Krypton

A keyboard-driven terminal emulator with a cyberpunk aesthetic. Built with Rust + Tauri v2 and TypeScript + xterm.js.

Single transparent native window. Multiple terminal windows rendered as DOM elements with custom chrome. Tiling layout engine. Vim-style modal keyboard system. Sound effects. Shader post-processing. Claude Code integration. Embedded AI coding agent.

Features

• Transparent workspace -- fullscreen borderless window with DOM-based terminal windows
• Tiling layouts -- Grid (auto-tile balanced) and Focus (65/35 split with pinned windows on right)
• Modal keyboard system -- Normal, Compositor, Resize, Move, Swap, Selection, Hint, TabMove, CommandPalette, Dashboard modes
• Tabs & panes -- split terminals horizontally/vertically within a window, tab bar with keyboard navigation
• Which-key popup -- Helix-style hint overlay showing context-aware keybindings per mode and pane type
• Command palette -- fuzzy-searchable action list (Cmd+Shift+P) with ~35 registered actions
• Quick Terminal -- persistent overlay terminal toggled with Cmd+I
• Animation engine -- morph, slide, crossfade transitions with entrance/exit effects and input buffering
• Background animations -- canvas-based effects (flame cursor trail, brainwave EEG, Matrix rain) during Claude Code processing
• Cyberpunk HUD chrome -- glowing borders, L-shaped corner accents, striped header bars, telemetry sidebar
• Sound effects -- 20+ event-driven sounds (window create/close, mode enter/exit, focus, tabs, panes) via rodio
• Shader effects -- post-processing presets: CRT, hologram, glitch, bloom, matrix
• Hint mode -- regex-pattern matching with keyboard label overlays for quick selection
• Selection mode -- vim-like keyboard-driven text selection (char/line-wise)
• Pin windows -- pinned windows stick to right column in Focus layout, skipped during focus cycling
• Theming -- built-in themes + custom TOML themes in ~/.config/krypton/themes/, hot-reloaded
• SSH support -- connection detection and OpenSSH ControlMaster multiplexing
• Claude Code hooks -- HTTP server receives Claude Code events, renders neural uplink bar, sigil badge, tool HUD, activity trace, and notification toasts in the window chrome
• AI Agent -- embedded coding agent (@mariozechner/pi-agent-core) in a dedicated tileable window with streaming responses, tool execution (bash, read_file, write_file), and session persistence
• Notification system -- persistent bottom-right notifications with glitch-decode reveal, captures OSC 9/777/99 from terminals
• Markdown viewer -- two-panel file browser + rendered preview with block select mode, reload, and heading navigation
• Git diff viewer -- syntax-highlighted diff view for staged/unstaged changes
• Dashboard system -- tabbed overlay dashboards (Git, OpenCode) with keyboard routing
• Extensions -- context-aware plugins that activate on process detection (Java, etc.)
• Cursor trail -- rainbow flame particle system on mouse and text cursor

Keyboard Shortcuts

Shortcut	Action
Cmd+P	Leader key (enter Compositor mode)
Cmd+I	Toggle Quick Terminal
Cmd+Shift+P	Command palette
Cmd+Shift+< / >	Cycle focus between windows
Ctrl+Shift+U / D	Scroll buffer up/down one page
Leader + n	New window
Leader + x	Close window
Leader + a	Open AI Agent window
Leader + f	Toggle Focus/Grid layout
Leader + z	Toggle maximize
Leader + p	Toggle pin on focused window
Leader + h/j/k/l	Focus window by direction
Leader + r	Enter Resize mode
Leader + m	Enter Move mode
Leader + s	Enter Swap mode
Leader + t	New tab
Leader + \ / -	Split pane vertical / horizontal
Leader + d / D	Git diff (unstaged / staged)
Leader + o	Open markdown viewer for CWD
Escape	Exit current mode / hide Quick Terminal

AI Agent shortcuts (when agent window focused):

• Enter -- Submit prompt
• Shift+Enter -- Insert newline
• Up/Down (empty input) -- Recall previous/next prompt
• Ctrl+C -- Abort turn / clear input
• Page Up/Down -- Scroll messages (stays in input mode)
• Escape (empty input) -- Enter scroll mode
• Scroll mode: j/k scroll lines, g/G top/bottom, y/Y yank to clipboard, i return to input

Configuration

Krypton is configured via TOML at ~/.config/krypton/krypton.toml (auto-created on first run). Changes are hot-reloaded.

Custom themes go in ~/.config/krypton/themes/*.toml. Built-in themes: krypton-dark, legacy-radiance.

See docs/06-configuration.md for the full config reference.

Development

npm install              # Install frontend dependencies
npx tauri dev            # Run full app (Rust + frontend dev server)
npm run build            # Build frontend
npx tauri build          # Build distributable app bundle
make dev                 # Shortcut for npx tauri dev
make build               # Shortcut for npx tauri build
make install             # Build + copy to /Applications (macOS)

Rust only (from src-tauri/)

cargo build              # Build backend
cargo clippy             # Lint (must pass with no warnings)
cargo fmt                # Format
cargo test               # Run tests

Type-check

npm run check            # or: npx tsc --noEmit

Architecture

krypton/
  src/                     # Frontend TypeScript
    main.ts                # Entry point
    compositor.ts          # Window lifecycle, layout, tabs, panes, Quick Terminal
    input-router.ts        # Modal keyboard system (10 modes)
    layout.ts              # Grid and Focus tiling algorithms
    animation.ts           # WAAPI-based transitions with input buffering
    command-palette.ts     # Fuzzy-searchable action registry
    which-key.ts           # Keybinding hint popup
    sound.ts               # Sound effect triggers (calls Rust backend)
    theme.ts               # Theme engine, CSS custom property application
    config.ts              # Frontend config bridge
    claude-hooks.ts        # Claude Code hook event UI
    dashboard.ts           # Tabbed overlay dashboard framework
    notification.ts        # Persistent notification control (OSC 9/777/99)
    flame.ts               # Background animation interface
    brainwave.ts           # EEG waveform animation for Claude Code
    matrix.ts              # Matrix 3D rain background animation
    hints.ts               # Regex-pattern label overlays
    markdown-view.ts       # Markdown viewer with file browser + block select
    diff-view.ts           # Git diff viewer with syntax highlighting
    selection.ts           # Vim-like text selection mode
    shaders.ts             # Post-processing shader presets
    cursor-trail.ts        # Rainbow flame particle effects
    extensions.ts          # Context-aware process extension framework
    agent/                 # AI Agent integration
      agent.ts             # AgentController wrapping pi-agent-core
      agent-view.ts        # ContentView with streaming message render
      tools.ts             # Krypton tools (read_file, write_file, bash, get_cwd)
      session.ts           # Session persistence to ~/.config/krypton/agent-sessions/
      index.ts             # Public API exports
    dashboards/            # Dashboard implementations
      git.ts               # Git status dashboard
      opencode.ts          # OpenCode dashboard
    extensions/            # Process-specific extensions
      java.ts              # Java context extension
    types.ts               # Shared type definitions
    styles.css             # Cyberpunk HUD styles (BEM)
  src-tauri/               # Rust backend
    src/
      lib.rs               # Tauri builder, plugin setup, command registration
      pty.rs               # PTY session management (portable-pty)
      commands.rs          # IPC command handlers
      config.rs            # TOML config loading + filesystem watcher
      theme.rs             # Theme resolution (built-in + custom)
      sound.rs             # Audio engine (rodio, dedicated thread)
      hook_server.rs       # HTTP server for Claude Code hooks
      ssh.rs               # SSH detection + ControlMaster multiplexing
  docs/                    # Specifications and progress tracking

Backend manages PTY sessions, config/theme loading, sound playback, SSH multiplexing, and the Claude Code hook server. Frontend handles rendering, layout, input routing, animations, and all UI. Communication uses Tauri IPC -- commands for request/response, events for streaming.

Tech Stack

• Rust + Tauri v2 -- native shell, PTY management, IPC, audio, HTTP hook server
• TypeScript + xterm.js -- terminal rendering, compositor, input system
• @mariozechner/pi-agent-core -- embedded AI coding agent
• Vite -- frontend build tooling
• portable-pty -- cross-platform PTY spawning
• rodio -- audio playback
• axum -- Claude Code hook HTTP server

License

MIT