app-ads.txt, Authorized Digital Sellers for Apps, is an open standard that provides a mechanism for publishers to publicly declare the companies authorized to sell digital ad inventory in their mobile and OTT apps.
By creating a public record of “Authorized Digital Sellers”, app-ads.txt makes it possible for advertisers and their partners to ensure that the mobile ads they are being sold in the programmatic marketplace are legitimate.
The IAB Tech Lab, a nonprofit research and development consortium charged with producing and helping companies implement global industry technical standards and solutions for the digital media and advertising industries, created app-ads.txt as an extension of the ads.txt standard, which is now used by approximately 90% of the top 10,000 sites on the internet.
Leading companies including Google, The Trade Desk and AppNexus support app-ads.txt and some of the largest DSPs (demand-side platforms) have begun requiring that publishers adopt app-ads.txt. Publishers that fail to do so could lose significant revenue.