The Programmatic Glossary
A practical glossary designed to help marketers, advertisers and ad-tech professionals understand the terminology that powers programmatic advertising
Supply Chain Transparency
Sellers.Json
A publicly accessible file that supply-side companies (SSPs, Supply-Side Platforms, exchanges and ad networks) publish to declare who they are and who they represent in the advertising supply chain. It works alongside ads.txt to give buyers full transparency about the origin of inventory.
HOW IT WORKS
Every SSP (Supply-Side Platform), exchange and intermediary in the supply chain publishes a sellers.json file at their domain listing all the publishers and resellers they work with. When a buyer receives a bid request, they can cross-reference the sellers.json to verify that the entity selling the inventory is who they claim to be.
EXAMPLE
A DSP (Demand-Side Platform) receives a bid request claiming to represent a major newspaper. The DSP checks the newspaper's ads.txt file, which confirms Limelight is an authorised seller, and Limelight's sellers.json file, which confirms the newspaper is a legitimate publisher on Limelight's platform. Both checks pass and the impression is genuine.
RELATED TERMS
ads.txt | Domain laundering | Supply path optimisation (SPO) | Ad fraud | SSP (Supply-Side Platform)
★ LIMELIGHT INSIGHT: Limelight maintains a fully compliant sellers.json file, ensuring complete transparency for all buyers accessing publisher inventory through the platform.
