Configuration
lmux is a macOS terminal on libghostty, and it's configured the way Ghostty is: one plain-text file in Ghostty's syntax. It reads your Ghostty config as it is, and its own Settings window covers the rest, about ten settings in all.
Your Ghostty config#
lmux reads the files Ghostty reads on macOS, in this order:
~/.config/ghostty/config(or$XDG_CONFIG_HOME/ghostty/config), andconfig.ghosttynext to it~/Library/Application Support/com.mitchellh.ghostty/config, andconfig.ghosttynext to it~/.config/lmux/config, which lmux's Settings writes. It's loaded last, so a key set here wins.
Themes, fonts, keybind, colors, padding and the rest of Ghostty's options work as they do in Ghostty (reference). Settings applies a change to every pane at once.
Where your config says nothing, lmux's defaults are:
theme = light:Nord Light,dark:Nord
window-padding-x = 14
window-padding-y = 10
minimum-contrast = 2
unfocused-split-opacity = 1minimum-contrast = 2 draws text black or white where a theme pair would make it unreadable (Claude Code's dark theme on a light terminal, say).
The font is Ghostty's default (JetBrains Mono), or D2Coding on a Mac whose system language is Korean. Hangul always renders in D2Coding at exactly two cells unless you map it yourself (see Korean input).
Where new workspaces and splits start#
| key | what lmux does |
|---|---|
working-directory | A new workspace starts here: an absolute path or ~/… that exists. home, unset or anything else: your home folder. |
working-directory = inherit | A new workspace starts in the focused pane's folder. |
window-inherit-working-directory = true | The same, set explicitly. (tab-inherit-working-directory = true works too.) |
split-inherit-working-directory = false | A split starts in working-directory instead of its pane's folder. |
Ghostty's own default for the inherit keys is true; lmux's, when they're unset, is home. lmux reads these four keys from the files above itself and doesn't follow config-file includes for them. A relaunch, History and the cmux import always use each session's own saved folder.
Settings#
⌘, opens Settings. Theme, font and size go into ~/.config/lmux/config (other lines and comments there are kept as you left them); the rest are lmux's own and live in ~/Library/Application Support/lmux/settings.plist.
| tab | setting | default |
|---|---|---|
| Appearance | Appearance: System, Light or Dark | System |
| Appearance | Theme for light mode and for dark mode, from a gallery of 26 (Catppuccin, Tokyo Night, Gruvbox, Solarized, Dracula and more) | Nord Light / Nord |
| Appearance | Sidebar matches the terminal background | off |
| Appearance | Tab bar on panes with one tab (off: shown only once a pane has two tabs) | on |
| Font | Family, size and fallbacks (for glyphs the font lacks, such as Nerd Font icons) | JetBrains Mono, or D2Coding on Korean systems |
| Notifications | Sound | Off |
| Notifications | Unread count on the Dock icon | off |
| Notifications | Ring around a pane that needs you | on |
| Notifications | Remind me after (a done or waiting row you haven't looked at breathes) | 3 minutes |
| Notifications | Remind again via notification | off |
| General | Ask before quitting while something runs | on |
| General | Restore terminal output after relaunch | on |
| General | Allow other apps to send input to lmux | off |
General also has the Claude Code and Codex hooks (install, update, uninstall), Import from cmux… and Open config file.
Allow other apps to send input to lmux lets scripts like Raycast or Hammerspoon use lmux send and lmux new-workspace --cmd from outside lmux. It's stored as defaults write dev.lmux.app allowExternalSend -bool true. Leave it off unless you need it; from inside a pane those commands always work. See The lmux CLI.
An example ~/.config/lmux/config#
# Loaded after ~/.config/ghostty/config, so a key set here wins.
theme = light:Nord Light,dark:Nord
font-family = D2Coding
font-family = Symbols Nerd Font Mono
font-size = 13A second font-family line is a fallback, tried for glyphs the first one lacks.