Migrate to Polaris

Version 2025-07 is the last API version to support React-based UI components. Later versions use web components, native UI elements with built-in accessibility, better performance, and consistent styling with Shopify's design system. Check out the migration guide to upgrade your extension.

Choose a version:

Cart Instructions API

Instructions used to create the checkout.

Anchor to StandardApiStandardApi

The base API object provided to purchase extension targets.

Anchor to instructions instructions StatefulRemoteSubscribable<> required: The cart instructions used to create the checkout and possibly limit extension capabilities.

These instructions should be checked prior to performing any actions that may be affected by them.

For example, if you intend to add a discount code via the applyDiscountCodeChange method, check discounts.canUpdateDiscountCodes to ensure it's supported in this checkout.

Caution
Check cart instructions before calling select APIs, as > some may not be available. See the > Cart Instructions API > for more information.
Caution: Check cart instructions before calling select APIs, as > some may not be available. See the > <a href="/docs/api/checkout-ui-extensions/apis/cart-instructions#examples">Cart Instructions API</a> > for more information.

CartInstructions

attributes
Cart instructions related to cart attributes.
```
AttributesCartInstructions
```
delivery
Cart instructions related to delivery.
```
DeliveryCartInstructions
```
discounts
Cart instructions related to discounts.
```
DiscountsCartInstructions
```
lines
Cart instructions related to cart lines.
```
CartLinesCartInstructions
```
metafields
Cart instructions related to metafields.
```
MetafieldsCartInstructions
```
notes
Cart instructions related to notes.
```
NotesCartInstructions
```

AttributesCartInstructions

canUpdateAttributes
Indicates whether or not cart attributes can be updated.
```
boolean
```

DeliveryCartInstructions

canSelectCustomAddress
Indicates whether a buyer can select a custom address. When true, this implies extensions can update the delivery address.
```
boolean
```

DiscountsCartInstructions

canUpdateDiscountCodes
Indicates whether or not discount codes can be updated.
```
boolean
```

CartLinesCartInstructions

canAddCartLine
Indicates whether or not new cart lines can be added.
```
boolean
```
canRemoveCartLine
Indicates whether or not cart lines can be removed.
```
boolean
```
canUpdateCartLine
Indicates whether or not cart lines can be updated.
```
boolean
```

MetafieldsCartInstructions

canDeleteCartMetafield
Indicates whether or not cart metafields can be deleted.
```
boolean
```
canSetCartMetafields
Indicates whether or not cart metafields can be added or updated.
```
boolean
```

NotesCartInstructions

canUpdateNote
Indicates whether or not notes can be updated.
```
boolean
```

Anchor to useInstructions
useInstructions()

Returns the cart instructions used to create the checkout and possibly limit extension capabilities.

Anchor to useInstructions-returnsReturns

Examples

import {

Banner,

Button,

useApplyDiscountCodeChange,

useInstructions,

reactExtension,

} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(

'purchase.checkout.block.render',

() => <Extension />,

);

function Extension() {

const applyDiscountCodeChange =

useApplyDiscountCodeChange();

const instructions = useInstructions();

if (

instructions.discounts.canUpdateDiscountCodes

) {

return (

<Button

onPress={() =>

applyDiscountCodeChange({

type: 'addDiscountCode',

code: 'FREE_SHIPPING',

})

}

Apply your loyalty discount

</Button>

);

} else {

return (

Loyalty discounts are unavailable

</Banner>

);

}

Examples

Discounts

Description

Check `instructions.discounts.canUpdateDiscountCodes` before calling `applyDiscountCodeChange()`.

React

import {
  Banner,
  Button,
  useApplyDiscountCodeChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyDiscountCodeChange =
    useApplyDiscountCodeChange();
  const instructions = useInstructions();

  if (
    instructions.discounts.canUpdateDiscountCodes
  ) {
    return (
      <Button
        onPress={() =>
          applyDiscountCodeChange({
            type: 'addDiscountCode',
            code: 'FREE_SHIPPING',
          })
        }
      >
        Apply your loyalty discount
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty discounts are unavailable
      </Banner>
    );
  }
}

JavaScript

import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.discounts
        .canUpdateDiscountCodes
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyDiscountCodeChange({
                type: 'addDiscountCode',
                code: 'FREE_SHIPPING',
              }),
          },
          'Apply your loyalty discount',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty discounts are unavailable',
        ),
      );
    }
  },
);

Attributes

Description

Check `instructions.attributes.canUpdateAttributes` before calling `applyAttributeChange()`.

React

import {
  Banner,
  Button,
  useApplyAttributeChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyAttributeChange =
    useApplyAttributeChange();
  const instructions = useInstructions();

  if (
    instructions.attributes.canUpdateAttributes
  ) {
    return (
      <Button
        onPress={() =>
          applyAttributeChange({
            type: 'updateAttribute',
            key: 'loyaltyPoints',
            value: '100',
          })
        }
      >
        Apply 100 loyalty points
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty points are unavailable
      </Banner>
    );
  }
}

JavaScript

import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.attributes
        .canUpdateAttributes
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyAttributeChange({
                type: 'updateAttribute',
                key: 'loyaltyPoints',
                value: '100',
              }),
          },
          'Apply 100 loyalty points',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty points are unavailable',
        ),
      );
    }
  },
);

Delivery

Description

Check `instructions.delivery.canSelectCustomAddress` before calling `applyShippingAddressChange()`. When `true`, this instruction implies that extensions can change the shipping address.

React

import {
  Banner,
  Button,
  useApplyShippingAddressChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyShippingAddressChange =
    useApplyShippingAddressChange();
  const instructions = useInstructions();

  if (
    instructions.delivery.canSelectCustomAddress
  ) {
    return (
      <Button
        onPress={() =>
          applyShippingAddressChange({
            type: 'updateShippingAddress',
            address: {
              zip: '90201',
            },
          })
        }
      >
        Change your postal code
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Shipping address cannot be modified
      </Banner>
    );
  }
}

JavaScript

import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.delivery
        .canSelectCustomAddress
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyShippingAddressChange({
                type: 'updateShippingAddress',
                address: {
                  zip: '90201',
                },
              }),
          },
          'Change your postal code',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Shipping address cannot be modified',
        ),
      );
    }
  },
);

Discounts

Description

Check `instructions.discounts.canUpdateDiscountCodes` before calling `applyDiscountCodeChange()`.

React

import {
  Banner,
  Button,
  useApplyDiscountCodeChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyDiscountCodeChange =
    useApplyDiscountCodeChange();
  const instructions = useInstructions();

  if (
    instructions.discounts.canUpdateDiscountCodes
  ) {
    return (
      <Button
        onPress={() =>
          applyDiscountCodeChange({
            type: 'addDiscountCode',
            code: 'FREE_SHIPPING',
          })
        }
      >
        Apply your loyalty discount
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty discounts are unavailable
      </Banner>
    );
  }
}

JavaScript

import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.discounts
        .canUpdateDiscountCodes
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyDiscountCodeChange({
                type: 'addDiscountCode',
                code: 'FREE_SHIPPING',
              }),
          },
          'Apply your loyalty discount',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty discounts are unavailable',
        ),
      );
    }
  },
);

Lines

Description

Check `instructions.lines.canAddCartLine` or `instructions.lines.canRemoveCartLine` or `instructions.lines.canUpdateCartLine` before calling `applyCartLinesChange()`.

React

import {
  Banner,
  Button,
  useApplyCartLinesChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyCartLinesChange =
    useApplyCartLinesChange();
  const instructions = useInstructions();

  if (instructions.lines.canAddCartLine) {
    return (
      <Button
        onPress={() =>
          applyCartLinesChange({
            type: 'addCartLine',
            merchandiseId:
              'gid://shopify/product/1234',
            quantity: 1,
          })
        }
      >
        Add a free gift to your order
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        The products in your cart cannot be
        modified
      </Banner>
    );
  }
}

JavaScript

import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.lines
        .canAddCartLine
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyCartLinesChange({
                type: 'addCartLine',
                merchandiseId:
                  'gid://shopify/product/1234',
                quantity: 1,
              }),
          },
          'Add a free gift to your order',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'The products in your cart cannot be modified',
        ),
      );
    }
  },
);

Metafields

Description

Check `instructions.metafields.canSetCartMetafields` or `instructions.metafields.canDeleteCartMetafields` before calling `applyMetafieldChange()` if you are working with cart metafields.

React

import {
  Banner,
  Button,
  useApplyMetafieldChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyMetafieldChange =
    useApplyMetafieldChange();
  const instructions = useInstructions();

  if (
    instructions.metafields.canSetCartMetafields
  ) {
    return (
      <Button
        onPress={() =>
          applyMetafieldChange({
            type: 'updateCartMetafield',
            metafield: {
              namespace: 'loyalty',
              key: 'loyaltyPoints',
              value: '100',
              type: 'string',
            },
          })
        }
      >
        Apply 100 loyalty points
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty points are unavailable
      </Banner>
    );
  }
}

JavaScript

import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.metafields
        .canSetCartMetafields
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyMetafieldChange({
                type: 'updateCartMetafield',
                metafield: {
                  namespace: 'loyalty',
                  key: 'loyaltyPoints',
                  value: '100',
                  type: 'string',
                },
              }),
          },
          'Apply 100 loyalty points',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty points are unavailable',
        ),
      );
    }
  },
);

Notes

Description

Check `instructions.notes.canUpdateNote` before calling `applyNoteChange()`.

React

import {
  Banner,
  Button,
  useApplyNoteChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyNoteChange = useApplyNoteChange();
  const instructions = useInstructions();

  if (instructions.notes.canUpdateNote) {
    return (
      <Button
        onPress={() =>
          applyNoteChange({
            type: 'updateNote',
            note: 'Please include a free gift.',
          })
        }
      >
        Include a free gift with your order
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Free gifts cannot be added to this order
      </Banner>
    );
  }
}

JavaScript

import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.notes.canUpdateNote
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyNoteChange({
                type: 'updateNote',
                note: 'Please include a free gift.',
              }),
          },
          'Include a free gift with your order',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Free gifts cannot be added to this order',
        ),
      );
    }
  },
);