> ## Documentation Index > Fetch the complete documentation index at: https://docs.kontext.so/llms.txt > Use this file to discover all available pages before exploring further. # app-ads.txt > Host the IAB authorized-sellers file at your developer site so demand partners trust your traffic. [`app-ads.txt`](https://iabtechlab.com/app-ads-txt/) is a plain-text file published at the root of a publisher's developer site. It lists the companies authorized to sell that publisher's ad inventory. Most advertisers check this file before bidding; a seller that isn't listed is assumed to be fraudulent and skipped. For Kontext to bring you demand, your `app-ads.txt` needs to list our authorization line. Adding it is a one-time setup and a hard requirement for ramping up fill rate. ## Where the file lives The file is hosted at the root of your **developer marketing site**: the domain linked from your App Store or Google Play listing as the developer URL. That is the domain advertisers check, so the file must live at `https://yourmarketingsite.com/app-ads.txt`. If you already host the file for other ad partners, **append** our line; don't replace the file. ## The line you add We send you the exact line during onboarding. It follows the standard IAB format: ``` , , DIRECT, ``` Once added, nothing else is needed on your side. Advertisers pick up the change the next time they crawl your file, typically within 24 hours. ## Later updates When we add a selling partner or change our seller domain, we send you a new line. Append it (and keep the old one until we say otherwise); the change propagates the same way. Unsure what your file contains, or whether our line is already there? Send the URL to [support@kontext.so](mailto:support@kontext.so) and we'll check. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.