AnyCable uses the same protocol as ActionCable, so you can use its JavaScript client without any monkey-patching.

AnyCable allows you to use any WebSocket server (written in any language) as a replacement for your Ruby server (such as Faye, Action Cable, etc).

According to official Actioncable guide, Actioncable creates multiple redis pubsub channels.

Yes, AnyCable uses only a single Redis pub/sub channel. Unlike Action Cable, anycable-go manages the actual subscriptions by itself (see hub.go), we only need a single channel to get broadcasts from web apps to a WS server, which performs the actual retransmission. Check out https://docs.anycable.io/#/v1/misc/how_to_anycable_server

they handled this with 4 1x dynos on Heroku (before switching to AnyCable they had 20 2x dynos for ActionCable).

So ActionCable needs Redis! Is this the first time Rails is aligning with a vendor product? Why not abstract it like AR/AJ?