ponytail lite
Stop agents from over-engineering. Inspired by Ponytail, but without the plugin madness. Just one AGENTS.md file.
Ponytail Lite
One file. No plugin. He would have wanted it this way.
"Ponytail Lite" is Ponytail without the plugin madness.
Not to be confused with Ponytail's lite mode. This is a separate one-file version.
Just copy AGENTS.md into the place your agent reads instructions. That's it. No plugin, hooks, commands, MCP, or mode switching.
The Joke
Ponytail is a beautiful contradiction: an anti-overengineering tool delivered as a whole plugin ecosystem, with lifecycle hooks, slash commands, MCP, statuslines, adapter tests, and enough install paths to make a senior engineer stare silently at the wall.
Ponytail Lite is what a lazy senior dev would have expected:
AGENTS.md
Why This Exists
Could you just copy AGENTS.md from Ponytail? Yes... But:
The AGENTS.md here is not a byte-for-byte copy. It is an opinionated cleanup of the original: same lazy senior dev idea, less plugin baggage, and guardrails rewritten for people who just want the file.
Install
Copy AGENTS.md, or copy the same text into whatever your agent calls "project instructions" or "rules".
| Agent | Put the Ponytail Lite text here |
|---|---|
| Aider | Your project instructions / conventions file |
| Antigravity CLI | AGENTS.md or .agents/rules/ponytail.md |
| Claude Code | CLAUDE.md or project instructions |
| Cline | .clinerules/ponytail.md |
| CodeWhale | AGENTS.md |
| Codex | AGENTS.md or Settings > Personalization > Custom instructions |
| Cursor | .cursor/rules/ponytail.mdc |
| Devin CLI | Custom instructions / project instructions |
| Gemini CLI | AGENTS.md |
| GitHub Copilot | .github/copilot-instructions.md |
| GitHub Copilot CLI | AGENTS.md, .github/copilot-instructions.md, or ~/.copilot/copilot-instructions.md |
| Hermes Agent | Custom instructions / system prompt |
| Kiro | .kiro/steering/ponytail.md |
| OpenClaw | Custom skill / instruction file |
| OpenCode | AGENTS.md or OpenCode instructions |
| Pi agent | Custom instructions / system prompt |
| Swival | AGENTS.md or ~/.config/swival/AGENTS.md |
| Windsurf | .windsurf/rules/ponytail.md |
| Zed | Custom instructions / rules |
Uninstall
Delete the file you copied.
If you pasted the text into a global instructions file, delete that paragraph.
No leftover mode flag, statusline entry, and hidden MCP server still thinking about your dependency graph.
What It Does
Before writing code, the agent climbs this ladder:
- Does this need to exist?
- Does it already exist in the codebase?
- Does the standard library do it?
- Does a native platform feature cover it?
- Does an installed dependency solve it?
- Can this be one line?
- Only then, write the minimum code that works.
License
MIT