Crypto/stablecoin payments via Omnipay (Payzum) — how would you like async settlement handled?

[payzum-hq]

Hi! Lychee's shop already speaks Omnipay, and I'd like to contribute support for Payzum, a non-custodial crypto/stablecoin gateway (USDC, USDT and more) — the Omnipay driver exists and the config/enum part is a tiny diff following the Mollie pattern.

The one design question is settlement: crypto confirmation is asynchronous, and right now handlePaymentReturn marks an order FAILED whenever completePurchase() is not successful on the buyer's return — which for a crypto payment is the normal case (the invoice is still confirming on-chain when the buyer comes back). Before opening a PR I'd love your preference between:

1. an inbound notification endpoint (the gateway signs each notification with HMAC-SHA-512; the driver verifies it over the raw bytes), following the custom-gateway pattern your app/Actions/Shop/Gateway/README.md describes, or
2. keeping it poll-based: leave the order in PROCESSING on return and re-check the invoice status (a scheduled job or on-view refresh).

Happy to implement whichever fits Lychee's architecture best — tests included.

Disclosure: I work on Payzum and would maintain the integration long-term.

[ildyria]

an inbound notification endpoint (the gateway signs each notification with HMAC-SHA-512; the driver verifies it over the raw bytes), following the custom-gateway pattern your app/Actions/Shop/Gateway/README.md describes, or

I think this is a better approach.
polling is very unreliable because it requires scheduled jobs to be setup etc.

Also a HMAC is not a signature. It is an authentication code. ;)

[payzum-hq]

Perfect — inbound endpoint it is, thanks for the quick guidance. I'll open a PR following the custom-gateway pattern described in app/Actions/Shop/Gateway/README.md: the Payzum config/enum part (Mollie-style), a notification route that verifies the HMAC-SHA-512 signature over the raw bytes and completes the order idempotently, and handlePaymentReturn leaving the order in PROCESSING until the verified notification lands. Tests included.