Ponytail

Why pick it

Agents love to over-build. You ask for a date picker — they install a library, write a wrapper, add a stylesheet, and start a debate about timezones. Ponytail makes them stop and reach for <input type="date"> instead.

It puts a lazy senior dev inside your agent: one who has seen everything, questions whether the task needs to exist at all, and reaches for the standard library before custom code. The result is ~54% less code, ~20% cheaper, ~27% faster — measured on real Claude Code sessions, not vibes.

What you get

Before writing code, the agent climbs a ladder and stops at the first rung that holds:

1. Does this need to exist? → skip it (YAGNI)
2. Already in this codebase? → reuse it
3. Stdlib does it? → use it
4. Native platform feature? → use it
5. Installed dependency? → use it
6. One line? → one line
7. Only then: the minimum that works

Lazy about the solution — never about reading. It traces the real flow first, then picks a rung. Trust-boundary validation, security, and accessibility are never cut.

Why it over a plain "be concise" prompt

vs telling your agent "write less code" — a bare terse-prose prompt cuts some lines but raises token cost and time (the agent spends words arguing about brevity). Ponytail is the only arm that cuts every metric while staying 100% safe. A naive "YAGNI + one-liners" prompt drops one safety guard; Ponytail keeps all of them.

vs Compound Engineering — CE adds planning and review discipline around execution. Ponytail shapes how the agent writes the code itself. They're complementary — many users run both: CE plans, Ponytail keeps the output lean.

Works with

Claude Code, Codex, Cursor, Cline, GitHub Copilot, OpenCode, Devin, and 13+ more agents — one install per host.

Quick start

In Claude Code: /plugin marketplace add DietrichGebert/ponytail, then /plugin install ponytail@ponytail. That's the most effort Ponytail will ever ask of you.

88k+ stars. The rule was never "fewest tokens" — it's: write only what the task needs, and never cut what keeps it safe.