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Brendan Riordan-Butterworth
Architect of ads.txt and sellers.json, the programmatic supply-chain transparency standards
Standards SetterNew York, New York, United States15+ years in industry
Last updated May 31, 2026 by the ATDb Editorial Team
Bio
Brendan Riordan-Butterworth is a digital advertising standards architect best known for developing ads.txt and sellers.json during his tenure at the IAB and IAB Tech Lab, where he worked from approximately 2012 to 2021. These supply-chain transparency specifications became foundational infrastructure for programmatic advertising. He has since joined Google, where his specific role has not been publicly confirmed.
Previous Roles
Technical standards lead (architect of ads.txt & sellers.json)
IAB Tech Lab (~2012–2021)
Expertise
ads.txtsellers.jsonSupply Chain Object (schain)Programmatic AdvertisingAd Fraud PreventionSupply Chain TransparencyTechnical Standards DevelopmentOpen RTB
Notable Achievements
- Principal author and evangelist for ads.txt, now adopted by hundreds of thousands of publishers globally to combat domain spoofing and unauthorized reselling
- Key contributor to sellers.json specification, enabling buyers to verify the entities in the programmatic supply chain
- Led development of the Supply Chain Object (schain), providing end-to-end transparency across programmatic transactions
- Instrumental in driving industry-wide adoption of IAB Tech Lab supply chain transparency standards across DSPs, SSPs, and publishers
Speaking Topics
Programmatic supply chain transparencyads.txt and sellers.json implementationAd fraud prevention through technical standardsOpen web infrastructure and identityTechnical standards development and industry consensus-building
Publications
- ads.txt Specification — IAB Tech Lab
- sellers.json and SupplyChain Object Specification — IAB Tech Lab