# cartLinesUpdate - storefront - MUTATION Version: 2025-01 ## Description Updates one or more merchandise lines on a cart. ### Access Scopes ## Arguments * [cartId](/docs/api/storefront/2025-01/scalars/ID): ID! - The ID of the cart. * [lines](/docs/api/storefront/2025-01/input-objects/CartLineUpdateInput): CartLineUpdateInput! - The merchandise lines to update. The input must not contain more than `250` values. ## Returns * [cart](/docs/api/storefront/2025-01/objects/Cart): Cart The updated cart. * [userErrors](/docs/api/storefront/2025-01/objects/CartUserError): CartUserError! The list of errors that occurred from executing the mutation. * [warnings](/docs/api/storefront/2025-01/objects/CartWarning): CartWarning! A list of warnings that occurred during the mutation. ## Examples