"App-ads.txt: How to Make It & Why You Need It"
Last year, the ad tech industry struck back at one of its most elusive problems — widespread domain spoofing that let unauthorized developers sell premium inventory they didn’t actually have. The solution? Over two million developers adopted ads.txt — a simple-text public record of Authorized Digital Sellers for a particular publisher’s inventory — to make sure they didn’t lose money from DSPs and programmatic buyers who avoid noncompliant publishers. Thanks to buyers’ ability to crawl ads.txt and verify seller authenticity, this has quickly become a standard for protecting brands. Ad fraud reduced by 11% in 2019 due to these efforts and publisher’s ability to implement more fraud prevention techniques.
The time has come for ads.text to evolve in-app. The introduction of apps-ads.txt is an important method for mobile app devs to similarly eliminate fraud and improve transparency.
What is app-ads.txt?
Like ads.txt, apps-ads.txt is a text file that app devs upload to their publisher website. It lists all ad sources authorized to sell that publisher’s inventory. The IAB created a system that allows buyers to distinguish the authorized sellers for specific in-app inventory, weeding out the undesirables.
How does app-ads.txt work for mobile apps?
A DSP wanting to bid on an app’s inventory crawls the app-ads.txt file on a developer’s website to verify which ad sources are authorized to sell that app’s inventory. The DSP will only accept bid requests from ad sources listed on the file and authorized by the app developer.
How does app-ads.txt help mobile app developers capture more ad revenue?
Authorized in-app inventory. An ever-increasing amount of brands are looking to advertise in-app today. Brand buyers now rely on an adherence to app-ads.txt to make sure they don’t buy unauthorized inventory from app developers and negatively impact campaign performance. Developers who don’t implement app-ads.txt can be removed from any brand buyer’s target media list. That’s why joining the app-ads.txt movement is crucial for publishers to maintain their revenue.
Ad fraud prevention. App-ads.txt blocks unauthorized developers who impersonate legitimate apps and mislead DSPs into spending brand budgets on fake inventory. With fraud instances minimized, authentic developers can retain more of the ad revenue from inventory genuinely targeted to their app.
How do I create an app-ads.txt?
**You must list your Developer Website URL in the GooglePlay and iTunes app stores. There must be a valid developer website URL in all app stores hosting your apps.**
Step 1: Provide the publisher website URL in your app store listing.
Make sure that your publisher website URL (not app specific URL) is added in your app store listings. Advertising platforms will use this site to verify the app-ads.txt file. Also, double-check that your ad network (e.g. Vungle) account also has the correct app store URL for your app.
Step 2: Reach out to all ad sources (direct, resellers, et cetera).
Get in touch with your direct ad sources and ask for their app-ads.txt line — according to the IAB’s structure below:
Ad source domain, your publisher account ID, type of relationship (direct or reseller), TAG cert ID
Example: vungle.com, 1234, DIRECT, 5678
If your partners are using third-party resellers to sell your inventory, they should be listed as “reseller.”
Example: vungle.com, 1234, RESELLER, 6789
(You shouldn’t add any provider to your app-ads.txt file unless you or your partner have a direct relationship with them.)
We have made it easier for you to include Vungle’s list of entries so that don’t have to construct it on your own. Please copy and paste the following text block and include in your txt file along with entries you may have from your other monetization partners:
vungle.com, [yourVunglePublisherAccountID], DIRECT, c107d686becd2d77
openx.com, 540280728, RESELLER, 6a698e2ec38604c6
appnexus.com, 10128, RESELLER, f5ab79cb980f11d1
indexexchange.com, 185774, RESELLER, 50b1c356f2c5c8fc
inmobi.com, 2e0484e00bf84f35b133019004ef76a4, RESELLER, 83e75a7ae333ca9d
loopme.com, s-2411, RESELLER, 6c8d5f95897a5a3b
loopme.com, 10999, RESELLER, 6c8d5f95897a5a3b
Remember to replace [yourVunglePublisherAccountID] with your Vungle Account ID, which can be found in your Vungle account management dashboard.
Step 3: Write the app-ads.txt file.
Create and save an app-ads.txt file in any text editor (e.g. Notepad) listing out all the lines you received from your ad source partners.
Step 4: Upload the app-ads.txt file.
Upload the app-ads.txt file to the root of your website domain (e.g. https://www.example.com/app-ads.txt).
To sum up...
Vungle is committed to more transparency and security in the mobile advertising ecosystem. It’s important both ad networks and developers do their part to participate in this movement to help remove fraud. We encourage all our developers to adopt app-ads.txt so they stay healthy on our network and earn the revenue they deserve.
Still have questions?
Please submit a technical support request!