A native macOS terminal multiplexer for AI-assisted development.
Efxmux wraps Claude Code and OpenCode terminal sessions in a structured, multi-panel workspace. It co-locates the AI agent terminal, a live GSD progress viewer with checkbox write-back, git diff, file tree, and a secondary bash terminal — all around a real PTY connected to tmux. No wrapping, no protocol hacks, just the raw binary in a native window.
Developers using Claude Code or OpenCode lose context switching between the terminal, their editor, and their planning docs. Efxmux collapses all of that into one native window with a terminal-first aesthetic — dark, fast, keyboard-driven.
- Zero wrapping — Claude Code and OpenCode run as native PTY processes inside tmux. Full color, full interactivity, zero compatibility issues.
- Persistent sessions — Close the app, reopen it. Your layout, tabs, and tmux sessions are exactly where you left them. Processes keep running in the background.
- Live planning panel — Render your GSD
PLAN.mdwith progress bars and checkboxes. Click a checkbox in the panel, it writes back to the.mdfile on disk, and Claude Code sees the change. Bidirectional. - Git diff at a glance — GitHub-style unified diff viewer powered by
git2(no shell-out). See what changed without leaving the workspace. - Project-scoped workspaces — Register multiple projects. Switch between them and the terminal session, git status, file tree, and GSD viewer all update atomically.
- Native performance — Tauri 2 + Rust backend. WebGL-accelerated terminal rendering via xterm.js 6.0. Sub-20ms input latency.
- Real xterm.js 6.0 terminal connected to a live PTY via tmux
- WebGL2 GPU-accelerated rendering with automatic DOM fallback
- Flow control with backpressure (400KB high / 100KB low watermark)
- PTY output streamed via Tauri IPC channels for ordered, low-latency delivery
- Correct terminal resize (SIGWINCH) when panel splits are dragged
- Multi-tab terminal with per-project tab isolation and persistence
- Crash recovery overlay with "Restart Session" button
- Navy-blue dark palette with layered depth and refined typography (Geist / Geist Mono)
- User-defined terminal colors via
~/.config/efx-mux/theme.json - iTerm2
.jsonprofile auto-conversion - Hot-reload: save
theme.jsonand all terminals re-theme instantly - Light mode with harmonized white palette
- 3-zone layout: collapsible sidebar + main terminal + right panel (top/bottom split)
- Drag-resizable splits with persisted ratios
- Sidebar toggles between 40px icon strip and full-width (Ctrl+B)
- Collapsible server pane at the bottom of the main panel (Ctrl+S)
| Tab | Description |
|---|---|
| GSD | Markdown viewer with live file watching, progress bars, and checkbox write-back |
| Diff | GitHub-style unified diff with colored additions/deletions and +/- stats |
| File Tree | Interactive directory tree with folder collapse, inline icons, and keyboard navigation |
| Bash | Independent xterm.js terminal for ad-hoc commands |
- Register projects with path, name, agent type, GSD file, and server command
- Sidebar shows project list with git branch badges and file change counts (M/S/U)
- Fuzzy-search project switcher (Ctrl+P)
- Atomic project switch: terminal session, git status, file tree, GSD viewer all update together
- Auto-detect
claudeoropencodebinary on PATH - Launch directly in tmux PTY — no wrapping, no protocol interception
- Per-project agent configuration
- Agent header card with version info, model name, and status pill
- Fallback to plain bash with informational banner if agent not found
- Collapsible bottom split with strip/expanded toggle
- Run your dev server with ANSI color output
- Controls: Open in Browser, Restart, Stop
- Per-project server isolation — servers keep running across project switches
| Shortcut | Action |
|---|---|
| Ctrl+B | Toggle sidebar |
| Ctrl+S | Toggle server pane |
| Ctrl+T | New terminal tab |
| Ctrl+W / Cmd+W | Close tab |
| Ctrl+Tab | Cycle tabs |
| Ctrl+P | Fuzzy project switcher |
| Ctrl+, | Preferences |
| Ctrl+/ | Keyboard cheatsheet |
| Cmd+K | Clear terminal |
| Ctrl+C/D/Z/L/R | Always passed through to PTY when terminal is focused |
- Full layout state saved to
~/.config/efx-mux/state.json - On reopen: layout restored, tabs restored, tmux sessions reattached
- Dead session detection with fresh session creation
- Corrupted state fallback to safe defaults
- First-run wizard for initial project setup
| Layer | Technology |
|---|---|
| Shell | Tauri 2 (Rust) |
| Frontend | Preact + Signals |
| Bundler | Vite |
| Styling | Tailwind CSS 4 |
| Language | TypeScript 6 |
| Terminal | xterm.js 6.0 + WebGL addon |
| PTY | portable-pty (Rust) |
| Sessions | tmux |
| Git | git2 (libgit2 bindings, no shell-out) |
| File watching | notify (Rust) |
| Markdown | marked |
| Icons | Lucide |
| Fonts | Geist, Geist Mono, FiraCode |
Efxmux uses a navy-blue palette with layered depth, designed for long coding sessions:
| Token | Dark | Light |
|---|---|---|
| Background | #111927 |
#FFFFFF |
| Elevated | #19243A |
#F6F8FA |
| Deep | #0B1120 |
#FFFFFF |
| Border | #243352 |
#D0D7DE |
| Surface | #324568 |
#E8ECF0 |
| Accent | #258AD1 |
#258AD1 |
| Text | #E6EDF3 |
#1F2328 |
| Text Muted | #8B949E |
#59636E |
Typography: Geist for UI chrome, Geist Mono for code and section labels, FiraCode inside xterm.js.
- macOS (Monterey 12+ recommended)
- tmux 3.x+ (
brew install tmux) - Rust toolchain (
rustup) - Node.js 18+ and pnpm
- Claude Code or OpenCode (optional — falls back to plain bash)
# Clone the repository
git clone https://github.com/your-username/efx-mux.git
cd efx-mux
# Install dependencies
pnpm install
# Run in development mode (Vite + Tauri hot-reload)
pnpm tauri dev
# Build for production
pnpm tauri buildOn first launch, the setup wizard will guide you through adding your first project and selecting your AI agent.
src/ # Frontend (Preact + TypeScript)
components/ # 16 UI components
sidebar.tsx # Project list, git status, collapsible
main-panel.tsx # Primary terminal + server pane
right-panel.tsx # Tabbed views (GSD/Diff/FileTree/Bash)
terminal-tabs.tsx # Tab lifecycle, per-project persistence
agent-header.tsx # Agent info card with status
gsd-viewer.tsx # Markdown viewer with write-back
diff-viewer.tsx # GitHub-style unified diff
file-tree.tsx # Interactive directory tree
server-pane.tsx # Dev server controls
...
terminal/ # xterm.js management
terminal-manager.ts # Create/configure xterm instances
pty-bridge.ts # Tauri IPC ↔ PTY communication
resize-handler.ts # SIGWINCH propagation
tokens.ts # Design system tokens
state-manager.ts # App state persistence
main.tsx # Entry point + keyboard handler
src-tauri/ # Backend (Rust)
src/
terminal/pty.rs # PTY spawning, flow control, tmux
theme/ # Theme loading, hot-reload, iTerm2 import
state.rs # State persistence (state.json)
project.rs # Project registration and switching
git_status.rs # git2 integration
file_watcher.rs # notify-based file watching
server.rs # Dev server process management
file_ops.rs # File read/write for frontend
- Not a text editor — Files open in your
$EDITORvia a terminal tab - Not an AI shell copilot — Claude Code is the AI; Efxmux is the workspace around it
- Not cross-platform — macOS first. No Windows/Linux support planned for v0.1
- Not a collaboration tool — Solo developer workspace, no cloud sync
- Not a plugin platform — Focused tool, not an extensible framework
MIT
Built with Tauri, Preact, xterm.js, and tmux. Designed for developers who live in the terminal.