Applications need the following input to take a payment:
- Amount to charge.
- Payment recipient. The payment goes to the account identified by the Authorization header in the API request.
- Payment source. It can be a secure token (nonce) or a card on file.
You can generate a nonce using the Square Payment Form and the In-App Payments SDK. For working code examples, see Connect API examples.
A card on file refers to a credit/debit or a gift card associated with a customer. You can create a customer and add a card to them using either the Customers API, the dashboard, or the Square mobile app.