The IAB Technology Lab has released another tool, comprising two parts: Sellers.json and OpenRTB SupplyChain Object.

Both are designed to give ad buyers more confidence in the multiple vendors involved in the reselling of an impression throughout the digital ad supply chain, not just the first reseller. The goal is to help increase overall confidence that buyers are not being duped by shady players who aren’t authorized to resell a publisher’s inventory.

VRTCAL welcomes these efforts for transparency. We only work directly with our publishers, through Prebid, oRTB, API, direct tags and soon to launch SDK, and these initiatives strengthen our publishers value to our direct brands & agencies.

What is sellers.json? The published file provides a mechanism for buyers to discover who the direct sellers of or intermediaries in the selling of digital advertising. You can refer to VRTCAL’s sellers.json file at

How does it work exactly?
Sellers.json is like the SSP’s version of the publisher’s ads.txt and app-ads.txt files. In the files, SSPs and exchanges will have to list all their authorized reseller partners along with their seller ID and any detail on the legal entity that owns that company.

What is OpenRTB SupplyChain object? The SupplyChain object enables buyers to see who are selling or reselling a given bid request and identify all parties involved in the payment flow from the buying platform to the publisher. This information can be important to buyers, including transparency of the supply chain, ensuring that all intermediaries are entities that the buyer wants to transact with and that inventory is purchased as directly as possible.

Who does this benefit? It increases confidence for ad buyers and DSPs to buy ads on the open exchange knowing every single reseller involved in the process. Trust has been eroded over time in the supply chain. Many advertisers have lost trust in their agencies, likewise agencies in their DSPs, and publishers in their SSPs. While ads.txt and now app-ads.txt have helped to reduce domain spoofing and unauthorized reselling of inventory, they can be cheated. Plus, it doesn’t provide end-to-end transparency. This, in theory does.

About IAB Tech Lab

The IAB Technology Laboratory is a non-profit research and development consortium that produces and provides standards, software, and services to drive growth of an effective and sustainable global digital media ecosystem. Comprised of digital publishers and ad technology firms, as well as marketers, agencies, and other companies with interests in the interactive marketing arena, IAB Tech Lab aims to enable brand and media growth via a transparent, safe, effective supply chain, simpler and more consistent measurement, and better advertising experiences for consumers.