A way to control tmux, a terminal tool that keeps interactive command-line sessions running in separate panes. It can send keyboard input to those sessions and read their visible output.

Use it to start, inspect, monitor, and interact with named tmux sessions and panes through an isolated socket.

It helps an agent work with programs that need a live terminal, such as interactive prompts or command-line interfaces that cannot run as simple background commands.

tmux — Skill for Claude Code and Codex by THU-SAGE/syll

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add THU-SAGE/syll --skill tmux

Clone the repo

git clone --depth 1 https://github.com/THU-SAGE/syll

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/thu-sage/syll/tmux/github.svg)](https://agentmods.dev/skills/thu-sage/syll/tmux)

Your own site

<a href="https://agentmods.dev/skills/thu-sage/syll/tmux"><img src="https://agentmods.dev/badge/skills/thu-sage/syll/tmux/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/thu-sage/syll/tmux"><img src="https://agentmods.dev/badge/skills/thu-sage/syll/tmux.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,268 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin 86% copy Near-identical to another mod in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00022	$0.01268
Opus 5.5	$0.00009	$0.00507
Sonnet 5.5	$0.00004	$0.00254
Haiku 4.5	$0.00002	$0.00127

Measured 2mo ago against content hash 7fc68631789d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

tmux scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/find-sessions.sh, scripts/wait-for-text.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

86% identical to tmux — 16 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

syll/skills/tmux/SKILL.md · 122 lines

How it starts

The opening of the file, as written. The whole thing — 122 lines — stays where its author put it; the contents beside it link to each section on GitHub.

tmux Skill

Use tmux only when you need an interactive TTY. Prefer exec background mode for long-running, non-interactive tasks.

Quickstart (isolated socket, exec tool)

SOCKET_DIR="${SYLL_TMUX_SOCKET_DIR:-${TMPDIR:-/tmp}/syll-tmux-sockets}"
mkdir -p "$SOCKET_DIR"
SOCKET="$SOCKET_DIR/syll.sock"
SESSION=syll-python

tmux -S "$SOCKET" new -d -s "$SESSION" -n shell
tmux -S "$SOCKET" send-keys -t "$SESSION":0.0 -- 'PYTHON_BASIC_REPL=1 python3 -q' Enter
tmux -S "$SOCKET" capture-pane -p -J -t "$SESSION":0.0 -S -200

After starting a session, always print monitor commands:

To monitor:
  tmux -S "$SOCKET" attach -t "$SESSION"
  tmux -S "$SOCKET" capture-pane -p -J -t "$SESSION":0.0 -S -200

Socket convention

Use SYLL_TMUX_SOCKET_DIR environment variable.
Default socket path: "$SYLL_TMUX_SOCKET_DIR/syll.sock".

Targeting panes and naming

Target format: session:window.pane (defaults to :0.0).
Keep names short; avoid spaces.
Inspect: tmux -S "$SOCKET" list-sessions, tmux -S "$SOCKET" list-panes -a.

Finding sessions

List sessions on your socket: {baseDir}/scripts/find-sessions.sh -S "$SOCKET".
Scan all sockets: {baseDir}/scripts/find-sessions.sh --all (uses SYLL_TMUX_SOCKET_DIR).

Sending input safely

Prefer literal sends: tmux -S "$SOCKET" send-keys -t target -l -- "$cmd".
Control keys: tmux -S "$SOCKET" send-keys -t target C-c.

Watching output

Capture recent history: tmux -S "$SOCKET" capture-pane -p -J -t target -S -200.
Wait for prompts: {baseDir}/scripts/wait-for-text.sh -t session:0.0 -p 'pattern'.
Attaching is OK; detach with Ctrl+b d.

Spawning processes

For python REPLs, set PYTHON_BASIC_REPL=1 (non-basic REPL breaks send-keys flows).

Windows / WSL

tmux is supported on macOS/Linux. On Windows, use WSL and install tmux inside WSL.
This skill is gated to darwin/linux and requires tmux on PATH.

Orchestrating Coding Agents (Codex, Claude Code)

tmux excels at running multiple coding agents in parallel:

Read the full file on GitHub · 122 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 122 lines · 22 tokens per session scan A 7fc68631789d

Subscribe to this mod's changes

tmux is a skill published in the GitHub repository THU-SAGE/syll (304 stars, last pushed 5mo ago), licensed MIT. It adds 22 tokens to every session and 1,268 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 86% identical to tmux, differing in 16 lines, and is treated as a copy.

tmux next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
tmuxTHU-SAGE/syll	Skill	304	5mo ago	MIT	A	22	Claude Code, Codex
imagegenopenai/codex	Skill	133k	yesterday	Apache-2.0	A	113	Codex
playwright-climicrosoft/playwright	Skill	99k	yesterday	Apache-2.0	A	19	Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	4d ago	MIT	A	200	Claude Code, Codex
systematic-debuggingobra/superpowers	Skill	313k	3d ago	MIT	A	21	Claude Code
next-cache-components-adoptionvercel/next.js	Skill	143k	today	MIT	A	95	Claude Code
next-partial-prefetching-adoptionvercel/next.js	Skill	143k	today	MIT	A	103	Claude Code