We assume you are familiar with the Overview section of the Payage User Guide so will not repeat that information here. This section describes Payage in more detail.
Applications interact with Payage through its API, described in detail in the next section. When an application is ready to request a payment from the user, it calls the Payage get_buttons() function, passing all known details of the transaction. Payage creates a payment record, stores all of the supplied data, and responds with the HTML for all the relevant payment buttons. The application then simply echos out the button HTML as part of its payment page.