Update a cart's own attributes, not its items
Changes cart-level attributes — currently just the locale — without touching its line items. This endpoint never adds, removes or re-prices items; use the /api/cart/lines endpoints for that. If the request carries nothing to change (no locale, or the same locale the cart already has), the cart is returned unmodified rather than treated as an error.
Headers
Identifies which store this request is for. Required on every store-scoped route. It is not authentication and not a secret — it grants no privileges and is safe to send from a browser. You receive the value once your Entria backend has been created and configured. Missing header returns 400; an unknown store returns 404.
Query parameters
BCP 47 locale code (e.g. da-DK, en-US). Defaults to DEFAULT_LOCALE env binding.