tmux configuration

.tmux.conf

# Kaush's tmux configuration
# https://kau.sh

# switch prefix key from Ctrl B → Ctrl A
unbind-key C-b
set-option -g prefix C-a
bind-key C-a send-prefix

set-window-option -g mode-keys vi

set -g default-shell    /opt/homebrew/bin/fish
set -g default-command  /opt/homebrew/bin/fish

set-option -sg escape-time 0
set-option -g history-limit 5000

# Notify when background work produces output (activity) or explicitly rings a bell.
# - Activity covers builds/tests that print output in another window.
# - Bell covers commands that end with `printf '\a'` (or similar).
set-window-option -g monitor-activity on
set-option -g visual-activity on
set-option -g activity-action other

set-option -g visual-bell on
set-option -g bell-action other

# Keep tmux alerts/messages visible slightly longer (milliseconds).
set-option -g display-time 1000

# automatically rename tmux-window to current path
set-option -g automatic-rename on
set-option -g automatic-rename-format '#{b:pane_current_path}'

# interpret mouse gestures properly
set-window-option -g mouse on
# bind-key -T copy-mode-vi MouseDragEnd1Pane send-keys -X copy-pipe-and-cancel "pbcopy"


# ------------------------------------
# rebinding common commands
bind-key V split-window -h
bind-key S split-window -v

bind-key J resize-pane -D 5
bind-key K resize-pane -U 5
bind-key H resize-pane -L 5
bind-key L resize-pane -R 5

bind h select-pane -L
bind j select-pane -D
bind k select-pane -U
bind l select-pane -R

# kill pane/window without confirmation
bind-key x kill-pane
bind-key & kill-window

# choose-tree with dimmer window names (sessions stay bright)
# note: tree prefix (-> + 0:) is rendered by tmux separately, color only affects description
bind-key w choose-tree -Zw -F '#{?window_format,#[fg=brightblack]#{window_name}#{window_flags}: "#{pane_title}"  #{pane_current_path},#{session_windows} windows#{?session_attached, (attached),}}'


# ------------------------------------
# True color (24-bit RGB) support for terminals like Ghostty
set -g default-terminal "tmux-256color"
set -ga terminal-overrides ",ghostty:Tc"
set -ga terminal-overrides ",xterm-ghostty:Tc"
set -ga terminal-overrides ",xterm-256color:Tc"

# customize status bar colors
set-window-option -g window-status-current-style fg=5
set-option -g status-bg '#282C34'
set-option -g status-fg colour240
set-option -g status-left '#[fg=colour82,bold][tmux] #[default]'
set-option -g status-right '#[fg=colour233,bg=colour241,bold] %d/%m #[fg=colour233,bg=colour245,bold] %H:%M:%S '
set-option -g status-right-length 80
set-option -g status-left-length 20

# pane border colors
# inactive border was too light; keep active border green
set-option -g pane-border-style fg=colour238
set-option -g pane-active-border-style fg=colour82


# ---------------------------------------------
# fzf file picker popup (Ctrl+A t)
# Ctrl+G: show gitignored files | Ctrl+H: hide gitignored files
bind-key t run-shell "tmux display-popup -E -w 80% -h 80% '~/bin/tmux-fzf-picker \"#{pane_current_path}\" \"#{pane_id}\"'"

# ---------------------------------------------
# Subagent menu (prefix + 9)
# Spawns a background window running a chosen CLI agent.
bind-key g display-menu -T "Subagent" \
    "Spawn (codex)"  c "run-shell -b '$HOME/bin/tmux-subagent prompt-spawn \"#{pane_id}\" \"#{pane_current_path}\" codex'" \
    "Spawn (claude)" a "run-shell -b '$HOME/bin/tmux-subagent prompt-spawn \"#{pane_id}\" \"#{pane_current_path}\" claude'" \
    "Spawn (gemini)" g "run-shell -b '$HOME/bin/tmux-subagent prompt-spawn \"#{pane_id}\" \"#{pane_current_path}\" gemini'"