--- title: CartLineUpdateInput - Storefront API description: The input fields to update a line item on a cart. api_version: unstable api_name: storefront source_url: html: >- https://shopify.dev/docs/api/storefront/unstable/input-objects/CartLineUpdateInput md: >- https://shopify.dev/docs/api/storefront/unstable/input-objects/CartLineUpdateInput.md --- # Cart​Line​Update​Input input\_object The input fields to update a line item on a cart. ## Fields * attributes [\[Attribute​Input!\]](https://shopify.dev/docs/api/storefront/unstable/input-objects/AttributeInput) An array of key-value pairs that contains additional information about the merchandise line. The input must not contain more than `250` values. * id [ID!](https://shopify.dev/docs/api/storefront/unstable/scalars/ID) non-null The ID of the merchandise line. * merchandise​Id [ID](https://shopify.dev/docs/api/storefront/unstable/scalars/ID) The ID of the merchandise for the line item. * quantity [Int](https://shopify.dev/docs/api/storefront/unstable/scalars/Int) The quantity of the line item. * selling​Plan​Id [ID](https://shopify.dev/docs/api/storefront/unstable/scalars/ID) The ID of the selling plan that the merchandise is being purchased with. *** ## Map No referencing types