app-ads.txt support
The app-ads.txt file consists of a list of authorized digital sellers. This file was created by IAB, to combat fraud and to create transparency in the advertising ecosystem. The file verifies the legitimacy of sellers, protecting against fraud and misrepresented domains.
Developers must host this file in the root of the developer website. Brand advertisers and demand-side platforms (DSPs) scrape this file and cross-reference it when they buy ad inventory programmatically by using exchanges, supply-side platforms (SSPs), and ad networks.
While implementing app-ads.txt is not mandatory in most cases, failing to do so will cause developers to lose significant ad revenue for the following reasons:
- DSPs use this file to understand the supply chain of inventory they are buying.
- Some DSPs will only buy from developers that have correctly implemented this file.
- Developers that properly declare their authorized sellers help advertisers greatly reduce the risk of counterfeit inventory, which over time funnels more advertising dollars to quality developers.
Important: Implementing app-ads.txt is required if you want to display banner ads. Not doing so will result in significantly decreased banner demand.
For more information, read the IAB Tech Lab spec and Unity's blog on elevating inventory quality.
Setting up app-ads.txt for the first time
To set up app-ads.txt from the Unity Ads Monetization dashboard:
- Select Setup > Organization Settings from the secondary navigation menu.
- Locate the Developer Website field in the Organization info and select the edit icon.
- Enter the URL of the website where your game is listed on the app store. This is usually simple, for example, "https://www.unity3d.com". This field should contain only the root of the developer’s website. For example, you can find this website on the Developer page of Google Play, and in settings on the Apple store.
- Go to the App-ads.txt section. The App-Ads URL field will automatically display a list of authorized digital sellers in the correct file format. If it doesn't, refer to this website root directory guide for more information.
- Click Show full list to view all the values for your
app-ads.txtfile, then copy this list. - Using a text editor, create an
app-ads.txtand paste the list from the Monetization dashboard into the file. - Copy the
app-ads.txtfile into the root of the developer website so that it's findable in the location listed in the app-ads URL field.
If everything worked correctly, you'll see a message informing you that no action is needed at this time.
Important: This list can change over time. Check the settings page monthly, or whenever you are notified.
Maintaining app-ads.txt
It's important to visit the app-ads.txt setting regularly to see if anything has changed, or to respond to error messages or notifications that you receive.
Here are some issues that can happen, and how to fix them.
Missing or incorrect website
Unity could not find your app-ads.txt file at the given App-Ads URL.
Solution: Review your Developer Website field in the Organization Info section to make sure it is accurate. Ensure that the correct root is listed as well.
Missing some app-ads.txt entries
You are missing some app-ads.txt entries.
Solution: Navigate to the App-ads.txt section in your Organization settings to refresh the list, then copy-paste the entire updated list into your file.
Ensure publisher transparency with OwnerDomain
As part of the ads.txt framework, publishers must include the OwnerDomain field in their app-ads.txt file.
Purpose of the OwnerDomain field
The IAB's OwnerDomain framework is designed to enhance publisher transparency and accountability in the digital advertising ecosystem. It plays a key role in clarifying the use of first-party and third-party data in programmatic advertising.
The OwnerDomain field identifies the business domain of the publisher that owns the media property, establishing a direct link between the ads.txt and sellers.json files.
Implementing OwnerDomain in your ads.txt file
To support OwnerDomain, ensure your app-ads.txt or ads.txt files include the required variables:
| Type | Variable | Description |
|---|---|---|
| OwnerDomain | ownerdomain=yourdomain.com | For publishers, an OwnerDomain entry must be added to ads.txt to specify the business domain of the site owner. The domain must align with the seller's domain in sellers.json files and resolve in a browser without redirects. If no business domain exists, the site's domain can be used. |
For more information, refer to the IAB documentation or the IAB standard implementation guide.
Frequently asked questions
Is this new? How does it differ from ads.txt?
app-ads.txt is specifically for mobile apps. It provides the same functionality as ads.txt, but resides on the developer's website.
What problem is this intended to solve?
app-ads.txt protects advertisers from buying invalid or fraudulent traffic, and protects publishers from losing revenue to malicious sources intercepting their demand.
Why should publishers adopt app-ads.txt?
Moving forward, a number of major Brand advertisers and DSPs will only buy inventory from authorized inventories, creating a strong incentive for publishers to adopt app-ads.txt. To stay ahead of this shift in the industry and avoid missing out on revenue, Unity recommends implementing this as early as possible.
What is Unity’s position on app-ads.txt?
Unity strongly supports this initiative because it combats fraud and creates more transparency for mobile advertising. App developers who implement this will, in turn, see more premium advertisers and incremental revenue.
Why should advertisers adopt app-ads.txt?
As with ads.txt for web, this file gives advertisers greater assurance that they are buying legitimate impressions from authorized resellers.