What do you mean by that ?
Discussion
Javascript code, that would run in a browser acting as a relay. It's tricky, but I think it could be done.
I think that initiating the web socket connections from the clients to the browser-relay would be the hard part, because browsers won't accept incoming network requests from random ip addresses, but maybe there is a round-about way to do it. Something like NWC.
But a relay has to store information right? So it would be just a dashboard of a relay that you could manage the storage ?
Every browser actually has a database in it. It's called "IndexedDB". You could use that.
In your desktop browser window hit ctrl-i
Then on the tabs across the top select Application.
Look down the side on the left and you will see a section for Storage, and then you can see IndexedDB is in there.