tmux Skill

Use tmux as a programmable terminal multiplexer — both to drive the panes the user is already watching (their dev server, test watcher, REPL, logs) and to run your own isolated sessions. Works on Linux and macOS with stock tmux.

If you were launched from inside tmux, a SessionStart hook will already have told you so and listed the visible panes — which means Mode A below is available. When in doubt, prefer acting on the surfaces the user can actually see; that's usually what they mean.

Mode A — observe & control the user's tmux

This is the high-value mode when you're running inside the user's tmux: you can read and drive the same panes they're looking at, instead of spinning up a sandbox they can't see.

Confirm you're inside their tmux and find the server ($TMUX is socket,pid,session; the socket is the first field):

[ -n "$TMUX" ] && echo "in tmux — socket=${TMUX%%,*} pane=$TMUX_PANE"

Plain tmux ... already targets that server; tmux -S "${TMUX%%,*}" ... is the explicit form. The user usually works one window per project, so the panes sharing your window are the relevant ones. The bundled scripts cover the common operations — prefer them over hand-rolling: