Remote Development from iPhone to macOS in the AI Era: Tailscale + Shellfish/Blink + Mosh + tmux

In the AI era, software development is no longer confined to powerful laptops or multi-monitor setups. With tools like Claude Code and Codex CLI, developers can now build and iterate through natural conversations with AI — reducing the need for heavy local environments.

This shift also changes how and where we work. Instead of always coding at a desk, we can now connect to our development machines remotely — even from an iPhone on the go.

In this guide, I'll explore how to set up a lightweight, secure, and persistent remote development environment using Tailscale, Shellfish/Blink Shell, Mosh, and tmux — enabling you to code anywhere, seamlessly switching between your Mac and iPhone without losing your workflow.

Overview

This guide shows how to achieve the following by combining Tailscale and Mosh:

• Secure access to your home Mac from anywhere without port forwarding
• Persistent connections when switching between Wi-Fi and LTE
• Continuous work sessions that survive disconnections and allow seamless resumption

Requirements

macOS Side

• Homebrew - Package manager for macOS
• The following tools (install with Homebrew):
  • Tailscale - VPN
  • Mosh - Mobile shell
  • tmux - Terminal multiplexer

iPhone/iOS Device

• App Store access
• The following apps (install from App Store):
  • Tailscale - VPN
  • SSH/Mosh client (choose from recommended apps below)

Tools Used

Tool	Role	Problem It Solves
Tailscale	Peer-to-peer VPN	Secure remote access without port forwarding
Shellfish / Blink	SSH/Mosh client	iPhone GUI operation, tap-to-connect, built-in Mosh support
Mosh	Mobile shell	Connection persistence during network switches, responsive input despite latency
tmux	Session management	Work persistence across disconnections, multi-device screen sharing

Connection Architecture

iPhone (Shellfish or Blink Shell)
↓
Tailscale VPN (peer-to-peer connection)
↓
macOS (development machine)
├─ SSH or Mosh server
└─ tmux session (persistent, multi-device sharing)

Each layer works together to provide stable remote development in mobile environments:

Layer	Technology	Role
Client	Shellfish / Blink	Tap-to-connect, GUI management
Network	Tailscale	Secure connection, NAT traversal, fixed IP
Protocol	Mosh	Connection persistence, local echo
Session	tmux	Session persistence, screen sharing

Setup Instructions

1. macOS Configuration

1.1 Installing Required Packages

Install the necessary tools using Homebrew:

# Install Tailscale (VPN)
brew install --cask tailscale-app

# Install Mosh (mobile shell)
brew install mosh

# Install tmux (terminal multiplexer)
brew install tmux

1.2 tmux Configuration (Recommended)

Create a tmux configuration file optimized for Claude Code and AI tools.

Save the following to ~/.tmux.conf:

# ====================================================================================
# Basic Settings - 2025 Recommended Configuration
# ====================================================================================

# Terminal Type: tmux-256color (modern recommendation, tmux 2.6+)
# Benefits over screen-256color:
#   - Italics support (screen doesn't support it)
#   - Better color rendering
#   - Improved CJK (Japanese/Chinese/Korean) character handling
set -g default-terminal "tmux-256color"

# True Color (24-bit RGB) Support
# Modern tmux 3.2+ recommended method
set -as terminal-features ",*:RGB"
set-option -sa terminal-overrides ",tmux*:Tc"

# Enable mouse support (essential for iOS touch operations)
set -g mouse on

# Start window/pane numbering from 1 (human-friendly)
set -g base-index 1
setw -g pane-base-index 1

# Renumber windows when one is closed (no gaps)
set -g renumber-windows on

# ====================================================================================
# Claude Code / AI Tools Optimization
# ====================================================================================

# Dramatically increase scrollback buffer
# Claude Code generates verbose output requiring large buffer
# Recommended: 500000 lines (~250MB)
# Reference: Default is 2000 lines, typical usage is 50000 lines
set -g history-limit 500000

# Minimize ESC key response time (vim/neovim comfort)
# tmux 3.5 default: 10ms
set -sg escape-time 0

# Enable focus events (vim/neovim integration)
set -g focus-events on

# Extend message display time (for reviewing Claude Code output)
set -g display-time 3000

# Extend pane number display time (better usability on small screens)
set -g display-panes-time 4000

# ====================================================================================
# Key Bindings
# ====================================================================================

# vi mode key bindings (use vim keys in copy mode)
setw -g mode-keys vi

# Emacs-style status bar (matches zsh default)
set -g status-keys emacs

# ====================================================================================
# Visual Settings
# ====================================================================================

# Status bar at top (iOS keyboard won't cover it)
set -g status-position top

# Status bar color settings (simple and readable)
set -g status-style bg=black,fg=white

# Highlight current window
setw -g window-status-current-style bg=blue,fg=white,bold

Benefits of this configuration:

• Claude Code Ready¹: 500000-line scrollback to fully review long outputs
• True Color²: Modern color schemes display correctly (using tmux-256color)
• CJK Character Optimized: Better Japanese/Chinese/Korean text quality
• iOS Optimized: Touch operations and keyboard position considered

1.3 Enable Remote Login

Enable macOS remote login (SSH server):

1. Open System Settings
2. Go to General > Sharing
3. Enable Remote Login
4. Select authorized users (recommended: administrators only)

1.4 Tailscale Setup

# Launch Tailscale app
open -a Tailscale

1. When Tailscale launches, follow the login instructions
2. Authenticate with an SSO provider (Google, GitHub, etc.)
3. Once connected, note the Tailscale IP address assigned to macOS:

tailscale ip -4

Example output: 100.64.1.2

Important: This is your macOS Tailscale IP address. Save this IP for use in later steps.

Note: Tailscale automatically assigns fixed IPs in the 100.x.y.z format. This IP remains constant while the device is part of the Tailscale network.

1.5 Enable Tailscale 2FA (Recommended)

1. Access the Tailscale admin console
2. Navigate to Settings > Users and select your account
3. Enable Two-factor authentication

2. iPhone Configuration

2.1 SSH Client Selection

Multiple SSH clients are available for iPhone/iPad. Here are the recommendations as of November 2025.

Recommended: Shellfish (Secure ShellFish)³

Features:

• ✅ Excellent tmux Support: Session thumbnail previews, continuously improved in 2025
• ✅ Native Mosh Support: High connection stability
• ✅ Files App Integration: Direct SSH server integration into iOS Files app
• ✅ Handoff Support: Session migration across devices (iPhone ↔ iPad ↔ Mac)
• ✅ iCloud Keychain Sync: Automatic server settings sync
• ✅ One-time Purchase: $29.99 for lifetime use (monthly $2.99, yearly $14.99 also available)

Why Recommended:

• Strong long-term cost-performance (one-time purchase)
• Excellent tmux integration, handles Claude Code's long outputs well
• Highly responsive developer support

Alternative: Blink Shell⁴

Features:

• ✅ Full Mosh Support: Connection maintained even after device reboot
• ✅ Open Source: Continuous community improvements
• ✅ Blink Code: Browser-based VSCode integration
• ✅ Advanced Customization: High flexibility in themes, fonts, and layouts
• ✅ iPad Multitasking Optimized: Excellent Split Screen / Slide Over support

Price: $19.99/year (no one-time purchase option)

Why Recommended:

• Highly rated as "Most complete SSH implementation on iOS"
• Ideal for those who want to use VSCode on mobile

2.2 Install Required Apps

Install from the App Store:

1. Tailscale - VPN connection
2. Shellfish or Blink Shell - SSH/Mosh client (see recommendations above)

2.3 Tailscale Setup

1. Launch the Tailscale app
2. Log in with the same account used on macOS
3. Once connected, you'll join the same VPN network as your Mac

2.4 SSH Client Setup

Configure SSH connection in your chosen SSH client (Shellfish or Blink Shell).

For Shellfish

1. Launch Shellfish
2. Tap the + button to add a new host
3. Enter the following:
   • Label: mac (any recognizable name)
   • Hostname: <macOS Tailscale IP> (e.g., 100.64.1.2)
     • This is the IP from step 1.4 that you saved
   • User: <macOS username>
     • Confirm with whoami command on macOS
   • Port: 22 (SSH default)
4. Tap Save

To use Mosh:

1. Tap the saved host and select Edit
2. In the Advanced section, enable Use Mosh
3. Tap Save

For Blink Shell

1. Launch Blink Shell
2. Type config command to add a host
3. Tap + in the Hosts tab
4. Enter the following:
   • Host: mac (any host name)
   • HostName: <macOS Tailscale IP> (e.g., 100.64.1.2)
   • User: <macOS username>
   • Port: 22
5. Tap Save

To use Mosh:

• Blink Shell has native Mosh support, so simply type mosh mac to connect via Mosh

Setup complete. Connect by tapping the host name.

3. Connection Testing

3.1 SSH Connection Test

Test the macOS connection using your SSH client.

Connection Steps:

1. Open your SSH client (Shellfish or Blink Shell)
2. Tap the mac host you created
3. On first connection, tap Continue or Trust in the host key dialog
4. Enter your macOS user password if prompted
5. You'll see the macOS terminal upon successful connection

Verification: Confirm the connection with:

hostname

If the macOS hostname appears, the connection succeeded.

3.2 Mosh Connection Benefits

Mosh is better suited for mobile environments than SSH. If you've already configured it (see step 2.4), you can experience these benefits:

Mosh Benefits:

• 📱 Connection Stability: Connection maintained even after sleeping iPhone for minutes
• 🔄 Network Switching: Connection continues when switching from Wi-Fi to LTE
• ⚡ Local Echo: Instant local character echo (responsive even with latency)
• 🔌 Device Reboot: With Blink Shell, connection maintained even after device reboot (full Mosh implementation)

When to Use Mosh vs SSH:

• Mosh Recommended: While traveling, unstable connections, long sessions
• SSH is OK: Stable home Wi-Fi, short tasks

3.3 Starting a tmux Session

Once connected to macOS, start or join a tmux session:

# Create a new session
tmux new -s dev

# Or join an existing session
tmux attach -t dev

Basic Usage

tmux Basic Commands

Session Management

# Create a new session
tmux new -s <session_name>

# Join an existing session
tmux attach -t <session_name>

# List sessions
tmux ls

# Temporarily detach from session (session continues)
# Ctrl+B → d

# End session
exit

Sharing Sessions Between iPhone and Mac

tmux allows you to share the same terminal session across devices.

1. Start a session (on either device):

   Connect to macOS and create a tmux session:

   tmux new -s dev
   

2. Join from the other device:

   • iPhone: Tap the mac host in your SSH client (Shellfish/Blink Shell)
   • Mac: Use ssh <Tailscale IP> or mosh <Tailscale IP> in Terminal

   After connecting, join the session:

   tmux attach -t dev
   

3. Synchronized screens:

   Any input from either device appears immediately on both screens. This enables starting work on iPhone and continuing on Mac, or vice versa.

Useful tmux Features

The configuration above enables:

• Mouse support: Touch-based pane selection
• vi key bindings: vim keys in scroll mode
• Automatic renumbering: Window numbers compress when closed
• No ESC delay: Eliminates vim usage delays

Customize by adding configurations to ~/.tmux.conf as needed.

Troubleshooting

Tailscale Can't Find macOS

Cause: Different accounts on devices, or connection not established

Solution:

1. Verify both devices use the same Tailscale account
2. Check macOS Tailscale connection:

   tailscale status
   

3. Verify macOS remote login is enabled
4. Check iPhone Tailscale app connection status

Can't Connect with Mosh (command not found: mosh-server)

Cause: PATH not properly set for SSH-executed commands

When your SSH client attempts Mosh connection, you may see:

Command executed with error: zsh:1: command not found: mosh-server
No response from Mosh server

This occurs because .zprofile or .zshrc aren't loaded in SSH non-interactive shells, so Homebrew's PATH isn't available.

Solution:

1. Create ~/.zshenv and add Homebrew's PATH:

   # Homebrew
   eval "$(/opt/homebrew/bin/brew shellenv)"
   

2. Verify the configuration:

   zsh -c 'which mosh-server'
   

   Success if you see /opt/homebrew/bin/mosh-server.

3. Retry Mosh connection from your SSH client.

Other Mosh Connection Issues

Cause: Mosh not installed, or UDP ports blocked by firewall

Solution:

1. Verify Mosh installation on macOS:

   which mosh-server
   

2. Check firewall settings (rarely an issue with Tailscale):
   • System Settings > Network > Firewall
3. Verify SSH connection works (Mosh requires SSH for initial connection)

SSH "Permission denied" Error

Cause: Remote login disabled, or user permission issues

Solution:

1. Verify macOS remote login is enabled:
   • System Settings > General > Sharing > Remote Login
2. Verify correct username:

   # Check current username on macOS
   whoami
   

tmux Session Not Found

Cause: Session not created, or incorrect session name

Solution:

1. Check existing sessions:

   tmux ls
   

2. Create new session if none exist:

   tmux new -s dev
   

Advanced: VS Code on Browser

code-server Setup

To use VS Code in iPhone Safari:

# Install code-server on macOS
brew install code-server

# Start code-server
code-server

# Access from iPhone Safari:
# http://<Tailscale IP>:8080

Find the password in ~/.config/code-server/config.yaml.

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Summary

You’ve now built a remote development environment that embodies the AI era of coding — mobile, connected, and resilient.

This setup isn’t just about convenience; it represents a fundamental shift in how developers work. By combining Tailscale’s secure networking, Mosh’s persistent connections, and tmux’s session sharing, you can collaborate with AI tools or teammates from anywhere — all through your pocket-sized device.

AI-assisted coding and mobile-first workflows are redefining productivity. Whether you're debugging during your commute, monitoring builds from a café, or quickly deploying fixes from your iPhone, this setup lets you stay in flow — the way modern development was meant to be.

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Disclaimer: The information in this article is current as of November 2025. Software updates and specification changes may make some content outdated. Please refer to each tool's official documentation for the latest information.

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Footnotes

1. Brian P. Hogan "Working with Claude Code" (June 2025) - Recommendation: "big scrollback buffer" for Claude Code | Related: pchalasani/claude-code-tools - Claude Code + tmux integration tools | ooloth/dotfiles - Practical dotfiles for Claude Code ↩

2. Terminal Type Configuration: The tmux-256color vs screen-256color debate is widely discussed in the community. Multiple forums including Unix & Linux Stack Exchange and Stack Overflow recommend tmux-256color for modern terminals. ↩

3. Shellfish (Secure ShellFish): App Store | Official Site | MacStories "Secure ShellFish Review" (2019) | 2025 Update: DECSLRM support for improved tmux compatibility ↩

4. Blink Shell: App Store | Official Site | GitHub | Open source, top developer tool on AppStore for 5+ years ↩