Ponytail

Ponytail is an AI-agent ruleset and plugin system that pushes coding assistants toward simpler, smaller, and less over-engineered solutions. It is built around the idea that the best code is often the code that does not need to be written. Before generating new code, it encourages the agent to check whether the feature is necessary, whether the standard library already solves it, whether the platform has a native capability, or whether an existing dependency can do the job. The project supports several agent environments, including Claude Code, Codex, GitHub Copilot CLI, OpenCode, Gemini CLI, and other instruction-based editors through copied rules files. It includes commands for changing intensity, reviewing diffs, auditing repositories, and tracking deferred shortcuts. It is useful for developers who want AI coding tools to act more like pragmatic senior engineers and less like generators of unnecessary abstractions.