Cost
The API for interacting with the cost of a checkout.
Anchor to orderstatusapiOrderStatusApi
The API object provided to this and other customer-account.order-status extension targets.
- Anchor to costcostcostCartCostCartCostrequiredrequired
Details on the costs of the purchase for the buyer.
CartCost
- subtotalAmount
A `Money` value representing the subtotal value of the items in the cart at the current step of checkout.
SubscribableSignalLike<Money> - totalAmount
A `Money` value representing the minimum a buyer can expect to pay at the current step of checkout. This value excludes amounts yet to be negotiated. For example, the information step might not have delivery costs calculated.
SubscribableSignalLike<Money> - totalShippingAmount
A `Money` value representing the total shipping a buyer can expect to pay at the current step of checkout. This value includes shipping discounts. Returns undefined if shipping has not been negotiated yet, such as on the information step.
SubscribableSignalLike<Money | undefined> - totalTaxAmount
A `Money` value representing the total tax a buyer can expect to pay at the current step of checkout or the total tax included in product and shipping prices. Returns undefined if taxes are unavailable.
SubscribableSignalLike<Money | undefined>
export interface CartCost {
/**
* A `Money` value representing the subtotal value of the items in the cart at the current
* step of checkout.
*/
subtotalAmount: SubscribableSignalLike<Money>;
/**
* A `Money` value representing the total shipping a buyer can expect to pay at the current
* step of checkout. This value includes shipping discounts. Returns undefined if shipping
* has not been negotiated yet, such as on the information step.
*/
totalShippingAmount: SubscribableSignalLike<Money | undefined>;
/**
* A `Money` value representing the total tax a buyer can expect to pay at the current
* step of checkout or the total tax included in product and shipping prices. Returns
* undefined if taxes are unavailable.
*/
totalTaxAmount: SubscribableSignalLike<Money | undefined>;
/**
* A `Money` value representing the minimum a buyer can expect to pay at the current
* step of checkout. This value excludes amounts yet to be negotiated. For example,
* the information step might not have delivery costs calculated.
*/
totalAmount: SubscribableSignalLike<Money>;
}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
Subscribes to value changes and calls the provided function whenever the value updates. Returns an unsubscribe function to clean up the subscription. Use to automatically react to changes in the signal's value.
(fn: (value: T) => void) => () => void - value
The current value of the signal. This property provides immediate access to the current value without requiring subscription setup. Use for one-time value checks or initial setup.
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>;
}Money
- amount
The price amount.
number - currencyCode
The ISO 4217 format for the currency.
CurrencyCode
export interface Money {
/**
* The price amount.
*/
amount: number;
/**
* The ISO 4217 format for the currency.
* @example 'CAD' for Canadian dollar
*/
currencyCode: CurrencyCode;
}CurrencyCode
'AED' | 'AFN' | 'ALL' | 'AMD' | 'ANG' | 'AOA' | 'ARS' | 'AUD' | 'AWG' | 'AZN' | 'BAM' | 'BBD' | 'BDT' | 'BGN' | 'BHD' | 'BIF' | 'BMD' | 'BND' | 'BOB' | 'BOV' | 'BRL' | 'BSD' | 'BTN' | 'BWP' | 'BYN' | 'BZD' | 'CAD' | 'CDF' | 'CHE' | 'CHF' | 'CHW' | 'CLF' | 'CLP' | 'CNY' | 'COP' | 'COU' | 'CRC' | 'CUC' | 'CUP' | 'CVE' | 'CZK' | 'DJF' | 'DKK' | 'DOP' | 'DZD' | 'EGP' | 'ERN' | 'ETB' | 'EUR' | 'FJD' | 'FKP' | 'GBP' | 'GEL' | 'GHS' | 'GIP' | 'GMD' | 'GNF' | 'GTQ' | 'GYD' | 'HKD' | 'HNL' | 'HRK' | 'HTG' | 'HUF' | 'IDR' | 'ILS' | 'INR' | 'IQD' | 'IRR' | 'ISK' | 'JMD' | 'JOD' | 'JPY' | 'KES' | 'KGS' | 'KHR' | 'KMF' | 'KPW' | 'KRW' | 'KWD' | 'KYD' | 'KZT' | 'LAK' | 'LBP' | 'LKR' | 'LRD' | 'LSL' | 'LYD' | 'MAD' | 'MDL' | 'MGA' | 'MKD' | 'MMK' | 'MNT' | 'MOP' | 'MRU' | 'MUR' | 'MVR' | 'MWK' | 'MXN' | 'MXV' | 'MYR' | 'MZN' | 'NAD' | 'NGN' | 'NIO' | 'NOK' | 'NPR' | 'NZD' | 'OMR' | 'PAB' | 'PEN' | 'PGK' | 'PHP' | 'PKR' | 'PLN' | 'PYG' | 'QAR' | 'RON' | 'RSD' | 'RUB' | 'RWF' | 'SAR' | 'SBD' | 'SCR' | 'SDG' | 'SEK' | 'SGD' | 'SHP' | 'SLL' | 'SOS' | 'SRD' | 'SSP' | 'STN' | 'SVC' | 'SYP' | 'SZL' | 'THB' | 'TJS' | 'TMT' | 'TND' | 'TOP' | 'TRY' | 'TTD' | 'TWD' | 'TZS' | 'UAH' | 'UGX' | 'USD' | 'USN' | 'UYI' | 'UYU' | 'UYW' | 'UZS' | 'VES' | 'VND' | 'VUV' | 'WST' | 'XAF' | 'XAG' | 'XAU' | 'XBA' | 'XBB' | 'XBC' | 'XBD' | 'XCD' | 'XDR' | 'XOF' | 'XPD' | 'XPF' | 'XPT' | 'XSU' | 'XTS' | 'XUA' | 'XXX' | 'YER' | 'ZAR' | 'ZMW' | 'ZWL'