tmux Skill

Use tmux as a programmable terminal multiplexer for interactive work. Works on Linux and macOS with stock tmux; avoid custom config by using a private socket.

Quickstart (isolated socket)

bash

SOCKET_DIR=${TMPDIR:-/tmp}/claude-tmux-sockets  # well-known dir for all agent sockets
mkdir -p "$SOCKET_DIR"
SOCKET="$SOCKET_DIR/claude.sock"                # keep agent sessions separate from your personal tmux
SESSION=claude-python                           # slug-like names; avoid spaces
tmux -S "$SOCKET" new -d -s "$SESSION" -n shell
tmux -S "$SOCKET" send-keys -t "$SESSION":0.0 -- 'python3 -q' Enter
tmux -S "$SOCKET" capture-pane -p -J -t "$SESSION":0.0 -S -200  # watch output
tmux -S "$SOCKET" kill-session -t "$SESSION"                   # clean up

After starting a session ALWAYS tell the user how to monitor the session by giving them a command to copy paste:

To monitor this session yourself:
  tmux -S "$SOCKET" attach -t claude-lldb

Or to capture the output once:
  tmux -S "$SOCKET" capture-pane -p -J -t claude-lldb:0.0 -S -200

This must ALWAYS be printed right after a session was started and once again at the end of the tool loop. But the earlier you send it, the happier the user will be.

Socket convention

Agents MUST place tmux sockets under
```
CLAUDE_TMUX_SOCKET_DIR
```
(defaults to
```
${TMPDIR:-/tmp}/claude-tmux-sockets
```
) and use
```
tmux -S "$SOCKET"
```
so we can enumerate/clean them. Create the dir first:
```
mkdir -p "$CLAUDE_TMUX_SOCKET_DIR"
```
.
Default socket path to use unless you must isolate further:
```
SOCKET="$CLAUDE_TMUX_SOCKET_DIR/claude.sock"
```
.

Targeting panes and naming

Target format:
```
{session}:{window}.{pane}
```
, defaults to
```
:0.0
```
if omitted. Keep names short (e.g.,
```
claude-py
```
,
```
claude-gdb
```
).
Use
```
-S "$SOCKET"
```
consistently to stay on the private socket path. If you need user config, drop
```
-f /dev/null
```
; otherwise
```
-f /dev/null
```
gives a clean config.

Inspect:

tmux -S "$SOCKET" list-sessions

tmux -S "$SOCKET" list-panes -a

Finding sessions

List sessions on your active socket with metadata:
```
./scripts/find-sessions.sh -S "$SOCKET"
```
; add
```
-q partial-name
```
to filter.

Scan all sockets under the shared directory:

./scripts/find-sessions.sh --all

(uses

CLAUDE_TMUX_SOCKET_DIR

${TMPDIR:-/tmp}/claude-tmux-sockets

Sending input safely

Prefer literal sends to avoid shell splitting:

tmux -L "$SOCKET" send-keys -t target -l -- "$cmd"

When composing inline commands, use single quotes or ANSI C quoting to avoid expansion:
```
tmux ... send-keys -t target -- $'python3 -m http.server 8000'
```
.

To send control keys:

tmux ... send-keys -t target C-c

C-d

C-z

Escape

, etc.

Watching output

Capture recent history (joined lines to avoid wrapping artifacts):
```
tmux -L "$SOCKET" capture-pane -p -J -t target -S -200
```
.
For continuous monitoring, poll with the helper script (below) instead of
```
tmux wait-for
```
(which does not watch pane output).
You can also temporarily attach to observe:
```
tmux -L "$SOCKET" attach -t "$SESSION"
```
; detach with
```
Ctrl+b d
```
.
When giving instructions to a user, explicitly print a copy/paste monitor command alongside the action don't assume they remembered the command.

Spawning Processes

Some special rules for processes:

when asked to debug, use lldb by default
when starting a python interactive shell, always set the
```
PYTHON_BASIC_REPL=1
```
environment variable. This is very important as the non-basic console interferes with your send-keys.

Synchronizing / waiting for prompts

Use timed polling to avoid races with interactive tools. Example: wait for a Python prompt before sending code:
bash
```
./scripts/wait-for-text.sh -t "$SESSION":0.0 -p '^>>>' -T 15 -l 4000
```
For long-running commands, poll for completion text (
```
"Type quit to exit"
```
,
```
"Program exited"
```
, etc.) before proceeding.

Interactive tool recipes

Python REPL:
```
tmux ... send-keys -- 'python3 -q' Enter
```
; wait for
```
^>>>
```
; send code with
```
-l
```
; interrupt with
```
C-c
```
. Always with
```
PYTHON_BASIC_REPL
```
.

gdb:

tmux ... send-keys -- 'gdb --quiet ./a.out' Enter

; disable paging

tmux ... send-keys -- 'set pagination off' Enter

; break with

C-c

; issue

bt

info locals

, etc.; exit via

quit

then confirm

Other TTY apps (ipdb, psql, mysql, node, bash): same pattern—start the program, poll for its prompt, then send literal text and Enter.

Cleanup

Kill a session when done:

tmux -S "$SOCKET" kill-session -t "$SESSION"

Kill all sessions on a socket:

tmux -S "$SOCKET" list-sessions -F '#{session_name}' | xargs -r -n1 tmux -S "$SOCKET" kill-session -t

Remove everything on the private socket:
```
tmux -S "$SOCKET" kill-server
```
.

Helper: wait-for-text.sh

./scripts/wait-for-text.sh

polls a pane for a regex (or fixed string) with a timeout. Works on Linux/macOS with bash + tmux + grep.