The transaction QR code payment solution uses the dynamically generated QR code to represent a transaction. In this payment solution, customers scan the generated QR code to complete the payment, without the need to enter the transaction amount.

To provide such a payment service, Alipay acquirers need to integrate with Alipay system through the interfaces that are developed for these payment solutions. 

Target audience

This document targets at the technical person who is intending to integrate with the transaction QR code payment solution.

Terms and definitions

QR code

Quick Response code (QR code) consists of black squares arranged in a square grid on a white background, which can be read by an imaging device and processed. The required data are then extracted from patterns that are present in both horizontal and vertical components of the image, as depicted below.

In the transaction QR code payment solution, the merchant system will send a request to the Alipay system with the transaction data, and the Alipay will respond a QR Code to represent the transaction.

Interface

In this context, the interface is the channel that the Alipay system provides the relevant service by invoking the corresponding APIs with the required parameter values. Throughout this guide, the interface and serive can be used interchangeably.

Product flow

The following graphic shows the work flow of the transaction QR code payment solution.

Process:

1. A customer is approaching the cashier to pay for the purchased items.
2. The cashier places an order in ECR Terminal for the items.
3. The ECR system sends a request to the Merchant Server/System Integrator to create a pre-order.
4. The Merchant Server/System Integrator transmits the request to Alipay.
5. Alipay server returns a payment URL.
6. After receiving the payment URL, the acquirer can take one of the following actions:

• Generate a QR code for the payment URL and pass the QR code to the ECR Terminal.
• Pass the payment URL to the ECR Terminal and let the ECR Terminal generate a QR code for the payment URL.

7. The ECR Terminal displays the QR code on the screen for the customer.
8. The customer scans the transaction QR code to complete the payment.
9. The Alipay system asynchronously sends a notification to the acquirer, and then the acquirer sends a notification to ECR Terminal, if the payment is successful.

User experience

Customers scan a dynamically generated QR code, and the transaction QR code payment solution is activated. Customers simply need to scan the QR code provided in the merchant's device and enter the password to complete the payment, no need to specify the payment amount. The payment process is as illustrated below.