Workflow 003: Pair Programming

Fresh

Share tmux sessions for collaborative coding and pair programming.

When to Use

Remote pair programming
Teaching/mentoring sessions
Collaborative debugging
Code reviews in real-time

How It Works

Both users connect to the same tmux session - everyone sees the same screen and can interact.

Setup Methods

Method 1: Shared User Account

Simplest approach - both users SSH as the same user.

bash

# User A starts session
ssh shared@server
tmux new -s pair

# User B joins
ssh shared@server
tmux attach -t pair

Security Note

Both users have the same permissions. Use only with trusted collaborators.

Method 2: Shared Socket

More secure - each user has their own account but shares a socket.

Setup

bash

# User A creates session with shared socket
tmux -S /tmp/pair-socket new -s pair

# Set permissions for group
chmod 770 /tmp/pair-socket

Join

bash

# User B (in same group) connects
tmux -S /tmp/pair-socket attach -t pair

Method 3: tmate (Recommended for Remote)

tmate is tmux with built-in sharing:

bash

# Install tmate
brew install tmate    # macOS
apt install tmate     # Ubuntu

# Start session (generates share URL)
tmate

# Share the SSH command shown:
# ssh ro-xxxxx@nyc1.tmate.io  # Read-only
# ssh xxxxx@nyc1.tmate.io     # Read-write

Session Modes

Full Collaboration

Both users can type and navigate:

bash

# Default mode - both attached to same view
tmux attach -t pair

Independent Views (Same Session)

Users share session but can view different windows:

bash

# User B creates new grouped session
tmux new-session -t pair -s pair-b

# Now User B can navigate independently
# Changes to files/commands still shared

Read-Only Viewer

For demos or presentations:

bash

# Presenter
tmux new -s demo

# Viewer (read-only)
tmux attach -t demo -r

Practical Pair Programming

Driver/Navigator Pattern

Setup

bash

# Driver creates session
tmux new -s pair

# Create coding layout
Ctrl+b %    # Split for terminal

Navigator joins

bash

tmux attach -t pair

Swap roles

bash

# Driver detaches keyboard focus
# Navigator takes over typing
# No technical change needed - just agree who types!

Code Review Session

bash

# Reviewee shares screen
tmux new -s review

# Setup review layout
# Pane 1: Code (vim)
# Pane 2: Terminal for testing
# Pane 3: Git log/diff

Ctrl+b %    # Split
Ctrl+b "    # Split again

# Reviewer joins
tmux attach -t review -r    # Read-only is fine for reviewers

Communication

Since tmux is terminal-only, combine with:

Voice call (Zoom, Meet, Discord)
Text chat in a tmux pane
Shared notes in a file

In-Session Chat

Create a chat window:

bash

# Create chat window
Ctrl+b c
Ctrl+b ,    # Rename to "chat"

# Both users can type messages here
# Use different colors/prefixes:
echo "[Alice] Ready to start?"
echo "[Bob] Yes, let's go!"

Best Practices

1. Establish Conventions

Who's driving?
How to request control?
Break signals?

2. Use Visual Cues

bash

# Add user indicator to status bar
# In ~/.tmux.conf
set -g status-right '#[fg=yellow]PAIR MODE #[fg=white]%H:%M'

3. Sync Environment

bash

# Both users should have similar:
# - Shell (bash/zsh)
# - Editor (vim/nvim)
# - Color schemes

4. Handle Conflicts

bash

# If both type simultaneously, chaos ensues!
# Use clear handoffs:
"Your turn" / "Taking over"

Troubleshooting

Screen size mismatch

Solution

The smaller terminal wins. Ask partner to resize:

bash

# Check attached clients
tmux list-clients

# Force resize to largest
:setw aggressive-resize on

Or use independent views (grouped sessions).

Can't see partner's cursor

Solution

tmux doesn't show multiple cursors. Use communication:

Voice: "I'm on line 42"
Or use different pane colors

Latency issues

Solution

Use server geographically between both users
Consider tmate's regional servers
Reduce status bar update frequency:

bash

set -g status-interval 15

Permission denied on socket

Solution

Check socket permissions:

bash

ls -la /tmp/pair-socket
chmod 770 /tmp/pair-socket
# Ensure both users in same group

Security Considerations

Shared user = shared access - Be careful what's accessible
Socket files - Clean up after session: rm /tmp/pair-socket
tmate - URLs are public-ish; don't share sensitive sessions
SSH keys - Don't share private keys for pairing

Workflow 003: Pair Programming ​

When to Use ​

How It Works ​

Setup Methods ​

Method 1: Shared User Account ​

Method 2: Shared Socket ​

Setup ​

Join ​

Method 3: tmate (Recommended for Remote) ​

Session Modes ​

Full Collaboration ​

Independent Views (Same Session) ​

Read-Only Viewer ​

Practical Pair Programming ​

Driver/Navigator Pattern ​

Setup ​

Navigator joins ​

Swap roles ​

Code Review Session ​

Communication ​

In-Session Chat ​

Best Practices ​

1. Establish Conventions ​

2. Use Visual Cues ​

3. Sync Environment ​

4. Handle Conflicts ​

Troubleshooting ​

Screen size mismatch ​

Can't see partner's cursor ​

Latency issues ​

Permission denied on socket ​

Security Considerations ​

See Also ​

Workflow 003: Pair Programming

When to Use

How It Works

Setup Methods

Method 1: Shared User Account

Method 2: Shared Socket

Setup

Join

Method 3: tmate (Recommended for Remote)

Session Modes

Full Collaboration

Independent Views (Same Session)

Read-Only Viewer

Practical Pair Programming

Driver/Navigator Pattern

Setup

Navigator joins

Swap roles

Code Review Session

Communication

In-Session Chat

Best Practices

1. Establish Conventions

2. Use Visual Cues

3. Sync Environment

4. Handle Conflicts

Troubleshooting

Screen size mismatch

Can't see partner's cursor

Latency issues

Permission denied on socket

Security Considerations

See Also