ponytail
He says nothing. He writes one line. It works. An agent skill that stops your AI from over-building. Two hooks, one command.
claude code · codex · copilot cli · opencode · all releases
What this is
You know him. Long ponytail, oval glasses, at the company longer than the version control. You show him fifty lines and he says nothing, then replaces them with one.
Ponytail puts him inside your AI agent. It ships as skills plus two lifecycle hooks, so before the agent writes code it has to justify writing any at all.
How it works
Before writing code, the agent goes down the ladder and stops at the first rung that holds.
1 does this need to exist? → no. skip it. (yagni)
2 is it already in this repo? → reuse it
3 does the stdlib do it? → use it
4 does the platform do it? → use it
5 does an installed dep do it? → use it
6 can it be one line? → write the line
──────────────────────────────────────────────────────────────
7 nothing above held → the minimum that works
The ladder runs after the problem is understood, never instead of understanding it. Lazy about the solution, thorough about reading.
[!NOTE] Lazy, not negligent. Validation, error handling, security and accessibility never go on the chopping block. The 100% figure below is that promise, measured.
Before and after
You ask for a date picker.
| your agent | ponytail |
|---|---|
| 3 files | 1 line |
| 50 lines | <input type="date"> |
| 1 dependency | |
| 1 open thread about timezones | the browser already had one |
Numbers
Measured over real Claude Code sessions on a real repository. On the tasks where agents over-build hardest, the drop reaches 94% less code.
Install
Unpack the archive and run ponytail.exe from its root. There is no installer
and no build step. Pick your agent when it asks, and it prints what to do next.
Works with
Claude Code · Codex · Copilot CLI · OpenCode · Pi · Antigravity ·
Hermes · OpenClaw · and more
The plugins run two small Node lifecycle hooks, so node has to be on your
PATH. Without it the skills still load, and the always-on activation simply
stays quiet.
Commands
| Command | What it does |
|---|---|
/ponytail [lite | full | ultra | off] | Set the intensity, or turn it off |
/ponytail-review | Review the current diff for over-engineering |
/ponytail-audit | Audit the whole repo, not just the diff |
/ponytail-debt | Collect the shortcuts you deferred into a ledger |
/ponytail-help | Quick reference |
FAQ
What if I really need the 120-line cache class?
You don't. Insist anyway and he builds it. Slowly. Correctly. While looking at you.
Does this make the agent worse at hard problems?
The ladder decides how much to build, not how much to think. Rung 7 exists for the cases where nothing simpler holds, and the guards above are never traded away for brevity.
Why "ponytail"?
You know exactly why.
License
MIT. The shortest license that works.
He says nothing. He writes one line. It works.