20:49 UTC
   The degradation has been mitigated. We are monitoring to ensure stability.
5. Monitoring · Aug 10, 20:39 UTC
   We are currently investigating reports of some Copilot users experiencing issues accessing certain models. Affected users may see errors or degraded functionality when attempting to use specific models. We are actively working on a fix and will provide updates as we have more information.
6. Investigating · Aug 10, 20:27 UTC
   We are investigating reports of impacted performance for some GitHub services.