In coming days, we will add guid (identifier) and code (sku) for each cart item as data attributes. Format is the same as for microdata on product listings, see section on structured data. This information will be available in all templates and in all components where cart items are displayed, with exception of the order summary page.
Example:
<table class="cart-table">
<tbody>
<tr class="removeable"
data-micro="cartItem"
data-micro-identifier="9512fff7-302f-11e9-a065-0cc47a6c92bc"
data-micro-sku="293"
>
...
</tr>
</tbody>
</table>