Is it a kind of nostr prtcl?
SimpleX Chat v6.0-beta.4 is released!
It is stable to use, and please let us know any issues - any help testing it is really great!
You can get beta version for iOS from Apple TestFlight, and for Android from GitHub or from our F-Droid repo (it's still in review in Play Store beta channel): https://simplex.chat/downloads/
The final release will be published on 8/14, together with the announcements.
Discussion
No, but it's a very similar design with relays. Nostr has largely failed to provide a private and secure DM protocol so far so that should be a good thing. nostr:nevent1qqs04jkx6rxfnzs8a3dc3gxsqpvjhe9yat74y3hdmfw53efeu22g6qcqrau8x
Actually, in a way it is, it's not THE Nostr protocol but it is notes (messages) and (not really other stuff) transmitted by relays.
Media and files could count as other stuff which is transmitted via relays rather than being uploaded to a single webserver like what happens on Nostr. Here's an article if you want to learn more about SimpleX's file transfer protocol specially https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.html