Makes your AI agent think like the laziest senior dev in the room.
The best code is the code you never wrote.
---
AI agents over-deliver. Ask for a date picker, get a component library.
With ponytail:
```html
```
More before/afters in [examples/](examples/).
## How it works
Before writing code, the agent stops at the first rung that holds:
```
1. Does this need to exist? → no: skip it (YAGNI)
2. Stdlib does it? → use it
3. Native platform feature? → use it
4. Installed dependency? → use it
5. One line? → one line
6. Only then: the minimum that works
```
Never lazy about: validation at trust boundaries, error handling against data loss, security, accessibility.
## Install
Claude Code:
```
/plugin marketplace add DietrichGebert/ponytail
/plugin install ponytail@ponytail
```
Active every session. `/ponytail lite|full|ultra|off` switches intensity, `/ponytail-review` hunts over-engineering, `/ponytail-help` explains the rest.
Cursor, Windsurf, Cline, Copilot, Aider: copy the matching rules file from this repo ([`.cursor/rules/`](.cursor/rules/), [`.windsurf/rules/`](.windsurf/rules/), [`.clinerules/`](.clinerules/), [`.github/copilot-instructions.md`](.github/copilot-instructions.md), [`AGENTS.md`](AGENTS.md)).
## Numbers
5 coding tasks, same agent with and without ponytail: **−16% tokens, ~4× faster, 293 → 47 lines of code.** Data: [benchmarks/](benchmarks/).
## License
[MIT](LICENSE). The shortest license that works.
