PECI Event-Driven Integration Fails With HTTP 415 Unsupported Media Type
What does "Summary: An error occurred while attempting to deliver" mean in Workday PECI?
When PECI runs in event-driven mode and pushes a change immediately after a hire or other trigger, the receiving vendor endpoint can reject the delivery with an HTTP 415 if the Content-Type header Workday sends doesn't match what the vendor's API expects for that payload. Because the event-driven push failed, the change is not marked delivered, and the worker is then missing from the next scheduled PECI run's output until reprocessed.
Quick fix
Manually trigger the standard scheduled PECI run, not the event-driven push, so the missed worker's change is picked up and delivered on the next cycle.
Permanent fix
Work with the vendor to confirm and lock in the exact Content-Type their endpoint accepts, and if Workday's default doesn't match, raise a support case referencing the specific HTTP 415 response so Workday or the vendor can adjust the delivery step's header configuration.
Troubleshooting
- Check the vendor's integration documentation for the exact Content-Type, including character encoding, their endpoint requires for EDI or PECI payloads.
- Compare that against the Content-Type Workday's Cloud Connect delivery step is actually sending, visible in the integration's connector configuration.
- Confirm the affected worker is genuinely missing from the next scheduled run's Diagnostic Audit output, not just delayed, before treating it as a delivery failure rather than a timing issue.
- Ask the vendor whether their endpoint recently changed its accepted Content-Type, since a 415 on a previously working integration is often a vendor-side contract change rather than a Workday configuration change.