It's also worth noting that the bundle that includes the Lua code is signed and its signature gets verified by the OS before running.

Very well done! I'm using it to keep track of the proposals

Hahahahaha true!

Yes, I went to the link quite happy because I thought it was related to AppleEvents and maybe Apple Scripts. Your app is definitely cool, congratulations on your work but the name got me fooled.

PS: Maybe the HN people haven't used MacOS 9 and AppleScript a lot and will not do the association I did.

I don't know which part you're most interested in, but in a nutshell: the events are fetched from the same API as the Apple TV Events app (found that using a proxy), the Chromecast streaming uses Bonjour to find Chromecast devices on the network and the CASTV2 protocol over TCP to send commands to them.

The Chromecast protocol specification (CASTV2) itself is sort of open. To implement it on macOS I did a little bit of reverse engineering and used a description of the protocol I found here: https://github.com/thibauts/node-castv2