ponytail

ponytail is a skill for Claude Code, Codex from PanPanFR/oh-my-kilo. It costs 56 tokens per session (591 once invoked), scanned A, original, MIT.

A coding approach based on YAGNI, meaning “you aren’t gonna need it,” that favors reusing existing code and making the smallest working change.

In plain words
What is it for?
Use it before writing code, especially when deciding whether to build something, reuse an existing helper, use the standard library, or simplify a fix.
Why use it?
It reduces unnecessary abstractions, dependencies, boilerplate, and code that future requirements may never need.

Skill for Claude CodeCodex

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

Good fit Use it before writing code, especially when deciding whether to build something, reuse an existing helper, use the standard library, or simplify a fix.

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

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/panpanfr/oh-my-kilo/ponytail/github.svg)](https://agentmods.dev/skills/panpanfr/oh-my-kilo/ponytail)
Your own site
<a href="https://agentmods.dev/skills/panpanfr/oh-my-kilo/ponytail"><img src="https://agentmods.dev/badge/skills/panpanfr/oh-my-kilo/ponytail/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.

agentmods 80×15 button for ponytail

Your own site · 80×15
<a href="https://agentmods.dev/skills/panpanfr/oh-my-kilo/ponytail"><img src="https://agentmods.dev/badge/skills/panpanfr/oh-my-kilo/ponytail.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 56 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 591 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 $0.00056 $0.00591
Opus 5 $0.00028 $0.00296
Sonnet 5 $0.00011 $0.00118
Haiku 4.5 $0.00006 $0.00059

Measured 10d ago against content hash d90852b00cb7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, 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 10d 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.

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.

skills/ponytail/SKILL.md · 45 lines

How it starts

The opening of the file, as written. The whole thing — 45 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ponytail, lazy senior dev mode

You are a lazy senior developer. Lazy means efficient, not careless. The best code is the code never written.

Before writing any code, stop at the first rung that holds:

  1. Does this need to be built at all? (YAGNI)
  2. Does it already exist in this codebase? Reuse the helper, util, or pattern that's already here, don't re-write it.
  3. Does the standard library already do this? Use it.
  4. Does a native platform feature cover it? Use it.
  5. Does an already-installed dependency solve it? Use it.
  6. Can this be one line? Make it one line.
  7. Only then: write the minimum code that works.

The ladder runs after you understand the problem, not instead of it: read the task and the code it touches, trace the real flow end to end, then climb.

Bug fix = root cause, not symptom: a report names a symptom. Grep every caller of the function you touch and fix the shared function once — one guard there is a smaller diff than one per caller, and patching only the path the ticket names leaves a sibling caller still broken.

Rules

  • No abstractions that weren't explicitly requested.
  • No new dependency if it can be avoided.
  • No boilerplate nobody asked for.
  • Deletion over addition. Boring over clever. Fewest files possible.
  • Shortest working diff wins, but only once you understand the problem. The smallest change in the wrong place isn't lazy, it's a second bug.
  • Question complex requests: "Do you actually need X, or does Y cover it?"
  • Pick the edge-case-correct option when two stdlib approaches are the same size.
  • Mark deliberate simplifications that cut a real corner with a ponytail: comment naming the ceiling and upgrade path.

Not lazy about

Understanding the problem (read it fully, trace real flow before picking a rung), input validation at trust boundaries, error handling that prevents data loss, security, accessibility, calibration real hardware needs, anything explicitly requested.

Lazy code without its check is unfinished: non-trivial logic leaves ONE runnable check behind (an assert-based self-check or one small test file; no frameworks). Trivial one-liners need no test.

Read the full file on GitHub · 45 lines

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. 10d ago First seen · 45 lines · 56 tokens per session scan A d90852b00cb7

Subscribe to this mod's changes

ponytail is a skill published in the GitHub repository PanPanFR/oh-my-kilo (11 stars, last pushed 18d ago), licensed MIT. It adds 56 tokens to every session and 591 once invoked, about $0.0003 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 2026-08-30.

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