Disruption with OpenAI Models
Lesson: Reliance on external AI models can lead to service disruptions if those models experience issues.
What happened
On May 28th, 2026, between approximately 18:27 and 20:41 UTC, the GitHub Copilot service was degraded due to an issue with the Responses API of an upstream provider affecting the GPT-5.2, GPT-5.3-Codex, GPT-5.4, and GPT-5.5 models. Requests routed to these models via the Responses API returned elevated error rates, which also affected Copilot coding agent and Copilot code review. No other models were impacted. We mitigated the incident by shifting traffic away from the affected models while the upstream provider deployed a fix. GitHub is working to improve automated failover for the affected models and strengthen monitoring to prevent similar incidents in the future.
Timeline
- Resolved · May 28, 20:41 UTC
On May 28th, 2026, between approximately 18:27 and 20:41 UTC, the GitHub Copilot service was degraded due to an issue with the Responses API of an upstream provider affecting the GPT-5.2, GPT-5.3-Codex, GPT-5.4, and GPT-5.5 models. Requests routed to these models via the Responses API returned elevated error rates, which also affected Copilot coding agent and Copilot code review. No other models were impacted. We mitigated the incident by shifting traffic away from the affected models while the upstream provider deployed a fix. GitHub is working to improve automated failover for the affected models and strengthen monitoring to prevent similar incidents in the future.
More from GitHub
Full history| Started | Incident | Impact | Duration |
|---|---|---|---|
| Sep 2416:51 UTC | Disruption with billing information updates | minor | 3h 50m |
| Sep 2310:11 UTC | Incident across several services | minor | 18h 44m |
| Sep 2022:13 UTC | Incident with Pull Requests | minor | 1h 9m |
| Sep 1720:59 UTC | Elevated rate of errors for OpenAI models provided by Copilot | minor | 50m |
| Sep 1607:20 UTC | Degradation with Gemini 3.8 Flash | major | 10h 28m |
| Sep 1519:11 UTC | Disruption with some GitHub services | minor | 49m |
Also caused by third-party dependency
All| Started | Vendor | Incident | Impact | Duration |
|---|---|---|---|---|
| Sep 1609:48 UTC |  DigitalOcean | Support Portal Service DisruptionDigitalOcean | minor | 11h 21m |
| Sep 1608:31 UTC |  Cloudflare | Support Helpdesk Availability IssuesCloudflare | minor | 6h 27m |
| Sep 417:03 UTC |  Grafana Labs | Degradation of Hosted Grafana in US Central RegionGrafana Labs | major | 3h 39m |
| Sep 416:05 UTC |  Expo | Elevated Linux worker queue timesExpo | major | 15h 4m |
| Sep 115:25 UTC | Grafana Labs | Investigating issues in US Central (prod-us-central-0, prod-us-central-5)Grafana Labs | minor | 4h 54m |
| Aug 3106:26 UTC |  Fly.io | Packet loss in ORDFly.io | minor | 1h 44m |
Sources: vendors' own status pages, published postmortems and SEC 8-K Item 1.05 filings, read daily. Times as reported. Logos via logo.dev; trademarks belong to their owners.