ponytail

Ponytail is a plugin that talks your coding agent out of writing code. It installs a decision ladder the agent has to walk before it types anything: can this be skipped entirely, can existing code be reused, is there a standard library function, is there already a dependency that does it, can it be one line. Building something new is the last rung. MIT licensed, nothing to host.

What started as a Claude Code skill now covers roughly twenty harnesses, each with its own install command: Codex, Copilot CLI, Cursor, Windsurf, Cline, Zed, Gemini CLI, Aider. Node on your PATH is the only hard requirement, for the lifecycle hooks. Six commands cover mode control, review, audit, tech debt, and a gain report, and three intensity levels dial how aggressive it gets.

The project's own benchmark on FastAPI and React edits claims 54% fewer lines, 20% lower cost, and 27% faster runs. Treat a maintainer's benchmark as directional rather than settled. Solo developers: the token savings alone repay ten minutes of setup. Small and medium teams: worth standardizing so agent output looks the same across the team. Large teams should wire the audit and debt commands into review.

The catch is that "write less code" is a preference, not a law. Push an agent hard enough toward minimalism and it will reach for a dependency that does not quite fit, or skip an abstraction you wanted. Start on lite, read what it declines to build, and turn it up once you trust its judgment.