In this lecture, we cover how to design fault‑tolerant workflows in ChatGPT Apps: classify failures (technical, model, business errors and UX interruptions), pick strategies (
retry,
fail-fast,
rollback, and involving the user), implement exponential backoff via
callWithRetry, protect critical steps with an
idempotencyKey, build compensations using the
Saga pattern, synchronize UI/backend/model steps, and present errors so both the model (a structure with
code and
retryable) and the user (brief, safe messages) can understand them. We finish with hands‑on practice on the GiftGenius checkout step and a checklist of common pitfalls.