# Authorized Sellers for Apps (app-ads.txt)

As an extension of its [Authorized Digital Sellers (`ads.txt`)](https://iabtechlab.com/wp-content/uploads/2022/04/Ads.txt-1.1.pdf) framework, the Interactive Advertising Bureau (IAB) provides the [Authorized Sellers for Apps (`app-ads.txt`)](https://iabtechlab.com/wp-content/uploads/2019/03/app-ads.txt-v1.0-final-.pdf) framework that defines how app publishers should list their authorized monetization partners. Using this file, buyers can confidently identify authorized sellers and prevent app domain spoofing and unauthorized selling of in-app inventory.

{% hint style="info" %}
The `app-ads.txt` initiative only takes into account apps that are listed on the Apple App Store or Google Play.
{% endhint %}

To verify authorized sellers:

1. Obtain the app's store listing URL from the `storeURL` parameter that DT passes in the bid request.
2. Obtain the publisher's developer or marketing URL from the store listing.
3. Search the developer or marketing URL for the `app-ads.txt` file.
4. Interpret the contents of the `app-ads.txt` file to verify authorized sellers and resellers.

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