Barzahlen API v2 allows you to create payment, payout, and refund slips customers can use in stores like supermarkets to pay or receive money. Slips are sent to users as an email with a PDF attachment or as a text message. When a store's point of sale system confirms the transaction, Barzahlen usually immediately calls a Webhook to notify your system about the payment. You can then use this confirmation e.g. to mark an invoice as paid or trigger shipping goods to the customer.