The Product Discount API enables you to create a new type of discount that is applied to particular product variants or cart lines. ## Extension targets The Product Discount API exposes the following [targets](/docs/apps/build/app-extensions/configure-app-extensions#targets): | Target | Output type | Description | | ------ | ----------- | ----------- | | `purchase.product-discount.run` | [FunctionRunResult](#functionrunresult) | Outputs the product-level discount that should be applied to the cart | ## Input The `RunInput` object is the complete schema that your function can receive as [input](/docs/apps/build/functions/input-output#input). For a list of fields that the Product Discount API's `Input` object accepts, refer to [Input](/docs/api/functions/reference/product-discounts/graphql/input). ### Input Example The following example shows an input query: <p> <div class="react-code-block" data-preset="file"> <div class="react-code-block-preload ThemeMode-dim"> <div class="react-code-block-preload-bar "></div> <div class="react-code-block-preload-placeholder-container"> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> </div> </div> <script data-option="filename" data-value="input.graphql"></script> <script type="text/plain" data-language="graphql"> RAW_MD_CONTENTquery Input { cart { lines { id attribute (key: "Engraving Name") { key value } merchandise { __typename ... on ProductVariant { id } } } } } END_RAW_MD_CONTENT</script> </div> </p> The following example shows the resulting input to the query: <p> <div class="react-code-block" data-preset="file"> <div class="react-code-block-preload ThemeMode-dim"> <div class="react-code-block-preload-bar "></div> <div class="react-code-block-preload-placeholder-container"> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> </div> </div> <script data-option="filename" data-value="input.json"></script> <script type="text/plain" data-language="json"> RAW_MD_CONTENT{ "cart": { "lines": [ { "id": "gid://shopify/CartLine/0", "attribute": null, "merchandise": { "id": "gid://shopify/ProductVariant/1" } }, { "id": "gid://shopify/CartLine/1", "attribute": { "key": "Engraving Name", "value": "Isabella Garcia" }, "merchandise": { "id": "gid://shopify/ProductVariant/1" } }, { "id": "gid://shopify/CartLine/2", "attribute": null, "merchandise": { "id": "gid://shopify/ProductVariant/2" } }, ] } } END_RAW_MD_CONTENT</script> </div> </p> ## FunctionRunResult The [`FunctionRunResult`][FunctionRunResult] object is the expected [output](/docs/apps/build/functions/input-output#output) for the `purchase.product-discount.run` target. ### Targets Each [`Discount`][Discount] returned in the output can have a collection of either [`ProductVariantTarget`][ProductVariantTarget]s or [`CartLineTarget`][CartLineTarget]s, but not both. This collection of [`Target`][Target] objects declare the cart line(s) to which the [`Discount`][Discount] will apply its value. A [`CartLineTarget`][CartLineTarget] specifies a specific cart line, whereas a [`ProductVariantTarget`][ProductVariantTarget] specifies a specific product variant, which could apply to one or more cart lines for that product variant. Additionally, each [`Target`][Target] has an optional `quantity` field which, when provided, limits the number of units to which the [`Discount`][Discount] will apply its value. Use [`CartLineTarget`][CartLineTarget]s when you want fine-grained control on specifically which cart lines will get discounted. Alternatively, use [`ProductVariantTarget`][ProductVariantTarget] if your discounting strategy is based on product variants, and you are not concerned which cart lines belonging to those product variants specifically get discounted. [Discount]: /docs/api/functions/reference/product-discounts/graphql/common-objects/discount [Target]: /docs/api/functions/reference/product-discounts/graphql/common-objects/target [ProductVariantTarget]: /docs/api/functions/reference/product-discounts/graphql/common-objects/productvarianttarget [CartLineTarget]: /docs/api/functions/reference/product-discounts/graphql/common-objects/cartlinetarget ### Output Example The following [`FunctionRunResult`][FunctionRunResult] includes a discount of 20% off for each cart line that has the targeted product variant ID: <p> <div class="react-code-block" data-preset="file"> <div class="react-code-block-preload ThemeMode-dim"> <div class="react-code-block-preload-bar "></div> <div class="react-code-block-preload-placeholder-container"> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> </div> </div> <script data-option="filename" data-value="output.json"></script> <script type="text/plain" data-language="json"> RAW_MD_CONTENT{ "discountApplicationStrategy": "FIRST", "discounts": [ { "value": { "percentage": { "value": "20.0" } }, "targets": [ { "productVariant": { "id": "gid:\/\/shopify\/ProductVariant\/1" } } ], "message": "20% off" } ] } END_RAW_MD_CONTENT</script> </div> </p> The following [`FunctionRunResult`][FunctionRunResult] includes a discount of $5 off for each cart line that has the targeted product variant ID, up to a maximum of 2 items total among those cart lines (and $10 off): <p> <div class="react-code-block" data-preset="file"> <div class="react-code-block-preload ThemeMode-dim"> <div class="react-code-block-preload-bar "></div> <div class="react-code-block-preload-placeholder-container"> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> </div> </div> <script data-option="filename" data-value="output.json"></script> <script type="text/plain" data-language="json"> RAW_MD_CONTENT{ "discountApplicationStrategy": "FIRST", "discounts": [ { "value": { "fixedAmount": { "amount": "5.0", "appliesToEachItem": true } }, "targets": [ { "productVariant": { "id": "gid:\/\/shopify\/ProductVariant\/1", "quantity": 2 } } ], "message": "$5 off shoes" } ] } END_RAW_MD_CONTENT</script> </div> </p> If a discount should only apply to cart lines that have a particular attribute, then target the cart lines instead. In the [example function input](/docs/api/functions/reference/product-discounts/graphql#input-example), there were two cart lines with the same product variant. For example, you can discount only the cart line with the `Engraving Name` attribute with following function output: <p> <div class="react-code-block" data-preset="file"> <div class="react-code-block-preload ThemeMode-dim"> <div class="react-code-block-preload-bar "></div> <div class="react-code-block-preload-placeholder-container"> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> <div class="react-code-block-preload-code-container"> <div class="react-code-block-preload-codeline-number"></div> <div class="react-code-block-preload-codeline"></div> </div> </div> </div> <script data-option="filename" data-value="output_2.json"></script> <script type="text/plain" data-language="json"> RAW_MD_CONTENT{ "discountApplicationStrategy": "FIRST", "discounts": [ { "value": { "percentage": { "value": "20.0" } }, "targets": [ { "cartLine": { "id": "gid:\/\/shopify\/CartLine\/1" } } ], "message": "20% off" } ] } END_RAW_MD_CONTENT</script> </div> </p> [FunctionRunResult]: /docs/api/functions/reference/product-discounts/graphql/functionrunresult