Important: Because RCS on Android relies entirely on Google’s secure routing servers, it requires a few specific steps to function properly within a hardened GrapheneOS environment.
Step 1: Set Up the Base Environment
- Open the GrapheneOS Apps app and install Google Play Services and the Google Play Store (this installs them securely in a sandbox).
- Open the Google Play Store and download the official Google Messages app. (Note: The default, pre-installed AOSP messaging app does not support RCS).
- Set Google Messages as your default SMS application.
- Confirm your Cape roaming app is set to "United States". You can also confirm this is correct by going to the Cape app, Support > Advanced > Phone Info, and then look for "IMSI" and the first 6 digits of your IMSI should be "314560".
Step 2: Configure App Permissions
Because GrapheneOS restricts background data by default, you must ensure the Google frameworks can talk to the network:
- Go to your phone's Settings > Apps > All Apps.
- Find Google Play Services and ensure Network access is allowed.
- Tap Play Services Special Permissions, then Allow ICC authentication with device identifiers
- Find Google Messages and ensure it has all necessary permissions enabled, including SMS and Network permissions.
Step 3: Activate RCS
- Open Google Messages.
- Tap your profile icon/menu in the top right and go to Messages settings > RCS chats.
- Toggle RCS chats to ON.
- Wait a few moments for the app to verify your phone number with Google's servers.
Troubleshooting: If RCS Gets Stuck on "Connecting" or Fails
If the status gets stuck verifying or fails to connect, the background token is likely corrupted. Follow these steps to force a clean registration:
- Go to Settings > Apps > Messages > RCS chats and toggle RCS OFF.
- Go to your phone's Settings > Apps > All Apps > Messages and select Storage & Cache.
- Tap Clear Data / Clear Storage (this will not delete your actual texts, just the app's system cache).
- Uninstall the Google Messages app.
- Reinstall Google Messages from the Play Store.
- Before opening the app: Go back to your phone's App settings for Messages, set it as your default SMS app, and grant it all available permissions.
- Open the app, head back to RCS settings, and toggle it ON to trigger a fresh verification.