I guess the worst case breakage here is just a return to the old world where users who opt-out of 3PCs may see some breakage they can only fix with cookie exceptions. It's a shame, but not really a new compat concern IMHO.
LGTM1 On Fri, Nov 7, 2025, 12:34 p.m. 'Johann Hofmann' via blink-dev < [email protected]> wrote: > Apologies, I used the wrong Chromestatus link (the original feature > status), this one is correct: > https://chromestatus.com/feature/5194473869017088 > > On Fri, Nov 7, 2025 at 2:47 PM Johann Hofmann <[email protected]> > wrote: > >> Contact emails >> >> [email protected], [email protected] >> >> Explainer >> >> https://github.com/WICG/first-party-sets >> >> Specification >> >> https://wicg.github.io/first-party-sets/ >> >> Summary >> >> Related Website Sets (RWS), formerly known as First Party Sets, provides >> a framework for developers to declare relationships among sites, to enable >> limited cross-site cookie access for specific, user-facing purposes. This >> is facilitated through the use of the Storage Access API >> <https://github.com/privacycg/storage-access> (SAA) and >> requestStorageAccessFor >> <https://github.com/privacycg/requestStorageAccessForOrigin/> (rSAFor). >> RWS was designed for use in a browser without third-party cookies. >> Following Chrome's announcement that the current approach to third-party >> cookies will be maintained, we are now planning to deprecate and remove >> Related Website Sets (RWS). >> >> Once RWS is deprecated; existing usage of SAA across contexts within a >> set will fall back to the API’s behavior outside of RWS as specified here >> <https://privacycg.github.io/storage-access/>. The difference in SAA >> behavior outside of RWS is well illustrated in our developer blogpost >> here >> <https://privacysandbox.google.com/cookies/storage-access-api#how_is_the_storage_access_api_different_when_used_with_rws> >> . >> >> The companion rSAFor API will also be deprecated via a separate intent. >> >> We also intend to deprecate RWS-related Chrome Enterprise policies >> <https://chromeenterprise.google/policies/#RelatedWebsiteSets>, as well >> as the chrome.privacy.relatedWebsiteSetsEnabled extension API; and will >> follow the relevant processes. >> >> Blink component >> >> Privacy <https://g-issues.chromium.org/issues?q=is:open> >> >> Web Feature ID >> >> None >> >> Motivation >> >> Chrome has announced >> <https://privacysandbox.com/news/update-on-plans-for-privacy-sandbox-technologies/> >> that the current approach to third-party cookies will be maintained. RWS >> usage is indicated by the number of registered sets (currently at 71 sets >> <https://github.com/GoogleChrome/related-website-sets/blob/main/related_website_sets.JSON>), >> and the usage of the requestStorageAccessFor API (currently at about 0.95% >> of pageloads >> <https://chromestatus.com/metrics/feature/timeline/popularity/4332>), >> and after this announcement we intend to archive the registration >> repository, and expect adoption of rSAFor to decrease over time. >> >> We will continue to monitor usage and aim to drive it down prior to >> removal by proactively informing set owners of the deprecation timelines >> and request them to turn down usage. Further, other browser engines have >> not signaled interest in launching the API, obviating any interoperability >> concerns. >> >> Debuggability >> >> N/A >> >> Requires code in //chrome? >> >> False >> >> Estimated milestones >> >> Deprecate in M144, and target M150 for removal. >> >> Link to entry on the Chrome Platform Status >> >> https://chromestatus.com/feature/5640066519007232 >> >> This intent message was generated by Chrome Platform Status >> <https://chromestatus.com/>. >> >> -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAD_OO4gxedpHS8XLQJVfax5V7hn%2BBPUqv%3DC%2BYAdsqDknd0baBQ%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAD_OO4gxedpHS8XLQJVfax5V7hn%2BBPUqv%3DC%2BYAdsqDknd0baBQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAFUtAY-31pekOvHWeJnHAzQSCPzzf-SZHmianvpx273pJLuGDg%40mail.gmail.com.
