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.
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.
git clone --depth 1 https://github.com/DietrichGebert/ponytailWrote 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.
[](https://agentmods.dev/commands/dietrichgebert/ponytail/ponytail-review)<a href="https://agentmods.dev/commands/dietrichgebert/ponytail/ponytail-review"><img src="https://agentmods.dev/badge/commands/dietrichgebert/ponytail/ponytail-review/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.
<a href="https://agentmods.dev/commands/dietrichgebert/ponytail/ponytail-review"><img src="https://agentmods.dev/badge/commands/dietrichgebert/ponytail/ponytail-review.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00000 | $0.00465 |
| Opus 5.5 | $0.00000 | $0.00186 |
| Sonnet 5.5 | $0.00000 | $0.00093 |
| Haiku 4.5 | $0.00000 | $0.00047 |
Grade A, and why
ponytail-review 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 17d 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.
Copies of this mod
3 near-identical copies found in the catalogue:
- ponytail-review — 100% identical, 4 lines differ
- ponytail-review — 100% identical, 4 lines differ
- ponytail-review — 92% identical, 6 lines differ
What it actually says
Review the current code changes like the senior developer who will be paged when they break. Review what the user names (uncommitted or staged changes, a branch, a PR link, files); nothing named: the uncommitted changes, or the last commit if there are none. First read the code the change touches: callers of every changed function, the functions it calls, the tests, the README (find the expected load: one person or many users and processes). A change can break code it does not touch. Look for, in this order: bugs (wrong result, crash, missed edge case, a caller broken by the change, a fix in one caller while the shared function stays broken), risk (security holes, data loss), scale (check-then-write races, the same work done by every process, memory that only grows, a query per item, O(n^2) on big input), risky logic without a test, slow code (big = problem, small = suggestion), lean (dead code, a helper the repo already has, stdlib or native instead of custom code or a new dependency, abstractions with one implementation, near-copies to merge, a function doing several unrelated jobs to split, never split by line count). Every finding needs a concrete case; re-read the lines to confirm it. A shortcut marked with a shortcut: (or older ponytail:) comment that names its limit is a decision, not a finding. Propose the smallest fix, prefer deleting code, never add layers. No style taste, no vague worries. Very simple English, explain technical terms. Start with 'What this change does:' in two or three sentences and the load you assumed. Then numbered findings grouped Must fix / Should fix / Nice to have; each finding: a bold title with file:lines, then four bullets: What this is, Problem, Fix, If we skip it (one or two short sentences each). End with 'Verdict:', 'Lean: -N lines possible.' when lean findings exist, and 'Not checked:' if something mattered and you could not check it. Nothing found: 'Looks good. Ship.' Change no code.
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.
- 17d ago Changed · -11 tokens per session 444d0b0a94e7
- 20d ago Changed 767fac58add0
- 22d ago Changed 8c0d200f5e64
- 1mo ago First seen · 6 lines · 11 tokens per session scan A ff09bd42b1d2
ponytail-review is a command published in the GitHub repository DietrichGebert/ponytail (176,199 stars, last pushed 8d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 465 tokens. 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.
Other commands, from other repositories
init
Install the formatters this repository needs, with every command visible before it runs.
simplify
The over-engineering review: five tags (delete, stdlib, native, yagni, shrink), a mandatory replacement per finding, and a real null result when there is nothing to cut.
git
The pre-finish status: branch, hygiene findings, message checks, workflow lint, template state.
extend
Capture a mid-PR sub-idea and implement it onto the current open PR's branch — no new branch, no new PR. Preserves Verify → Review → Deliver.
fec-smell
Diagnose frontend code smells with evidence and candidate refactorings without changing business code.
security-review
Depth-first security audit of the current git diff — OWASP Top 10, secret leakage, insecure-by-default APIs, and language-specific foot-guns. Pass a PR number to audit a specific PR's diff.