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CRT

Getting Started with CRT Terminal

CRT Terminal (“CRT’s a Ridiculous Terminal”) is a GPU-accelerated terminal emulator with CSS-based theming and visual effects. This tutorial walks you from a fresh install to a working, customized terminal. You will install CRT, explore its built-in themes, change your font and window size, and see live hot reload in action by editing a theme file.

No prior experience with CRT is required. You need a macOS or Linux system and a text editor.

Prerequisites

Section titled “Prerequisites”
  • macOS 12+ or a modern Linux distribution
  • curl available in your current shell
  • A text editor (any editor works; examples use nano)

Step 1: Install CRT Terminal

Section titled “Step 1: Install CRT Terminal”

Run the one-line installer:

Terminal window
curl -sSL https://raw.githubusercontent.com/colliery-io/crt/main/scripts/install.sh | sh

The installer detects your platform automatically:

  • macOS: CRT is installed to /Applications/crt.app
  • Linux: CRT is installed to ~/.local/bin/crt

After installation finishes, the installer prints the path and any first-run instructions.

Verify the installation:

On macOS, open Finder and look for crt.app in your Applications folder, or launch it from Spotlight with Cmd+Space then type crt.

On Linux, verify the binary is on your PATH:

Terminal window
which crt
# Expected: /home/yourname/.local/bin/crt

If which crt returns nothing, add ~/.local/bin to your PATH:

Terminal window
echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc

Step 2: Launch CRT Terminal

Section titled “Step 2: Launch CRT Terminal”

macOS: Double-click crt.app in Applications, or launch it with:

Terminal window
open /Applications/crt.app

Linux:

Terminal window
crt

CRT opens with the default synthwave theme — a deep purple background with cyan text and a neon perspective grid in the backdrop. You should see a working shell prompt.

Step 3: Explore Themes with the Context Menu

Section titled “Step 3: Explore Themes with the Context Menu”

CRT ships with 19 built-in themes. The fastest way to browse them is the right-click context menu.

  1. Right-click anywhere in the terminal window.
  2. A context menu appears. Look for the Theme submenu.
  3. Click any theme name to switch to it immediately.

Try a few themes to get a feel for the range of visual styles:

Theme Style
dracula Classic dark purple with bright pastels
matrix Green-on-black cascading characters
tron Electric cyan on deep black
vaporwave Pink and purple pastel gradients
rain Animated rainfall backdrop
particles Floating particle backdrop
pokemon Animated Pikachu sprite with an indigo night background
minimal Clean, no-effects, distraction-free

Theme switching is instant — no restart required.

Step 4: Understand the Config Directory

Section titled “Step 4: Understand the Config Directory”

CRT reads its configuration from ~/.config/crt/. The directory structure looks like this:

~/.config/crt/
├── config.toml        # Main configuration file
└── themes/            # Theme CSS files live here
    ├── mytheme.css    # (you will create this later)
    └── images/        # Images used by themes

The main config file uses TOML format. If it does not exist yet, CRT creates it with defaults on first run.

Open the config file in your editor:

Terminal window
nano ~/.config/crt/config.toml

If the file is empty or does not exist, create it:

Terminal window
mkdir -p ~/.config/crt
nano ~/.config/crt/config.toml

Step 5: Change the Active Theme

Section titled “Step 5: Change the Active Theme”

Inside config.toml, find or add the [theme] section:

[theme]
name = "tron"

Save the file. CRT detects the change and reloads immediately — you do not need to restart.

Switch back to synthwave (the default release theme):

[theme]
name = "synthwave"

The name value matches the filename of the CSS file, without the .css extension. Built-in themes are always available by name. Custom themes go in ~/.config/crt/themes/ and are referenced the same way.

Step 6: Adjust Font and Window Size

Section titled “Step 6: Adjust Font and Window Size”

Still in config.toml, add [font] and [window] sections. Here is a complete example with common customizations:

[theme]
name = "synthwave"


[font]
family = ["JetBrains Mono", "Fira Code", "SF Mono", "Menlo"]
size = 16.0
line_height = 1.4


[window]
columns = 120
rows = 36
title = "My Terminal"

Font settings explained:

  • family — An ordered list of font names. CRT tries each in order and uses the first one installed on your system. The default list is ["MesloLGS NF", "JetBrains Mono", "Fira Code", "SF Mono", "Menlo"].
  • size — Font size in points. Default is 14.0.
  • line_height — Line spacing multiplier. Default is 1.5. Values between 1.2 and 1.6 are common.

Window settings explained:

  • columns — Terminal width in character columns. Default is 80.
  • rows — Terminal height in rows. Default is 24.
  • title — The window title bar text.

Save the file. Font size and window title update immediately via hot reload. Window dimensions apply on next launch.

Font size keyboard shortcuts:

You can also adjust font size interactively without editing the config:

Shortcut Action
Cmd+= Increase font size
Cmd+- Decrease font size
Cmd+0 Reset font to configured size

Step 7: Configure the Cursor

Section titled “Step 7: Configure the Cursor”

Add a [cursor] section to customize the cursor style and blink behavior:

[cursor]
style = "bar"
blink = true
blink_interval_ms = 530

Available cursor styles:

Style Appearance
block Full character cell (default)
bar Thin vertical bar
underline Horizontal line under character

Save the file to apply the change immediately.

Step 8: Experience Hot Reload by Editing a Theme File

Section titled “Step 8: Experience Hot Reload by Editing a Theme File”

Hot reload is one of CRT’s most useful features for theme development. Any time you save a theme CSS file, CRT reloads it instantly — no restart, no flicker.

Let’s create a minimal custom theme to see this in action.

Create the theme file:

Terminal window
touch ~/.config/crt/themes/mytest.css

Set it as the active theme in config.toml:

[theme]
name = "mytest"

Save config.toml. The terminal will appear blank or use default colors because mytest.css is empty.

Open the theme file in your editor (use a second terminal window, or your graphical editor):

Terminal window
nano ~/.config/crt/themes/mytest.css

Add some initial styling:

:terminal {
    color: #e0e0e0;
    background: #1a1a2e;
    font-size: 14;
    line-height: 1.5;
}


:terminal::cursor {
    background: #e94560;
}

Save the file. Watch the CRT window — it should update immediately with a dark blue background, light gray text, and a red cursor.

Now change the background color while CRT is still open:

:terminal {
    color: #e0e0e0;
    background: #0f3460;
    font-size: 14;
    line-height: 1.5;
}

Save again. The background updates in real time — this is hot reload working. You can iterate on your theme as quickly as you can save the file.

Step 9: Learn the Essential Keyboard Shortcuts

Section titled “Step 9: Learn the Essential Keyboard Shortcuts”

Get familiar with these shortcuts before moving on:

Shortcut Action
Cmd+T New tab
Cmd+W Close current tab
Cmd+1 through Cmd+9 Switch to tab by number
Cmd+Shift+[ Switch to previous tab
Cmd+Shift+] Switch to next tab
Cmd+N New window
Cmd+C Copy selection
Cmd+V Paste
Cmd+F Search
Cmd+Q Quit

On Linux, substitute Ctrl for Cmd.

Next Steps

Section titled “Next Steps”

You now have CRT installed, configured with a custom font size and window size, and know how to use hot reload to iterate on themes in real time.

Where to go next: