Processing a payment

Payment processing begins when Shopify makes an HTTP call to your payments app. Your app responds with a redirect URL that Shopify uses to redirect the customer to your app's payment page. After the payment is finalized, you need to communicate the result to Shopify using either the PaymentSessionResolve or PaymentSessionReject mutations. After the PaymentSessionResolve or PaymentSessionReject mutation is called, you can't change the payment state.

This guide assumes that you have: