The server is super-simple, it just relays messages between the clients, it doesn't interpret or change messages at all. We're keeping the server simple so that we can do things like replace it with WebRTC data channels, or... just basically keep our options open. It's also great for development or freezing – since the changes are almost exclusively in the client there's no special coordination you have to do to switch versions, you just make a copy of the client code.

I'm guessing at some point we'll have to make the server a little more sophisticated, like maybe for authorization. But maybe not! We'll try our best to find other ways.

Also of course it's completely open source, so we can't actually pull a Reader ;)

haha fair points! Best of luck; exciting work!

Mozilla is already running Persona free at scale. If they let WebRTC do most the heavy lifting I don't see why they would have any issues running TowTruck free at scale.

Persona is cheating -- the more popular it becomes, at least with browsers and email providers, the cheaper Mozilla's bill. :)