# Storefront API changes when Cart ID is missing the key param — Shopify developer changelog --- ## Storefront API changes when Cart ID is missing the key param We are modifying how cart queries and mutations behave when the [Storefront API Cart ID](https://shopify.dev/docs/storefronts/headless/building-with-the-storefront-api/cart/manage#cart-id) is missing the key param. This behavior is applied retroactively to all versions of the Storefront API. An example cart ID: gid://shopify/Cart/c1-7a2abe82733a34e84aa472d57fb5c3c1?**key=824bdj25mhg1242bdb385** * **Queries:** Querying a cart without including the key param will result in a cart with the buyer's private details removed. * **Mutations** Updating a cart without including the key param will result in an error : `The specified cart does not exist`. *Published: August 15, 2024* Tags: API, Update Link: https://shopify.dev/changelog/storefront-api-changes-when-cart-id-is-missing-the-key-param ---