Integrators should only update to API version 2019-07-30 to enable this feature if they are already using the SMARTTERMINAL_REQUEST webhook subscription or the Polling API for native applications.
Required API Version: 2019-07-30
For instructions on how to set your API version please see: Developer API Versioning
This feature allows a payment request to be cancelled from the Smart Terminal by pressing the red X button on the Smart Terminal keypad prior to the card data being entered. This allows a cardholder to prevent the transaction from being processed if the amount is incorrect, which can be particularly useful for unattended kiosk and self-checkout solutions. It also allows merchants using the Smart Terminal for manual keyed card entry to cancel the payment from the Smart Terminal.
Integrators still using the SMARTTERMINAL_TRANSACTION subscription do not receive state information and therefore are unable to respond to cancellations raised by the Smart Terminal. Unless the integration is only subscribing to SMARTTERMINAL_TRANSACTIONS for passive data collection and not for Point-of-Sale applications, do not upgrade to API version 2019-07-30.