Issue Identified calling the Schedules API
This summary is created by Generative AI and may differ from the actual content.
Overview
On June 3, 2026, between 11:15 UTC and 14:08 UTC, a subset of customers (<10% of accounts per region) were unable to view, create, or update schedules via the PagerDuty Schedules REST API. Requests returned HTTP 401 Unauthorized. All other PagerDuty services—including event ingestion, incident notification, and the web/mobile UI—remained fully functional.
Impact
The incident affected fewer than 10 % of customer accounts in each service region (EU and US). Only the Schedules API endpoints were impacted; other REST API endpoints, event ingestion, incident notification delivery, and the PagerDuty UI were unaffected. No revenue impact was reported, but customers experienced inability to manage schedules during the outage.
Trigger
A configuration change deployed as part of internal network modernization altered the way customer account information was propagated along the internal request path. The dependent authentication service could no longer associate requests with accounts, causing the Schedules API to reject them as unauthenticated.
Detection
Monitoring systems flagged an elevated rate of HTTP 401 responses on the Schedules REST API shortly after the rollout began at 11:15 UTC. The anomaly triggered alerts that led the on‑call team to declare a major incident at 13:39 UTC.
Resolution
The offending configuration change was rolled back across both EU and US regions at 14:08 UTC, restoring proper account identity propagation and normal authentication behavior. A fix was deployed, and the service was confirmed to be operating normally thereafter.
Root Cause
The root cause was the configuration change that broke the internal request routing, preventing the Schedules API’s downstream authentication service from determining the originating customer account. This resulted in legitimate requests being treated as unauthenticated and returning HTTP 401 errors.