Getting Started with arb

Install

Option 1: Homebrew (recommended)

Run a single command in any terminal:

arb is Apple-notarized — it opens without security warnings on macOS.

Option 2: Download DMG

Download the latest release from GitHub Releases. Open the DMG and drag arb to your Applications folder.

First Launch

Open arb from Applications, Spotlight, or the command line. On your first launch, you'll see:

• Starship prompt — a minimal, fast prompt showing your current directory, git branch, and language versions
• Syntax highlighting — commands light up as you type them, with different colors for valid commands, arguments, and flags
• Autosuggestions — ghost text from your command history appears as you type. Press right arrow to accept
• Tab completions — press Tab for context-aware completions of commands, paths, and arguments

All of this works immediately. No configuration required.

Built-in Tools

arb ships with six tools pre-installed and pre-configured:

Starship Prompt

A cross-shell prompt that shows your current directory, git branch and status, language versions, and command duration. It's fast (<10ms render time) and updates in real time.

z (Directory Jumping)

Navigate to frequently visited directories by typing partial names:

• z proj — jumps to ~/projects if that's your most visited match
• z web — jumps to ~/projects/webapp

z learns from your cd usage automatically. The more you visit a directory, the higher it ranks.

Delta (Diff Viewer)

Every git diff is automatically rendered with syntax highlighting, line numbers, and color-coded additions/deletions. This is especially useful when reviewing AI-generated code changes from Claude Code or Aider.

Syntax Highlighting

Commands are colored as you type: valid commands in green, unknown commands in red, strings in yellow, flags in blue. This gives instant visual feedback before you hit Enter.

Autosuggestions

Fish-like suggestions appear as gray ghost text based on your command history. Press right arrow to accept the full suggestion, or Ctrl+right arrow to accept word by word.

Completions

Press Tab for context-aware completions. arb includes completions for common tools (git, npm, cargo, docker, etc.) out of the box.

Key Bindings

arb uses standard macOS key bindings plus terminal-specific shortcuts:

• Cmd+T — new tab
• Cmd+N — new window
• Cmd+D — split pane vertically
• Cmd+Shift+D — split pane horizontally
• Cmd+W — close current pane/tab
• Cmd+[/] — switch between panes
• Cmd+1-9 — switch to tab by number
• Cmd+Shift+F — search scrollback
• Cmd++/- — increase/decrease font size

Customization

arb is fully customizable via a single Lua config file. The defaults are tuned for most developers, so customization is entirely optional.

Config File Location

Create your config at:

Example: Change Font

-- ~/.config/arb/arb.lua
local config = {}

config.font = wezterm.font("Fira Code")
config.font_size = 14.0

return config

Example: Change Color Scheme

-- ~/.config/arb/arb.lua
local config = {}

config.color_scheme = "Catppuccin Mocha"

return config

Example: Custom Key Bindings

-- ~/.config/arb/arb.lua
local wezterm = require("wezterm")
local act = wezterm.action
local config = {}

config.keys = {
  { key = "h", mods = "CMD", action = act.ActivatePaneDirection("Left") },
  { key = "l", mods = "CMD", action = act.ActivatePaneDirection("Right") },
}

return config

arb uses the same Lua configuration format as WezTerm. If you're migrating from WezTerm, most of your existing config will work with minimal changes.

AI Coding Workflow

arb is purpose-built for AI coding. Here's a typical workflow:

1. Open arb — your shell boots in ~100ms with all tools ready
2. Run Claude Code — type claude "refactor auth module" and watch AI edit your files
3. Review with Delta — run git diff to see syntax-highlighted changes
4. Navigate with z — jump between project directories instantly
5. Split panes — run tests in one pane while coding in another

Ready to start?

Install arb in seconds. Zero config, zero plugins.

$ brew tap szj2ys/arb && brew install arb

or

Download from GitHub Releases