head to head · open source
ponytail vs agent-rules-books
ponytail has 182,779 GitHub stars, 10,094 forks, 270 open issues and last shipped 5 days ago. agent-rules-books has 3,170 stars, 552 forks, 5 open issues and last shipped 2 months ago. ponytail leads on adoption by 5,666% (182,779 vs 3,170 stars). ponytail is written in JavaScript under MIT; agent-rules-books is written in various languages under MIT. ponytail has attracted 6% as many forks as stars, agent-rules-books 17%. ponytail was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (agent-skills, claude-code), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| ponytail | agent-rules-books | |
|---|---|---|
| GitHub stars | ★ 183K | ★ 3.2K |
| License | MIT | MIT |
| Written in | JavaScript | — |
| Last push | 2026-10-29 | 2026-09-10 |
| Forks | ⑂ 10K | ⑂ 552 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick ponytail if
- You weight community size — 183K stars and counting
- You want the MIT license terms
- Your stack matches JavaScript
- You value the larger contributor base for long-term maintenance
pick agent-rules-books if
- You want the agent-rules-books feature set and don't need the biggest community
- You prefer the MIT license terms
- You evaluated both and agent-rules-books fits your workflow better
About ponytail
Ponytail He says nothing. He writes one line. It works. 54% less code (up to 94%) · 20% cheaper · 27% faster · 100% safe Measured on real Claude Code sessions editing a real open source repo (FastAPI + React), against the same agent with no skill. 54% is the mean across 12 feature tasks (Haiku 4.5, n=4); it reaches 94% where an agent over builds (a date picker) and is near zero where the code is already minimal. ponytail keeps every safety guard while a bare "write one liners" prompt drops one. (The earlier single shot benchmark reported 80 94% as a flat figure; against a fair agentic…
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About agent-rules-books
AI agents Rules / Skills from Programming Books v0.6 AGENTS.md rules / skills for Codex , Cursor , Claude Code , distilled from classic software engineering books about refactoring, architecture, DDD and code quality. About · Installation · Rules / Skills · Books List · Usage · Books Compatibility About MIT licensed universal project rules for coding agents. This repository contains ready to use rule sets inspired by well known books on software design, architecture, refactoring, legacy code, reliability, and data intensive systems. For editor specific setup in Codex, Claude Code, and Cursor, see USAGE.md. It…
read the full agent-rules-books overview →
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Frequently asked questions
Is ponytail or agent-rules-books more popular?
ponytail has 182,779 GitHub stars and agent-rules-books has 3,170. ponytail has the larger community by that measure.
Are ponytail and agent-rules-books free?
Both are open source. ponytail is licensed under MIT and agent-rules-books under MIT. Neither carries a licence fee.
What is the difference between ponytail and agent-rules-books?
ponytail is written in JavaScript and agent-rules-books in various languages. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, ponytail or agent-rules-books?
Choose ponytail if you want the larger community (182,779 stars) or its MIT licence terms. Choose agent-rules-books if its feature set, stack or MIT licence fits better. Both are self-hostable.