clsh gives you real terminal access to your Mac from your phone. One command, scan the QR code, and you're in. Multiple live terminal sessions, a custom keyboard built for terminal use, 6 keyboard skins, and session management. Open source, zero config.
Key highlights:
Run Claude Code from your phone and watch it work in real time
Multiple terminal sessions with live grid preview
Custom keyboard with sticky modifiers, key repeat, and context strip
3-tier tunnel: ngrok → SSH → Wi-Fi (works without any signup)
npx clsh-dev starts the backend agent + React frontend
The agent spawns real terminal sessions via node-pty
When tmux is installed, sessions are wrapped in tmux for persistence — they survive server restarts
A tunnel (ngrok, SSH, or Wi-Fi) exposes the agent over HTTPS
A one-time bootstrap token + QR code authenticates your phone
xterm.js renders the terminals in your browser with full color and interactivity
Security
Security is our top priority. clsh gives remote terminal access to your machine, so any vulnerability could mean full machine compromise. We take this extremely seriously.
What we do
| Layer | Protection |
|-------|-----------|
| Authentication | One-time bootstrap tokens (single-use, 5-min TTL), scrypt password hashing (N=16384, 64-byte key, random salt), WebAuthn/Face ID biometric auth |
| Token security | JWT issued via HS256, bootstrap token passed in URL hash fragment (never sent to servers), WebSocket auth via first message (not query string) |
| Transport | HTTPS enforced via ngrok/SSH tunnels, CORS restricted to known origins, security headers (X-Frame-Options, X-Content-Type-Options, CSP) |
| Rate limiting | Auth endpoints: 5-10 requests per 15 minutes, prevents brute force |
| WebSocket | Origin validation on upgrade, 64KB max payload, resize dimension bounds checking |
| Password storage | Server-side scrypt with crypto.timingSafeEqual (constant-time comparison prevents timing attacks) |
| PWA support | Lock screen with Face ID + password, biometric credentials synced server-side for cross-context restoration |
Responsible disclosure
Found a vulnerability? Please report it. See SECURITY.md for our disclosure policy, or email security@clsh.dev directly. We respond within 48 hours.
We believe in transparency. If you find something, open a security advisory or email us. We will credit all responsible disclosures.
Features
Terminal
Multiple live sessions — create, rename, close; up to 8 concurrent PTYs
Real PTY — full zsh/bash with colors, vim, tmux, everything
Session persistence — sessions survive server restarts via tmux (auto-detected, graceful fallback if tmux isn't installed)
Session grid — 2-column card layout with live terminal previews
Claude Code streaming — run AI coding agents remotely from your phone
Keyboard
Two layouts — iOS Terminal (6-row, big keys for phone) and MacBook (5-row, compact)
Sticky modifiers — tap Shift/Ctrl/Opt/Cmd once, it stays for the next key
Key repeat — hold any key for auto-repeat (400ms delay, 60ms interval)
If no tunnel works, clsh falls back to your local IP. Same LAN only.
Force a specific tunnel
TUNNEL=ssh npx clsh-dev # force SSH tunnel
TUNNEL=local npx clsh-dev # force local Wi-Fi only
Session Persistence
When tmux is installed, clsh automatically wraps sessions in tmux using control mode (-CC). This means your terminal sessions survive server restarts — stop clsh, start it again, and your sessions are still there with full scrollback history.
No configuration needed. clsh auto-detects tmux and enables persistence. If tmux isn't installed, sessions work normally but are ephemeral (lost on restart).
To disable persistence even with tmux installed:
CLSH_NO_TMUX=1 npx clsh-dev
How it works under the hood: clsh uses tmux control mode (-CC) instead of normal tmux attachment. Control mode sends raw terminal output as structured notifications (%output) instead of screen redraws, which means xterm.js gets the original byte stream and scrollback works perfectly. User input is forwarded via send-keys -H (hex-encoded). On server restart, capture-pane recovers the existing scrollback and control mode resumes live streaming.
Lid-Close Mode (optional)
By default, macOS powers down Wi-Fi about 30 seconds after you close the lid, even if the CPU is still running. This kills the tunnel and your phone loses connection.
If you want clsh to stay reachable with the lid closed (while plugged in), run this once:
sudo pmset -c tcpkeepalive 1
This tells macOS to keep network connections alive during display sleep on AC power. It persists across reboots. clsh will print a reminder on startup if this isn't configured.
What it does: Keeps Wi-Fi and TCP connections alive when the lid is closed and the Mac is charging. Your phone stays connected to clsh without interruption.
What it doesn't do: This has no effect on battery. When unplugged with the lid closed, macOS forces full sleep regardless. There's no software workaround for that.
To undo:
sudo pmset -c tcpkeepalive 0
Note: Even without this setting, clsh auto-recovers when you open the lid. The tunnel recreates itself and your phone reconnects automatically.
Add to Home Screen
With a permanent ngrok URL, add clsh as a PWA:
iOS: Safari → Share (↑) → Add to Home Screen
Android: Chrome → Menu (⋮) → Add to Home Screen
It runs fullscreen — no URL bar, no browser chrome. Looks like a native app.
Keyboard Skins
| Skin | Vibe |
|------|------|
| iOS Terminal | Default — big letter keys, iOS-style, optimized for phone |
| MacBook Silver | Traditional MacBook aluminum — compact 5-row
The agent harness performance optimization system. Skills, instincts, memory, security, and research-first development for Claude Code, Codex, Opencode, Cursor and beyond.
