Verified project record

DietrichGebert/ponytail

Ponytail is a Node-based, locally runnable skill for AI coding assistants that applies a reuse-first decision ladder before new code is written. On skill-capable hosts, it also supports diff review and repository audits that produce a delete-list of unnecessary code; other adapters load only the always-on ruleset.

Project overview

Project type: AI Agent · AI Coding
Use cases: Coding & Development
Deployment: Refer to project documentation
License: MIT

Best for

Developers using a supported AI coding assistant who want agents to favor existing code, standard libraries, and native platform features before adding implementation.
Teams that want to inspect a current Git diff or repository for over-engineering while retaining validation, security, accessibility, and data-loss safeguards.

Key capabilities

Instructs agents to evaluate whether work is necessary, then consider existing code, standard libraries, and native platform features before writing new code.
Retains existing safeguards for trust boundaries, data loss, security, and accessibility during code reduction.
Provides commands to review the current Git diff or audit an entire repository for over-engineering and produce a delete-list.
Supports lite, full, ultra, and off rule intensity through commands or environment variables.

Limitations and risks

Commands and slash functions work only on skill-capable hosts. Other adapters load the always-on ruleset without those commands.
For lifecycle hooks to work, Node.js must be available on the non-interactive shell PATH.

Getting started

For the documented Claude Code path, send `/plugin marketplace add DietrichGebert/ponytail`, then send `/plugin install ponytail@ponytail`.

Evidence and sources

GitHub project description: Makes your AI agent think like the laziest senior dev in the room. The best code is the code you never wrote.
README: You ask for a date picker. Your agent installs flatpickr, writes a wrapper component, adds a stylesheet, and starts a discussion about timezones.
README: Works with 20 agents
README: ~54% less code (up to 94%) · ~20% cheaper · ~27% faster · 100% safe
README: Before writing code, the agent stops at the first rung that holds: ``` 1. Does this need to exist? → no: skip it (YAGNI) 2. Already in this codebase? → reuse it, don't rewrite 3.…

Reviewed at: 2026-07-17T04:33:53Z