Ha, I like the claude2asciinema name!
I did think about asciinema-style output, but I wanted the player to expose the structured steps rather than just replay the terminal output. Supporting other agent CLIs could definitely be interesting.
I just added a Claude alias that calls Claude with flags wrapped in asciinema. Only annoying thing is that people have wanted video or gifs and the conversion has been annoying a few times. Will fix it later.