Returns a shopping cart by prefixed ID. Authorize via x-spree-token header (guest) or JWT Bearer token (authenticated user).
Publishable API key for store access
JWT token for authenticated customers
Cart prefixed ID (e.g., cart_abc123)
Comma-separated associations to expand (items, fulfillments, payments, discounts, billing_address, shipping_address, gift_card, payment_methods). Use "none" to skip associations.
Comma-separated list of fields to include (e.g., total,amount_due,item_count). id is always included.
cart with out-of-stock item removed (warnings returned)