Skip to main content
Tabs guarantees reliable at-least-once delivery for all event notifications. If your server is temporarily unavailable or returns an error status code, Tabs automatically queues and retries delivery according to an exponential backoff schedule.

​
Delivery requirements

For a webhook delivery to be marked as successful, your webhook receiver must:
  1. Respond with an HTTP 2xx status code (such as 200 OK or 204 No Content).
  2. Respond within 10 seconds. Requests exceeding 10 seconds are terminated and treated as failed timeouts.
If your webhook processing involves heavy tasks (such as generating PDF invoices or sending emails), acknowledge the webhook with 200 OK immediately upon signature verification and process work asynchronously in a background queue.

​
Retry schedule

If your endpoint returns an HTTP status outside the 2xx range (e.g. 500 Internal Error, 502 Bad Gateway, 404 Not Found) or times out, Tabs initiates retries: After 6 total failed attempts (initial attempt + 5 retries), delivery transitions to FAILED and automatic retries cease.

​
Manual retries & delivery logs

You can review every delivery attempt, inspect HTTP status codes, latency, and request payloads:
  1. Open the Tabs Merchant Portal.
  2. Go to Developers > Webhooks.
  3. Scroll to the Recent Deliveries section.
  4. Click on any failed delivery to inspect the exact error response returned by your server.
  5. Click Retry Delivery to immediately re-dispatch the event payload to your endpoint.

​
Idempotency on webhook receivers

Because webhooks may be retried upon network timeouts, your server might occasionally receive the same event more than once. To prevent duplicate processing:
  • Record processed event IDs (event.id) in your database.
  • If an incoming event has already been recorded as processed, return 200 OK immediately without re-executing business logic.