Payment processor
The transaction engine that passes approvals, captures, refunds, and other payment messages between merchants and the card system.
See it
What it is
When a card charge leaves your checkout, the payment processor carries its messages among the merchant, acquirer, card network, and issuer. It handles authorization, capture, refund, and reversal, then helps turn cleared transactions into settlement records.
You need processor access whenever you accept electronic payments, but a payment service provider may hide it behind a single API. Larger merchants sometimes choose processors separately to control routing, acquiring relationships, reporting, and cost.
Gotcha: the processor moves messages and transaction instructions, not necessarily the money itself. It also cannot overrule an issuer's decline, and the same company may sell gateway, acquiring, and processor services under one brand.
Ask AI for it
Build concrete adapters for the Stripe PaymentIntents API and Adyen Payments API behind one internal payments interface. Model authorization, capture, reversal, refund, decline, and settlement as separate operations, attach an idempotency key to every write, persist Stripe and Adyen references and raw status codes, verify signed webhooks, and map both APIs into stable internal states without discarding the original reason codes.