> ## Documentation Index
> Fetch the complete documentation index at: https://wpay-feat-edp-guide.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Anti-fraud

> Managing risk in your transaction flow

As part of Flow our system allows you to build rules
which use decisions and scores from anti-fraud services.

![Flow rule with an anti fraud decision](https://mintlify.s3-us-west-1.amazonaws.com/wpay-feat-edp-guide/assets/images/anti-fraud/flow-rule.png)

You can use these scores and decisions for card transactions
to evaluate the risk of a transaction and take
appropriate actions to, for example, force 3-D Secure, decline a transaction, or route to
a specific payment service.

## How does it work?

For every transaction, your anti-fraud service will only be called **once**.

When a request is made for a transaction, your active anti-fraud provider will only be called
once, assuming a rule is triggered for which an anti-fraud score or decision is the condition.
This feature will prevent incurring any extra cost by calling your anti-fraud service multiple times,
or calling your service unnecessarily if the rule is not triggered.