tmux-which-key

A plugin for tmux that allows users to select actions from a customizable popup menu. Inspired by the likes of vscode-which-key, emacs-which-key, and which-key.nvim, this plugin aims to make users more effective at using tmux by reducing keyboard shortcut memorization and increasing feature discoverability.

Key presses

Key	Action
w	Windows menu
/	Split horizontal

Key	Action
p	Panes menu
h	Left pane

✨ Features

• An action menu with many of the common tmux commands
• Mnemonic layout for easy memorization
• Easily customizable and extensible via YAML configuration
• Support for user macros (multiple commands in one action)
• Transient states (menus that stay open for repeated commands)
• Runs in pure tmux script for speed

Demo

Here are a few examples of the plugin in action:

Navigation

Key presses

Key	Action
w	Windows menu
/	Split horizontal

Key	Action
w	Windows menu
c	Create window

Key	Action
w	Windows menu
p	Previous window

Key	Action
w	Windows menu
w	Select window
2	Window 2

Changing layouts

Key presses

Key	Action
w	Windows menu
/	Split horizontal

Key	Action
w	Windows menu
-	Split vertical

Key	Action
w	Windows menu
l	Layouts menu
l (6 times)	Next layout

Key	Action
p	Panes menu
p	Select pane
0	Pane 0

User macros

Key presses

Key	Action
C	Client menu
P	Plugins menu
u	Update plugins

Key	Action
C	Client menu
r	Reload

📦 Installation

Requirements:

• tmux>=3.0
• python>=3.8 (optional)

TPM (Tmux Plugin Manager)

Add the plugin to the list of TPM plugins in your ~/.tmux.conf:

set -g @plugin 'alexwforsythe/tmux-which-key'

Hit prefix + I to install and load the plugin. You'll be presented with a wizard to complete the installation.

Manual installation

Installation steps

1. Clone this repository flag using the --recursive flag:

git clone --recursive https://github.com/alexwforsythe/tmux-which-key $HOME/.tmux/plugins/

2. Register the plugin in your ~/.tmux.conf:

run-shell $PATH_TO_PLUGIN/plugin.sh.tmux

3. Reload your tmux config to load the plugin:

tmux source-file $HOME/.tmux.conf

🎬️ Quickstart

Once you've installed the plugin and reloaded your tmux config, you can open the action using:

• The default root keybinding ctrl + space, or
• The default prefix keybinding prefix + space

⚙️ Configuration

Menus can be customized either by:

1. Editing config.yaml (requires python3), or
2. Editing plugin/init.tmux directly

YAML config

Note

This method requires python3 to be installed on your system. Most Unix systems ship with it installed by default these days, so it shouldn't be a problem for most users. If you don't have python3 installed and aren't willing to use it, you'll need to edit plugin/init.tmux directly.

The default configuration is defined in config.example.yaml. Here's the structure:

# The starting index to use for the command-alias option, used for macros
# (required). This value must be at least 200
command_alias_start_index: 200
# The keybindings that open the action menu (required)
keybindings:
  prefix_table: Space # The keybinding for the prefix key table (required)
  root_table: C-Space # The keybinding for the root key table (optional)
# The menu title config (optional)
title:
  style: align=centre,bold # The title style
  prefix: tmux # A prefix added to every menu title
  prefix_style: fg=green,align=centre,bold # The prefix style
# The menu position (optional)
position:
  x: R
  y: P
# tmux-only environment variables that can be used in commands and macros
# (optional)
custom_variables:
  my_var: my_value
# User-defined macros that can be triggered by the menu (optional)
macros:
  restart-pane: # The macro name
    # The macro commands
    - "respawnp -k -c #{pane_current_path}"
    - display "#{log_info} Pane restarted"
# The root menu items (required)
items:
  - name: Next pane
    key: space # The key that triggers this action
    command: next-pane # A command to run
  - name: Respawn pane
    key: R
    macro: restart-pane # A custom macro (defined above)
  - separator: true # A menu separator
  - name: +Layout # A submenu
    key: l
    menu: # The submenu items
      - name: Next
        key: l
        command: nextl
        transient: true # Whether to keep the menu open until ESC is pressed

User options

@tmux-which-key-disable-autobuild

By default, the menu is rebuilt from config.yaml each time TPM initializes the plugin. If you aren't using the YAML configuration or want to reduce the plugin's impact on tmux startup time, you can disable this behavior by adding this to your ~/.tmux.conf before loading the plugin:

set -g @tmux-which-key-disable-autobuild=1
# ...
set -g @plugin 'alexwforsythe/tmux-which-key'

@tmux-which-key-xdg-enable

Changes the location of configuration and init files to use XDG directories. By default, these paths will be used instead of this plugin's installation directory:

• $XDG_CONFIG_HOME/tmux/plugins/tmux-which-key/config.yaml
• $XDG_DATA_HOME/tmux/plugins/tmux-which-key/init.tmux.

The relative path from XDG_*_HOME can be changed using the @tmux-which-key-xdg-plugin-path option for additional customization.

set -g @tmux-which-key-xdg-enable=1
set -g @tmux-which-key-xdg-plugin-path=tmux/plugins/tmux-which-key # default

# ...

set -g @plugin 'alexwforsythe/tmux-which-key'

This allows the plugin to also be used with immutable or declarative operating systems.

Example Home Manager Nix Config

{
  lib,
  pkgs,
  ...
}: let
  tmux-which-key =
    pkgs.tmuxPlugins.mkTmuxPlugin
    {
      pluginName = "tmux-which-key";
      version = "2024-01-10";
      src = pkgs.fetchFromGitHub {
        owner = "alexwforsythe";
        repo = "tmux-which-key";
        rev = "<commit hash>";
        sha256 = lib.fakeSha256;
      };
      rtpFilePath = "plugin.sh.tmux";
    };
in {
  xdg.configFile = {
    "tmux/plugins/tmux-which-key/config.yaml".text = lib.generators.toYAML {} {
      command_alias_start_index = 200;
      # rest of config here
    };
  };
  programs.tmux.plugins = [
    {
      plugin = tmux-which-key;
      extraConfig = ''
        set -g @tmux-which-key-xdg-enable 1;
      '';
    }
  ];
}

Manual config

You can customize the action menu by editing plugin/init.tmux directly.

Tip

I strongly recommend using YAML to customize your action menu because editing tmux script can be error-prone and difficult to debug.

Zsh

You can open tmux-which-key from the command line by running its tmux alias:

tmux show-wk-menu-root

You can trigger the menu with Space from vicmd mode--similarly to Spacemacs or VSpaceCode--by adding a ZLE widget and keybinding to your ~/.zshrc:

tmux-which-key() { tmux show-wk-menu-root ; }
zle -N tmux-which-key
bindkey -M vicmd " " tmux-which-key

❓ Known issues

Menu or submenu doesn't appear

Menus will silently fail to open if the number of items causes them to exceed the height of the terminal. If you run into this issue frequently, consider breaking your menu into multiple submenus.

Plugin overrides custom aliases

tmux-which-key uses tmux command-alias to execute certain actions, such as macros, quickly. command-alias is a global option, though, so these actions can collide with user aliases or ones defined by other plugins.

This plugin's aliases start at index 200 by default, but if there are already aliases mapped in this range, you can change the default starting index in config.yaml.

Similar projects

• tmux-modal
• tmux-menus
• tmux-easy-menu
• tmux-pain-control

Resources

• man tmux
• Tmux Wiki
• How to create Tmux plugins
• The Tao of tmux