tmux-interactive

name	tmux-interactive
description	Use when running interactive CLI programs (Python REPL, gdb, psql, node, lldb) that require keystroke-level control, output scraping, or waiting for prompts inside a tmux pane.

tmux Interactive Sessions

Remote-control interactive programs via tmux: send keystrokes, scrape output, wait for prompts.

Quickstart

# Isolated socket — never touches your personal tmux sessions
SOCKET_DIR="${TMPDIR:-/tmp}/claude-tmux-sockets"
mkdir -p "$SOCKET_DIR"
SOCKET="$SOCKET_DIR/claude.sock"
SESSION="claude-work"   # slug-like, no spaces

tmux -S "$SOCKET" new-session -d -s "$SESSION" -x 220 -y 50
tmux -S "$SOCKET" send-keys -t "$SESSION" -- 'python3 -q' Enter
tmux -S "$SOCKET" capture-pane -p -J -t "$SESSION" -S -200

After starting any session, immediately print this for the user:

Monitor this session:
  tmux -S /tmp/claude-tmux-sockets/claude.sock attach -t claude-work

Or capture output once:
  tmux -S /tmp/claude-tmux-sockets/claude.sock capture-pane -p -J -t claude-work -S -200

Print this again at the end of the tool loop.

Sending Input

# Literal send — safe, no shell expansion
tmux -S "$SOCKET" send-keys -t "$SESSION" -l -- 'print("hello")'
tmux -S "$SOCKET" send-keys -t "$SESSION" -- Enter

# Control keys
tmux -S "$SOCKET" send-keys -t "$SESSION" -- C-c   # interrupt
tmux -S "$SOCKET" send-keys -t "$SESSION" -- C-d   # EOF / exit

Capturing Output

# Capture last 200 lines, join wrapped lines
tmux -S "$SOCKET" capture-pane -p -J -t "$SESSION" -S -200

Waiting for Prompts (Polling)

Do NOT proceed after sending input without waiting for the prompt. Poll:

# Poll until pattern appears (max 15s, check every 0.5s)
end=$((SECONDS + 15))
while [ $SECONDS -lt $end ]; do
  out=$(tmux -S "$SOCKET" capture-pane -p -J -t "$SESSION" -S -200)
  echo "$out" | grep -qE '^>>>' && break
  sleep 0.5
done

Common prompt patterns:

Program	Pattern
Python REPL	^>>>
psql	=# or =#\s
node	^>
gdb/lldb	\(gdb\) / \(lldb\)
bash/fish	\$\s*$

Program-Specific Notes

Python REPL — always set PYTHON_BASIC_REPL=1 or the readline UI breaks send-keys:

tmux -S "$SOCKET" send-keys -t "$SESSION" -- 'PYTHON_BASIC_REPL=1 python3 -q' Enter
# wait for ^>>>
tmux -S "$SOCKET" send-keys -t "$SESSION" -l -- 'import os; print(os.getcwd())'
tmux -S "$SOCKET" send-keys -t "$SESSION" -- Enter

gdb/lldb — disable pager immediately to avoid --More-- pauses:

# gdb
tmux ... send-keys -l -- 'set pagination off' && tmux ... send-keys -- Enter
# lldb (preferred debugger per mitsuhiko skill)
tmux ... send-keys -l -- 'settings set term-width 200' && tmux ... send-keys -- Enter

psql / mysql — connect, wait for prompt, then send queries normally.

Cleanup

tmux -S "$SOCKET" kill-session -t "$SESSION"    # one session
tmux -S "$SOCKET" kill-server                   # all claude sessions

Your Session Model

Your tmux uses <repo>/<branch> session naming (e.g. nix-config/main). Interactive tool sessions are intentionally separate — use the isolated socket pattern above so they never collide with your worktree sessions. The worktree-tmux-integration skill handles the <repo>/<branch> sessions; this skill handles throwaway interactive ones.

Common Mistakes

Mistake	Fix
Not waiting for prompt after send	Always poll before sending next command
Using -L (socket name) instead of -S (socket path)	Always use -S "$SOCKET"
Forgetting PYTHON_BASIC_REPL=1	Python's readline UI garbles send-keys
Starting without explicit width/height	Add -x 220 -y 50 to new-session to avoid narrow pane wrapping
Not telling user how to monitor	Print monitor command immediately after session start