cmux — macOS Ghostty Wrapper; Two Separate Configs

cmux is a macOS GUI workspace/multiplexer application that delegates actual terminal rendering to Ghostty. Configuring cmux appearance requires editing two separate config files — one for Ghostty (font/colors/terminal behaviour) and one for cmux itself (workspaces/panes/UI layout).

Config File Split

What	File	Controls
Terminal rendering (font, colors, cursor, keybinds)	`~/.config/ghostty/config`	Ghostty settings
Workspaces, panes, window layout, UI chrome	`~/.config/cmux/cmux.json` (or `~/Library/Application Support/cmux/`)	cmux settings

A common mistake: editing cmux.json to change font size and seeing no effect because font is a Ghostty concern, not cmux's.

Example Ghostty Config

# ~/.config/ghostty/config
font-family = "JetBrains Mono"
font-size = 14
theme = "Catppuccin Mocha"
cursor-style = block
window-padding-x = 8
window-padding-y = 8

macOS Quarantine After Download

cmux installed via zip download from the web may be blocked by macOS Gatekeeper:

# Symptom: "cmux is damaged and can't be opened"
# Fix: remove quarantine attribute
xattr -cr /Applications/cmux.app

# Or for files in a specific path
xattr -cr ~/Downloads/cmux.app
# Then move to /Applications/

wiki/concepts/fish-shell-path-config — Fish shell and PATH configuration for terminal tools
wiki/concepts/remote-server-dotfiles-bootstrap — Full-stack remote dotfiles bootstrap including terminal config

Sources

daily/2026-05-08.md — Discovered while setting up cmux as a terminal workspace manager; had to separately configure Ghostty for font/colors and cmux.json for workspace layout; also encountered macOS quarantine block on first launch

2 KiB Raw Blame History

cmux — macOS Ghostty Wrapper; Two Separate Configs

Config File Split

Example Ghostty Config

macOS Quarantine After Download

Related Concepts

Sources

2 KiB

Raw Blame History