## Overview

If a user is a Decision API client (firing impression and click urls server-to-server) the pixel method does not work because Kevel is not dropping a cookie at time of ad request. Instead, the user needs to make a server-to-server call when the conversion event is triggered.

> 📘
>
> ### Note  
>
> To enable server conversion tracking in the Kevel UI, go to the [Flight's General Settings](https://dev.kevel.co/v1.0/docs/flights#section-general-setting-fields) page and click the **Track Conversions** checkbox next to Rate and Price.
>
> To enable server conversion tracking using the Kevel API, set the `IsTrackingConversions` value to `TRUE`.

## Enabling If Conversion Event is On Your Site

1. Add the macro of `?conv=%conversionid%` to the Click URL when [Setting up a Creative](https://dev.kevel.co/docs/creatives#section-creative-details-settings), such as, `http://www.nike.com/?conv=%conversionid%`. This generates a GUID like `http://www.nike.com/?conv=1231242.`

2. In the [Decision API Response](https://dev.kevel.co/v1.0/reference/response), the GUID will be included in the `clickURL` field. Save this GUID and keep it tied to the user. Options include:

a. Storing it on a cookie.

b. Tying it to a persistent ID and storing in a database.

c. Persisting the `conv=GUID` in the URL.

3. Once the user has made a conversion, the user needs to use the GET API call for the endpoint shown below, and then append the GUID from the original click. Because the GUID is tied to a specific ad, the endpoint is pinged, and Kevel registers a conversion for that ad and adds it to reporting. The GUID does not have an expiration date.

The endpoint is: `https://e-{networkId}.adzerk.net/conv/{GUID}`

> 📘
>
> ### Note  
>
> The conversion macro does not unfurl until after the click is called, therefore, a user is unable to retrieve the conversionId from the response itself - only from the clickURL.

## Enabling If Conversion Event is On Advertiser's Site

Server-to-server conversion tracking works the same as above, however, this requires an advertiser to perform steps 2 and 3 in their system. This is not a turn-key setup for the advertiser.

## Additional Parameters

Some additional parameters that can be appended to the endpoint are:

- `override`: replaces the revenue value of the conversion (f.e. appending `?override=1.23` would set the revenue to $1.23)
- `additional`: adds the specified value to the original revenue value of the conversion (f.e. appending `?additional=1.23` would add $1.23 to the original revenue for the conversion)

Conversion Endpoint

```curl
curl -g https://e-1234.adzerk.net/conv/1231221?override=1.23
```