Android zero-tap sign-in restoration: comparing approaches for self-hosted apps

Hi I'm one of the maintainer of the Home Assistant Android app! We’re investigating Google’s upcoming zero-tap sign-in restoration requirement https://support.google.com/googleplay/android-developer/answer/17492799?#zero-tap_sign-in_restoration for Home Assistant, which takes effect in April 2027.

Have you already looked into supporting Restore Credentials in NextCloud? Since both projects connect to user-hosted servers, we might face similar challenges around RP IDs, domain association, and instances that are only accessible locally or without HTTPS.

We’re tracking our investigation in [this Home Assistant discussion](https://github.com/orgs/home-assistant/discussions/4858). We haven’t settled on an approach yet and would be interested in comparing notes.

This isn’t a bug report or a request for an immediate implementation, just an opportunity to share findings on a requirement that appears to affect both projects.

Start with the linked Google zero-tap sign-in restoration requirement and the Home Assistant discussion referenced in the issue. Compare how Restore Credentials might apply to RP IDs, domain association, and locally accessible or non-HTTPS instances; done would be a documented comparison and a settled implementation direction.

Written by the indexing model from the issue text.