Using RCS with Google Messages on GrapheneOS

Syberkonda This worked perfectly for me! (Granted, I only did it last night, and it took overnight for it to go from "Verifying" to "Connected," and it's possible that it may disconnect in a few days, as that's an issue others have reported here...)
Your comment needs to be pinned or something so folks can find it in the future. In fact, I'm going to copy the steps here just in case the reddit thread ever got deleted:

download the beta app version of Google Messages:
https://www.apkmirror.com/apk/google-inc/messenger-google-inc/messenger-google-inc-5-2-051-release/
From there, follow the next set of steps:

1. Turn off Wi-Fi (it can interfere with the setup).

NOTE: If you have a VPN, either disable it or whitelist (aka split-tunnel) Google Messages, Play Store, Play Services, and GSF.

2. Open the Activity Launcher app.
3. Tap the drop-down menu at the top of the screen, select "All activities."
4. Scroll down to "Messages," tap it.
5. In the Messages sub-list, scroll to "Set RCS Flags," tap it.

NOTE: Activity launcher apps include Nova Launcher and Shortcut Maker.
If you have ADB access thru a PC or an app like LADB, Ashell, Termux, or Tasker, you can directly launch the activity by running
am start -n com.google.android.apps.messaging/.ui.appsettings.rcs.overrides.OverrideFlagsActivity

6. In the screen that opens, tap the drop-down menu below "ACS Url" so we can input the address for the Jibe/RCS server to use.
7. a) If you want to try Google's sandbox server, tap the option named "http://rcs-acs-prod-us.sandbox.google.com" in the drop-down menu.
8. b) If you'd prefer to use a server for your carrier, then manually enter your details into the "ACS Url" box based on the list here. Also, note that this will probably fail if you tried the sandbox server first without wiping Google Messages' app data before trying again. (You can attempt one or the other, if one doesn't work).

NOTE: Use acs-vzw.jibe.google.com for Verizon.

8. Tap the drop-down menu for "OTP Pattern" and set it to "Your\sMessenger\sverification\scode\sis\sG-(\d{6})" which should be an option already present in the list.
9. Tap "Apply" at the bottom of the list.
10. Force close the Messages app. (Lots of ways to access this: via Settings -> Apps -> All apps -> Messages -> Force stop in Android Q, sometimes long-holding the app or tapping the app icon in the multitasking/recents menu will show an "App info" option that takes you to the same screen.)
11. Re-open Messages, you should have a banner at the bottom of the screen — something along the lines of "New! See when friends are typing" — prompting you to set up RCS/Chat for Messages.
12. Tap "Upgrade Now" in that banner and follow the setup process, it should complete within a few minutes

Other notes from me: You should be able to revoke SMS permissions from Google Play Store and Play services after setup is complete. The Carrier Services app does not appear to be necessary, although this may depend on your carrier. I have Verizon. The APK to download from ApkMirror is safe and legitimate. The "Pegasus" in the name predates the Pegasus hacking software; it's just the internal development name for that version of Messages (other versions have names like Unicorn and Minotaur). If your phone were hacked by Pegasus—and it's unclear whether Graphene phones are even vulnerable to it—there certainly wouldn't be an apk with "pegasus" in the file name.

N3rdTek By the way, did you ever do some DNS filtering to figure out if there are any telemetry domains that can be safely blocked without disrupting RCS?

Welp, my RCS finally disconnected. It lasted one day off from two weeks. No DNS filtering and I had revoked SMS permission in Google Play Services and Store in the middle of the week.

[deleted] that's interesting. I tried revoking SMS from Play Services and RCS immediately stopped working. (It still said "Connected," but messages were only getting sent as SMS not RCS)

billinmtl Are stock android users getting consistently de-registered every few days? I've only seen that issue here. Having done a lot of reading, most of them have rather basic solutions that permanently fix their problems.

Syberkonda

I'm at this point too. And I've only did it once. Something is broken and suppose we can only hope it gets fixed accidentally or intentionally at this point.

bluesl33ves

Did yours ever sort itself out?

I finally gave it a try. Used Aurora store to download the old APK, put the Verizon ACL in, RCS connected and I updated to the current beta. RCS has remained connected for a week or so now.

I did attempt to toggle it off then on, and it would not reconnect so I had to go through the whole process again.

A word of warning for those of you who like to keep a clean inbox, switching to the old APK unarchives everything. You will have to manually archive everything again. 😮‍💨

[deleted] what option did you turn off? I'm not following.

patienttruth99
SMS permission in Google Play Services. Last week Wednesday or so. And RCS disconnected on Saturday.

Syberkonda Agreed. Though I'm not sure that the ACS URL is the entire problem. I've had it disconnect on me even though the Debug menu in the most recent version of Google Messages still showed the correct URL.

Ninja4694 when I first tried the big workaround last week and then immediately tried turning RCS off and on, (it wouldn't turn back on) he ACS url stayed in the debug menu for a couple hours. Then it went away. I had to start over. It's been working since (just a week or so).

Has anyone tried updating the old Google Messages Beta to the latest Beta version and staying on that?

[deleted] yes, that's what I understood @bluesl33ves had done, so I tried it and have been on it for about a week. Don't turn it off though as it wouldn't reconnect.

Ninja4694
It must work for some setups or maybe different carriers. All I know is it works for some. You can also try having SMS off then toggling it on and get positive results as well. Of course, depending on if it is possible on said device.

So I signed up for beta and now I'm trying to redo the process. I installed the older version but in activity launcher there is a lock icon next to the flags option. It wasn't there before and I'm not able to change the URL. Has anyone overcome this issue?

This is the error I'm getting when trying from usb:

cheetah:/ $ am start -n com.google.android.apps.messaging/.ui.appsettings.rcs.overrides.OverrideFlagsActivity
Starting: Intent { cmp=com.google.android.apps.messaging/.ui.appsettings.rcs.overrides.OverrideFlagsActivity }

Exception occurred while executing 'start':
java.lang.SecurityException: Permission Denial: starting Intent { flg=0x10000000 cmp=com.google.android.apps.messaging/.ui.appsettings.rcs.overrides.OverrideFlagsActivity } from null (pid=1660, uid=2000) not exported from uid 10232
	at com.android.server.wm.ActivityTaskSupervisor.checkStartAnyActivityPermission(ActivityTaskSupervisor.java:1136)
	at com.android.server.wm.ActivityStarter.executeRequest(ActivityStarter.java:1081)
	at com.android.server.wm.ActivityStarter.execute(ActivityStarter.java:742)
	at com.android.server.wm.ActivityTaskManagerService.startActivityAsUser(ActivityTaskManagerService.java:1290)
	at com.android.server.wm.ActivityTaskManagerService.startActivityAsUser(ActivityTaskManagerService.java:1241)
	at com.android.server.am.ActivityManagerService.startActivityAsUserWithFeature(ActivityManagerService.java:3295)
	at com.android.server.am.ActivityManagerShellCommand.runStartActivity(ActivityManagerShellCommand.java:724)
	at com.android.server.am.ActivityManagerShellCommand.onCommand(ActivityManagerShellCommand.java:233)
	at com.android.modules.utils.BasicShellCommandHandler.exec(BasicShellCommandHandler.java:97)
	at android.os.ShellCommand.exec(ShellCommand.java:38)
	at com.android.server.am.ActivityManagerService.onShellCommand(ActivityManagerService.java:9862)
	at android.os.Binder.shellCommand(Binder.java:1109)
	at android.os.Binder.onTransact(Binder.java:926)
	at android.app.IActivityManager$Stub.onTransact(IActivityManager.java:5311)
	at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:2767)
	at android.os.Binder.execTransactInternal(Binder.java:1392)
	at android.os.Binder.execTransact(Binder.java:1328)

thed0ctor Try clearing storage for Activity Launcher and force stopping it. That should get it to refresh the available options.