# Ponytail (AI)
Ponytail is an open-source ([[MIT License]]) AI-agent plugin/skill that enforces minimalist code generation, "He says nothing. He writes one line. It works." It counters the tendency of coding agents to over-engineer (extra dependencies, boilerplate, building when something already exists) by injecting a pragmatic decision ladder the agent must follow before writing code.
## The decision ladder
> Does this need to exist? → no: skip it (YAGNI). Stdlib does it? → use it. Native platform feature? → use it. Installed dependency? → use it. One line? → one line. Only then: the minimum that works.
Safety guardrails (validation, error handling, security, accessibility) remain non-negotiable.
## Key aspects
- Intensity levels: lite, full, ultra, off
- Code-review commands: `/ponytail-review`, `/ponytail-audit`
- Ships as Node.js lifecycle hooks; works across 14+ agents/IDEs ([[Claude Code]], Codex, GitHub Copilot CLI, OpenCode, Gemini CLI, Cursor, Windsurf, Cline, …) via plugins, rules files, or instruction-only modes
- JavaScript + Python codebase
## Measured results
Against baseline agents on real FastAPI + React tasks (mean over 12 tasks): 54% fewer lines of code, 22% fewer tokens, 20% lower cost, 27% faster, 100% safety compliance.
## References
- https://github.com/DietrichGebert/ponytail
## Related
- [[Claude Code]]
- [[AI Agents]]
- [[Agentic Engineering]]
- [[Context Engineering]]
- [[MIT License]]