The Shipping Discount API enables you to create a new type of discount that is applied to one or more shipping rates at checkout.

## Extension targets

The Shipping Discount API exposes the following [targets](/docs/apps/build/app-extensions/configure-app-extensions#targets):

| Target | Output type | Description |
| ------ | ----------- | ----------- |
| `purchase.shipping-discount.run` | [FunctionRunResult](#functionrunresult) | Outputs the shipping rate discounts |

## 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 Shipping Discount API's `Input` object accepts, refer to [Input](/docs/api/functions/reference/shipping-discounts/graphql/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>
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<div class="react-code-block-preload-codeline-number"></div>
<div class="react-code-block-preload-codeline"></div>
</div>
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<div class="react-code-block-preload-codeline-number"></div>
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</div>
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<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>
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<div class="react-code-block-preload-code-container">
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</div>
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</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="src/run.graphql"></script>

<script type="text/plain" data-language="graphql">
RAW_MD_CONTENTquery Input {
  cart {
    deliveryGroups {
      id
      deliveryOptions {
        handle
        title
      }
      selectedDeliveryOption {
        handle
        title
      }
    }
  }
}
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>
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<div class="react-code-block-preload-codeline-number"></div>
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</div>
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</div>
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<div class="react-code-block-preload-codeline"></div>
</div>
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<div class="react-code-block-preload-codeline-number"></div>
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</div>
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</div>
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<div class="react-code-block-preload-codeline-number"></div>
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</div>
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</div>
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</div>
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</div>
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<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": {
    "deliveryGroups": [
      {
        "id": "gid://shopify/CartDeliveryGroup/0",
        "deliveryOptions": [
          {
            "handle": "handle0-standard",
            "title": "Standard"
          },
          {
            "handle": "handle1-express",
            "title": "Express"
          }
        ]
      }
    ]
  }
}
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.shipping-discount.run` target.

Unlike other discount Function APIs, the Shipping Discount Functions API  [`FunctionRunResult`][FunctionRunResult]
object doesn't have a `DiscountApplicationStrategy` field. Instead, all discounts included in the
[`FunctionRunResult`][FunctionRunResult] are applied, as long as each of these discounts target the same shipping rate
no more than once, whether by targeting it specifically using [`DeliveryOptionTarget`](/docs/api/functions/reference/shipping-discounts/graphql/common-objects/deliveryoptiontarget)
or generally using [`DeliveryGroupTarget`](/docs/api/functions/reference/shipping-discounts/graphql/common-objects/deliverygrouptarget).
The [`FunctionRunResult`][FunctionRunResult] is ignored if individual shipping rates are targeted more than once.

[FunctionRunResult]: /docs/api/functions/reference/shipping-discounts/graphql/functionrunresult

### Example

The following function result includes one free shipping discount for the Standard shipping rate:

<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>
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<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">
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</div>
<div class="react-code-block-preload-code-container">
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</div>
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<div class="react-code-block-preload-codeline"></div>
</div>
<div class="react-code-block-preload-code-container">
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</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">
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</div>
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<div class="react-code-block-preload-codeline-number"></div>
<div class="react-code-block-preload-codeline"></div>
</div>
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<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{
  "discounts": [
    {
      "value": {
        "percentage": {
          "value": "100"
        }
      },
      "targets": [
        {
          "deliveryOption": {
            "handle": "handle0-standard"
          }
        }
      ],
      "message": "100% off Standard shipping"
    }
  ]
}
END_RAW_MD_CONTENT</script>

</div>
</p>