Disruption with GPT 5.3 Codex

lowGitHubCopilotJul 20, 2026 16:03Duration: 2h 33m
dnsapirouting
DNS FailureNetwork / RoutingAPI Issue

Summary

This incident has been resolved. Thank you for your patience and understanding as we addressed this issue. A detailed root cause analysis will be shared as soon as it is available.

Impact

minor

Timeline

Jul 20, 2026 16:03

[investigating] We are investigating reports of degraded performance for Copilot AI Model Providers

via statuspage
+1m
Jul 20, 2026 16:04

[investigating] We are investigating GPT Codex 5.3 performance.

via statuspage
+35m
Jul 20, 2026 16:39

[investigating] We identified that an upstream provider is returning errors for GPT 5.3 Codex requests, causing some users to experience failed or interrupted responses. Traffic is being automatically rerouted to mitigate impact. We are working with the upstream provider to resolve the underlying issue. We recommend using a different model at this time while we resolve the problem.

via statuspage
+42m
Jul 20, 2026 17:21

[investigating] The upstream provider continues to return intermittent errors for GPT 5.3 Codex requests. Some users may experience failed or interrupted responses when using this model. Traffic continues to be automatically rerouted to reduce impact, and we are actively working with the upstream provider on a resolution. In the meantime, selecting an alternative model will avoid disruption.

via statuspage
+1h 5m
Jul 20, 2026 18:25

[investigating] We are seeing signs of sustained recovery from the upstream provider for GPT 5.3 Codex requests. Requests are succeeding as expected. We are awaiting confirmation from the provider that the issue is fully mitigated before resolving this incident.

via statuspage
+11m
Jul 20, 2026 18:37

[resolved] This incident has been resolved. Thank you for your patience and understanding as we addressed this issue. A detailed root cause analysis will be shared as soon as it is available.

via statuspage

Lessons Learned

GitHub has experienced 116 incidents in the past year. This frequency suggests systemic reliability challenges that may warrant additional monitoring.

📊Incidents related to dns, api, routing have occurred 799 times across all providers in the past year. This is one of the most common failure categories in cloud infrastructure.

💡This incident is categorized as: DNS Failure, Network / Routing, API Issue. Consider implementing preventive measures specific to this failure category.