For more complex or custom implementations of Checkout, where the use of an API is preferred to the Widgets, we provide a fully featured API. The latest release of the API is version 8.
To retrieve the list of valid delivery options, the client system must invoke the GetCheckoutOrder (ProcessCheckoutOrder) method on the CheckoutProvider interface. This will evaluate the properties of the order and return a set of appropriate delivery methods pertinent to the order.
Once the order is complete, the CloseCheckout method on the CheckoutProvider interface should be called. This should specify the selected delivery option along with any associated credentials. Furthermore, CloseCheckout supports modifications of the initial order contents.
Nodification of an order can happen by the following rules:
(Note that modifying an order does NOT have any effect on the calculation of the delivery services)