EU - Disruption with Copilot Coding Agent Sessions

Update timeline

1. investigating Mar 20, 2026, 12:58 AM UTC

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

2. investigating Mar 20, 2026, 01:00 AM UTC

   We are seeing widespread issues starting and viewing Copilot Agent sessions. We understand the cause and are working on remediation.

3. investigating Mar 20, 2026, 01:26 AM UTC

   We are rolling out our mitigation and are seeing recovery.

4. resolved Mar 20, 2026, 01:58 AM UTC

   On March 19, 2026, between 01:05 UTC and 02:52 UTC, and again on March 20, 2026, between 00:42 UTC and 01:58 UTC, the Copilot Coding Agent service was degraded and users were unable to start new Copilot Agent sessions or view existing ones. During the first incident, the average error rate was ~53% and peaked at ~93% of requests to the service. During the second incident, the average error rate was ~99%% and peaked at ~100%% of requests with significant retry amplification. Both incidents were caused by the same underlying system authentication issue that prevented the service from connecting to its backing datastore. We mitigated each incident by rotating the affected credentials, which restored connectivity and returned error rates to normal. The mitigation time was 01:24. The second occurrence was due to an incomplete remediation of the first. We are implementing automated monitoring for credential lifecycle events and improving operational processes to reduce our time to detection and mitigation of issues like this one in the future.