Ponytail

Ponytail provides a ruleset designed to make AI coding agents write the least code that works, reducing output tokens, cost, and time while maintaining correctness. It works with various AI tools and assistants including Claude Code, Codex, Copilot, Gemini, and Cursor. The system evaluates requests by checking if features already exist in the codebase, standard library, platform, or dependencies before writing new code. It also includes review and audit commands to analyze code changes and repositories for bugs, security issues, and missing tests.