Ghostty's AppleScript support replaced my tmux habit

iTerm2

I've used iTerm2 for as long as I can remember — probably since the first day I owned a Mac. It won me over with triggers, smart selection, and a look far nicer than Terminal.app's at the time.

But over the years it's grown bulky, and I've tried plenty of alternatives — Kitty, Alacritty, Warp, you name it. Each is better than iTerm2 in some way, but none of them made me switch, because of one very specific need that, until recently, only iTerm2 could meet. Let me explain.

Always in tmux

I like to always work inside tmux. I even have this in my .zshrc:

if [[ -z "$TMUX" ]]; then
    exec tmux new-session -AD -s main
fi

so that every new terminal drops me straight into tmux.

Capture pane

Beyond the obvious continuity — I never lose a session by accidentally closing the terminal — the one tmux feature I lean on most is capture-pane.

So often I want to capture the output of a command after I've already run it — without re-running it just to redirect the output, and without dragging a mouse selection across pages of scrollback. Eventually I landed on this:

tmux capture-pane -pS - | pick-cmd

pick-cmd is a script I wrote: it reads from stdin, parses command boundaries (by looking for my custom starship prompt as the delimiter), presents them in fzf, and prints the selected command blocks to stdout. Very convenient.

iTerm2 profiles

But always staying inside tmux has a downside: ssh-ing into other hosts becomes a nuisance, because I also auto-attach to tmux on remote machines.

Run ssh remote-host from inside a local tmux session and I'd end up with tmux inside ssh inside tmux.

That's where iTerm2 profiles came to the rescue. I could set up a remote-host profile that runs ssh remote-host as the command, instead of launching my normal login shell and triggering the local tmux auto-attach. Problem solved.

Ghostty's AppleScript support

For all the emulators I'd tried, none could cover my iTerm2-profiles workflow — until Ghostty came along.

Plenty about Ghostty won me over before I even got to the niche feature I needed: it's fast, it's genuinely pretty out of the box, it has a built-in quick (drop-down) terminal, and it's configured through a plain text file I can keep in version control instead of clicking through a preferences pane. That last point alone is a breath of fresh air after years of iTerm2's settings UI.

Ghostty doesn't have iTerm2-style profiles in the way I used them. Instead, it solves the problem from the other direction: if I don't need tmux locally, the nesting never happens — and profiles have nothing left to fix. And the biggest thing keeping tmux in my local sessions, capture-pane, is exactly what Ghostty offers through AppleScript:

tell application "Ghostty"
    set t to focused terminal of selected tab of front window
    perform action "write_screen_file:copy" on t
end tell

That replaces capture-pane. The other thing tmux gave me, continuity, hardly matters on a local machine: there's no flaky connection to drop, and Ghostty's shell integration warns me before I close a window with a command still running. For the first time, I don't have to live inside tmux locally.

With local tmux gone, ssh remote-host from a plain Ghostty window lands me in exactly one tmux — the remote one. No nesting, no profiles required. The only wrinkle: my capture trick now has to work in two worlds, Ghostty locally and tmux over ssh. So I wrapped both in a small script that detects which one it's running in and uses the matching capture method.

Final picture

So here's where I've landed: Ghostty for everything local, tmux only when I ssh out. The one feature I couldn't give up — capturing a command's output after I've already run it — came with me; it just runs through AppleScript now instead of tmux.

After all these years, I didn't expect an AppleScript hook to be the thing that finally moved me off iTerm2. But that was the missing piece — and once it clicked, the switch was easy.