curl --request GET \
  --url https://storefront-api.fourthwall.com/v1/carts/{cartId}

{
  "id": "<string>",
  "items": [
    {
      "variant": {
        "id": "<string>",
        "name": "<string>",
        "sku": "<string>",
        "unitPrice": {
          "value": 10,
          "currency": "USD"
        },
        "attributes": {
          "description": "Black, L",
          "color": {
            "name": "Black",
            "swatch": "#000000"
          },
          "size": {
            "name": "L"
          }
        },
        "stock": {
          "type": "<string>",
          "inStock": 5
        },
        "weight": {
          "value": 1,
          "unit": "kg"
        },
        "dimensions": {
          "length": 1,
          "width": 2,
          "height": 3,
          "unit": "cm"
        },
        "images": [
          {
            "id": "00aa4abd-5778-4199-8161-0b49b2f212e5",
            "url": "https://fourthwall.com/image.png",
            "width": 800,
            "height": 600,
            "transformedUrl": "https://fourthwall.com/image.png"
          }
        ],
        "product": {
          "id": "<string>",
          "name": "<string>",
          "slug": "<string>"
        },
        "compareAtPrice": {
          "value": 10,
          "currency": "USD"
        }
      },
      "quantity": 123,
      "groupedBy": {
        "type": "<string>",
        "bundleId": "<string>",
        "groupedId": "<string>"
      }
    }
  ],
  "metadata": {}
}