@projectmoon I question AI about android ROM's : you are right :
The answer :
In summary: the RCS protocol is very difficult to deploy on most alternative Android ROMs independent of the Google Play Store. Here's why:
Main Technical Issues
1. RCS heavily depends on Google services
- The standard RCS stack uses Google's proprietary Jibe backend
- It requires Play Services to function properly
- The Google Messages application is virtually indispensable, as most carriers only authorize it through this app
2. Blocking integrity checks Recently, Google has implemented Play Integrity API attestations that prevent using Google Messages on modified systems like:
- GrapheneOS: explicitly states that "RCS is practically impossible" without Google services
- LineageOS without GApps: the default AOSP messaging app does not support RCS because it is not open source
Possible Alternative Solutions
Option 1: Installing microG + Google Messages has low viability due to being blocked by Play Integrity checks.
Option 2: Self-hosted RCS server remains theoretical since there is currently no mainstream open-source implementation available.
Option 3: Using partial GApps offers medium viability but represents a compromise on the privacy you sought when choosing an alternative ROM.
Conclusion
To use RCS reliably, you are practically forced to keep some form of Google services. If your priority is privacy (hence the choice of an alternative ROM), this represents a notable compromise between modern messaging features and de-googling your system.
Fully open solutions exist theoretically but severely lack operational implementations accessible to average users.
Maybe possible but very difficult !