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Everifin UI is the simplest method of integration and will be the easiest for maintenance over. It takes the user to a trusted and licensed payment services provider Everifin (e.g. using a redirect or a modal window). The user can safely authorize the payment and return back without sharing any sensitive data with the original client application (an accounting system, an ERP, an e-shop, etc). Unless there are API breaking changes to the payment status call or link creation call, no additional development should be required to match the latest Everifin Paygate updates.
Everifin API
Everifin API is a more complex integration method which requires the client application to take care about the specifics of the payment authorization process itself. E.g. it must store the list of connected bank accounts, monitor the status of each connection, handle different types of payment authorization processes supported by the banks (redirect to a bank, embedded in the application and decoupled) each with multiple types of authorization factors (push notification, SMS, one-time code, QR code scan, etc).
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