Authorized Sellers for Apps (app-ads.txt)
Authorized Sellers for Apps, or app-ads.txt, is an IAB Tech Lab initiative that helps ensure your app ad inventory is only sold through channels you’ve identified as authorized. In other words, it’s a way for app developers to verify to advertisers that they own the app where an ad request is originating from, thus preventing in-app advertising fraud.
Creating an app-ads.txt file gives you more control over who’s allowed to sell ads on your app and helps prevent fake inventory from being shown to advertisers.
The app-ads.txt files are made publicly available and crawlable by exchanges, supply-side platforms (SSP), and other buyers and third-party vendors. App developers host this file on the root domain of their website, which is linked from the Google Play Store or Apple App Store. When an ad request with an app is sent out, an advertiser can check the app marketplace page for the app, find the corresponding app-ads.txt file, and verify that the developer ID included in the ad request matches the corresponding ID in the app-ads.txt file.
This prevents malicious actors from faking ad requests under the guise of an app because the developer ID in their ad request will not match the developer ID included in the app-ads.txt file. Read more about it from Interactive Advertising Bureau here.
Authorized Sellers for Apps (app-ads.txt) is an extension to the Authorized Digital Sellers (ads.txt) standard, which was originally designed to protect web ad inventory.