--- title: Discounts API description: The API for interacting with discounts. api_version: 2026-04 api_name: checkout-ui-extensions source_url: html: >- https://shopify.dev/docs/api/checkout-ui-extensions/latest/target-apis/checkout-apis/discounts-api md: >- https://shopify.dev/docs/api/checkout-ui-extensions/latest/target-apis/checkout-apis/discounts-api.md --- # Discounts API The API for interacting with discounts. ### Support Targets (31) ### Supported targets * purchase.​checkout.​actions.​render-before * purchase.​checkout.​block.​render * purchase.​checkout.​cart-line-item.​render-after * purchase.​checkout.​cart-line-list.​render-after * purchase.​checkout.​chat.​render * purchase.​checkout.​contact.​render-after * purchase.​checkout.​delivery-address.​render-after * purchase.​checkout.​delivery-address.​render-before * purchase.​checkout.​footer.​render-after * purchase.​checkout.​header.​render-after * purchase.​checkout.​payment-method-list.​render-after * purchase.​checkout.​payment-method-list.​render-before * purchase.​checkout.​pickup-location-list.​render-after * purchase.​checkout.​pickup-location-list.​render-before * purchase.​checkout.​pickup-location-option-item.​render-after * purchase.​checkout.​pickup-point-list.​render-after * purchase.​checkout.​pickup-point-list.​render-before * purchase.​checkout.​reductions.​render-after * purchase.​checkout.​reductions.​render-before * purchase.​checkout.​shipping-option-item.​details.​render * purchase.​checkout.​shipping-option-item.​render-after * purchase.​checkout.​shipping-option-list.​render-after * purchase.​checkout.​shipping-option-list.​render-before * purchase.​thank-you.​announcement.​render * purchase.​thank-you.​block.​render * purchase.​thank-you.​cart-line-item.​render-after * purchase.​thank-you.​cart-line-list.​render-after * purchase.​thank-you.​chat.​render * purchase.​thank-you.​customer-information.​render-after * purchase.​thank-you.​footer.​render-after * purchase.​thank-you.​header.​render-after ## StandardApi The base API object provided to `purchase` extension targets. * **discountAllocations** **SubscribableSignalLike\** **required** The discount allocations applied to the entire cart, including automatic discounts, code-based discounts, and custom discounts from [Shopify Functions](https://shopify.dev/docs/apps/build/functions). Each allocation indicates how much was discounted and how the discount was triggered. * **discountCodes** **SubscribableSignalLike\** **required** The discount codes currently applied to the checkout. The list is empty if no discount codes have been applied. Use `applyDiscountCodeChange()` to add or remove codes. ### SubscribableSignalLike Represents a reactive signal interface that provides both immediate value access and subscription-based updates. Enables real-time synchronization with changing data through the observer pattern. This interface extends \`ReadonlySignalLike\` with deprecated fields that are still supported for backwards compatibility. * current The current value of the signal. Equivalent to \`.value\`, accessing this property subscribes to changes when used in a reactive context. ```ts T ``` * destroy Cleans up the subscription and releases any resources held by this signal. After calling \`destroy()\`, the signal stops receiving updates from the main thread. ```ts () => Promise ``` * 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. ```ts (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. ```ts T ``` ### CartDiscountAllocation A discount allocation applied to the cart. Use the \`type\` property to determine how the discount was triggered: - \`CartCodeDiscountAllocation\` (\`type: 'code'\`): Triggered by a discount code the buyer entered. - \`CartAutomaticDiscountAllocation\` (\`type: 'automatic'\`): Applied automatically based on merchant-configured rules. - \`CartCustomDiscountAllocation\` (\`type: 'custom'\`): Applied by a \[Shopify Function]\(/docs/api/functions/latest/discount). ```ts CartCodeDiscountAllocation | CartAutomaticDiscountAllocation | CartCustomDiscountAllocation ``` ### CartCodeDiscountAllocation * code The discount code string that the buyer entered during checkout, such as \`"SAVE10"\` or \`"FREESHIP"\`. ```ts string ``` * discountedAmount The monetary value that was deducted from the line item or order total by this discount allocation. ```ts Money ``` * type Identifies this as a code-based discount, triggered by a discount code the buyer entered at checkout. ```ts 'code' ``` ### Money * amount The decimal amount of the price. For example, \`29.99\` represents twenty-nine dollars and ninety-nine cents. ```ts number ``` * currencyCode The three-letter currency code in \[ISO 4217]\(https://en.wikipedia.org/wiki/ISO\_4217) format. ```ts CurrencyCode ``` ### CurrencyCode ```ts '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' ``` ### CartAutomaticDiscountAllocation * discountedAmount The monetary value that was deducted from the line item or order total by this discount allocation. ```ts Money ``` * title The merchant-defined title of the automatic discount as displayed to the buyer, such as "Summer Sale 10% Off". ```ts string ``` * type Identifies this as an automatic discount, applied based on merchant-configured rules without a code. ```ts 'automatic' ``` ### CartCustomDiscountAllocation * discountedAmount The monetary value that was deducted from the line item or order total by this discount allocation. ```ts Money ``` * title The title of the custom discount, typically applied by a \[Shopify Function]\(/docs/api/functions/latest/discount). ```ts string ``` * type Identifies this as a custom discount applied by a \[Shopify Function]\(/docs/api/functions/latest/discount). ```ts 'custom' ``` ### CartDiscountCode * code The discount code string entered by the buyer during checkout or applied programmatically, such as \`"SAVE10"\` or \`"FREESHIP"\`. Use this to display which discount codes were applied. ```ts string ``` ## CheckoutApi The API object provided to `purchase.checkout` extension targets. * **applyDiscountCodeChange** **(change: DiscountCodeChange) => Promise\** **required** Adds or removes a discount code on the checkout. The returned promise resolves when the change has been applied by the server, and the [`discountCodes`](https://shopify.dev/docs/api/checkout-ui-extensions/2026-04/apis/discounts#standardapi-propertydetail-discountcodes) property updates with the new state. **Caution:** \> See \security considerations\ if your extension retrieves discount codes through a network call. **Note:** This method returns an error if the \cart instruction\ \\discounts.can\Update\Discount\Codes\\ is false, or the buyer is using an accelerated checkout method, such as Apple Pay or Google Pay. ### DiscountCodeChange The input for \`applyDiscountCodeChange()\`. Pass either a \`DiscountCodeAddChange\` (with \`type: 'addDiscountCode'\`) to apply a code or a \`DiscountCodeRemoveChange\` (with \`type: 'removeDiscountCode'\`) to remove it. ```ts DiscountCodeAddChange | DiscountCodeRemoveChange ``` ### DiscountCodeAddChange Applies a discount code to the checkout. Pass this to \`applyDiscountCodeChange()\` to add a code. * code The discount code to apply. Codes are case-insensitive. ```ts string ``` * type Identifies this as a discount code addition. Set this when creating a change to apply a discount code to the checkout. ```ts 'addDiscountCode' ``` ### DiscountCodeRemoveChange Removes a discount code from the checkout. Pass this to \`applyDiscountCodeChange()\` to remove a code. * code The discount code to remove. Codes are case-insensitive. ```ts string ``` * type Identifies this as a discount code removal. Set this when creating a change to remove a discount code from the checkout. ```ts 'removeDiscountCode' ``` ### DiscountCodeChangeResult The result of calling \`applyDiscountCodeChange()\`. Use the \`type\` property to determine whether the change succeeded or failed. ```ts DiscountCodeChangeResultSuccess | DiscountCodeChangeResultError ``` ### DiscountCodeChangeResultSuccess The result of a successful discount code change. The \`type\` property is \`'success'\`. * type Indicates that the discount code change was applied successfully. ```ts 'success' ``` ### DiscountCodeChangeResultError The result of a failed discount code change. Check the \`message\` property for details about what went wrong. * message A message that explains the error. This message is useful for debugging. It isn't localized and shouldn't be displayed to the buyer. ```ts string ``` * type Indicates that the discount code change couldn't be applied. Check the \`message\` property for details. ```ts 'error' ``` ## use​Apply​Discount​Code​Change() Returns a function to add or remove discount codes. ### Returns * **(change: DiscountCodeChange) => Promise\** ## use​Discount​Allocations() Returns the current discount allocations applied to the cart. ### Returns * **CartDiscountAllocation\[]** ## use​Discount​Codes() Returns the current discount codes applied to the cart. ### Returns * **CartDiscountCode\[]** ## Related [Reference - Targets](https://shopify.dev/docs/api/checkout-ui-extensions/targets) [Reference - Components](https://shopify.dev/docs/api/checkout-ui-extensions/components) [Reference - Configuration](https://shopify.dev/docs/api/checkout-ui-extensions/configuration) [Learn - Tutorials](https://shopify.dev/apps/checkout)