---
title: Configuration
description: Configure cmux appearance and behavior
---

# Configuration

cmux reads configuration from Ghostty config files, giving you familiar options if you're coming from Ghostty.

## Config File Locations

cmux looks for configuration in these locations (in order):

1. `~/.config/ghostty/config`
2. `~/Library/Application Support/com.mitchellh.ghostty/config`

Create the config file if it doesn't exist:

```bash
mkdir -p ~/.config/ghostty
touch ~/.config/ghostty/config
```

## Appearance Options

### Font

```ini
font-family = JetBrains Mono
font-size = 14
```

### Colors

```ini
# Theme (or use individual colors below)
theme = Dracula

# Custom colors
background = #1e1e2e
foreground = #cdd6f4
cursor-color = #f5e0dc
cursor-text = #1e1e2e
selection-background = #585b70
selection-foreground = #cdd6f4
```

### Split Panes

```ini
# Opacity for unfocused splits (0.0 to 1.0)
unfocused-split-opacity = 0.7

# Fill color for unfocused splits
unfocused-split-fill = #1e1e2e

# Divider color between splits
split-divider-color = #45475a
```

## Behavior Options

### Scrollback

```ini
# Number of lines to keep in scrollback buffer
scrollback-limit = 10000
```

### Working Directory

```ini
# Default directory for new terminals
working-directory = ~/Projects
```

## App Settings

In-app settings are available via **cmux → Settings** (⌘,):

### Theme Mode

Choose between:
- **System** - Follow macOS appearance
- **Light** - Always light mode
- **Dark** - Always dark mode

### Automation Mode

Control socket access level:

- **Off** - No socket control (most secure)
- **Notifications only** - Only allow notification commands
- **Full control** - Allow all socket commands

<Callout type="warn">
  On shared machines, consider using "Notifications only" mode to prevent other processes from controlling your terminals.
</Callout>

### Update Channel

- **Stable** (default) - Production releases only
- **Nightly builds** - Opt in to nightly main-branch builds

Nightly builds can include incomplete features or regressions; use them if you want the latest changes quickly.

## Example Config

Here's a complete example configuration:

```ini
# Font
font-family = SF Mono
font-size = 13

# Colors
theme = One Dark

# Scrollback
scrollback-limit = 50000

# Splits
unfocused-split-opacity = 0.85
split-divider-color = #3e4451

# Working directory
working-directory = ~/code
```
