when a new shell is launched zshmux checks if there are any tmux sessions.
if you are not already in a tmux session zshmux will list all currently active sessions, then ask if you want to attach a currently running session, or make a new session in the shell. if there is only one tmux session running and not attached to any clients, zshmux will just automatically attach the session to the current shell.
source zshmux in your zshrc:
[[ -d PATH/TO/ZSHMUX ]] && source PATH/TO/ZSHMUX/zshmux.sh
open a new shell
zshmux should work with any bash compliant shell, as it no longer implements any zsh specific functions.
download or clone this repo and move zshmux.sh to desired directory. then source in your .zshrc