---
title: useApplyCartLinesChange
description: Returns a function to mutate the `lines` property of checkout.
api_version: 2023-07
api_name: checkout-ui-extensions
source_url:
  html: >-
    https://shopify.dev/docs/api/checkout-ui-extensions/2023-07/react-hooks/cart/useapplycartlineschange
  md: >-
    https://shopify.dev/docs/api/checkout-ui-extensions/2023-07/react-hooks/cart/useapplycartlineschange.md
---

# use​Apply​Cart​Lines​Changehook

Returns a function to mutate the `lines` property of checkout.

## use​Apply​Cart​Lines​Change()

### Returns

* (change: CartLineChange) => Promise\<CartLineChangeResult>

### CartLineChange

```ts
CartLineAddChange | CartLineRemoveChange | CartLineUpdateChange
```

### CartLineAddChange

* type

  An identifier for changes that add line items.

  ```ts
  "addCartLine"
  ```

* merchandiseId

  The merchandise ID being added.

  ```ts
  string
  ```

* quantity

  The quantity of the merchandise being added.

  ```ts
  number
  ```

* attributes

  The attributes associated with the line item.

  ```ts
  Attribute[]
  ```

* sellingPlanId

  The identifier of the selling plan that the merchandise is being purchased with.

  ```ts
  string
  ```

```ts
export interface CartLineAddChange {
  /**
   * An identifier for changes that add line items.
   */
  type: 'addCartLine';

  /**
   * The merchandise ID being added.
   * @example 'gid://shopify/ProductVariant/123'
   */
  merchandiseId: string;

  /**
   * The quantity of the merchandise being added.
   */
  quantity: number;

  /**
   * The attributes associated with the line item.
   */
  attributes?: Attribute[];

  /**
   * The identifier of the selling plan that the merchandise is being purchased
   * with.
   */
  sellingPlanId?: SellingPlan['id'];
}
```

### Attribute

* key

  The key for the attribute.

  ```ts
  string
  ```

* value

  The value for the attribute.

  ```ts
  string
  ```

```ts
export interface Attribute {
  /**
   * The key for the attribute.
   */
  key: string;

  /**
   * The value for the attribute.
   */
  value: string;
}
```

### CartLineRemoveChange

* type

  An identifier for changes that remove line items.

  ```ts
  "removeCartLine"
  ```

* id

  Line Item ID.

  ```ts
  string
  ```

* quantity

  The quantity being removed for this line item.

  ```ts
  number
  ```

```ts
export interface CartLineRemoveChange {
  /**
   * An identifier for changes that remove line items.
   */
  type: 'removeCartLine';

  /**
   * Line Item ID.
   * @example 'gid://shopify/CartLine/123'
   */
  id: string;

  /**
   * The quantity being removed for this line item.
   */
  quantity: number;
}
```

### CartLineUpdateChange

* type

  An identifier for changes that update line items.

  ```ts
  "updateCartLine"
  ```

* id

  Line Item ID.

  ```ts
  string
  ```

* merchandiseId

  The new merchandise ID for the line item.

  ```ts
  string
  ```

* quantity

  The new quantity for the line item.

  ```ts
  number
  ```

* attributes

  The new attributes for the line item.

  ```ts
  Attribute[]
  ```

* sellingPlanId

  The identifier of the selling plan that the merchandise is being purchased with or \`null\` to remove the the product from the selling plan.

  ```ts
  string
  ```

```ts
export interface CartLineUpdateChange {
  /**
   * An identifier for changes that update line items.
   */
  type: 'updateCartLine';

  /**
   * Line Item ID.
   * @example 'gid://shopify/CartLine/123'
   */
  id: string;

  /**
   * The new merchandise ID for the line item.
   * @example 'gid://shopify/ProductVariant/123'
   */

  merchandiseId?: string;
  /**
   * The new quantity for the line item.
   */
  quantity?: number;

  /**
   * The new attributes for the line item.
   */
  attributes?: Attribute[];

  /**
   * The identifier of the selling plan that the merchandise is being purchased
   * with or `null` to remove the the product from the selling plan.
   */
  sellingPlanId?: SellingPlan['id'] | null;
}
```

### CartLineChangeResult

```ts
CartLineChangeResultSuccess | CartLineChangeResultError
```

### CartLineChangeResultSuccess

* type

  Indicates that the line item was changed successfully.

  ```ts
  "success"
  ```

```ts
export interface CartLineChangeResultSuccess {
  /**
   * Indicates that the line item was changed successfully.
   */
  type: 'success';
}
```

### CartLineChangeResultError

* type

  Indicates that the line item was not changed successfully. Refer to the \`message\` property for details about the error.

  ```ts
  "error"
  ```

* message

  A message that explains the error. This message is useful for debugging. It is \*\*not\*\* localized, and therefore should not be presented directly to the buyer.

  ```ts
  string
  ```

```ts
export interface CartLineChangeResultError {
  /**
   * Indicates that the line item was not changed successfully. Refer to the `message` property for details about the error.
   */
  type: 'error';

  /**
   * A message that explains the error. This message is useful for debugging.
   * It is **not** localized, and therefore should not be presented directly
   * to the buyer.
   */
  message: string;
}
```

## Related

[APIs - StandardApi](https://shopify.dev/docs/api/checkout-ui-extensions/apis/standardapi)

[APIs - CheckoutApi](https://shopify.dev/docs/api/checkout-ui-extensions/apis/checkoutapi)

[APIs - OrderStatusApi](https://shopify.dev/docs/api/checkout-ui-extensions/apis/orderstatusapi)

[APIs - CartLineItemApi](https://shopify.dev/docs/api/checkout-ui-extensions/apis/cartlineitemapi)

[APIs - PickupPointListApi](https://shopify.dev/docs/api/checkout-ui-extensions/apis/pickuppointlistapi)

[APIs - PickupLocationListApi](https://shopify.dev/docs/api/checkout-ui-extensions/apis/pickuplocationlistapi)

[APIs - ShippingOptionItemApi](https://shopify.dev/docs/api/checkout-ui-extensions/apis/shippingoptionitemapi)

[APIs - ExtensionTargets](https://shopify.dev/docs/api/checkout-ui-extensions/apis/extensiontargets)