So after a bit of tinkering I was able to get it to sync perfectly with GrapheneOS! The only drawback which I am sure most people who use this OS won't accept is you have to provide a lot of permissions to Google Play Services in order for the watch to activate and function. It's a beautiful piece of hardware and I was able to add a credit card to it. I have yet to test whether or not I can successfully transact with GPay, but I will report back when I know for sure. Only thing I haven't been able to do is activate LTE service on it. I will be patient for now since I am not the only one with that problem (there is a Reddit thread about it already) with a "Server Error Encountered" message.

PS - I just made the switch from Stock to GrapheneOS last night on my Pixel 6 Pro and I LOVE it! This is hands down the best Android experience and loosening the grip Google has on my data is so satisfying. Thank you for the amazing work devs!

    mylesofsmiles Please post as soon as you get LTE working. I noticed on the Google Store there's trouble shooting section that speaks of people having trouble if they had another watch hooked up through their carrier before trying to activate the Pixel Watch. Did you by chance have another smart watch on your carrier account before switching to the PW? I have a Samsung so that's why I'm curious. I'm wondering if I should remove it from my carrier service, remove all apps pertaining to it THEN start the PW set-up. Please let me know if any of this pertains to you.
    Thank you.

        Fhggyy5767 Still haven't gotten it to work yet. My neighbor bought a Pixel Watch from Best Buy so he had to call up T-Mobile so they could add his IMEI and EID to their database before he was able to provision it to his account using the Pixel Watch app. His watch was missing network info just like mine before he called T-Mobile so I will probably have to end up doing the same thing tomorrow despite buying the watch directly from them with the requisite plan add-on. How annoying! This would be my first LTE smartwatch so I never had one on my account before.

            mylesofsmiles K. Thank you for replying. My Samsung is already setup with a plan on T-Mobile. I guess I'll just have to do what your neighbor did as well. Just have them swap the info. That's cool.

                Fhggyy5767 I finally called T-Mobile and had them add the watch IMEI and EID to my account. Turns out they don't come pre-activated when purchased from the carrier directly despite the invoice implying otherwise. On the bright side in doing so the rep screwed up and I am only paying $5/month for the watch line instead of the $10/month I was originally quoted so that's awesome. However, I still can't get the Pixel Watch app to provision the eSIM. My best guess is either one of two things:
                1) I need to wait for the info to be fully added into their network which can take up to 24 hours.
                2) There is some unpublished dependency that GrapheneOS is missing in order to activate cell service in addition to needing the Play Store, Google Services Framework and/or Google Play Services.
                Worst case if this won't provision by tomorrow I will have to "Disconnect and Reset" the watch and pair it with my old stock Pixel 6 Pro and hope that works. I will report back with my findings tomorrow.

                    mylesofsmiles Wow! Alright let's hope for the best. Maybe there'll be some kind of workaround to get it working on GOS if it doesn't get up and running within that 24 hours. I haven't purchased mine yet. I'm kinda watching what happens with you and anyone else who joins in trying to get LTE up and running. I'm sure we can find a workaround 🤞

                        Fhggyy5767 Yeah, so after a bunch of trial and error it would appear that option #2 applies in this case. I am not sure what, but GrapheneOS is missing some component used to talk with T-Mobile servers. So what I ended up doing was wiping the eSIM from my GrapheneOS phone, reinstating it on my old stock Pixel 6 Pro and activating it using the Pixel Watch app. You only have to activate the watch one time so I just unpaired the watch from stock and back to GrapheneOS with mobile service activated. It is critical that you don't toggle "Erase downloaded SIM" from the watch when wiping it in order to pair it back with GrapheneOS successfully. I am stoked it finally works but let this be a PSA to those out there: you need to activate Pixel Watch LTE service on a device running something other than GrapheneOS!

                            mylesofsmiles Sweet! Thanks for figuring that out. Let us know how the features work with Graphene. Curious about the pulse monitor as well. I do a lot of running. Need the pulse monitor to not stop reading. That's a problem with this Samsung

                                Fhggyy5767 No problem, I am just glad to contribute something to this. From what I have seen everything works great so far. The AOSP phone app is compatible with Phone by Google on the Watch which is nice. I had Google Messages on GrapheneOS already so that works seamlessly. Play Store, Fitbit, ECG, it all works as it should. The heart rate monitoring is one of the reasons why I bought this in the first place and it is stellar. I came from a Garmin Fenix 5X and although it had some decent heart rate tracking, this one is truly on another level. The one second refresh rate is really cool. Only thing I have yet to try is GPay which should work because the watch itself is whitelisted by Google. As for the battery "concerns" I have read time and time again... Ignore them because I can get up to 24 hours consistently if you disable the extras like always on display, tilt to wake and always on Google Assistant. The other thing is you don't have to opt-in to location tracking, usage & diagnostic reports and Google Cloud Sync and the watch works just fine without them!

                                    mylesofsmiles Sounds like everything I was hoping to hear. Looking forward to picking one up. Thank you for all the great info. Really appreciate it. Cheers

                                      Kryptos Are you referring to Google Voice (formerly Grand Central) or voice recording? If it is the former then not yet but they do have LINE available. If it is the latter then there are plenty of options.

                                          Has anyone considered what they might be giving up in terms of privacy / security if they pair a Pixel Watch with a Pixel running GOS? Since the watch can establish its own internet connection, it would not seem that we can rely on GOS to restrict network access.

                                          I really hope I am wrong about this, as I would love to acquire an LTE Pixel Watch, but do not want to neutralize the gains I have made in privacy / security just for the convenience / functionality the Watch brings to the table?

                                          Sorry if I appear to be hijacking this thread. If so, please let me know and I will spawn another. Congrats to the individual(s) who got it working.

                                            mylesofsmiles Hi, did you ever get around to testing Google Pay with the Pixel Watch, paired to a GrapheneOS phone? I'm thinking of also buying a Pixel Watch (WiFi version), and I'm just wondering if everything works on GrapheneOS.

                                                Duct9143 Not yet unfortunately. I really want to test it out but I am experiencing some health issues that prevent me from safely going out in public for the time being. I was able to successfully add my card and it is reflected in my Google Account as well. I don't see why it wouldn't work but I will give you an update if the opportunity to try it presents itself. The only reason why it doesn't work in GrapheneOS is because it isn't certified hardware whereas the Pixel Watch is so theoretically it should be fine.

                                                  Kamaehuakanaloa I briefly touched on this earlier. In order to pair the watch with your phone you need to give Google Play Services some extra permissions. If you aren't comfortable with trading some privacy for convenience and the ability to have a functional Google Pay implementation then I wouldn't recommend getting one. I am not too concerned because I restrict what the watch can access through GrapheneOS and the respective privacy settings on the Pixel Watch itself can be disabled. Now if you want to get carried away you could experiment with a program like this one: [https://forum.xda-developers.com/attachments/wearos-tools-v4-0-rar.5735771/?hash=8b942d3d9c2e0addf1dfcc703861041b]

                                                      BalooRJ I don't have any inside knowledge, but would venture to say that GOS on a Pixel watch would be significantly more challenging than GOS on a Pixel tablet. The native tablet is already running Android, whereas the I am pretty sure the Pixel watch is natively running wearos. But anyone please feel free to correct me if I am incorrect.