Ads.txt and app-ads.txt exchange policy

The IAB Tech Lab's Authorized Digital Sellers (ads.txt and app-ads.txt) standards have been an important tool in providing transparency into the supply chain, helping prevent domain spoofing, and disallowing unauthorized reselling of inventory. These standards allow publishers to publicly declare the list of all authorized sellers eligible to sell their inventory.

Starting August 22nd, 2022, Index will begin to only sell inventory that has been granted seller authorization by the underlying publisher or developer through their ads.txt/app-ads.txt file. Inventory will not be accepted in any instance that Index cannot verify authorization. This includes:

  • The respective Index entry is not found in the underlying file
  • There is an error in reading the respective Index entry in the file
  • The file cannot be found or accessed by our crawler provider

Below are the implementation guidelines and specific policies Index will require for seller authorization. For Web and Mobile App supply, media owners must follow the Ads.txt and App-ads.txt respectively. Additionally we have outlined implementation requirements for CTV inventory for both Content Owners and CTV Distributor Apps in accordance with the IAB Tech Lab guidance.

Implementing Index as an authorized seller for web and mobile app

View your Index ads.txt or app-ads.txt entry

Publishers and developers must add their unique Index account entry to their respective ads.txt/app-ads.txt file in order to grant Index seller authorization.

To view the unique Index ads.txt/app-ads.txt entry please see Viewing authorized sellers.

The Index entry can be used for both ads.txt and app-ads.txt files.

Be sure to include an entry for each Index account that will be authorized to sell your inventory.

Adding Index ads.txt or app-ads.txt entry

Your unique Index entry for your account will be populated automatically with DIRECT in the field #3 of your unique Index entry. For intermediary sellers you must update the entry to include RESELLER for field #3. DIRECT and RESELLER values should be used under the following guidance.

  • DIRECT is used when you are the owner and operator of the domain or app being sold
  • RESELLER is used when you are acting as an intermediary to sell inventory on behalf of the underlying domain or app

For any question on how to implement your entry, please reach out to your account team.

Example file with Index entry for direct

Intermediaries that do not own and operate the underlying domain or app they are selling inventory for must must have the underlying media owner add their resepective entries. If the intermediary is not explicitly authorized in the file, the traffic will be blocked from transacting on the exchange. An example of a RESELLER entry can be seen below:

example.com/ads.txt file

indexexchange.com, 234567, DIRECT, 50b1c356f2c5c8fc
bluessp.com, xyz789, DIRECT
greenexchange.com, 9876, RESELLER
Example file with Index entry for reseller (intermediaries)

Intermediaries that do not own and operate the underlying domain or app they are selling inventory for must must have the underlying media owner add their resepective entries. If the intermediary is not explicitly authorized in the file, the traffic will be blocked from transacting on the exchange. An example of a RESELLER entry can be seen below:

example2.com/ads.txt file

indexexchange.com, 234567, RESELLER, 50b1c356f2c5c8fc
bluessp.com, xyz789, DIRECT
greenexchange.com, 9876, RESELLER

Index will not auction any inventory until properly authorized through the ads.txt or app-ads.txt file.

Implementing ads.txt for CTV apps and inventory partners

For CTV, Index Exchange authorization must be implemented in Ads.txt and App-ads.txt for CTV based on the IAB Tech Lab’s guidance. Index will require the following implementation for selling CTV inventory when you own the App or when you are an Inventory Partner that has the rights to sell inventory through another App.

CTV app owners selling ad space on their own app
  • CTV App owners selling their own app ad space are expected to follow the standard app-ads.txt guidance as listed in the section above.
  • They must list their respective Index Exchange entry in their own app-ads.txt file to be authorized to sell on the exchange.
Content owners and distributors selling ad space as inventory partners
  • Companies selling as inventory partners on a CTV App they do not own (“inventory sharing”), must follow the new IAB guidelines for inventorypartnerdomain, this includes:
    • Adding your Index Exchange entry within your own ads.txt file (e.g. contentowner.com/ads.txt)
    • Being included as an inventorypartnerdomain entry in the distributing app’s underlying apps-ads.txt file (e.g. inventorypartnerdomain = contentowner.com within distributorapp.com/app-ads.txt)
    • The app.ext.inventorypartnerdomain field to be sent in OpenRTB for all requests sold through an inventory partner relationship.
    • It is strongly recommended that you also have your Index Exchange entries included in the app-ads.txt file for the app you are an inventory partner of. (e.g. distributorapp.com/app-ads.txt)
      • Not all DSPs support the inventorypartnerdomain for app-ads.txt and this will help ensure your inventory is considered authorized while DSPs transition to inventorypartnerdomain.
  • Please reference the diagram below for implementation.
Example file for content owners and distributors apps using inventory partners

dsitributorapp.com/app-ads.txt

inventorypartner.com = contentowner.com
indexexchange.com, 123456, DIRECT, 50b1c356f2c5c8fc

contentowner.com/ads.txt

indexexchange.com, 123456, DIRECT, 50b1c356f2c5c8fc

 

Bid request flow including "inventorypartnerdomain" field