The Shopify Storefront API has been enhanced to allow the management of a cart, making it easier for developers to build headless e-commerce sites. This enhancement is particularly useful when integrating with frameworks like Nuxt, which has seen the release of the Shopify + Nuxt Kit that leverages this new API to provide features such as product filtering and detailed item variants in the shopping cart. The kit also implements features related to user interaction with the cart, including adding items, removing items, and displaying subtotal, tax, and total amounts. By utilizing this kit, developers can more easily create seamless e-commerce experiences for their customers.