API ReferenceWebhooks

Idempotency and the X-Event-ID Header

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X-Event-ID is added as a header to the request. It is a unique identifier assigned to each event.

  • Uniqueness: Each X-Event-ID value will be globally unique for each event that occurs.
  • Re-Delivery: Events are delivered at least once. We will redeliver events on failure due to network issues, timeouts and listener errors. The X-Event-ID will remain the same across retries.
  • Idempotent Processing: We recommend that you use the X-Event-ID to handle events in an idempotent way. If you encounter the same X-Event-ID again, simply skip and acknowledge the duplicate event rather than processing it a second time.