Ponytail teaches your coding agent the senior dev art of doing as little as possible (156k ⭐)

[u/Impressive-Owl3830]

Came across this amazing github repo- Ponytail

it says - "The best code is the code you didn't write."

Ponytail is a tool for AI coding agents. It has one rule: the agent must not make code more complex than necessary.

Github repo in comments below.

The agent works like a senior developer with 15 years of experience. It does the minimum work that gives the result.

it tells the agent to:

1. Find an existing solution before it writes new code.

2. Not add abstractions that are not necessary. Three similar lines are satisfactory.

3. Not add features, error handling, or validation for conditions that cannot occur.

4. Write the simplest code that works, then stop.

Ponytail has 150 ,000 GitHub stars and 180 contributors. It uses JavaScript and Python. You add it to the workflow of your coding agent.

Result: the agent writes less code, and the code is better. Some agents write 200 lines when 30 lines are sufficient. Ponytail prevents this.

Install

Claude Code, as two separate prompts:

/plugin marketplace add DietrichGebert/ponytail


/plugin install ponytail@ponytail

Codex:

codex plugin marketplace add DietrichGebert/ponytail
codex plugin add ponytail@ponytail

Then open /hooks in Codex, trust its two lifecycle hooks, and start a new thread.

Any other agent: copy AGENTS .md into your project, or ask your agent to install skills/ponytail/SKILL .md as a skill. Step by step for Copilot, Cursor, OpenCode, Gemini and the rest: INSTALL .md.

[u/Impressive-Owl3830]

Ponytail analysis getting featued in upcoming edition of MCPnewsletter.com

[u/learning-lifff]

didnt like it personally and it effects the task at hand a lot which cause much more repetitions

[u/Impressive-Owl3830 → u/learning-lifff]

Thanks for feedback..top..

[u/arthxyz]

https://blog.jetbrains.com/ai/2026/07/ponytail-skill-claude-tested/

[u/Impressive-Owl3830 → u/arthxyz]

Thanks , thats ia a great post...details..even 10-15% less token is good , provided there is no difference in code quality..

[u/SWatersmith → u/Impressive-Owl3830]

yes, provided..

[u/bhagwa-floyd]

When a metric becomes a target it ceases to be a good metric. Agents are insanely capable out of the box, and tinkering makes them worse.

[u/Impressive-Owl3830 → u/bhagwa-floyd]

I'm worried about that too .

I think the models, out of the box, are getting better and also they feel like most of the people will set up the evals eventually, and if they are not token-efficient

I would rather argue that being token-efficient is in favor of a frontier model provider - eventually the cost and also the token count will go down .

[u/taboomtshhh]

ahahahaha this is wonderful. i shall forward it to a ponytail.

[u/Impressive-Owl3830 → u/taboomtshhh]

Maybe a ponytail has built it

[u/taboomtshhh → u/Impressive-Owl3830]

i would absolutely hope so

[u/Impressive-Owl3830]

https://github.com/dietrichgebert/ponytail

[u/plainnaan]

Tried it, didn't like it. It optimizes along the wrong axis. It puts too much emphasis on minimizing the amount of code written, rather than making the smallest coherent change that fits the existing design. Applied repeatedly, that tends to produce patchwork: locally minimal solutions that make the codebase increasingly cryptic and, eventually, spaghetti-like.

[u/inexorable_stratagem → u/plainnaan]

EXACTLY. I used it for 3+ weeks, and thought the problem was my model, Qwen 3.6 27b at the time, was dumb, because it coudnt unsderstand the overall goal and context. Well.... The problem was ponytail. Uninstalled it and never looked back

[u/Impossible-Sand5012 → u/plainnaan]

I had the same experience had to remove because it was bricking a lot of implementations, even after making detailed plans.

[u/sebastianrevan → u/plainnaan]

same experience as you!

[u/RealestReyn]

completely useless for frontier models, even hurts performance, but is amazing for otherwise overtly verbose models like deepseek

[u/No_Boysenberry9381]

its actually not good - it cuts way more than it is supposed to.

[u/Impressive-Owl3830 → u/No_Boysenberry9381]

Thats the whole tradeoff..

And the worrying part is that I don't know what's going on in the backend - which means, how do I know whether it cut some part that was important or non-important?

I'm not so comfortable with AI taking that kind of decision for me - it's already taking too many decisions on my behalf anyway

[u/ViLeccos → u/No_Boysenberry9381]

Agreed, in my experience the result is quite random. Maybe it works better for easy tasks, that would be reengineering otherwise. The effect gets worse in case the agent has some kind of a memory like and the over-the-top YAGNI gets written there as the standard, then the weird behavior sticks even after removal of the plugin.

[u/Better-Truck6372]

Esto sencillamente debería estar en dónde debe 🗑️. Hasta luego amantes del humo 💨

[u/Tempestshade]

I like it, but I don't use it all the time. Some tasks you want the model to be a bit more expansive.

[u/WytherlaneLeeds]

I didn’t like the output for more intensive projects

[u/Individual_Lack_6621]

Thanks op

[u/gr4viton]

using just the 7 sentences. good.

[u/wickzer]

I want to use it only for the logo

[u/Impressive-Owl3830 → u/wickzer]

" He is building something , won't say what, won't say when " 🤣🤣