Delivery retries
Response handling and recovery.
Each delivery cycle has 5 attempts including the first. Retry delays are 30 seconds, 5 minutes, 30 minutes and 2 hours (30/300/1800/7200 seconds). Network errors, timeouts, 408, 429 and 5xx are retryable. Other 4xx and all 3xx are terminal.
Return a small 2xx only after durable acceptance; keep response bodies below 4096 bytes. Success stops automatic attempts. After FAILED, manual redelivery opens a new cycle and keeps eventId/deliveryId; the lifetime attempt counter continues. Delivery is best effort and can repeat after your server commits. Deduplicate event and order fulfillment transactionally. See deduplication.