Verdict. I keep it off by default and call /ponytail-review on diffs an agent wrote. It matches my own rule of trying the simplest thing first.
what it is
A “lazy senior dev” plugin for Claude Code. It walks a ladder before writing code. Skip it, reuse something, use the standard library, use a native feature, write one line, and only then write the minimum.
/plugin marketplace add DietrichGebert/ponytail
/plugin install ponytail@ponytail
Run those as two separate prompts.
how I use it
Installed on 2026-09-27 after a scan of the top ten skill repos. Before installing I set ~/.config/ponytail/config.json to {"defaultMode":"off"}. In that mode its SessionStart hook exits before emitting any rules, so it costs nothing per turn until I call it.
what I found
- It ships three lifecycle hooks (SessionStart, SubagentStart, UserPromptSubmit). While a mode is on, they inject the ruleset every turn and into every subagent. That’s why I keep it off.
- The hook scripts make no network calls. I read them before installing.
- The headline numbers (54% fewer lines of code, 20% lower cost) come from the author’s own benchmark. That was Haiku 4.5, n=4, twelve tasks on one FastAPI and React repo.
- It went from repo creation on 2026-06-12 to 146,872 stars by 2026-09-27. Stars here measure virality, not quality.
- There’s a waitlist for a paid product at ponytail.dev.