Extends the Attribution Reporting API to allow attributing conversions that happen on the web to events that happen off the browser, within other applications. The proposal here takes advantage of OS-level support for attribution. In particular, it gives the developer an option to allow events on the mobile web to be joinable with events in Android’s Privacy Sandbox, although support for other platforms could also be implemented.
Currently, the Attribution Reporting API supports attributing events within a single browser instance. This proposal expands the scope of attribution to allow attributing conversions that happen on the web to events that happen off the browser, within other applications.
Explainers: https://github.com/WICG/attribution-reporting-api/blob/main/app_to_web.md