The simplest part of Astral is the actual CDP-compatible binary that you use. What does that actually mean?
Ignoring all of the complexities of implementation, all Astral does is interface with a well-defined protocol which is the Chrome DevTools Protocol.
The best documentation that exists on this protocol can be found here, from the official github repo. I should note that while this documentation is extensive (it's auto-generated), there are no good examples on how to interact with the protocol itself. Most of the learnings I've had on that side were by reading the code on how others interface with the protocol.
Ideally we'd interact with the protocol through a unix pipe, but we currently do it through an exposed port and a websocket.
All of this is to say that all browsers that implement the CDP protocol should just work out of the box with Astral. This includes Firefox, though I haven't tested it. I believe Webkit-backed browsers do not work yet, though we'll see about that in the future.