schematic of how Pluto works?

Hi Pluto devs,

Thanks for this wonderful package, I use nothing else these days to develop :-)

I'd like to start looking at how Pluto works and was wondering if there is some schematics on states of the javascript/julia side and how they talk to each other. Just asking in case you guys had one while developing it, it would be very useful to see an overview. e.g. how do the message look that are sent between browser and julia, and how and where is the current state keps in both sides? I am starting to dig through the code but its getting quite big :-)