app-ads.txt(this previously only applied to web inventory via
ads.txt). As a reminder,
app-ads.txtlets publishers declare sellers for their mobile app and lets advertisers know which sources are authorized to sell the inventory. This helps prevent inventory from being spoofed by bad actors and ensures that advertiser spend reaches the intended audience, bringing increased transparency to the programmatic buying space. See the Authorized seller bidding in Display & Video 360 and Frequently Asked Questions sections for more details.
What's changed (starting November 2, 2020):
- The existing 'Inventory Source - Quality' targeting options now extend to cover both web and mobile app inventory. Before this change, Display & Video 360 only allowed buyers to apply authorized seller targeting via
ads.txtto web inventory.
- TV app inventory (CTV, Linear TV) was not impacted or included in this change.
- There were no changes to the targeting options themselves or to where the options are applied (at the partner, campaign, insertion order, or line item levels).
- Existing line items that contain mobile app inventory now have the 'Inventory Source - Quality' targeting applied to mobile app inventory as well (this previously only applied to web inventory).
- If an existing line item targeted either 1) Authorized Direct Sellers and Resellers or 2) Authorized Direct Sellers only, behavioral changes should be anticipated since the targeting setting now also apply to mobile app inventory and will thus stop bidding on non-participating inventory.
- Both 'Ads in mobile apps' and 'Mobile app install' line items have the 'Inventory Source - Quality' targeting options available (this previously only existed in display, video, and audio line item types). Existing ‘Ads in mobile apps’ and ‘Mobile app install’ line items will maintain the current behavior, targeting ‘Authorized and Non-Participating Publishers’ by default, while new line items will inherit settings from the insertion order.
Topics in this article
Authorized Digital Sellers for web (ads.txt) is an IAB initiative to improve transparency in programmatic advertising by allowing publishers to identify who is authorized to sell their inventory. Declaring authorized sellers in an ads.txt file helps protect buyers from counterfeit inventory. The files are publicly available and crawlable by exchanges, Supply-Side Platforms (SSP), and other buyers and third-party vendors.
Authorized Sellers for apps (app-ads.txt) is an extension to the Authorized Digital Sellers standard. It expands compatibility to support ads shown in mobile apps.
A publisher is considered to be participating if their inventory has an associated ads.txt file:
For web-based inventory (e.g.
mydomain.com), an ads.txt file is posted and reachable from the root domain at
For app-based inventory, the app has a published Google Play or App Store listing that references the developer's app website (e.g.
myappwebsite.com) and the developer's app website has an app-ads.txt file posted and reachable from the root domain (e.g.
A publisher is considered to be non-participating if their web or app inventory does not have an associated ads.txt/app-ads.txt file. While the use of ads.txt/app-ads.txt is not mandatory for publishers, it is highly recommended. Display & Video 360 excludes non-participating inventory on new campaigns by default, but buyers may purchase non-participating inventory at their own risk by modifying the ads.txt/app-ads.txt targeting option.
A seller can be authorized to sell inventory by declaring a row with the following details in the ads.txt or app-ads.txt file:
- Field 1: Exchange/SSP domain name (e.g.
- Field 2: Exchange-specific publisher ID
- Field 3: Type of account/relationship (must be
- (Optional) Field 4: Certification authority ID
google.com, pub-0000000000000000, DIRECT, f08c47fec0942fa0
greenadexchange.com, 12345, DIRECT, AEC242
blueadexchange.com, 4536, DIRECT
silverssp.com, 9675, RESELLER
Authorized Sellers are sellers whose publisher ID has been declared in the ads.txt/app-ads.txt file on the inventory being monetized. Authorized sellers may be categorized as Direct or Resellers, depending on whether the seller directly owns or resells the inventory being monetized.
Unauthorized Sellers are sellers whose publisher ID has not been declared in the ads.txt/app-ads.txt file on the inventory being monetized. Display & Video 360 automatically excludes and disallows bidding on unauthorized sellers, protecting you from buying counterfeit inventory that is intentionally mislabelled.
Inventory such as Out-of-Home, linear TV, and CTV are not currently covered by the ads.txt or app-ads.txt specification. Authorized Seller targeting options may also not be visible on some Line Item types which exclusively target inventory for which ads.txt/app-ads.txt restrictions does not apply.
Display & Video 360 allows buyers to apply ads.txt and app-ads.txt targeting options at the Partner, Campaign, Insertion Order or Line Item level. Ads.txt and app-ads.txt targeting options for new entities (e.g. Line item) inherit the settings applied on the parent entity (e.g. the Insertion Order that the line item belongs to).
The following targeting options are available:
Authorized Direct Sellers and Resellers: All authorized sellers, including those that directly own or resell the inventory being monetized, as indicated by a
RESELLERdeclaration in the ads.txt and/or app-ads.txt file respectively. Note that this is the default option for new Display & Video 360 campaigns.
Authorized Direct Sellers only: Only authorized sellers that directly own the inventory being monetized, as indicated by a DIRECT declaration in the ads.txt and/or app-ads.txt file.
- Authorized and Non-Participating Publishers: All authorized sellers, including publishers that have not posted an ads.txt and/or app-ads.txt file. Display & Video 360 automatically disallows unauthorized sellers.
|Has ads.txt/app-ads.txt?||Seller status||Targeting status||Does Display & Video 360 bid?*|
|Yes||Authorized Direct||Authorized and Non-Participating Publishers||Yes|
|Yes||Authorized Direct||(Default**) Authorized Direct Sellers and Resellers||Yes|
|Yes||Authorized Direct||Authorized Direct Sellers only||Yes|
|Yes||Authorized Reseller||Authorized and Non-Participating Publishers||Yes|
|Yes||Authorized Reseller||(Default**) Authorized Direct Sellers and Resellers||Yes|
|Yes||Authorized Reseller||Authorized Direct Sellers only||No|
|No||Non-Participating||Authorized and Non-Participating Publishers||Yes|
|No||Non-Participating||(Default**) Authorized Direct Sellers and Resellers||No|
|No||Non-Participating||Authorized Direct Sellers only||No|
* Other bid rejection reasons may apply
** The default value set at the partner level. This can be overwritten at the campaign, insertion order, or line item level
In Display & Video 360 you can use the "Authorized Seller state" dimension to report on the ads.txt and app-ads.txt participation or authorization status of inventory bought. The "Authorized Seller state" dimension categorizes inventory into Authorized Direct Sellers, Authorized Resellers, Non-Participating Publishers, and Ineligible. Learn more about publisher participation and seller authorization.
The reach impact of ads.txt and app-ads.txt targeting options can also be estimated using the Inventory Availability report. Learn more about how Display & Video 360 calculates potential reach.
What can I do to minimize the impact of Authorized Seller targeting on my campaign delivery?
Expand reach of authorized app inventory (recommended)
- Expand inventory source targeting to include more authorized app inventory and use reach forecasts or Inventory Availability reports to estimate incremental reach. Target Open Auction for broader app-ads.txt coverage, explore the Marketplace or work with publishers to recommend premium authorized app inventory.
- If targeting channels, use App/URL suggestions to find brand-safe app inventory to expand channel reach.
- If inventory source targeting cannot be expanded (e.g. for private deals), encourage publishers to adopt app-ads.txt on the desired inventory.
Adjust Inventory Quality targeting based on your inventory buying policies
- Within Brand Controls at the Advertiser level (Resources > Brand Controls > Authorized sellers), review the breakdown across Authorized Seller states. To make bulk updates to Inventory Quality targeting, click View BreakdownActionsSDF Download for export of line items potentially impacted by app-ads.txt coverage.
- Depending on your inventory buying policies, if your campaign is inventory constrained, consider adjusting Inventory Quality targeting to ‘Authorized and non-participating publishers’. Due to higher inventory quality risk, consider doing this as a temporary measure, and only for private deals. We recommend encouraging publishers to adopt app-ads.txt.
- If you have separate inventory quality policies for app vs web inventory, consider temporarily separating line items for buying web and app inventory.
How does app-ads.txt enforcement affect campaign delivery?
How can I improve ads.txt adoption on desired web or app inventory?
How does the Authorized Seller targeting option affect app-based inventory?
The Authorized Seller targeting options only affect web-based and mobile app inventory. TV app-based inventory is not affected by the targeting options at this time.
How can I assess the impact of Authorized Seller targeting on campaign reach?
How can I troubleshoot the impact of Authorized Seller targeting on campaign spend?
TV app-based inventory is not affected by the Authorized Seller targeting options at this time.For web-based and mobile app inventory, you can check the Targeting section of the Troubleshooter to determine if a significant percentage of bid requests are filtered due to "Authorized Seller state". Learn more about the Troubleshooter.
Why does Display & Video 360 show a domain/app as non-participating, although it has an ads.txt or app-ads.txt file?
For Display & Video 360 to categorize a domain/app as participating, the ads.txt/app-ads.txt file must be posted according to the IAB specification and must be discoverable by the Google crawler.
For apps specifically, publishers must:
Ensure the app is registered with the Google Play or App Store
Include a valid developer website in the Google Play or App Store listing
Ensure that the app-ads.txt file is reachable from the root domain or a valid subdomain, as allowed by the app-ads.txt specification