Payments. 8 operations.

GatewayInfo is one enabled payment gateway as the owner sees it: its name, as store.yaml's payment.gateways names it; whether it takes real money (payment.live); and the capabilities it declares, as names them and in its order. A reserved capability never shows.

GatewayKey is one key field of a gateway in one mode, test or live: whether it is set, its last four characters when it is long enough, and who saved it and when. A key is write-only: no operation gives it back.

GatewayKeyRequest sets a gateway's key of a mode, test or live, and a field; an empty value clears it.

GatewaySettings is one gateway's settings: its name; whether it is enabled; its position on the checkout, from 1; its mode, test or live, which the live switch sets, or offline for a gateway that takes no money online and so has no test or live keys (ModeOffline); the label buyers see in place of its own ("" for its own); its keys; who saved its settings and when (none while store.yaml's rules); and, for the cash on delivery gateway, whether the checkout can offer it now.

GatewaySettingsRequest changes a gateway's settings: each field it sets; one it leaves out stays as it is. A move to a position moves the others along.

LiveRequest sets the store's live switch; Confirm must be true, either way: on, real cards are charged; off, no real money is taken.

PaymentSettings are the payment settings as the owner sees them: the store's live switch (payment.live), whether the owner saved it, by whom and when (none while store.yaml's rules), and every gateway the engine knows, by position.

UnmatchedNotification is one payment event, of a notification the store accepted, that named no order the store holds: the notification's id and gateway, when it came, the event, the reference it named, and why it matched nothing. It holds no secret and no body.