Publisher first-party IDs are a first-party cookie (on web) or ID (on app) set by Google when third-party cookies or device identifiers are not available. These IDs are scoped to a publisher’s domain or apps, and are not shared with other publishers.
They can be used for interest-based ad personalization, allowing buyers to generate first-party user profiles based on user activity on the publisher's site/apps. These IDs can also be used for frequency capping.
To support publisher first-party ID signals in your OpenRTB integration, refer to the protocol guide.
Publisher first-party ID buyer access
Most publishers share first-party IDs with both Google demand and RTB (Authorized Buyers, Open Bidders, and SDK bidders), potentially giving buyers high coverage access to these identifiers across a wide range of inventory where permitted.
Interaction of publisher first-party IDs with other identifiers
If a publisher supports both Publisher first-party IDs and PPIDs, and both identifiers are available to be sent in an ad request, only one will be sent. Publisher-first party IDs are not passed when third-party cookies or device identifiers are available.
Learn more about publisher first-party identifiers.
Manage first-party data deletion requests
Buyers that support data deletion may receive requests from Ad Manager, AdSense, or AdMob publishers to delete first-party data. The data deletion API supports the IAB Data Deletion Request Framework.
To complete these data deletion requests, buyers (Authorized Buyers, Open Bidders, and SDK Bidders) can review technical requirements at Use Data Deletion Request Framework.