{
  "$schema": "https://json-structure.org/meta/extended/v0/#",
  "$id": "cartitem-structure.json",
  "title": "CartItem",
  "description": "An item in the shopping cart.",
  "type": "object",
  "properties": {
    "productId": {
      "type": "string",
      "description": "Product SKU."
    },
    "quantity": {
      "type": "int32",
      "description": "Quantity."
    },
    "unitPrice": {
      "type": "float",
      "description": "Price per unit."
    }
  }
}