Guidance for designing command-line tools that work well with Unix pipelines and other programs. It covers command structure, standard output and error streams, output formats, exit codes, terminal detection, and error handling.

Use it to build command trees, design text or JSON output, separate normal results from errors, choose exit codes, detect interactive terminals, and test CLI behaviour.

It helps command-line programs remain understandable for people and predictable when scripts pass their output to other commands.

cli-design — Skill for Claude Code by citypaul/.dotfiles

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 citypaul/.dotfiles --skill cli-design

Clone the repo

git clone --depth 1 https://github.com/citypaul/.dotfiles

Made for: Claude Code.

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/citypaul/.dotfiles/cli-design/github.svg)](https://agentmods.dev/skills/citypaul/.dotfiles/cli-design)

Your own site

<a href="https://agentmods.dev/skills/citypaul/.dotfiles/cli-design"><img src="https://agentmods.dev/badge/skills/citypaul/.dotfiles/cli-design/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/citypaul/.dotfiles/cli-design"><img src="https://agentmods.dev/badge/skills/citypaul/.dotfiles/cli-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 6,074 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin unknown No closer match found 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	$0.00084	$0.06074
Opus 5.5	$0.00034	$0.02430
Sonnet 5.5	$0.00017	$0.01215
Haiku 4.5	$0.00008	$0.00607

Measured 2mo ago against content hash 8926ead6ffb0, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

cli-design scanned grade A with 1 finding 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.

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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- Support `-` for stdin/stdout file arguments: `curl ... | mycli process -`

claude/.claude/skills/cli-design/SKILL.md · 521 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Files

What ships with it

6 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 Changed · +17 lines 8926ead6ffb0
2mo ago First seen · 504 lines · 84 tokens per session scan A 217b2acf6425

Subscribe to this mod's changes

cli-design is a skill published in the GitHub repository citypaul/.dotfiles (757 stars, last pushed 4d ago), with no licence file. It adds 84 tokens to every session and 6,074 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

cli-design next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
cli-designcitypaul/.dotfiles	Skill	757	4d ago	none	A	84	Claude Code
imagegenopenai/codex	Skill	134k	today	Apache-2.0	A	113	Codex
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	yesterday	MIT	A	200	Claude Code, Codex
playwright-climicrosoft/playwright	Skill	100k	yesterday	Apache-2.0	A	19	Claude Code
browser-automationopenclaw/openclaw	Skill	394k	today	MIT	A	36	Claude Code
systematic-debuggingobra/superpowers	Skill	314k	4d ago	MIT	A	21	Claude Code
next-cache-components-adoptionvercel/next.js	Skill	143k	today	MIT	A	95	Claude Code