On April 21, 2026, between 13:35 UTC and 01:24 UTC the following day the projects service was degraded. During this time period, projects may have been out of sync and users may have experienced delays in changes to projects and their items. Delays in reflected changes peaked at approximately 45 minutes. The delays were caused by serialization errors that failed events and triggered a flood of resyncs, overloading our event processing layers.We mitigated the incident by speeding up processing time for incoming changes and otherwise waiting for all changes to be processed.We are working to increase our capacity for processing updates to projects to reduce our time to mitigation of issues like this one in the future.
On April 20, 2026 between 10:28 UTC and 15:04 UTC GitHub experienced degraded service for code scanning default setup, code quality, and project boards. Repair of affected project boards additionally lasted until April 21, 05:04 UTC During this time, code scanning default setup and code quality analyses were not triggered on newly opened pull requests. Additionally, newly created issues were not appearing on project boards. The cause was a serialization error that prevented proper triggering of code scanning, code quality analyses, and project board updates. We mitigated the issue by deploying a fix, restoring event publishing for code scanning and code quality. For project boards, an additional code change was deployed to update event consumers, followed by a reindex of affected project items. We are working to prevent recurrence by strengthening our schema validations and improving monitoring for drops in publishing on critical hydro topics.
On April 17, 2026, between 14:46 UTC and 15:12 UTC, users experienced a degraded web experience on GitHub.com. During this time, approximately 1.5% of web requests resulted in errors, with some users encountering slow page loads or failed requests. The issue was caused by capacity saturation of a caching component in one of our data center regions. We mitigated the issue by redirecting traffic to an unaffected region and rolling back a recent deployment. The incident was fully resolved at 15:18 UTC. We are taking steps to provide appropriate capacity for this caching path to prevent recurrence.
On April 16, 2026 between 09:30 UTC and 17:15 UTC, users experienced failures when attempting to connect to GitHub Codespaces via the VS Code editor. During this time, approximately 40% of codespace start operations failed. Users connecting via SSH were not impacted. The issue was caused by a failure in an upstream download service that prevented the VS Code Server from being retrieved during codespace startup. The impact was mitigated by implementing a workaround to use an alternative download path when the primary endpoint is degraded. We are working with the upstream dependency to address the root cause of the download service failure, and we are improving our fallback mechanisms to reduce the impact of similar upstream failures in the future.
On April 14, between 00:58 UTC and 06:08 UTC, GitHub Enterprise Cloud customers experienced 500 errors when attempting to access Copilot Insights pages which was caused by an authentication failure in our metrics pipeline. We fully mitigated the issue and validated the fix in production. Approximately 709 users were impacted. The total impact duration was approximately 5 hours and 10 minutes. Our investigation determined the incident was caused by a change in a tenant credential which caused authentication errors to retrieve the required data needed on our Copilot Insights pages. We understand this disruption impacted customers' ability to access the Copilot Insights page. To prevent similar issues and reduce resolution time in the future, we are investing in improved diagnostics tooling to quickly identify the root cause of failures, enhanced monitoring, and alerting to detect issues at a more granular level. GitHub is a critical infrastructure for your work, your teams, and your businesses. We are focused on these remediations and continued reliability improvements for Copilot Insights and related metrics experiences.
On Sunday April 13th, 2026, between 18:53 UTC and 20:30 UTC, the GitHub Pages service experienced elevated error rates. On average, the error rate was 10.58% and peaked at 12.77% of requests to the service, resulting in approximately 17.5 million failed requests returning HTTP 500 errors. This was due to an automated DNS management tool (octodns) erroneously deleting a DNS record for a Pages backend storage host after its upstream data source intermittently failed to return the record, causing the tool to treat it as stale and remove it.We mitigated the incident by re-creating the deleted DNS record. To prevent future incidents, we are implementing availability-zone-tolerant routing in the Pages frontend so that an unresolvable backend host triggers failover to healthy hosts rather than returning errors, adding safeguards to prevent automated deletion of DNS records owned by other systems, and improving logging and alerting for DNS resolution failures in the Pages serving path.
On April 13, 2026, between 14:41 UTC and 17:29 UTC, the Copilot service experienced degraded performance. All Copilot users were impacted by increased latency, and approximately 20% experienced request failures when interacting with Copilot Cloud Agent (CCA). On average, request latency increased to approximately 950ms. The GitHub User Dashboard also displayed intermittent errors loading Copilot quota information. CCA and the User Dashboard were impacted for approximately 2 hours and 56 minutes. This was due to an infrastructure change that reduced the available compute capacity for a backend service responsible for Copilot rate limiting and quota management. The reduced capacity caused resource exhaustion under normal traffic load, leading to cascading failures in downstream request processing. We mitigated the incident by increasing compute resources allocated to the affected service and scaling out the number of service instances to distribute load more effectively. We are working to improve proactive capacity monitoring to detect resource degradation before it impacts users, reviewing retry and timeout configurations across dependent services to reduce amplification during degraded states, and evaluating connection management strategies to improve resilience under constrained resources.
On April 9, 2026, between 22:59 UTC and April 10, 2026, 13:24 UTC, the Copilot Mission Control service was degraded and did not display Claude and Codex Cloud Agent sessions in the agents tab dashboard. Customers were unable to see, list, or manage their third party agent sessions during this period. The underlying agent sessions continued to function normally. This was a visibility and management issue only, and no HTTP errors were generated. The API returned successful responses with incomplete results, with an average error rate of 0% and a maximum error rate of 0%. This was due to a code change that introduced a filter which inadvertently excluded third party agent sessions.We mitigated the incident by reverting the problematic code change and deploying the fix to production.We are working to add automated monitoring for dashboard content visibility and improve integration test coverage for third party agent session listing to reduce our time to detection and mitigation of issues like this one in the future.
On April 9, 2026, between 16:05 UTC and 20:36 UTC, the Copilot cloud agent service was degraded, causing new agent sessions to be delayed or fail to start. Users who attempted to start Copilot cloud agent sessions during this period experienced jobs getting stuck in the queue, with wait times peaking at 54 minutes compared to the normal 15–40 seconds. On average, approximately 84% of requests to start agent sessions failed, peaking at 97.5% during the worst period.This was due to an internal service exceeding API rate limits, compounded by a caching bug that persisted the rate-limited state beyond the actual rate limit window, causing recurring outage waves rather than a single recovery.We mitigated the incident by deploying a configuration change to bypass the affected cache and shifting API traffic to an alternative authentication path that reduced rate limit exposure. We have since added automated monitoring and alerting for this failure mode, deployed per-endpoint rate limit controls, and added caching for high-traffic API calls to reduce overall load. We are also working on longer-term improvements to rate limit isolation and traffic management to prevent similar issues in the future.This incident shared the same underlying root causes with an incident declared in the time frame https://www.githubstatus.com/incidents/zn1t56bfxdzg
On April 9, 2026, between 09:05 UTC and 19:05 UTC, the Copilot coding agent service was degraded and users experienced significant delays starting new agent sessions. Approximately 84% of new agent session requests were delayed across four separate outage waves, with queue wait times peaking at 54 minutes compared to a normal baseline of 15–40 seconds. On average, the error rate was 83.9% and peaked at 97.5% of requests to the service. Approximately 22,700 workflow creations were delayed or failed during the incident.This was due to a bug in our rate limiting logic that incorrectly applied a rate limit globally across all users, rather than scoping it to the individual installation that triggered the limit. A contributing factor was a surge in API traffic from a client update that increased requests to an internal endpoint by 3–4x, which accelerated rate limit exhaustion.We mitigated the incident by disabling the faulty rate limit caching mechanism via feature flag and updating our service to use per-installation credentials for API calls, ensuring rate limits are correctly scoped to individual installations.We have since added automated monitoring and alerting to detect this failure mode proactively, deployed fixes to reduce unnecessary API traffic through caching improvements, and are continuing work to further isolate rate limit scoping across client types to prevent similar issues in the future.This incident shared the same underlying root causes with an incident declared in the time frame https://www.githubstatus.com/incidents/2rqwxl8y7m0j