Disruption with some GitHub services

Final update

On April 22, 2026, between 09:00 UTC and 22:05 UTC, the Copilot coding agent and pull request comment event processing were degraded. During this period, approximately 0.5% of total pull request and issue comments mentioned @copilot (~23,000 invocations), explicitly requested work from the Copilot coding agent but were not acted upon. Creating, viewing, and replying to pull request comments was unaffected, and other Copilot functionality continued to operate normally. The impact was limited to @copilot mentions on pull request comments not triggering Copilot coding agent runs, and to some downstream systems not receiving new pull request comment events during the impact window. The cause was a serialization error that prevented pull request comment events from being published to downstream consumers, including the Copilot coding agent. This was related to the same class of issue as incident #4295 on April 20, affecting a another event type. We mitigated the incident by deploying a fix that restored event publishing, after which the Copilot coding agent and other downstream consumers resumed processing pull request comment events normally. We are working to complete our audit of rel

1. Resolved · Apr 22, 22:43 UTC
   On April 22, 2026, between 09:00 UTC and 22:05 UTC, the Copilot coding agent and pull request comment event processing were degraded. During this period, approximately 0.5% of total pull request and issue comments mentioned @copilot (~23,000 invocations), explicitly requested work from the Copilot coding agent but were not acted upon. Creating, viewing, and replying to pull request comments was unaffected, and other Copilot functionality continued to operate normally. The impact was limited to @copilot mentions on pull request comments not triggering Copilot coding agent runs, and to some downstream systems not receiving new pull request comment events during the impact window. The cause was a serialization error that prevented pull request comment events from being published to downstream consumers, including the Copilot coding agent. This was related to the same class of issue as incident #4295 on April 20, affecting a another event type. We mitigated the incident by deploying a fix that restored event publishing, after which the Copilot coding agent and other downstream consumers resumed processing pull request comment events normally. We are working to complete our audit of related event schemas, migrate remaining consumers to use the updated identifier fields, and improve monitoring to detect drops in publishing on critical event topics, to reduce our time to detection and mitigation of issues like this one in the future.