Radar.Chat secure messaging app with Bitcoin lightning payments

So, this new open-source app just dropped yesterday. It offers encrypted messaging along with Bitcoin lightning payments that you can control yourself. The folks behind this are the same ones who made Cake Wallet. Plus, radar.chat is actually a fork of the Signal messenger, so it’s using that solid encryption tech. Right now, it’s only for Android users.

It doesn't use Lightning, it uses statechains (which are custodial).

Radar.Chat claims that everything is self-custodial and if you lose your seed, you lose your bitcoin. They have no way to recover anything, is what they say. But at the same time, the idea was to make the app as simple as possible. Users aren't managing the channels or the liquidity. Radar.Chat owns the nodes and take care of everything in the background. It's worth asking what would happen if all that infrastructure fails and gets wrecked? So it's probably not as self-custodial as managing your own lightning node. Feels weird saying that. Something either is or isn't (self) custodial. There is no middle. Anyways, Radar.Chat claims they created their app with privacy in mind. There are no ads and no trackers. At the moment it can only be installed from GitHub. The app is not yet available on the PlayStore.

They are lying, the statechain operator can track every transaction.

Some details on their homepage really confuse me. It currently don't have FAQ section that cover common question such as how to backup and restore the wallet and LN channel. AFAIK Signal itself use centralized server. Since Radar is different application, i don't understand how they have access to use "Signal’s trusted messaging network", which probably refer to Signal centralized server. On non-technical side, what happen if someone install both Radar and Signal? Will new message from other people shown on both apps?

Thumbs up for bringing this here. Anyways it's a good one looks a lot like Venmo and a couple other payment softwares I haven't really tried it out but it's really a fine idea looks a lot like having something as easy as apple pay but in this case for bitcoin. I tried looking them up on play store but they aren't there yet. I'll go through their GitHub. Nevertheless how encrypted and private is their chat? It would be really interesting if they had something very private like simple X or even better.

The website shows it's in the Apple App Store now. If all you need to recover the channel state is a seed phrase, I don't think it's really self-custody. That's not necessarily a bad thing, but if it is, they should say so. I've never really liked LN in self-custody. The fact that you need to create a backup after each transaction is just annoying. There's always a potential point of failure. I've seen that on many projects: they don't offer details, they don't tell you how it really works, but apparently that's what the average internet user wants: just install something without knowing what it does. Byteball had this almost 10 years ago already, on an altcoin.

Thread you linked have no mention of "signal" and i didn't find anything related from quick google search with keyword "site:obyte.org signal". But i found this podcast (i only read the transcript) that mostly answer my question. It's really long, so i'll just snip few interesting parts.

I didn't mean Signal, I mean a wallet with built-in chat and payment requests.

Looks like Seth is talking about backing up and recovering the communication part of the application. Your Signal account with messages and contacts. But you shouldn't be able to back up something non-custodial in that way. If your bitcoin and LN data is tied to your Signal account and a username with a password, it's not non-custodial. If Seth only means the communication part of Radar.Chat is backed up by default in that way, then it's fine. But if you can access your bitcoin in the same manner, then it's account-based and custodial. He makes it sound like both ways are possible and there is no difference between them. That's the confusing part. Maybe I am the only one who is confused. What I understood from the last part is that the 12-word seed backup is equal to the data saved to your Radar.Chat account/profile.

More info about the surveillance built into Rader: https://x.com/matthewvuk2/status/2076344901478892028