Skip to content

How It Works: Sellers.json Release

October 25, 2019

Today we are releasing Sellers.json and SupplyChain in compliance with the new IAB industry standard. Sellers.json and SupplyChain are separate items, but work in tandem in order to fully reveal all entities involved in a given supply chain transaction.

How it works:

First, the SSP/Exchange posts the identity of its supply sources (publishers) in a file called sellers.json, along with the type of relationship. (i.e. direct, intermediary). This file is publicly available for anyone to see and consume on the web at the SSP/Exchange’s business domain. Example: Then, the SSP/Exchange includes its business domain name in the supplyChain object sent in bid requests going out to DSPs/buyers, along with the id of the publisher. With the domain name, the buyer can now find the sellers.json file ( and identifying information about that publisher. Finally, since the publisher id in the supplyChain object, and publisher id on the sellers.json file must match the exchange-generated publisher id in the publisher’s ads.txt file, the buyer can go full circle, and verify legitimacy of the impression being auctioned.

This initiative brings even more transparency into the ecosystem and is aimed at building trust in Programmatic spend, by allowing buyers to quickly and systematically identify the entities involved in a given ad request transaction.

Author: Auric Adames
Sr. Product Director, Exchange, EMX