I haven’t found any. Event listeners will trigger on all nodes “simultaneously” (disregarding networking delays) and that could be problematic, or advantageous depending on your goal.
Nothing built directly into AppDaemon will allow you to do this. Two options I can think of immediately…
through the Home Assistant platform itself by reading/writing to entities.
I share data between two HA instances with the built in webserver.
If you want to use Home Assistant to host or serve static files then create a directory called www under the .homeassistant configuration path. The static files in .homeassistant/www/ can be accessed by the following URL http://your.domain:8123/local/.
Yes, I don’t think JSON serializes, so if you want to pass complex binary data you may need to do that yourself, but basically anything you can put in a dictionary you should be able to send.