Checkout

Checkout is customizable presentation around platform-owned commerce truth. The theme owns all visible form markup, labels, grouping, buttons and CSS. Upstorr owns validation, inventory reservations, shipping quotes, discounts, GST, payment actions and order creation.

The main checkout section registers the checkout behavior in its schema. The runtime then supplies checkout state and approved attributes for contact, delivery, address, shipping, billing, discount and submission elements.

Developer-mode code may use fetchThemeCheckout, saveThemeCheckoutDraft, submitThemeCheckout, useThemeCheckout and the generated checkout reference. Use themeRuntimeProps.checkout* to connect visible elements to platform behavior.

Do not insert payment-provider script URLs, payment globals, direct checkout requests or tax calculations in a theme.

Test blank, partially completed, valid and rejected submissions; unavailable items; pickup, shipping and local delivery; billing-address choices; discounts; mobile layout; loading state and payment return. An error element must remain hidden until the platform supplies an actual message.