Did you receive an email from Google recently telling you to Protect your apps with app-ads.txt? I did. I run Google Ads on a bunch of my iOS apps, and decided to figure out how easy or hard it is to set this up.

From the email:

What is app-ads.txt? App-ads.txt is a simple, flexible, and secure method for app publishers and distributors to fight ad fraud by declaring authorized sellers for their inventory. Developed by the IAB Tech Lab, the standard is a way to secure your inventory and ensure advertiser spend is reaching the intended publisher. Similar to robots.txt, app-ads.txt can only be posted to a developer’s domain by the app developer’s webmaster, making it valid and authentic.

There is a Google support link to read more about how to set it up provided in the email.

First step is creating the actual app-ads.txt file, for which the article links to Authorised Sellers for Apps specification. I decided that that specification was too long, and simply started with a blank file.

Say what? Yes, if you are looking for an example app-ads.txt file that works, you just need a blank text file.

Then head over to your AdMob account, and click the How to setup app-ads.txt button, which will present a popup with a code snippet. Mine looks like this:

google.com, pub-5817733678647789, DIRECT, f08c47fec0942fa0

Grab that, and paste it into that blank text file, and host the file at the root of your domain, eg here

You can confirm it is setup correctly via the status light on the AdMob app-ads.txt page. I had to wait over a day for the status became green.

Also, not all of my apps had a value in the app-ads.txt URL column on that page. This base url is determined from the Marketing URL property on your App Store listing (for iOS), so make sure you have the correct value set there. …