> For the complete documentation index, see [llms.txt](https://docs.rocketfuel.inc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rocketfuel.inc/developer-guides/api-reference/payins/utility-apis/exchange-payment/payable-amount.md).

# Payable amount

The RKFL provides an API to return the payable amount for the selected cryptocurrency. The cryptocurrency market is volatile and changes frequently. The RKFL backend system calculates the payable amount based on the current cryptocurrency rate.

Merchant websites should call this API whenever a shopper switches between cryptocurrencies. This API also returns a unit rate of the cryptocurrency.

{% hint style="info" %}
The merchant website should never cache the rate of the cryptocurrencies to use in the future because it changes frequently.
{% endhint %}

The below screenshot shows the payable amount in the bold text of "You Pay" and the crypto conversion rate just below.

![](/files/vCRCl709VqHtvLkvTJ4D)

<mark style="color:blue;">`GET`</mark> `/users/payable-amounts?invoice={uuid}&cc={cryptocurrency}`

![](/files/LzLdq4kvD9pupzLBp9ED) The value of "invoice", returns as "uuid" in the "POST /invoices"

![](/files/LzLdq4kvD9pupzLBp9ED) The value of "cryptocurrency" could be "btc/eth/ltc/xrp/etc"

#### Headers

| Name                                            | Type   | Description                     |
| ----------------------------------------------- | ------ | ------------------------------- |
| Authorization<mark style="color:red;">\*</mark> | String | "Bearer" + shopper access token |

{% tabs %}
{% tab title="200: OK Success" %}

```javascript
{
    "ok": true,
    "result": {
        "order_amount": 2,
        "order_currency": "2.00",
        "payable_amount": 31.47376371,
        "payable_currency": "DOGE",
        "conversion_rate_per_unit": "0.06507"
    }
}
```

{% endtab %}
{% endtabs %}


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