IAB Tech Lab proposed an update to OpenRTB SupplyChain (schain) object that would significantly change the support for supply-path optimization.
If accepted, the update
to SupplyChain v1.1 would, for the first time, give buyers visibility into the participates carrying out a bid request's technical programmatic transactions as it moves through the ad
ecosystem, as well as those involved in the payment flow of the transaction.
The update is expected to help buyers improve supply-path optimization, reduce duplicative bid requests and better
identify all companies involved in the programmatic transaction.
“This is one of the most significant transparency enhancements to the digital advertising supply chain in years,”
stated Anthony Katsur, CEO, IAB Tech Lab. “Advertisers deserve to understand not only who participates in a transaction financially, but also who takes full control of a given request before it
reaches a buyer."
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SPO largely assumed the shortest path between publisher and buyer was the best path to take, because buyers had limited visibility into how bid requests were created and
routed.
SupplyChain v1.1 changed that. It introduces a framework that would allow buyers to distinguish between those tracking the money and those tracking the data and routing the files. It
would allow advertisers to see how inventory is actually created, handled, and transmitted before reaching a demand-side platform (DSP).
As a result, buyers can evaluate supply quality based
on transparency and accountability rather than just node count.
The larger significance is that SPO may mature from rewarding the shortest-looking path to rewarding the most transparent and
fully disclosed path, which is the type of market visibility IAB Tech Lab is working to enable.
The proposed update is open for public comment through August 21, 2026.
The Programmatic
Supply Chain Working Group, guided by the Programmatic Supply Chain Commit Group, developed the update to expand the role of schain beyond the traditional payment-flow view of the supply chain. It
will let companies see those that "take technical custody of a bid request as it moves through systems such as Prebid, ad servers, SSAI platforms, SDKs, wrappers, and other infrastructure."
Multiple types of implementation approaches, but then recommended an update where the model "adds custody-taking entities directly to the main schain, using the hp=0 designation when an entity is
not part of the payment flow," according to the update.
The group decided on this approach, because it "preserves the integrity of the schain model while giving buyers a complete view of
technical participation in the bid request lifecycle."