Notification delivery

The Lifecycle

Transitions Explained

The transition rows describe stored state changes, their checks and their recorded effects. A queue receive, provider outcome and staff action can reach different lifecycle boundaries.

What Cannot Happen

Successful terminal delivery cannot return to the queue. A competing consumer cannot acquire an existing sending claim. A retry must first requeue work; ambiguous failures do not qualify. Skipped deliveries retain their reason and remain terminal.

Concurrency and Timing

Expected-state updates decide which consumer owns a send. Queue receive count supplies the retry budget; there is no database attempt counter. Operator retry uses a separate conditional update. Provider-event identities deduplicate the retained history, which is capped at fifty events.