Intent to Prototype: Attribution Reporting: support for aggregate reports

Skip to first unread message

John Delaney

Jul 8, 2021, 2:56:35 PM7/8/21
to blink-dev
Contact emails



Extends the Attribution Reporting API to support a mechanism for generating and sending reports in a way that reporting endpoints can only learn aggregate data, not any data associated with a particular click or user.

This proposal allows a site to specify reports they want to aggregate within an isolated worklet environment. These reports can later be forwarded to a set of aggregation services which generate usable reports and can apply differentially private noise.

Blink component

There are numerous web ad measurement use-cases which cannot be supported by the event-level reports provided in the existing Attribution Reporting API proposal[1].

By sending aggregated data, we can provide meaningful privacy protections while allowing for higher fidelity measurement of attribution trigger data to be received at a faster rate alongside event-level reports.

TAG review
Not started

TAG review status


Interoperability and Compatibility
The aggregate reports build on the pre-existing mechanisms of the Attribution Reporting API which on its own has its own interop risks. 

Safari has separately proposed the Private Click Measurement API, which also allows for some aggregate measurement of events. We believe our proposal offers more utility, and a different form of privacy guarantee from their API. There is a risk in having two different web APIs which provide similar functionality.

Gecko: No signal

WebKit: No signal

Web developers: No signals

Is this feature fully tested by web-platform-tests?
No, planning to have tests before shipping.

Flag name

Link to entry on the Chrome Platform Status

Reply all
Reply to author
0 new messages