> For the complete documentation index, see [llms.txt](https://docs.digitalriver.com/digital-river-api/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.digitalriver.com/digital-river-api/payments/payment-integrations-1/drop-in/how-drop-in-works.md).

# How Drop-in payments work

When customers initiate checkout, the client-server sends a [create checkout request](https://docs.digitalriver.com/digital-river-api-reference/2021-12-13/checkouts#checkouts-1) to Digital River, and Digital River returns a [checkout](https://docs.digitalriver.com/digital-river-api-reference/2021-12-13/checkouts). The client-server then sends the [payment session](/digital-river-api/integration-options/checkouts/creating-checkouts/payment-sessions.md) identifier to the client's front end. The client front end uses this payment session identifier and other configuration settings to instantiate Drop-in payments. Once instantiated, transaction applicable payment methods are displayed in a modal window. When customers select a payment method and provide their payment details, an [`onSuccess`](/digital-river-api/payments/payment-integrations-1/drop-in/drop-in-integration-guide.md#onsuccess) event is triggered, and the [source](https://docs.digitalriver.com/digital-river-api-reference/2021-12-13/sources) identifier is sent to the client-server. The client-server uses that identifier to associate the source with [checkouts ](https://docs.digitalriver.com/digital-river-api-reference/2021-12-13/checkouts)and/or [customers](https://docs.digitalriver.com/digital-river-api-reference/2021-12-13/customers).

{% hint style="info" %}
To better understand how the process works, check out the [interactive Drop-in builder](https://drapi.io/drop-in-builder/).
{% endhint %}

{% embed url="<https://player.vimeo.com/video/683888702?h=2b803b92e0>" %}

![](/files/CKkEECgQfbCJW41BwjHx)

## Drop-in payments flows

The following table is meant to help you better understand your embed options for Drop-in payments:

| Collect payment as part of a checkout flow                                                       | No  | See [Using Drop-in payments within your checkout flow](/digital-river-api/payments/payment-integrations-1/drop-in/drop-in-integration-guide.md#using-drop-in-within-your-checkout-flow).                                    |
| ------------------------------------------------------------------------------------------------ | --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Offer customers the ability to store payment methods                                             | Yes | See [Allowing the customer to save their payment credentials](/digital-river-api/payments/payment-integrations-1/drop-in/drop-in-integration-guide.md#optional-allowing-the-customer-to-save-their-payment-credentials).    |
| Collect payment data from a page where customers manage or add payment methods to their accounts | Yes | See [Using Drop-in to collect payment details on a My Account page](/digital-river-api/payments/payment-integrations-1/drop-in/drop-in-integration-guide.md#using-drop-in-to-collect-payment-details-on-a-my-account-page). |