[DANmode]

> What's left in terms of meaningful technical barriers, that would prevent this all from being baked into Android instead of requiring Play Services?

The short version: no open source RCS libraries exist.

The implementation in AOSP is out of date/dead.

[grapheneos]

AOSP fully supports everything needed for RCS. AOSP doesn't provide any actively developed messaging app so an app with RCS support needs to come from elsewhere. AOSP never provided an RCS messaging app. AOSP only provides a sample SMS/MMS app for testing purposes which is intended to be replaced. GrapheneOS is well into the process of replacing it including replacing nearly the whole user interface in our development branch followed by improving the under the hood code. It's not an RCS app and never was but we plan to eventually make our own RCS implementation instead of only providing fully functional compatibility with Google Messages.

[OneDeuxTriSeiGo]

oh nice is there a tracking issue for this somewhere? I've taken a peek at the issues in the org on github but i didn't see one off the bat (mainly because there's a ton of other SMS related issues that pop up from history)

[grapheneos]

We have a dedicated issue tracker for the Messaging app now. The user interface has been nearly entirely overhauled already but we haven't made a new release yet. That's coming soon and then we'll be overhauling it under the hood too.

https://github.com/GrapheneOS/Messaging/issues

https://github.com/GrapheneOS/Messaging/issues/44