A PSP abstraction layer decouples your application from the specific wire formats of individual payment service providers. Instead of coding to each PSP's API, you code to one stable contract; the abstraction layer translates that contract into whatever each provider expects.

Link is that layer for Hellgate. It means adding a provider, or switching between them, becomes a configuration change rather than a new engineering integration – the difference between weeks of work and re-pointing a contract.

→ How PSP abstraction works