ai-automation-consultant / Failure Lab

OAuth Refresh Expired

A calendar integration works for one user but fails after a long idle period.

Category

oauth

Difficulty

advanced

Last Run

none

Incident Brief

Diagnose the auth lifecycle problem and the least surprising user recovery.

Broken State

The refresh token expired after inactivity, but the app keeps retrying token refresh.

Symptoms

  • Reconnect fixes the user's calendar immediately.
  • Automatic refresh requests return invalid_grant.

Trace

oauth.refresh status=400 error=invalid_grant
calendar.sync user=pat@example.com last_success=2026-06-02

Diagnosis