Wezterm + TMUX Integration Question

[sins621]

I wanted to ask if there is compatibility between Wezterm and TMUX using this plugin. When I have the plugin enabled in my Wezterm configuration switching between TMUX panes using ctrl+h,j,k,l. doesn't seem to work anymore. If I disable the plugin in Wezterm then I can switch panes as normal.

Here is my Wezterm config:

local wezterm = require("wezterm")
local smart_splits = wezterm.plugin.require("https://github.com/mrjones2014/smart-splits.nvim")
local config = wezterm.config_builder()
local is_windows = wezterm.target_triple:find("windows") ~= nil

config.color_scheme = "Gruvbox Dark (Gogh)"
config.font = wezterm.font("FiraCode Nerd Font")
config.font_size = 14
config.window_decorations = "TITLE|RESIZE"
config.tab_bar_at_bottom = true
config.use_fancy_tab_bar = false
config.window_close_confirmation = "AlwaysPrompt"
config.term = "wezterm"

if is_windows then
	config.default_prog = { "powershell.exe" }
else
	config.default_prog = { "zsh" }
end

config.hide_tab_bar_if_only_one_tab = true
config.adjust_window_size_when_changing_font_size = false

config.leader = { key = "a", mods = "CTRL", timeout_milliseconds = 1000 }

config.keys = {
	{ key = "v", mods = "LEADER", action = wezterm.action({ SplitVertical = { domain = "CurrentPaneDomain" } }) },
	{ key = "h", mods = "LEADER", action = wezterm.action({ SplitHorizontal = { domain = "CurrentPaneDomain" } }) },
	{ key = "z", mods = "LEADER", action = "TogglePaneZoomState" },
	{ key = "c", mods = "LEADER", action = wezterm.action({ SpawnTab = "CurrentPaneDomain" }) },
	{ key = "1", mods = "LEADER", action = wezterm.action({ ActivateTab = 0 }) },
	{ key = "2", mods = "LEADER", action = wezterm.action({ ActivateTab = 1 }) },
	{ key = "3", mods = "LEADER", action = wezterm.action({ ActivateTab = 2 }) },
	{ key = "4", mods = "LEADER", action = wezterm.action({ ActivateTab = 3 }) },
	{ key = "5", mods = "LEADER", action = wezterm.action({ ActivateTab = 4 }) },
	{ key = "6", mods = "LEADER", action = wezterm.action({ ActivateTab = 5 }) },
	{ key = "7", mods = "LEADER", action = wezterm.action({ ActivateTab = 6 }) },
	{ key = "8", mods = "LEADER", action = wezterm.action({ ActivateTab = 7 }) },
	{ key = "9", mods = "LEADER", action = wezterm.action({ ActivateTab = 8 }) },
	{ key = "&", mods = "LEADER|SHIFT", action = wezterm.action({ CloseCurrentTab = { confirm = true } }) },
	{ key = "d", mods = "LEADER", action = wezterm.action({ CloseCurrentPane = { confirm = true } }) },
	{ key = "x", mods = "LEADER", action = wezterm.action({ CloseCurrentPane = { confirm = true } }) },
	{
		key = "i",
		mods = "ALT",
		action = wezterm.action.ActivateTabRelative(-1),
	},
	-- Navigate to the right tab
	{
		key = "o",
		mods = "ALT",
		action = wezterm.action.ActivateTabRelative(1),
	},
	{
		key = "i",
		mods = "ALT|SHIFT",
		action = wezterm.action.MoveTabRelative(-1),
	},
	-- Navigate to the right tab
	{
		key = "o",
		mods = "ALT|SHIFT",
		action = wezterm.action.MoveTabRelative(1),
	},
}

smart_splits.apply_to_config(config, {
  direction_keys = { 'h', 'j', 'k', 'l' },
  modifiers = {
    move = 'CTRL', -- modifier to use for pane movement, e.g. CTRL+h to move left
    resize = 'ALT', -- modifier to use for pane resize, e.g. ALT+h to resize to the left
  },
})
return config

And my TMUX config:

set -g mouse on

set-option -g default-terminal "wezterm"
set-option -g focus-events on

set -g default-shell /bin/zsh
set -g @plugin 'tmux-plugins/tpm'
set -g @plugin 'tmux-plugins/tmux-sensible'
set -g @plugin 'niksingh710/minimal-tmux-status'
set -g base-index 1
setw -g pane-base-index 1

# '@pane-is-vim' is a pane-local option that is set by the plugin on load,
# and unset when Neovim exits or suspends; note that this means you'll probably
# not want to lazy-load smart-splits.nvim, as the variable won't be set until
# the plugin is loaded

# Smart pane switching with awareness of Neovim splits.
bind-key -n C-h if -F "#{@pane-is-vim}" 'send-keys C-h'  'select-pane -L'
bind-key -n C-j if -F "#{@pane-is-vim}" 'send-keys C-j'  'select-pane -D'
bind-key -n C-k if -F "#{@pane-is-vim}" 'send-keys C-k'  'select-pane -U'
bind-key -n C-l if -F "#{@pane-is-vim}" 'send-keys C-l'  'select-pane -R'

# Alternatively, if you want to disable wrapping when moving in non-neovim panes, use these bindings
# bind-key -n C-h if -F '#{@pane-is-vim}' { send-keys C-h } { if -F '#{pane_at_left}'   '' 'select-pane -L' }
# bind-key -n C-j if -F '#{@pane-is-vim}' { send-keys C-j } { if -F '#{pane_at_bottom}' '' 'select-pane -D' }
# bind-key -n C-k if -F '#{@pane-is-vim}' { send-keys C-k } { if -F '#{pane_at_top}'    '' 'select-pane -U' }
# bind-key -n C-l if -F '#{@pane-is-vim}' { send-keys C-l } { if -F '#{pane_at_right}'  '' 'select-pane -R' }

# Smart pane resizing with awareness of Neovim splits.
bind-key -n M-h if -F "#{@pane-is-vim}" 'send-keys M-h' 'resize-pane -L 3'
bind-key -n M-j if -F "#{@pane-is-vim}" 'send-keys M-j' 'resize-pane -D 3'
bind-key -n M-k if -F "#{@pane-is-vim}" 'send-keys M-k' 'resize-pane -U 3'
bind-key -n M-l if -F "#{@pane-is-vim}" 'send-keys M-l' 'resize-pane -R 3'

tmux_version='$(tmux -V | sed -En "s/^tmux ([0-9]+(.[0-9]+)?).*/\1/p")'
if-shell -b '[ "$(echo "$tmux_version < 3.0" | bc)" = 1 ]' \
    "bind-key -n 'C-\\' if -F \"#{@pane-is-vim}\" 'send-keys C-\\'  'select-pane -l'"
if-shell -b '[ "$(echo "$tmux_version >= 3.0" | bc)" = 1 ]' \
    "bind-key -n 'C-\\' if -F \"#{@pane-is-vim}\" 'send-keys C-\\\\'  'select-pane -l'"

bind-key -T copy-mode-vi 'C-h' select-pane -L
bind-key -T copy-mode-vi 'C-j' select-pane -D
bind-key -T copy-mode-vi 'C-k' select-pane -U
bind-key -T copy-mode-vi 'C-l' select-pane -R
bind-key -T copy-mode-vi 'C-\' select-pane -l


run '~/.tmux/plugins/tpm/tpm'

I didn't open an issue because I'm not entirely sure if the plugin is intended to integrate these two tools together or if it's just a mistake in my configuration. Any help is appreciated.

[mrjones2014]

It sounds like you're a bit confused about the function of the Wezterm plugin.

Wezterm has built-in terminal multiplexing support. smart-splits.nvim supports Wezterm's multiplexer as a backend.

Tmux is also a terminal multiplexer. You should choose one or the other, as they do the same job (mostly, with some slightly differing features).

If I disable the plugin in Wezterm then I can switch panes as normal.

Right, because then it's falling back to the tmux integration, and Wezterm is not swallowing the key presses. By default, smart-splits.nvim checks for tmux first, because some people use tmux in Wezterm and just disable Wezterm's multiplexer; if tmux is not found, then it tries to set up the Wezterm integration.

So what's happening for you is, smart-splits.nvim is setting itself up to use the tmux integration, but the Wezterm plugin is setting up Wezterm keymaps that are the same as your tmux keymaps, therefore Wezterm swallows the key presses and tmux never receives the key press events.

Personally, I switched from tmux to Wezterm's built-in mux quite a while ago, it's more than sufficient for my needs, and wezterm ssh is quite nice.

tl;dr: the solution is to pick one or the other from tmux or Wezterm's built-in mux. If you choose tmux, don't install the Wezterm plugin, since it isn't needed if you're using tmux.

[sins621]

That makes sense, thanks for the clarification 🙏