tmux

tmux Session Control

Control tmux sessions by sending keystrokes and reading output. Essential for managing Claude Code sessions.

When to Use

✅ USE this skill when:

• Monitoring Claude/Codex sessions in tmux
• Sending input to interactive terminal applications
• Scraping output from long-running processes in tmux
• Navigating tmux panes/windows programmatically
• Checking on background work in existing sessions

When NOT to Use

❌ DON'T use this skill when:

• Running one-off shell commands → use exec tool directly
• Starting new background processes → use exec with background:true
• Non-interactive scripts → use exec tool
• The process isn't in tmux
• You need to create a new tmux session → use exec with tmux new-session

Example Sessions

Common Commands

List Sessions

tmux list-sessions
tmux ls

Capture Output

# Last 20 lines of pane
tmux capture-pane -t shared -p | tail -20
 
# Entire scrollback
tmux capture-pane -t shared -p -S -

Send Keys

Window/Pane Navigation

Session Management

Sending Input Safely

For interactive TUIs (Claude Code, Codex, etc.), split text and Enter into separate sends to avoid paste/multiline edge cases:

Claude Code Session Patterns

Check if Session Needs Input

Approve Claude Code Prompt

Check All Sessions Status

Send Task to Session

Notes

• Use capture-pane -p to print to stdout (essential for scripting)
• -S - captures entire scrollback history
• Target format: session:window.pane (e.g., shared:0.0)
• Sessions persist across SSH disconnects