• Advertising
  • Trust and Brand Safety

8 GIFs that Perfectly Explain App-Ads.txt, Sellers.json and the OpenRTB Supply Chain Object

Matt Kaplan
Matt Kaplan
Content Strategist
5 min read
Posted on September 09, 2019
8 GIFs that Perfectly Explain App-Ads.txt, Sellers.json and the OpenRTB Supply Chain Object

In 2019, the IAB Tech Lab has released a number of new standards and technologies designed to dramatically increase transparency in the programmatic mobile advertising world. App-ads.txt, the in-app extension of ads.txt, first went live officially in March, and sellers.json and the OpenRTB SupplyChain Object were released for public comment the very next month.

But what do these technology standards do and how can they be used in tandem with one another across the entire supply chain? To help answer these questions, some of the best GIFs on the internet are here to help.


As has been noted before on the InMobi blog, “Ads.txt is a simple solution that gives publishers complete control over who is selling their inventory. The publisher creates a depository of authorized sellers that can be accessed by the buyers. Buyers can hence identify the legitimate sellers of the ad inventory they desire.”

In short, app-ads.txt is a file that states clearly who can and can’t work with a particular app for ad monetization.

What about Sellers.json and the OpenRTB SupplyChain Object? As Sergio Serra, product manager for InMobi’s SSP strategic business unit, explained in MarTech Series in May, the OpenRTB SupplyChain Object and Sellers.json are like a map and key for programmatic advertisers. The SupplyChain Object provides a mapped-out overview of everyone involved in a particular transaction, and Sellers.json helps programmatic pros make heads or tails of the SupplyChain Object.

How All Three Work Together

Ideally, app-ads.txt, sellers.json and the OpenRTB SupplyChain Object are deployed in tandem with one another, to provide unprecedented transparency and clarity to in-app programmatic media buying.

How would it work? Let’s consider a hypothetical scenario:

  1. Wendy’s and its agency, Spark Foundry, wants to reach younger Americans the mobile devices they’re glued to, and turn to InMobi Exchange to help them do that.
  2. The app-ads.txt will tell the buyer/exchange if the inventory has been routed through the authorized set of intermediate partners. In this case InMobi Exchange can ensure that buyers only bid on the right inventory sold through the authorized partners, essentially nullifying any scope for inventory spoofing.
  3. After a successful placement, the Wendy’s/Spark Foundry team can review what happened and who was involved in the transactions through the SupplyChain Object (and by extension Sellers.json).

With all three in place, everyone in the ecosystem has greater transparency than before, knowing who precisely was involved from start to finish.

What All Stakeholders Need to Know

What do these IAB Tech Lab standards and technologies mean for everyone in the programmatic mobile advertising space? Here’s who needs to implement what, and how everyone can encourage adoption.

Who Needs to Implement New Files?

  • App developers and publishers need to implement app-ads.txt files.
  • Supply-side platforms will need to implement sellers.json files once the standard is live.

How Can Everyone Encourage Wide Adoption?

  • Advertisers, agency trading desks and demand-side platforms can encourage adoption of these standards by only working with partners that have seller.json and app-ads.txt files in place.
  • Mobile ad exchanges and supply-side platforms can aid adoption by implementing sellers.json files and helping their publisher partners get their app-ads.txt files in place.
  • Apps should implement an app-ads.txt file, and make sure their partners are implementing sellers.json files and staying true to their claims of prioritizing apps with app-ads.txt files.

Interested in Learning More?

For more information about app-ads.txt, sellers.json and the OpenRTB SupplyChain Object, check out these blogs and articles:

About the Author

Matt Kaplan has over a decade of digital marketing experience, working to support the content goals of the world’s biggest B2B and B2C brands. He is a passionate app user and evangelist, working to support diverse marketing campaigns across devices.

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