Instructions for setting up App-ads.txt, a crucial step in enabling CTV and In-App advertising Demand.
You are likely familiar with Ads.txt – an IAB initiative to reduce fraud and improve transparency in the digital ad space. App-ads.txt is the same standard, but for mobile and OTT/CTV apps.
Ad service providers will often send you app-ads.txt lines to host for your app, and you may be wondering where these need to be hosted. The location is obvious for most display websites, you simply host the file at “/ads.txt” on the root of the website being monetized. However apps need additional steps to associate an app-ads.txt with a specific application.
Mobile and CTV/OTT apps both work in the same way. The app store listing for your application will identify the app developer, and they will host the app-ads.txt. So lets get into the details.
When you publish an app to any app store (Android, iOS, Roku, etc..) they are typically associated with a developer, which is the company that creates and publishes the application. The developer profile must have a published “developer URL” on the app store. Some stores may allow this to be entered with the app details itself, other stores may require the Developer to configure this. In either case, you want your published application to be associated with a Developer who has a published Developer URL (eg: https://www.BestAppDeveloper.com).
The App Store listing for your application will list this developer URL in a hidden HTML tag called a Meta Tag. The META tag will published the developer’s website in a way that 3rd party systems can read.
This Developer URL is used to generate the path to the “app-ads.txt”. The rules for converting a Developer URL to a path to app-ads.txt is detailed, but typically the domain name (without www.) is used and any path is removed and replaced with “/app-ads.txt”. Your hosted app-ads.txt must contain all the lines for every published app, mobile and CTV/OTT released by this developer.
For example, this is how a network would validate the inventory of an Android app:
- Given the app ID “ie.irishtimes.reader”, a potential buy-side system retrieve the app details from the associated app store: https://play.google.com/store/apps/details?id=ie.irishtimes.reader&hl=en_US
- Find the meta tag “appstore:store_id” and confirm a match to “ie.irishtimes.reader” (although Google does not, some platforms may differentiate “bundle_id” and “store_id”);
- Find the meta tag “appstore:developer_url” and the URL contents
- Follow the rules in the specification about translating from a developer URL to an app-ads.txt path
- Retrieve the contents of app-ads.txt
- Interpret the contents of app-ads.txt following the existing ads.txt specification.
For full details from the IAB you can check out their guide on app-ads.txt: