# Shopify Functions

## Add `useIgCart()`

* Use the [`useIgCart()`](/version-1.2.16/reference/hooks/cart-and-checkout-hooks.md#useigcart) hook if your site uses the Storefront **Cart** API.
* The `wrapCustomAttributes` helper is only needed if you're performing shipping tests or need line item properties added to ATC requests.

## Add `useIgCartAttributes()` (optional)

If you build carts manually (for example, via `cartCreate` or `cartLinesAdd`), use [`useIgCartAttributes()`](/version-1.2.16/reference/hooks/cart-and-checkout-hooks.md#useigcartattributes) for the attributes payload that should be included in your cart requests.


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