Choose a version:

Metafields

Requires access to protected customer data for some properties.

The API for interacting with metafields.

Anchor to standardapiStandardApi

The base API object provided to purchase extension targets.

Anchor to appMetafields appMetafields <[]> required: The metafields requested in the shopify.extension.toml file. These metafields are updated when there's a change in the merchandise items being purchased by the customer.

App owned metafields are supported and are returned using the $app format. The fully qualified reserved namespace format such as app--{your-app-id}[--{optional-namespace}] is not supported. See app owned metafields for more information.

Requires access to protected customer data.
Anchor to metafields metafields <[]> required: The metafields that apply to the current checkout.

Metafields are stored locally on the client and are applied to the order object after the checkout completes.

These metafields are shared by all extensions running on checkout, and persist for as long as the customer is working on this checkout.

Once the order is created, you can query these metafields using the GraphQL Admin API

Tip
> Cart metafields are only available on carts created via the Storefront API version 2023-04 or later.

SubscribableSignalLike

Represents a read-only value managed on the main thread that an extension can subscribe to. Example: Checkout uses this to manage the state of an object and communicate state changes to extensions running in a sandboxed web worker. This interface is compatible with [Preact's ReadonlySignal](https://github.com/preactjs/signals/blob/a023a132a81bd4ba4a0bebb8cbbeffbd8c8bbafc/packages/core/src/index.ts#L700-L709). Some fields are deprecated but still supported for backwards compatibility. In version 2025-10, [`StatefulRemoteSubscribable`](https://github.com/Shopify/remote-dom/blob/03929aa8418a89d41d294005f219837582718df8/packages/async-subscription/src/types.ts#L17) was replaced with `ReadonlySignalLike`. Checkout will remove the old fields some time in the future.

current
```
T
```
destroy
```
() => Promise<void>
```
subscribe
```
(fn: (value: T) => void) => () => void
```
value
```
T
```

export interface SubscribableSignalLike<T> extends ReadonlySignalLike<T> {
  /**
   * @deprecated Use `.value` instead.
   */
  readonly current: T;
  /**
   * @deprecated No longer needed. Use Preact Signal management instead.
   */
  destroy(): Promise<void>;
}

AppMetafieldEntry

A metafield associated with the shop or a resource on the checkout.

metafield
The metadata information.
```
AppMetafield
```
target
The target that is associated to the metadata. {% include /apps/checkout/privacy-icon.md %} Requires access to [protected customer data](/docs/apps/store/data-protection/protected-customer-data) when the type is `customer`, `company` or `companyLocation`.
```
AppMetafieldEntryTarget
```

export interface AppMetafieldEntry {
  /**
   * The target that is associated to the metadata.
   *
   * {% include /apps/checkout/privacy-icon.md %} Requires access to [protected customer data](/docs/apps/store/data-protection/protected-customer-data) when the type is `customer`, `company` or `companyLocation`.
   */
  target: AppMetafieldEntryTarget;

  /** The metadata information. */
  metafield: AppMetafield;
}

AppMetafield

Represents a custom metadata attached to a resource.

key
The key name of a metafield.
```
string
```
namespace
The namespace for a metafield. App owned metafield namespaces are returned using the `$app` format. See [app owned metafields](/docs/apps/build/custom-data/ownership#reserved-prefixes) for more information.
```
string
```
type
The metafield's type name.
```
string
```
value
The value of a metafield.
```
string
```

valueType

The metafield’s information type.

'boolean' | 'float' | 'integer' | 'json_string' | 'string'

export interface AppMetafield {
  /** The key name of a metafield. */
  key: string;

  /**
   * The namespace for a metafield.
   *
   * App owned metafield namespaces are returned using the `$app` format. See [app owned metafields](/docs/apps/build/custom-data/ownership#reserved-prefixes) for more information.
   */
  namespace: string;

  /** The value of a metafield. */
  value: string;

  /** The metafield’s information type. */
  valueType: 'boolean' | 'float' | 'integer' | 'json_string' | 'string';

  /** The metafield's type name. */
  type: string;
}

AppMetafieldEntryTarget

The metafield owner.

id
The numeric owner ID that is associated with the metafield.
```
string
```
type
The type of the metafield owner. {% include /apps/checkout/privacy-icon.md %} Requires access to [protected customer data](/docs/apps/store/data-protection/protected-customer-data) when the type is `customer`, `company` or `companyLocation`.
```
| 'customer'
    | 'product'
    | 'shop'
    | 'shopUser'
    | 'variant'
    | 'company'
    | 'companyLocation'
    | 'cart'
```

export interface AppMetafieldEntryTarget {
  /**
   * The type of the metafield owner.
   *
   * {% include /apps/checkout/privacy-icon.md %} Requires access to [protected customer data](/docs/apps/store/data-protection/protected-customer-data) when the type is `customer`, `company` or `companyLocation`.
   */
  type:
    | 'customer'
    | 'product'
    | 'shop'
    | 'shopUser'
    | 'variant'
    | 'company'
    | 'companyLocation'
    | 'cart';

  /** The numeric owner ID that is associated with the metafield. */
  id: string;
}

Metafield

Metadata associated with the checkout.

key
The name of the metafield. It must be between 3 and 30 characters in length (inclusive).
```
string
```
namespace
A container for a set of metafields. You need to define a custom namespace for your metafields to distinguish them from the metafields used by other apps. This must be between 2 and 20 characters in length (inclusive).
```
string
```
value
The information to be stored as metadata. Always stored as a string, regardless of the metafield's type.
```
string | number
```
valueType
The metafield’s information type.
```
'integer' | 'string' | 'json_string'
```

export interface Metafield {
  /**
   * The name of the metafield. It must be between 3 and 30 characters in
   * length (inclusive).
   */
  key: string;

  /**
   * A container for a set of metafields. You need to define a custom
   * namespace for your metafields to distinguish them from the metafields
   * used by other apps. This must be between 2 and 20 characters in length (inclusive).
   */
  namespace: string;

  /**
   * The information to be stored as metadata. Always stored as a string, regardless of the metafield's type.
   */
  value: string | number;

  /** The metafield’s information type. */
  valueType: 'integer' | 'string' | 'json_string';
}

Anchor to useAppMetafields
useAppMetafields(
filters
)

Returns the metafields configured with shopify.extension.toml.

Anchor to useAppMetafields-parametersParameters

Anchor to filters filters Default: {}

Anchor to useAppMetafields-returnsReturns

[]

AppMetafieldFilters

id
```
string
```
key
```
string
```
namespace
To filter for app owned metafields, use the `$app` format. The fully qualified reserved namespace format such as `app--{your-app-id}[--{optional-namespace}]` is not supported. See [app owned metafields](/docs/apps/build/custom-data/ownership#reserved-prefixes) for more information.
```
string
```

type

'customer' | 'product' | 'shop' | 'shopUser' | 'variant' | 'company' | 'companyLocation' | 'cart'

interface AppMetafieldFilters {
  id?: AppMetafieldEntryTarget['id'];
  type?: AppMetafieldEntryTarget['type'];
  /**
   * To filter for app owned metafields, use the `$app` format. The fully qualified reserved namespace format such as `app--{your-app-id}[--{optional-namespace}]` is not supported.
   *
   * See [app owned metafields](/docs/apps/build/custom-data/ownership#reserved-prefixes) for more information.
   */
  namespace?: Metafield['namespace'];
  key?: Metafield['key'];
}

AppMetafieldEntry

A metafield associated with the shop or a resource on the checkout.

metafield
The metadata information.
```
AppMetafield
```
target
The target that is associated to the metadata. {% include /apps/checkout/privacy-icon.md %} Requires access to [protected customer data](/docs/apps/store/data-protection/protected-customer-data) when the type is `customer`, `company` or `companyLocation`.
```
AppMetafieldEntryTarget
```

export interface AppMetafieldEntry {
  /**
   * The target that is associated to the metadata.
   *
   * {% include /apps/checkout/privacy-icon.md %} Requires access to [protected customer data](/docs/apps/store/data-protection/protected-customer-data) when the type is `customer`, `company` or `companyLocation`.
   */
  target: AppMetafieldEntryTarget;

  /** The metadata information. */
  metafield: AppMetafield;
}

AppMetafield

Represents a custom metadata attached to a resource.

key
The key name of a metafield.
```
string
```
namespace
The namespace for a metafield. App owned metafield namespaces are returned using the `$app` format. See [app owned metafields](/docs/apps/build/custom-data/ownership#reserved-prefixes) for more information.
```
string
```
type
The metafield's type name.
```
string
```
value
The value of a metafield.
```
string
```

valueType

The metafield’s information type.

'boolean' | 'float' | 'integer' | 'json_string' | 'string'

export interface AppMetafield {
  /** The key name of a metafield. */
  key: string;

  /**
   * The namespace for a metafield.
   *
   * App owned metafield namespaces are returned using the `$app` format. See [app owned metafields](/docs/apps/build/custom-data/ownership#reserved-prefixes) for more information.
   */
  namespace: string;

  /** The value of a metafield. */
  value: string;

  /** The metafield’s information type. */
  valueType: 'boolean' | 'float' | 'integer' | 'json_string' | 'string';

  /** The metafield's type name. */
  type: string;
}

AppMetafieldEntryTarget

The metafield owner.

id
The numeric owner ID that is associated with the metafield.
```
string
```
type
The type of the metafield owner. {% include /apps/checkout/privacy-icon.md %} Requires access to [protected customer data](/docs/apps/store/data-protection/protected-customer-data) when the type is `customer`, `company` or `companyLocation`.
```
| 'customer'
    | 'product'
    | 'shop'
    | 'shopUser'
    | 'variant'
    | 'company'
    | 'companyLocation'
    | 'cart'
```

export interface AppMetafieldEntryTarget {
  /**
   * The type of the metafield owner.
   *
   * {% include /apps/checkout/privacy-icon.md %} Requires access to [protected customer data](/docs/apps/store/data-protection/protected-customer-data) when the type is `customer`, `company` or `companyLocation`.
   */
  type:
    | 'customer'
    | 'product'
    | 'shop'
    | 'shopUser'
    | 'variant'
    | 'company'
    | 'companyLocation'
    | 'cart';

  /** The numeric owner ID that is associated with the metafield. */
  id: string;
}

Anchor to useMetafield
useMetafield(
filters
)

Returns a single filtered Metafield or undefined.

Anchor to useMetafield-parametersParameters

Anchor to filters filters required

Anchor to useMetafield-returnsReturns

| undefined

MetafieldFilter

key
```
string
```
namespace
```
string
```

interface MetafieldFilter {
  namespace: string;
  key: string;
}

Metafield

Metadata associated with the checkout.

key
The name of the metafield. It must be between 3 and 30 characters in length (inclusive).
```
string
```
namespace
A container for a set of metafields. You need to define a custom namespace for your metafields to distinguish them from the metafields used by other apps. This must be between 2 and 20 characters in length (inclusive).
```
string
```
value
The information to be stored as metadata. Always stored as a string, regardless of the metafield's type.
```
string | number
```
valueType
The metafield’s information type.
```
'integer' | 'string' | 'json_string'
```

export interface Metafield {
  /**
   * The name of the metafield. It must be between 3 and 30 characters in
   * length (inclusive).
   */
  key: string;

  /**
   * A container for a set of metafields. You need to define a custom
   * namespace for your metafields to distinguish them from the metafields
   * used by other apps. This must be between 2 and 20 characters in length (inclusive).
   */
  namespace: string;

  /**
   * The information to be stored as metadata. Always stored as a string, regardless of the metafield's type.
   */
  value: string | number;

  /** The metafield’s information type. */
  valueType: 'integer' | 'string' | 'json_string';
}

Anchor to useMetafields
useMetafields(
filters
)

Returns the current array of metafields applied to the checkout. You can optionally filter the list.

Anchor to useMetafields-parametersParameters

Anchor to filters filters

Anchor to useMetafields-returnsReturns

[]

MetafieldsFilters

key
```
string
```
namespace
```
string
```

interface MetafieldsFilters {
  namespace: string;
  key?: string;
}

Metafield

Metadata associated with the checkout.

key
The name of the metafield. It must be between 3 and 30 characters in length (inclusive).
```
string
```
namespace
A container for a set of metafields. You need to define a custom namespace for your metafields to distinguish them from the metafields used by other apps. This must be between 2 and 20 characters in length (inclusive).
```
string
```
value
The information to be stored as metadata. Always stored as a string, regardless of the metafield's type.
```
string | number
```
valueType
The metafield’s information type.
```
'integer' | 'string' | 'json_string'
```

export interface Metafield {
  /**
   * The name of the metafield. It must be between 3 and 30 characters in
   * length (inclusive).
   */
  key: string;

  /**
   * A container for a set of metafields. You need to define a custom
   * namespace for your metafields to distinguish them from the metafields
   * used by other apps. This must be between 2 and 20 characters in length (inclusive).
   */
  namespace: string;

  /**
   * The information to be stored as metadata. Always stored as a string, regardless of the metafield's type.
   */
  value: string | number;

  /** The metafield’s information type. */
  valueType: 'integer' | 'string' | 'json_string';
}

Anchor to checkoutapiCheckoutApi

The API object provided to purchase.checkout extension targets.

Anchor to applyMetafieldChange applyMetafieldChange (change: ) => Promise<> required: Performs an update on a piece of metadata attached to the checkout. If successful, this mutation results in an update to the value retrieved through the metafields property.

Note
This method will return an error if the cart instruction metafields.canSetCartMetafields is false, or the buyer is using an accelerated checkout method, such as Apple Pay or Google Pay.

MetafieldChange

MetafieldRemoveChange | MetafieldUpdateChange | MetafieldRemoveCartChange | MetafieldUpdateCartChange

MetafieldRemoveChange

Removes a metafield.

key
The name of the metafield to remove.
```
string
```
namespace
The namespace of the metafield to remove.
```
string
```
type
The type of the `MetafieldRemoveChange` API.
```
'removeMetafield'
```

export interface MetafieldRemoveChange {
  /**
   * The type of the `MetafieldRemoveChange` API.
   */
  type: 'removeMetafield';

  /**
   * The name of the metafield to remove.
   */
  key: string;

  /**
   * The namespace of the metafield to remove.
   */
  namespace: string;
}

MetafieldUpdateChange

Updates a metafield. If a metafield with the provided key and namespace does not already exist, it gets created.

key
The name of the metafield to update.
```
string
```
namespace
The namespace of the metafield to add.
```
string
```
type
The type of the `MetafieldUpdateChange` API.
```
'updateMetafield'
```
value
The new information to store in the metafield.
```
string | number
```
valueType
The metafield’s information type.
```
'integer' | 'string' | 'json_string'
```

export interface MetafieldUpdateChange {
  /**
   * The type of the `MetafieldUpdateChange` API.
   */
  type: 'updateMetafield';

  /** The name of the metafield to update. */
  key: string;

  /** The namespace of the metafield to add. */
  namespace: string;

  /** The new information to store in the metafield. */
  value: string | number;

  /**
   * The metafield’s information type.
   */
  valueType: 'integer' | 'string' | 'json_string';
}

MetafieldRemoveCartChange

Removes a cart metafield.

key
The name of the metafield to remove.
```
string
```
namespace
The namespace of the metafield to remove.
```
string
```
type
The type of the `MetafieldRemoveChange` API.
```
'removeCartMetafield'
```

export interface MetafieldRemoveCartChange {
  /**
   * The type of the `MetafieldRemoveChange` API.
   */
  type: 'removeCartMetafield';

  /**
   * The name of the metafield to remove.
   */
  key: string;

  /**
   * The namespace of the metafield to remove.
   */
  namespace?: string;
}

MetafieldUpdateCartChange

Updates a cart metafield. If a metafield with the provided key and namespace does not already exist, it gets created.

metafield

{ key: string; namespace?: string; value: string; type: string; }

type
The type of the `MetafieldUpdateChange` API.
```
'updateCartMetafield'
```

export interface MetafieldUpdateCartChange {
  /**
   * The type of the `MetafieldUpdateChange` API.
   */
  type: 'updateCartMetafield';

  metafield: {
    /** The name of the metafield to update. */
    key: string;

    /** The namespace of the metafield to add. */
    namespace?: string;

    /** The new information to store in the metafield. */
    value: string;

    /**
     * The metafield’s information type.
     * See the [`metafields documentation`](/docs/apps/custom-data/metafields/types) for a list of supported types.
     */
    type: string;
  };
}

MetafieldChangeResult

MetafieldChangeResultSuccess | MetafieldChangeResultError

MetafieldChangeResultSuccess

type
The type of the `MetafieldChangeResultSuccess` API.
```
'success'
```

export interface MetafieldChangeResultSuccess {
  /**
   * The type of the `MetafieldChangeResultSuccess` API.
   */
  type: 'success';
}

MetafieldChangeResultError

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.
```
string
```
type
The type of the `MetafieldChangeResultError` API.
```
'error'
```

export interface MetafieldChangeResultError {
  /**
   * The type of the `MetafieldChangeResultError` API.
   */
  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;
}

Anchor to useApplyMetafieldsChange
useApplyMetafieldsChange()

Returns a function to mutate the metafields property of the checkout.

Anchor to useApplyMetafieldsChange-returnsReturns

(change: ) => Promise<>

MetafieldChange

MetafieldRemoveChange | MetafieldUpdateChange | MetafieldRemoveCartChange | MetafieldUpdateCartChange

MetafieldRemoveChange

Removes a metafield.

key
The name of the metafield to remove.
```
string
```
namespace
The namespace of the metafield to remove.
```
string
```
type
The type of the `MetafieldRemoveChange` API.
```
'removeMetafield'
```

export interface MetafieldRemoveChange {
  /**
   * The type of the `MetafieldRemoveChange` API.
   */
  type: 'removeMetafield';

  /**
   * The name of the metafield to remove.
   */
  key: string;

  /**
   * The namespace of the metafield to remove.
   */
  namespace: string;
}

MetafieldUpdateChange

Updates a metafield. If a metafield with the provided key and namespace does not already exist, it gets created.

key
The name of the metafield to update.
```
string
```
namespace
The namespace of the metafield to add.
```
string
```
type
The type of the `MetafieldUpdateChange` API.
```
'updateMetafield'
```
value
The new information to store in the metafield.
```
string | number
```
valueType
The metafield’s information type.
```
'integer' | 'string' | 'json_string'
```

export interface MetafieldUpdateChange {
  /**
   * The type of the `MetafieldUpdateChange` API.
   */
  type: 'updateMetafield';

  /** The name of the metafield to update. */
  key: string;

  /** The namespace of the metafield to add. */
  namespace: string;

  /** The new information to store in the metafield. */
  value: string | number;

  /**
   * The metafield’s information type.
   */
  valueType: 'integer' | 'string' | 'json_string';
}

MetafieldRemoveCartChange

Removes a cart metafield.

key
The name of the metafield to remove.
```
string
```
namespace
The namespace of the metafield to remove.
```
string
```
type
The type of the `MetafieldRemoveChange` API.
```
'removeCartMetafield'
```

export interface MetafieldRemoveCartChange {
  /**
   * The type of the `MetafieldRemoveChange` API.
   */
  type: 'removeCartMetafield';

  /**
   * The name of the metafield to remove.
   */
  key: string;

  /**
   * The namespace of the metafield to remove.
   */
  namespace?: string;
}

MetafieldUpdateCartChange

Updates a cart metafield. If a metafield with the provided key and namespace does not already exist, it gets created.

metafield

{ key: string; namespace?: string; value: string; type: string; }

type
The type of the `MetafieldUpdateChange` API.
```
'updateCartMetafield'
```

export interface MetafieldUpdateCartChange {
  /**
   * The type of the `MetafieldUpdateChange` API.
   */
  type: 'updateCartMetafield';

  metafield: {
    /** The name of the metafield to update. */
    key: string;

    /** The namespace of the metafield to add. */
    namespace?: string;

    /** The new information to store in the metafield. */
    value: string;

    /**
     * The metafield’s information type.
     * See the [`metafields documentation`](/docs/apps/custom-data/metafields/types) for a list of supported types.
     */
    type: string;
  };
}

MetafieldChangeResult

MetafieldChangeResultSuccess | MetafieldChangeResultError

MetafieldChangeResultSuccess

type
The type of the `MetafieldChangeResultSuccess` API.
```
'success'
```

export interface MetafieldChangeResultSuccess {
  /**
   * The type of the `MetafieldChangeResultSuccess` API.
   */
  type: 'success';
}

MetafieldChangeResultError

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.
```
string
```
type
The type of the `MetafieldChangeResultError` API.
```
'error'
```

export interface MetafieldChangeResultError {
  /**
   * The type of the `MetafieldChangeResultError` API.
   */
  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;
}

Examples

import '@shopify/ui-extensions/preact';

import {render} from 'preact';

import {useAppMetafields} from '@shopify/ui-extensions/checkout/preact';

export default function extension() {

render(<Extension />, document.body);

}

function Extension() {

const [energyRating] = useAppMetafields({

namespace: '$app',

key: 'energy-rating',

type: 'product',

}).filter(

(entry) =>

entry.target.id ===

shopify.target.value.merchandise.id,

);

return (

energyRating && (

<s-text>

Energy rating:{' '}

{energyRating.metafield.value}

</s-text>

)

);

}

Examples

Use app owned metafields

Description

Use the `$app` format to request metafields that are owned by your app in your extension configuration file. Your app exclusively controls structure, data, permissions and optional features for this type of metafield. See [app owned metafields](/docs/apps/build/custom-data/ownership#reserved-prefixes) for more information.

Preact

import '@shopify/ui-extensions/preact';
import {render} from 'preact';

import {useAppMetafields} from '@shopify/ui-extensions/checkout/preact';

export default function extension() {
  render(<Extension />, document.body);
}

function Extension() {
  const [energyRating] = useAppMetafields({
    namespace: '$app',
    key: 'energy-rating',
    type: 'product',
  }).filter(
    (entry) =>
      entry.target.id ===
      shopify.target.value.merchandise.id,
  );

  return (
    energyRating && (
      <s-text>
        Energy rating:{' '}
        {energyRating.metafield.value}
      </s-text>
    )
  );
}

TOML

# other configs omitted

[[extensions.metafields]]
# tip: you can use $app:some-namespace to further segment your data
namespace = "$app"
key = "energy-rating"