ponytail

ponytail is a skill for Claude Code, Codex from kleosr/kleosrules. It costs 25 tokens per session (352 once invoked), scanned A, original, MIT.

A quality guide for Lean-style coding: first reuse existing code, then prefer the language standard library and platform before adding dependencies. It also sets rules for small files, clear types, shallow control flow, and minimal changes.

In plain words
What is it for?
Use it when writing application code, choosing between implementation options, splitting large files, naming exports, handling errors, or reviewing a change for maintainability.
Why use it?
It helps prevent unnecessary code, dependencies, oversized files, weak typing, and inconsistent patterns. It encourages checking nearby code before introducing a new solution.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it when writing application code, choosing between implementation options, splitting large files, naming exports, handling errors, or reviewing a change for maintainability.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/kleosr/kleosrules/ponytail
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 kleosr/kleosrules --skill ponytail
Clone the repo
git clone --depth 1 https://github.com/kleosr/kleosrules

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.

agentmods badge for ponytail

README.md
[![agentmods](https://agentmods.dev/badge/skills/kleosr/kleosrules/ponytail.svg)](https://agentmods.dev/skills/kleosr/kleosrules/ponytail)
Your own site
<a href="https://agentmods.dev/skills/kleosr/kleosrules/ponytail"><img src="https://agentmods.dev/badge/skills/kleosr/kleosrules/ponytail.svg" alt="Measured on agentmods" height="20"></a>
Per session 25 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 352 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 original 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00025 $0.00352
Opus 5 $0.00013 $0.00176
Sonnet 5 $0.00005 $0.00070
Haiku 4.5 $0.00003 $0.00035

Measured today against content hash 280dafdba401, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

ponytail 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 today.

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.

shared/skills/ponytail/SKILL.md · 39 lines

What it actually says

Ponytail

Thin roof: ponytail.mdc. stop.sh checks rewrite and mass reindent only.

Ladder

First rung that still does the job:

  1. No code — config, delete, existing API.
  2. Reuse — Grep this repo.
  3. Stdlib.
  4. Framework native.
  5. Already-installed dep (new package: one chat line why lower rungs fail).
  6. One clear line.
  7. Minimum private-native diff. Soft ~80 LOC. Split before 120. Hard 300. Never 500. Files >700: modules ≤300.

Skipping a rung: one chat line naming why.

Quality

Match 1–2 siblings. Named exports. Early return. Nesting ≤2. No any / un-narrowed unknown / blind casts. Zero prose comments. Zero dead or redundant code. Infer loading from data. Jargon: bans.txt beside this file (fail-open if missing). Behavior change: test when the testing skill applies.

Split

Read → plan → Write new modules → StrReplace original to imports → Grep callers. Never Shell sed/echo>/tee.

domains/ trees: domains-ddd.md. frontend/ + backend/: fe-be-layout.md.

Floors

Trust, authz, data-loss, a11y, explicit asks. Cyclo: complexity.mdc. Off only if the user says stop ponytail.

Files

What ships with it

3 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.

  1. today Changed · -44 lines 280dafdba401
  2. 2d ago Changed · -1 lines · -28 tokens per session 32b6adf18e42
  3. 7d ago First seen · 84 lines · 53 tokens per session scan A 2909979f759d

Subscribe to this mod's changes

ponytail is a skill published in the GitHub repository kleosr/kleosrules (2 stars, last pushed yesterday), licensed MIT. It adds 25 tokens to every session and 352 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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