> For the complete documentation index, see [llms.txt](https://docs.mychips.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mychips.io/reward-handling/deduction-s2s-webhook-postback.md).

# Deduction S2S Webhook Postback

## **What is the Deduction S2S Webhook Postback?**

The Deduction S2S Webhook Postback is a server-to-server notification sent to publishers immediately after a deduction is confirmed.

***

## **Deduction Postback Content**

#### **Parameters**

You may use any of the standard postback parameters available in your **Dashboard → Settings** page.\
These parameters will be dynamically replaced at delivery time.

#### **Example of a Deduction Postback URL**

```
https://yourdomain.org/postback?clickid={click_id}&event_name={event_name}&payout={payout}&user_payout={user_payout}&user_id={user_id}&postback_id={postback_id}
```

Once configured, the publisher will receive **one deduction postback per deducted conversion**.

***

## **How Deductions Are Sent**

If a fraudulent user completes multiple conversion events, for example:

* Install – $0.50
* Level 5 – $1.00
* Level 10 – $2.00

…and the associated **click\_id** is deducted, the publisher will receive **three separate deduction postbacks**, each containing the corresponding `{payout}` value.

The `{payout}` in the postback is sent as a **positive value**.\
If your internal system requires a negative amount, you may prepend a minus sign directly in the URL configuration, e.g.:

```
payout=-{payout}
```

***

## Relationship with Anti-Fraud System

Our anti-fraud system blocks fraudulent conversions in real time (see **Rejected Postback** for more information).

In most cases, fraudulent conversions are identified and rejected immediately upon occurrence.

However, in some cases, more sophisticated fraud patterns may only be detected at the **post-install event level**.

When this happens:

* The related install and/or associated events will be retroactively deducted.
* A Deduction Postback will be sent for each affected conversion

***

## **How to Set Up a Deduction S2S Webhook Postback**

To configure a Deduction S2S Webhook Postback in your dashboard:

1. Go to **Settings**
2. Scroll to the **Additional Postback (optional)** section at the bottom-left

   <figure><img src="/files/1VpSaQ4I9OTIwbcoUVpS" alt=""><figcaption></figcaption></figure>
3. Select **Detuction** from the dropdown
4. Enter your full Deduction S2S Webhook Postback URL
5. Click **Add+**

Your URL will now be used to notify you of any deducted conversions.