Issue Identified - Slack Outage
This summary is created by Generative AI and may differ from the actual content.
Overview
Between 2026-05-27 22:21 UTC and 2026-05-28 00:10 UTC, PagerDuty customers in the US and EU service regions experienced a disruption to Slack‑based incident management. During this window customers could not receive Slack notifications nor interact with incident cards via Slack. PagerDuty’s core platform, event ingestion pipeline, and web UI remained fully operational, and all non‑Slack notification channels (email, phone, push, webhooks) continued to function normally.
Impact
The impact was limited to the Slack integration: customers using Slack for incident notifications or incident‑card updates did not receive alerts or could not update cards during the outage. No degradation was observed in the core PagerDuty service, event ingestion, or other notification channels.
Trigger
An outage in Slack’s platform caused its API to become unavailable, preventing PagerDuty’s integration from communicating with Slack.
Detection
PagerDuty’s monitoring detected failures in the Slack integration (e.g., errors when calling Slack’s API) and identified the issue as an external Slack platform outage.
Resolution
When Slack’s API returned to a fully operational state at 00:10 UTC on 2026‑05‑28, PagerDuty’s Slack integration automatically resumed normal operation, restoring notification delivery and incident‑card functionality. The incident was then declared resolved.
Root Cause
The root cause was an external outage of Slack’s platform, which broke the API that PagerDuty relies on for its Slack integration. No changes to PagerDuty’s own systems were required.