Rill will not currently work one to one with Express however I think it would be pretty trivial to write a wrapper around Rill that simply mapped a “Express Request/Response” to a “Rill Express/Response” and have it work that way. I have plans to make these adapters but time is short :p.
Also I personally do not use flux or redux anymore. The thing is with Rill the goal is to progressively enhance everything, so you should try to achieve everything with existing browser functionality and http requests. Sometimes it requires a bit of creativity but usually you can achieve the same user experience while maintaining the functionality of the website. For example, for a few sites I’ve built with Rill I have needed drag and drop, the solution was to just add move arrows (which were links handled by Rill) and then implement drag and drop on top of that. The thing that is initially lame is that this can cause you to write the business logic twice here (once for dnd and once for move arrows) however I have found a way to share this as well. Basically I always implement the business logic in Rill routes, then if I need to trigger this logic using something that can’t be represented with forms and links then I use https://github.com/DylanPiercey/submit-form to submit a form. This way I am just adding on to functionality to make it more user friendly, but the core of the app(s) just work. Ultimately you can avoid flux with Rill if you treat the router as a dispatcher and forms and links as your actions.