Ponytail

The heart of Ponytail is a decision ladder the agent walks before writing anything. It asks whether the code needs to exist, whether the repo already has a helper, whether the standard library or a native platform feature covers it, whether an installed dependency solves it, and whether it fits in one line. New code is the last resort. This is what turns a fifty-line cache manager into a single lru_cache decorator.

Ponytail isn't tied to one assistant. It ships install paths for Claude Code, Codex, Copilot CLI, Gemini CLI, Pi, OpenCode, Cursor, Windsurf, Cline, Kiro and Zed, among others. That matters if your team uses different agents, because the same guidance applies wherever you code.

You set how aggressive the ruleset is. lite builds what you asked but names a lazier alternative in one line. full enforces the ladder and favors the shortest diff. ultra is the YAGNI extremist that ships the one-liner and challenges the rest of the requirement. Three levels, one switch. You can also turn it off entirely.

Ponytail adds slash-style commands so you can drive it from the chat. /ponytail-review finds over-engineering in the current diff, /ponytail-audit scans the repo for bloat, and /ponytail-debt collects deferred shortcuts into a ledger so laziness doesn't turn into forgotten work. No dashboards to open. Everything runs where you already work.

The vendor reports roughly 54% less code, about 20% cheaper runs and 27% faster tasks, measured on real Claude Code sessions editing an open-source FastAPI and React repo. The savings vary, hitting 94% where an agent over-builds and near zero where the code is already minimal.

The ruleset simplifies toward less code, but the vendor says validation, error handling, security and accessibility are never simplified away. A bare "write one-liners" prompt tends to drop a safety guard, which is the problem Ponytail is trying to avoid.