Replay failed callback deliveries

Queues redelivery of SMS callbacks that failed. The window runs from since (default: the last 24 hours) to until, and events whose callback was already received successfully within that window are skipped. An event can still arrive more than once: a failure inside the window followed by a success outside it is replayed, and a live delivery can overlap a replay. Your receiver must deduplicate on the webhook-id header. Each event goes to the callback URL its original attempts used.

Only failed attempts are replayed, and the window selects on attempt time rather than on when the event occurred. Replay reads the delivery-attempt log, which retains three days, so that is the oldest history it reaches: an earlier since widens the window without recovering anything older.

The 202 response means the replay is queued. Each redelivery then takes a single attempt rather than the retry schedule a live delivery follows, so a replay into a callback URL that is still failing costs one request per event; fix the receiver and replay again. No count or task ID is returned, so track results with the callback delivery attempts list.

One replay redelivers at most the oldest 10,000 events in the window. Callback replays count toward the same limit of 20 replays per organization per UTC day as Replay failed deliveries; beyond that the request returns a 429 WebhookReplayQuotaExceeded.