> ## Documentation Index
> Fetch the complete documentation index at: https://docs.byzly.com/llms.txt
> Use this file to discover all available pages before exploring further.

# 3-D Secure in Embed

Any merchant using Embed automatically benefits from **Universal 3-D
Secure** once it has been [set up](/guides/features/3ds/setup) for a payment service.

<Frame caption="Example of a sandbox 3DS prompt">
  <img src="https://mintcdn.com/flexxbuy/39tfKGesfNHyX7HE/assets/images/3ds/3dsecure-prompt.png?fit=max&auto=format&n=39tfKGesfNHyX7HE&q=85&s=d54ddafab974aa46d19068d7f97d5bc2" alt="3-D Secure prompt" width="2894" height="1988" data-path="assets/images/3ds/3dsecure-prompt.png" />
</Frame>

Additionally, **Dynamic 3-D Secure** can be set up using Flow rules, allowing dynamic
skipping or forcing of 3-D Secure based on anti-fraud decisions, cart items, or any other transaction data.

## Buyers and billing details

To optimize 3-D Secure it is highly recommended to provide a buyer with billing details attached to Embed.

A buyer can be set up via the [`POST /buyers`](/reference/buyers/new-buyer)
API. The buyer can then be attached to Embed by using the `buyerId` or
`buyerExternalIdentifier` property. The buyer's name, email address, and billing
address are used to help reduce buyers being asked to complete a 3-D Secure
challenge.

<CodeGroup>
  ```js React theme={"system"}
  <Embed
    gr4vyId="example"
    amount={1299}
    curency="AUD"
    country="AU"
    buyerExternalIdentifier="user-1234"
    ...
  />
  ```

  ```js Node theme={"system"}
  gr4vy.setup({
     gr4vyId: "example",
     amount: 1299,
     currency: "AUD",
     country: "AU",
     buyerExternalIdentifier: "user-1234",
     ...
  });
  ```
</CodeGroup>

The system uses these billing details when contacting payment services, 3-D Secure Server, anti-fraud services, and more.

## Features

For every transaction, the system handles the following steps.

1. Detect if any Flow rule explicitly requires or skips 3-D Secure
2. Detect if the selected payment service for this transaction has 3-D Secure
   enabled
3. Detect if the card used in the transaction is enrolled for 3-D Secure
4. Handle the seamless frictionless 3-D Secure flow including the device finger
   printing
5. Handle the 3-D Secure challenge flow, where a buyer is directed in-page to
   their bank to approve the transaction

## Usage

To use 3-D Secure in Embed, [set up](/guides/features/3ds/setup)
3-D Secure on any of the enabled payment services. Once configured, Embed
handles all the user interactions.