The proposed version of Host-to-Host APIs uses message calls that are equivalent to the Authorization Request, Financial Request and Financial Advice used in the IFSF ISO8583 based H2H standard. For clarity, however, it is not intended that this API is a direct conversion of ISO8583 messages into JSON message structures nor is it intended that this API be completely interoperable with ISO8583. It may be convertible in some limited use cases, but this is not guaranteed.
This proposal enables reusing backend logic and co-existence of traditional and APIs based integration. Limiting the number of APIs to accomplish a payment transaction, also reduces the potential exceptions that might occur executing the payment process; it eliminates the necessity of a stateful handling of multiple APIs, before completing mandatory and optionally information required for authorization and capture of the payment transaction
This approach assumes that the application server accepting the payment requests and sending the Payment APIs has the capability to manage the status of the requests till their completion (responsibility that might reside in an eCommerce platform, or ultimately in a payment terminal connecting into this server
- depending on the use case).