Revise README for Claude Code installation and security

README.md

@@ -2,6 +2,8 @@
 
 Run Claude Code on a VPS and access it from your phone, tablet, or any device with a terminal app. Code from anywhere.
 
+> Tested on Ubuntu 20.04+ / Debian 10+. Other distros may require adjustments.
+
 ## What You'll Need
 
 - A VPS (Hostinger, Hetzner, DigitalOcean, etc.) - $5/mo tier is plenty
@@ -22,42 +24,63 @@ For manual installation on any VPS:
 # SSH into your VPS
 ssh root@your-vps-ip
 
-# Install Node.js and npm
-apt update && apt install -y nodejs npm
+# Install Claude Code (native installer - recommended)
+curl -fsSL https://claude.ai/install.sh | bash
+
+# Ensure the native install symlink is on your PATH
+export PATH="$HOME/.local/bin:$PATH"
 
-# Install Claude Code globally
-npm install -g @anthropic-ai/claude-code
+# Make it persistent for future logins
+echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc
+source ~/.bashrc
+
+# Verify installation
+claude doctor
 
 # Start Claude Code
 claude
 ```
 
+**Note:** The native installer is the recommended path. npm install is deprecated and requires Node.js 18+ only for that legacy method.
+
 ---
 
 ### 2. Secure Your VPS (Important!)
 
 Before accessing from mobile, lock down your server:
 
 ```bash
-# Disable password authentication (SSH keys only)
-sudo sed -i 's/^#*PasswordAuthentication.*/PasswordAuthentication no/' \
-  /etc/ssh/sshd_config /etc/ssh/sshd_config.d/*.conf && \
-  sudo systemctl restart ssh
+# Make sure you have a non-root user with an SSH key before doing this
+
+# Add a clear SSH hardening drop-in (SSH keys only)
+sudo mkdir -p /etc/ssh/sshd_config.d
+sudo tee /etc/ssh/sshd_config.d/99-claude-hardening.conf >/dev/null <<'EOF'
+PasswordAuthentication no
+KbdInteractiveAuthentication no
+PermitRootLogin no
+EOF
+
+# Test SSH config before restarting
+sudo sshd -t && sudo systemctl restart ssh
 
 # Install fail2ban to block brute force attacks
 sudo apt install fail2ban -y
 
 # Enable firewall - only allow SSH
-sudo ufw allow 22 && sudo ufw enable
+sudo ufw allow OpenSSH
+sudo ufw enable
+sudo ufw status
 ```
 
+**Tip:** Run Claude Code as a non-root user. Avoid working as `root`.
+
 ---
 
 ### 3. Set Up Mobile Access
 
 1. Download **Termius** on your phone (iOS/Android) - it's free
 2. Add a new host with your VPS IP address
-3. Connect using your SSH key or password
+3. Connect using your SSH key (passwords disabled)
 
 ---
 
@@ -90,6 +113,29 @@ tmux attach -t claude
 
 ---
 
+### 5. Optional: Claude Code Self-Hardening (Recommended)
+
+Create a project-level `.claude/settings.json` to block access to common secret files:
+
+```bash
+mkdir -p .claude
+cat > .claude/settings.json <<'EOF'
+{
+  "permissions": {
+    "deny": [
+      "Read(./.env)",
+      "Read(./.env.*)",
+      "Read(./secrets/**)"
+    ]
+  }
+}
+EOF
+```
+
+This uses Claude Code permissions to make those files invisible to the tool. Commit the file for team-wide safety, or use `.claude/settings.local.json` if you want it to stay local.
+
+---
+
 ## Quick Reference
 
 | Command | What it does |
@@ -108,12 +154,21 @@ tmux attach -t claude
 If Claude Code can't complete OAuth login:
 
 ```bash
-# Option 1: SSH port forwarding (run from your local machine)
-ssh -L 15735:localhost:15735 user@your-vps-ip
+# If the browser doesn't open, press "c" to copy the OAuth URL
+# Paste it into your browser and finish login there
+```
 
-# Option 2: Use API key directly
-export ANTHROPIC_API_KEY=your-key-here
-claude
+If login gets stuck, try:
+1. `/logout`
+2. Exit Claude
+3. Run `claude` again
+
+### `claude` Command Not Found / PATH Issues
+
+The native installer creates a symlink at `~/.local/bin/claude`. Make sure `~/.local/bin` is on your PATH, then run:
+
+```bash
+claude doctor
 ```
 
 ### Can't Scroll in tmux on Mobile
@@ -135,7 +190,8 @@ tmux attach -t claude
 
 ### Memory Issues on Long Sessions
 
-Claude Code can use significant memory. Monitor with `htop` and restart Claude periodically if needed.
+Claude Code can use significant memory. Use `/compact` to reduce context size and restart between major tasks if needed.
+If you're on a 4GB VPS and hit memory pressure, consider enabling swap.
 
 ---
 
@@ -152,9 +208,17 @@ Claude Code can use significant memory. Monitor with `htop` and restart Claude p
 
 ## Resources
 
-- [Claude Code Documentation](https://docs.anthropic.com/en/docs/claude-code)
-- [Termius](https://termius.com/) - Mobile SSH client
-- [tmux Cheat Sheet](https://tmuxcheatsheet.com/)
+| Resource | Notes |
+|----------|-------|
+| [Claude Code Documentation](https://docs.anthropic.com/en/docs/claude-code) | Official docs |
+| [Termius](https://termius.com/) | Mobile SSH client |
+| [tmux Cheat Sheet](https://tmuxcheatsheet.com/) | tmux reference |
+
+---
+
+## Security Note
+
+Treat Claude Code as a powerful local agent. Review permissions, avoid running as root, and audit `.claude/settings.json` in shared repos.
 
 ---