Disruption with some GitHub services

Resolved

On December 8, 2025, between 21:15 and 22:24 UTC, Copilot code completions experienced a significant service degradation. During this period, up to 65% of code completion requests failed.The root cause was an internal feature flag that caused the primary model supporting Copilot code completions to appear unavailable to the backend service. The issue was resolved once the flag was disabled.To prevent recurrence, we expanded test coverage for Copilot code completion models and are strengthening our detection mechanisms to better identify and respond to traffic anomalies.

Investigating

We are beginning to see signs of resolution after applying a mitigation. We expect full resolution within approximately 30 minutes.

Investigating

We're continuing to investigate and mitigate issues with the GPT 4o model for Copilot completions. Users can currently work around this issue by updating their VS Code settings with "github.copilot.advanced.debug.overrideEngine": "gpt-41-copilot".

Investigating

We are currently investigating failures with the GPT 4o model for Copilot completions.

Investigating

We are investigating reports of impacted performance for some GitHub services.