Questions

This is a great question, and in my experience with payment providers, it’s usually safest to assume at-least-once delivery rather than exactly-once delivery for webhooks. Network issues, timeouts, and delayed acknowledgements can all cause providers to retry the same event, which means duplicate deliveries should generally be expected and handled gracefully on the receiving side.

Checking and storing the event ID is actually a common and recommended approach. Many systems maintain a table of processed webhook event IDs and simply ignore any event that has already been handled. This makes the processing idempotent and protects against duplicate charges, duplicate order updates, or other unintended side effects.

One additional best practice is to make the business operation itself idempotent whenever possible. For example, before marking an order as paid, verify its current status. If the order is already in a completed or paid state, the webhook can be safely acknowledged without performing the action again. This provides an extra layer of protection even if duplicate events somehow bypass the event-ID check.

I'm also curious whether anyone here has found official Paynova documentation that explicitly discusses webhook retries, duplicate event handling, or idempotency recommendations. Some payment platforms provide unique event identifiers in the payload free top games, while others include request headers specifically intended for deduplication. If Paynova documents a preferred pattern, it would be useful to follow that guidance rather than relying solely on custom logic.

For now, storing processed event IDs, making webhook processing idempotent, and responding quickly with a successful HTTP status after validation would be the approach I would trust most in a production payment environment.