Publish a sellers.json file and adopt the OpenRTB SupplyChain object for programmatic supply chain transparency
domain: iabtechlab.com · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
As an SSP/exchange, publish a sellers.json file listing the direct sellers and intermediaries transacting through the platform
Populate each seller entry consistently so buyers can resolve identities that are otherwise inconsistently populated in Publisher.name/Publisher.domain within bid requests
Upgrade OpenRTB bid request integrations (2.x or 3.0) to include the SupplyChain extension object, representing each participating entity as a node in the chain
As a buyer/DSP, verify inventory by cross-referencing the SupplyChain object's nodes against the relevant sellers.json files and ads.txt/app-ads.txt records
Cache sellers.json lookups offline where possible rather than requiring the full seller list on every bid request
Known gotchas
sellers.json and the SupplyChain object were finalized together (July 31, 2019) by the OpenRTB Working Group and are meant to be used in tandem, not as alternatives to each other
sellers.json enables smaller bid request payloads by moving seller identity out of the request itself — treat it as a lookup/cache source, not something to re-fetch per request
Give your agent this knowledge — and 15,500+ more routes
One MCP install gives any agent live access to the full route map across 5,700+ domains, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp
Need this verified for your stack — or a route we don't have yet?