Decrement Item Quantity

Use the decrementItemQuantity mutation to increment only the cart item quantity.

Mutation

decrementItemQuantity(input: UpdateItemQuantityInput!): Cart!

Arguments	Type
`input`	`UpdateItemQuantityInput!`

The decrementItemQuantity mutation will always return the updated Cart object.

`UpdateItemQuantityInput!`

Argument	Type	Description
`cartId`	`ID!`	The `id` of the cart you are working with.
`id`	`ID!`	The `id` of the item you are decrementing the quantity of.
`by`	`Int!`	The amount you wish to decrement the cart item quantity by.

If no cart item exists with the id provided, an error will be returned.

Example

mutation {
  decrementItemQuantity(
    input: { cartId: "ck5r8d5b500003f5o2aif0v2b", id: "5e3293a3462051", by: 10 }
  ) {
    id
    items {
      id
      quantity
    }
  }
}

{
  "data": {
    "decrementItemQuantity": {
      "id": "ck5r8d5b500003f5o2aif0v2b",
      "items": [
        {
          "id": "ck5r8d5b500003f5o2aif0v2b",
          "quantity": 1
        }
      ]
    }
  }
}