Currency of CheckoutRequest.grossAmountMinor.
Gross amount to charge, including VAT, in integer minor units.
OptionallinesOptional per-line breakdown of the charged selection, in neutral facts.
The selected payment provider requires priced line items with a mandatory
per-line tax entry, so a real adapter cannot build a valid order from a bare
gross total. These lines are therefore neutral catalog facts captured before
the charge — never provider field names — and the sum of grossUnitMinor * quantity equals CheckoutRequest.grossAmountMinor. The deterministic
fake ignores them, so local and automated acceptance are unchanged; only a
provider adapter reads them. Absent lines mean "no breakdown was supplied",
which a provider adapter must treat as a request that cannot be charged rather than
inventing prices.
Stable identity of this checkout operation, owned by the application.
Every attempt of the same operation reuses it, so a later retry policy can recognize a repeated initiation. It is never a provider identifier.
Provider-neutral request for one commercial checkout operation.
The contract deliberately carries only what a charge needs. Line items, VAT breakdowns, payment methods, provider customer references, and every protocol/authentication concern stay outside it until the discovery record proves that a provider supports them (MVP-TECH-002), so the application never guesses a provider capability.