The Transaction Flows

The vending process using the Nayax Marshall SDK involves steps that ensure the secure and efficient handling of cashless transactions.

Transaction Flow

Each transaction begins with the consumer wanting to buy a product. Now, depending on the required flow, meaning whether you want the consumer to select the product before securing the payment (Pre-selection) or first secure the payment, and once secured, allow the consumer to select the product (Pre-authorization). This only affects only the start of the transaction flow.

• Pre-selection: Once the client selects a product, the device will be ready to accept payment.
  Once the payment is presented, the VMC host machine will notify the device about the required amount to authorize, and the device will try to authorize it. Whether successful or not, the VMC host will be notified. If successful, the VMC host, notified about the successful authorization, will try to dispense the product. Once successfully dispensed, it will notify the VPOS about it, and the VPOS will settle the transaction – meaning the payment is now completed.
• Pre-Authorization: The consumer presents its payment card (swipe, tap or insert) and once card is detected,
  the device will communicate with the banks to secure a pre-authorized amount. Once the authorization is successful, the vending machine will be notified about card presented, and will in turn, notify the consumer to select a product. Since the card was already authorized (pre-authorized…), the VMC host machine, which will ask the VPOS to authorize, will be immediately notified about successful authorization. the VMC host, which is notified about the successful authorization, will try to dispense the product. Once successfully dispensed, it will notify the VPOS about it, and the VPOS will settle the transaction – meaning the payment is now completed.

Pre-selection

The transaction Flow for Pre-selection is as follows:

1. The consumer selects a product.
2. VMC Host sends reader-enable requests to the VPOS.
3. The consumer presents a payment card.
4. Card information and the session begin notification are delivered to the VMC Host.
5. VMC host sends vend request requests to the VPOS.
6. VPOS try to authorize the required amount.
7. VPOS will respond with vend approved or vend denied.
   1. In case of vend approval, the VMC host will try to dispense product and notify with vend success or vend failure.
   2. In case of vend success, VPOS will settle the transaction.
   3. In case of vend failure, VPOS will cancel and refund the amount.
8. VMC host will notify the VPOS about it’s readiness for another transaction (end session).

Pre-Authorization

1. The consumer wants to buy something;
2. VMC Host sends reader to enable request to the VPOS;
3. Consumer presents a payment card;
4. VPOS try to authorize a pre-configured amount;
   1. If authorized successfully.
      1. Card information is delivered to VMC Host along with the session-beginning notification;
      2. VMC host send vend request request to the VPOS;
      3. VPOS will immediately respond with vend approved;
      4. VMC host will try to dispense product and notify with vend success or vend failure;
   2. in case of vend success, VPOS will settle the transaction;
   3. in case of vend failure, VPOS will cancel and refund the amount;
5. VMC host will notify the VPOS about it’s readiness for another transaction (end session);