Make a payment

To enable the Adyen SDK to handle payments, you need to add code to your POS app. This code starts a transaction with:

• A Terminal API payment request.
• The payment interface you want to use: your iPhone for Tap to Pay, or the card reader.
• The presentation mode you want to use.

After you have added this code, payments take place as follows:

1. Your POS app creates a Terminal API payment request that is serialized to JSON, or you receive the Terminal API payment request from your backend.
2. You pass the payment request to the Adyen SDK.
3. The Adyen SDK checks if the session is still valid, and if necessary establishes a new session.
4. The transaction starts on your mobile device.
   In the card reader solution, the Adyen SDK shows instructions on your mobile device to guide the customer.
5. The Adyen SDK passes the Terminal API payment response to your POS app.

Add code to start a transaction

In your POS app, add code for the following steps:

1. If you create the Terminal API payment request in your POS app, use PaymentService.installationId as POIID in the MessageHeader of the payment request. (If you create the payment request in the backend, the backend uses the installationId from the /sessions response.)
2. Create an instance of Transaction.Request using Transaction.Request(data:), and pass the Terminal API payment request from your POS app or backend.

   let transaction = try Transaction.Request(data: requestData)

3. Get a PaymentInterface from an instance of PaymentService, using PaymentService.getPaymentInterface(with:).

   Value	Description
   tapToPay	Use the iPhone for Tap to Pay.
   cardReader	Use the card reader.

   let paymentService = PaymentService(...)
   let paymentInterface = try paymentService
                           .getPaymentInterface(with: .cardReader)

4. Specify a TransactionPresentationMode that matches the UI framework of the POS app.

   Value	Description
   viewModifier	The UI is embedded in a View as a ViewModifier.
   presentingViewController	The UI is presented on top of the provided UIViewController.

   let presentationMode: TransactionPresentationMode = .viewModifier

5. Invoke PaymentService.performTransaction(with:paymentInterface:presentationMode:) on your instance of PaymentService:

   let transactionResponse = await paymentService.performTransaction(
      with: transaction,
      paymentInterface: paymentInterface,
      presentationMode: presentationMode
   )

   The Adyen SDK now checks for a session, and starts the transaction. In the card reader solution, the Adyen SDK shows screens on your mobile device to guide the customer.
6. Pass the transactionResponse to your POS app. This is the Terminal API payment response, including data you can use to generate a receipt.

See also