explaingit

popbones/tmux.skill

14ShellAudience · developerComplexity · 2/5ActiveSetup · easy

TLDR

A tiny Codex agent skill that teaches the model to run long-lived commands inside tmux panes, with a helper script for sending input and capturing output.

Mindmap

mindmap
  root((tmux.skill))
    Inputs
      tmux target
      Send text
      Capture lines
    Outputs
      Pane output
      Queued input
    Use Cases
      Long-running dev servers
      File watchers in agents
      Log tailing
    Tech Stack
      Shell
      tmux
      Codex
    Files
      SKILL.md
      tmux-send-and-capture
      openai.yaml

Things people build with this

USE CASE 1

Let a Codex agent start a dev server in a tmux pane and return to it later

USE CASE 2

Send text into a tmux pane and capture the last N lines of output

USE CASE 3

Queue input to a pane where Codex is already running so it reads it after the current task

Tech stack

Shelltmux

Getting it running

Difficulty · easy Time to first run · 5min

Requires tmux already installed and a working Codex setup with the skills directory in place.

In plain English

This repository, tmux.skill by popbones, packages a small skill for OpenAI's Codex coding agent that teaches it how to use tmux as a place to run long-running commands. tmux is a Unix tool that keeps terminal sessions alive in named windows and panes, so the idea here is to give an AI agent a way to start a dev server, a file watcher, a build, a log tail, or any interactive command, and then come back to it later instead of running everything in one short-lived shell. The repo is intentionally tiny. It contains three pieces: SKILL.md, which holds the instructions Codex itself reads to learn the workflow; a shell helper at scripts/tmux-send-and-capture, which sends text into a chosen tmux pane and reads back the most recent lines of output; and agents/openai.yaml, which carries the metadata Codex uses to show the skill in its interface. To install it, the README says to clone or copy the folder into the Codex skills directory, which lives at $CODEX_HOME/skills/tmux, or under ~/.codex/skills/tmux if that variable is not set. After a fresh Codex session, the new skill is picked up. The helper script takes a tmux target in the usual session:window.pane format, an optional number of lines to capture, and the text to send. One example sends the string status please to a coordination pane and grabs the last 80 lines. A second example uses a --codex-queue flag to push text into a pane where Codex is already busy, so the message waits until the current task finishes before being read. The README does not describe a license, tests, or any wider configuration. It is meant as a building block for agent workflows that need durable shells, and it expects the user to already have tmux installed and a working Codex setup.

Copy-paste prompts

Prompt 1
Install tmux.skill into ~/.codex/skills/tmux and verify Codex picks it up
Prompt 2
Use tmux-send-and-capture to start npm run dev in a pane and tail its output
Prompt 3
Show me how the --codex-queue flag changes the send-and-capture behavior
Prompt 4
Wire this skill into an agent loop that runs a build, watches output, and reacts to errors
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Generated 2026-05-22 · Model: sonnet-4-6 · Verify against the repo before relying on details.