A coding-agent instruction set that prefers the shortest working solution, uses standard-library features first, and avoids unrequested abstractions.

Use it when implementing or reviewing changes where avoiding speculative features and extra layers is important.

It helps reduce unnecessary code and design work when a simpler implementation is enough.

ponytail — Plugin for Gemini CLI by DietrichGebert

About the project

Ponytail is a set of instructions and extensions that guides AI coding agents toward smaller, simpler code changes while retaining safety checks. It is intended for developers using agents such as Claude Code, and the catalogue entries are its skills, instructions, plugin, and rule.

DietrichGebert/ponytail · 175,654 stars · on GitHub · ponytail.dev

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.

Clone the repo

git clone --depth 1 https://github.com/DietrichGebert/ponytail

Made for: Gemini CLI.

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/plugins/dietrichgebert/ponytail/gemini-extension/github.svg)](https://agentmods.dev/plugins/dietrichgebert/ponytail/gemini-extension)

Your own site

<a href="https://agentmods.dev/plugins/dietrichgebert/ponytail/gemini-extension"><img src="https://agentmods.dev/badge/plugins/dietrichgebert/ponytail/gemini-extension/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/plugins/dietrichgebert/ponytail/gemini-extension"><img src="https://agentmods.dev/badge/plugins/dietrichgebert/ponytail/gemini-extension.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session not measured What this adds to a session before it is invoked.

When invoked not measured Not applicable: nothing here is loaded into a session.

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.

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 8d 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.

gemini-extension.json · 7 lines

What it actually says

{
  "name": "ponytail",
  "version": "5.3.2",
  "description": "Lazy senior dev mode. Forces the simplest, shortest solution that actually works: YAGNI, stdlib first, no unrequested abstractions.",
  "contextFileName": "AGENTS.md"
}

Files

What ships with it

60 files beside gemini-extension.json 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.

8d ago Changed 11a7c184f48e
11d ago Changed 4de16224ac50
12d ago Changed 6c7f1930fb59
16d ago Changed 7eaba24d9435
19d ago Changed 68d24eff22b8
20d ago Changed 0a94fc8b35d8
21d ago Changed 19775221872a
22d ago Changed 5d0d6a59e04d
1mo ago Changed 183aa7f6dbbe
1mo ago First seen · 7 lines scan A 2ce1e6ae8bf9

Subscribe to this mod's changes

ponytail is a plugin published in the GitHub repository DietrichGebert/ponytail (175,654 stars, last pushed 7d ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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 2026-09-08.

Claude Code Productivity agent-skills ai-agents claude claude-code-plugin cursor-rules

ponytail

Getting it into your agent

Wrote this? Show the measurements

Grade A, and why

Nothing flagged

What it actually says

What ships with it

What this file has done since we first saw it

Other plugins, from other repositories

i-have-adhd

dev-skills

cloudflare-browser-rendering

hermitd-feed

handbook

hush