Working on fmsg - open protocol for instant messaging, distributed by domain like email..

Its a message definition and protocol, addresses look like @user@domain, anyone can run a host, and threaded messages are linked by cryptographic parent hashes..

The idea is to take the best from email: open protocol, domain ownership, interoperability (unsolicited mail is a feature not a bug), and the best from closed instant messaging rebuilt: efficient binary messages, conversational threads, sender verification, message integrity etc. built-in. Originally envisaged for human-to-human messaging but partculalrly interesting time right now with human-to-agent and agent-to-agent messaging...

The OSS stack is up and running: Go host, Dockerised full setup, CLI, Web API, and a spec nearing v1.0. Did Show HN post week ago: https://markmnl.github.io/fmsg/show-hn.html

Seeking feedback, criticism, validation :) protocol bikeshedding, and especially interest from founding-engineer types who want to help build an open messaging ecosystem rather than another closed app..

What is the unique selling point that it has over Matrix?

Matrix addresses have a similar format, anyone can run a host, open protocol, domain ownership, interop... Threaded messages are supported AFAIK, the details of the crypto will be different but overall it feels like it is close enough that a new protocol will have a hard time having enough advantages to overcome the huge network effect (Matrix being one of the few open messengers that actually have some following already).