Sovrn's sellers.json file is hosted at lijit.com/sellers.json.
It is not hosted at sovrn.com/sellers.json. This is intentional and worth knowing if you (or a DSP partner) are trying to verify Sovrn's supply-chain transparency declarations.
lijit.com is Sovrn's ad serving domain — it's the domain that handles bid requests, ad calls, and other programmatic infrastructure for Sovrn Ad Exchange. Because the IAB sellers.json specification requires the file to be hosted on the domain that participates in the OpenRTB supply chain, Sovrn's sellers.json is hosted on lijit.com, not on the corporate marketing domain at sovrn.com.
This pairs correctly with the SSP_DOMAIN value that DSPs (demand-side platforms) see in the SupplyChain Object (schain) on bid requests originating from Sovrn Ad Exchange. Buyers verifying the supply chain will be directed to lijit.com/sellers.json and should find Sovrn's seller listings there.
Questions? Concerns? Our team would be more than happy to help. Reach out to our Support Team here.