I know it's not precisely what you're asking, but in the python world there's this new and pretty interesting library, Automat [1]. I believe it's used in Twis

I know it's not precisely what you're asking, but in the python world there's this new and pretty interesting library, Automat [1]. I believe it's used in Twisted, or at least that use case strongly influenced the lib design. I also found this talk about Automat [2] very interesting (though, to be honest, I don't fully like the example described.) Anyway, this is not js nor ui, but if you decide to go for building your own js lib, I'd definitely look into porting automat. [1] https://github.com/glyph/automat https://github.com/glyph/automat [2] https://youtu.be/MtHscXjWbVs https://youtu.be/MtHscXjWbVs