When Liquid Barcodes receives the transaction information, the user profile with coupons is obtained from the registry.
Liquid Barcodes does mix-matching to add personal discounts according to the coupon conditions. Liquid Barcodes tries to minimize the price for the customer while avoiding double discounting.
Liquid Barcodes replies to the /applicator/sale request with an adjusted transaction list. Liquid Barcodes adds rebate lines and highlights changes to the transaction.
Next: POS adjusts transaction and proceeds to payment.