The Card API is defined by distinct services that create several flows.
| Flow | Description | Impact on Customer's Account |
|---|---|---|
| CardVerification | Verifies whether a user's card is valid or not. | None. |
| FundsTransfer | Transfer's funds from a user's account for a purchase. | Single message capture of customer's funds. |
| ReserveCapture | Reserves funds on a user's account and then asynchronously can capture them later. | Dual message, reservation and subsequent capture of customer's funds. |
| Refund | Returns funds to a user's account that were captured by either a FundsTransfer or a ReserveCapture. | Funds returned to user. |
CardVerification
The CardVerification flow is composed of a single method that is implemented by the Payment Integrator. VerifyCard is used to validate a user's card. This is typically done with a $0 or $1 authorization, but no funds are ever captured for this flow.
FundsTransfer
The FundsTransfer flow is composed of a single method that is implemented by the Payment Integrator. Capture is used to capture funds from a user's account. This method synchronously checks for availible funds and captures those funds.
Reserve Capture
The ReserveCapture flow is composed of multiple methods that are implemented both by the Payment Integrator and by Google. It is a dual message payment flow where funds are first reserved synchronously and then captured asynchronously. After the funds are reserved, the reservation can be captured or canceled. A capture initiates the money movement and a cancel will release the hold on the user's funds.
The Payment Integrator implements the ReserveFunds, AsynchronousCaptureFundsReservation and AsynchronousCancelFundsReservation methods and Google implements the CaptureFundsReservationResultNotification and CancelFundsReservationResultNotification methods.
Capture Flow
Cancel Flow
Refund
The Refund flow is composed of a method implemented by the Payment Integrator and a method implemented by Google. It is used to return funds that have been captured through either the FundsTransfer or the ReserveCapture flows. The Payment Integrator implements the AsynchronousRefund and Google implements the RefundResultNotification
Chargeback
The Chargeback flow is still in development. When ready it's documentation can be found in this spot.