
<aside class="note beta">
<h4>Developer preview</h4>

<p>This Function API is available only in the <a href="/docs/api/developer-previews#discounts-allocator-developer-preview">Discounts Allocator developer preview</a>.</p>
</aside>


## Extension targets

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

| Target | Output type | Description |
| ------ | ----------- | ----------- |
| `purchase.discounts-allocator.run` | [FunctionRunResult](#functionrunresult) | Outputs a list of discounts allocations 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 Shipping Discount API's `Input` object accepts, refer to [Input](/docs/api/functions/reference/discounts-allocator/graphql/input).


### Input Example

The following example shows an input query:


```graphql
query Input {
  discounts {
    id
    title
    code
    discountApplicationStrategy
    discountProposals
    {
      handle
      message
      valueType
      value
      targets {
        cartLineId
        quantity
      }
    }
    metafield(namespace: "testing-app-allocator", key: "single-discount-cap") {
      value
    }
  }
  presentmentCurrencyRate
  cart {
    lines {
      id
      quantity
      cost {
        amountPerQuantity {
          amount
          currencyCode
        }
      }
      merchandise {
        __typename
        ... on ProductVariant {
          id
          title
          product {
            id
            title
          }
        }
      }
    }
  }
  shop {
    metafield(namespace: "testing-app-allocator", key: "per-cart-cap") {
      value
    }
  }
}
```


The following example shows the resulting input to the query:


```json
{
  "discounts": [
    {
      "id": "gid:\/\/shopify\/DiscountNode\/13",
      "title": "CAPS",
      "code": "CAPS",
      "type": "CodePriceRule",
      "discountApplicationStrategy": "FIRST",
      "discountProposals": [
        {
          "handle": "8d783e44-14b9-4c2c-b431-2be340f1f4e1",
          "message": "CAPS",
          "valueType": "FIXED_AMOUNT",
          "value": "10.0",
          "targets": [
            {
              "cartLineId": "gid:\/\/shopify\/CartLine\/0",
              "quantity": 5
            }
          ]
        }
      ]
    }
  ],
  "presentmentCurrencyRate": "1.2706752",
  "cart": {
    "lines": [
      {
        "id": "gid:\/\/shopify\/CartLine\/0",
        "quantity": 5,
        "cost": {
          "amountPerQuantity": {
            "amount": "32.0",
            "currencyCode": "CAD"
          }
        },
        "merchandise": {
          "__typename": "ProductVariant",
          "id": "gid:\/\/shopify\/ProductVariant\/17",
          "title": "Shorts",
          "product": {
            "id": "gid:\/\/shopify\/Product\/9",
            "title": "Shorts"
          }
        }
      },
      {
        "id": "gid:\/\/shopify\/CartLine\/1",
        "quantity": 6,
        "cost": {
          "amountPerQuantity": {
            "amount": "20.0",
            "currencyCode": "CAD"
          }
        },
        "merchandise": {
          "__typename": "ProductVariant",
          "id": "gid:\/\/shopify\/ProductVariant\/17",
          "title": "Shorts",
          "product": {
            "id": "gid:\/\/shopify\/Product\/9",
            "title": "Shorts"
          }
        }
      }
    ]
  },
  "shop": {
    "metafield": null
  }
}
```


## FunctionRunResult

The [`FunctionRunResult`][FunctionRunResult] object is the expected [output](/docs/apps/build/functions/input-output#output)
for the `purchase.discounts-allocator.run` target.

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

### Result Example

The following function result includes two line discounts:


```json
{
  "lineDiscounts": [
    {
      "cartLineId": "gid://shopify/CartLine/0",
      "quantity": 5,
      "allocations": [
        {
          "discountProposalId": "8d783e44-14b9-4c2c-b431-2be340f1f4e1",
          "amount": 10.0
        }
      ]
    },
    {
      "cartLineId": "gid://shopify/CartLine/1",
      "quantity": 6,
      "allocations": [
        {
          "discountProposalId": "a7194cec-d807-4c46-9284-4fec7a3f5fbe",
          "amount": 24.0
        }
      ]
    }
  ],
  "displayableErrors": []
}
```