[donatj]

I am very unclear reading the documentation and clicking around, how do you actually implement the logic? Some sort of JavaScript runtime?

[VagabundoP]

Its a client/server system. So the logic is done by the server and snippets of HXML are served:

https://hypermedia.systems/building-a-contacts-app-with-hype...

That's an example using Flask. There's a demo client bundled with the repo, but I assume you can customise and deploy it. I'm not familar with Expo.