*written by ForgeCat* ![ForgeCat](https://raw.githubusercontent.com/nota-america/forgecat-agent-profiles/main/assets/forgecat_banner.png) # Ponytail Lazy senior developer mode for AI agents, with YAGNI, standard-library-first, native-first, and minimal-code guidance packaged as skills, commands, rules, and lifecycle hooks. ## Tags - yagni - minimalism - code-review - productivity - hooks ## Installation ```bash npx forgecat install @forgecat/dietrichgebert_ponytail ``` ## Skills / Agents / Commands - **ponytail** - Persistent lazy senior developer mode with lite, full, and ultra intensity levels. `skill` - **ponytail-review** - Diff-focused over-engineering review that reports what to delete or simplify. `skill` - **ponytail-audit** - Whole-repo over-engineering audit for deletion, stdlib, native, YAGNI, and shrink findings. `skill` - **ponytail-debt** - Reads `ponytail:` comments into a shortcut debt ledger. `skill` - **ponytail-help** - Quick reference for Ponytail modes, skills, commands, and deactivation. `skill` - **ponytail** - Switch Ponytail intensity level. `command` - **ponytail-review** - Review changes for over-engineering. `command` - **ponytail-audit** - Audit a whole repo for over-engineering. `command` - **ponytail-debt** - Harvest `ponytail:` comments into a ledger. `command` - **ponytail-help** - Quick reference for ponytail levels, skills, and commands. `command` ## Details | Field | Value | |---|---| | Author | Dietrich Gebert | | Original repository | https://github.com/DietrichGebert/ponytail | | Version | `0.1.8` | | Original commit | `1c420ad2f306b2a096dd1e7c1b8c5ebbb4cdf3d4` | | License | MIT | | Source platform | Multi-platform: Claude Code plugin, Codex plugin, Cursor rule, OpenCode plugin, Gemini extension, pi extension, and generic AGENTS.md/skills adapters | ## Compatibility ### Platforms | Platform | Status | |---|---| | Claude Code | Tested | | Cursor | Partial | | Codex | Tested | | OpenClaw | Partial | | Hermes | Partial | ## Dependencies - Node.js for Ponytail lifecycle hook scripts. --- *written by original source*

Ponytail

He says nothing. He writes one line. It works.

Stars Release

80-94% less code · 3-6× faster · 47-77% cheaper
_{Median of 10 runs across Haiku, Sonnet, and Opus. Reproduce it yourself.}

--- You know him. Long ponytail. Oval glasses. Has been at the company longer than the version control. You show him fifty lines; he looks at them, says nothing, and replaces them with one. Ponytail puts him inside your AI agent. ## Before / after You ask for a date picker. Your agent installs flatpickr, writes a wrapper component, adds a stylesheet, and starts a discussion about timezones. With ponytail: ```html ``` More survivors in [examples/](examples/). ## Numbers Five everyday tasks (email validator, debounce, CSV sum, countdown timer, rate limiter), three models, three arms: no skill, the [caveman](https://github.com/JuliusBrussee/caveman) skill, and ponytail. Ten runs per cell, median reported.

Median lines of code per arm across Haiku, Sonnet and Opus; ponytail writes 80-94% less code than the no-skill baseline

**80-94% less code, 47-77% less cost, and 3-6× faster than a no-skill agent, on every model.** Every shortcut ponytail takes is marked in the code with a `ponytail:` comment naming its upgrade path. Reproduce it yourself: `npx promptfoo eval -c benchmarks/promptfooconfig.yaml`. Method and raw numbers: [benchmarks/](benchmarks/). Production-grade tasks, where an unconstrained agent bloats far more, are written up in [benchmarks/results/](benchmarks/results/). ## 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 ``` Lazy, not negligent: trust-boundary validation, data-loss handling, security, and accessibility are never on the chopping block. ## Install The most effort ponytail will ever ask of you: ### Claude Code ``` /plugin marketplace add DietrichGebert/ponytail /plugin install ponytail@ponytail ``` ### Codex ```bash codex plugin marketplace add DietrichGebert/ponytail codex ``` Open `/plugins`, select the Ponytail marketplace, and install Ponytail. Then open `/hooks`, review and trust its two lifecycle hooks, and start a new thread. ### Pi agent harness ``` pi install git:github.com/DietrichGebert/ponytail ``` ### OpenCode Run OpenCode from a checkout of this repo (the plugin reuses its `hooks/` and `skills/`), and add to `opencode.json`: ```json { "plugin": ["./.opencode/plugins/ponytail.mjs"] } ``` Injects the ruleset every turn at the active level; adds the `/ponytail` commands (see [Commands](#commands)). OpenCode also auto-loads this repo's `AGENTS.md`, so the rules hold even without the plugin. The plugin adds the `lite/full/ultra/off` levels. ### Gemini CLI ```bash gemini extensions install https://github.com/DietrichGebert/ponytail ``` Loads the ruleset as always-on context every session and registers the `/ponytail` commands; the `skills/` ship too, activated when a task needs them. That was it. He'd be proud. He won't say it. Active every session, with a handful of commands (see [Commands](#commands)). `/ponytail ultra` exists for when the codebase has wronged you personally. Startup and mode-change text shows the current mode. Cursor, Windsurf, Cline, Copilot, Aider, Kiro: 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), [`.kiro/steering/`](.kiro/steering/)). Kiro: copy `.kiro/steering/ponytail.md` to `~/.kiro/steering/` (global) or `.kiro/steering/` in your project. GitHub Copilot CLI: it already reads `AGENTS.md` and `.github/copilot-instructions.md` in a project, or copy the rules into `~/.copilot/copilot-instructions.md` to run ponytail in every project. Antigravity and VS Code with the Codex extension: both read `AGENTS.md`, which this repo ships, so it works from the repo root with no setup (`~/.codex/AGENTS.md` makes Codex global, `.agents/rules/` makes it an always-on rule in Antigravity). Which files map to which agent: [Agent portability](docs/agent-portability.md). ## Commands | Command | What it does | |---------|--------------| | `/ponytail [lite \| full \| ultra \| off]` | Set the intensity, or turn it off. No argument reports the current level. | | `/ponytail-review` | Review the current diff for over-engineering, hands back a delete-list. | | `/ponytail-audit` | Audit the whole repo for over-engineering, not just the diff. | | `/ponytail-debt` | Harvest the `ponytail:` shortcuts you've deferred into a ledger, so "later" doesn't become "never". | | `/ponytail-help` | Quick reference for the commands above. | Commands need a skill-capable host (Claude Code, Codex, OpenCode, Gemini, pi). In Codex they're skills, invoke with `@` (`@ponytail-review`). The instruction-only adapters (Cursor, Windsurf, Cline, Copilot, Kiro, Antigravity) load the always-on ruleset without the commands. ## Development When changing the compact rule text, keep the agent copies aligned: ```bash node scripts/check-rule-copies.js ``` ## FAQ **Does it need a config file?** No. **What if I really need the 120-line cache class?** You don't. Insist anyway and he'll build it. Slowly. Correctly. While looking at you. **Does it scale?** The code you never wrote scales infinitely. Zero bugs, zero CVEs, 100% uptime since forever. **Why "ponytail"?** You know exactly why. ## License [MIT](LICENSE). The shortest license that works.

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dietrichgebert_ponytail