Cart API

Create cart

POST /api/v1/carts

{ "currency": "USD" }

Response includes cart_id.

Get cart

GET /api/v1/carts/:id

Returns cart with items, totals, and applied coupons.

Add item

POST /api/v1/carts/:id/items

{
  "product_id": "uuid",
  "quantity": 2,
  "variant_id": "uuid"  // optional
}

Update item quantity

PATCH /api/v1/carts/:id/items/:item_id

{ "quantity": 3 }

Remove item

DELETE /api/v1/carts/:id/items/:item_id

Apply coupon

POST /api/v1/carts/:id/coupons

{ "code": "SUMMER20" }

Remove coupon

DELETE /api/v1/carts/:id/coupons/:coupon_id

Cart totals

Cart totals are calculated automatically:

• Subtotal (sum of line items)
• Discount (from coupons)
• Tax (based on shipping address)
• Shipping (calculated at checkout initiate)
• Total