Measures advertising performance by providing a way to register ad impressions and later attribute conversions (e.g. purchases) to them in a way that does not enabling tracking.
To define a means of performing attribution for advertising that does not enable tracking, unlike the way much web-based ad measurement is done today (e.g. via third-party cookies).
This API is a multi-browser effort, informed by the prior work on attribution in Chrome’s Attribution Reporting API (ARA), as well as Meta and Mozilla’s Interoperable Private Attribution (IPA) and WebKit’s Private Click Measurement (PCM) work.