There was an unexpected error authorizing you. Please try again.

IAB Tech Lab Releases for Comment Common Ad Transport Standard (CATS) for Direct Buying and Selling of Digital Media

CATS Specification Complements OpenRTB, Standardizing Ad Requests for Direct Media Transactions in Public Comment until April 24.

SAN FRANCISCO (March 26, 2020) – IAB Tech Lab today released CATS (Common Ad Transport Standard) for public comment for a 30-day period until April 24. Designed to complement OpenRTB (Real-Time Bidding), CATS is a new standard to execute ad requests in non-biddable ad transactions, and aims to:

  • Standardize server-to-server communications
  • Solve for limitations in payload size in HTTP GET macro-based implementations, which supports enabling consent, reducing fraud, and complying with specific state regulations including California Consumer Privacy Act (CCPA)
  • Enable better verification support
  • Work across all media formats with an emphasis on video, as a replacement for macro-based ad requests.
  • Work with VAST (digital Video Ad Serving Template), which is the standard way that ad servers and video players communicate

“With the wide adoption of OpenRTB, it became abundantly clear that the industry needed a flexible and easy-to-adopt standard for other, non-bidded digital transactions,” said Dennis Buchheim, President, IAB Tech Lab. “CATS is designed to allow buyers, sellers, and intermediaries to share more, privacy-compliant metadata with each other in more consistent ways.”

CATS has many use cases for publishers, ad servers, supply- and demand-side platforms in the transfer of information and ad requests.

“CATS will be particularly beneficial for supporting video formats, and was designed to work with VAST,” said Amit Shetty, Sr Director, Product Management, IAB Tech Lab, who had led the Digital Video Technical Working Group. “With VAST 4.1, we standardized macros to help with ad requests. But, as the need to send more context grows (as with consent strings and URLs for brand safety checks), we need a more robust mechanism to support all video transactions. CATS, along with Tech Lab’s AdCOM (Advertising Common Object Model), serves as that standard.”

To review the proposed standard and provide feedback, please go to

About IAB Technology Laboratory
Established in 2014, the IAB Technology Laboratory (Tech Lab) is a non-profit consortium that engages a member community globally to develop foundational technology and standards that enable growth and trust in the digital media ecosystem. Comprised of digital publishers, ad technology firms, agencies, marketers, and other member companies, IAB Tech Lab focuses on solutions for brand safety and ad fraud; identity, data, and consumer privacy; ad experiences and measurement; and programmatic effectiveness. Its work includes the OpenRTB real-time bidding protocol, ads.txt anti-fraud specification, Open Measurement SDK for viewability and verification, VAST video specification, and DigiTrust identity service. Board members/companies are listed at For more information, please visit

IAB Tech Lab Media Contacts
Kate Tumino / Britany Tibaldi
212-896-1252 / 347-487-6794 /