pi-karpathy-guidelines

A Pi extension that enforces Andrej Karpathy's coding guidelines to reduce common LLM coding mistakes.

Install

pi install npm:pi-karpathy-guidelines

Or from git:

pi install git:github.com/parkiyong/pi-karpathy-guidelines

Guidelines

The extension injects four behavioral rules into every LLM turn:

1. Think Before Coding — State assumptions. Ask when uncertain. Surface tradeoffs.
2. Simplicity First — Minimum code that solves the problem. No speculative features or abstractions.
3. Surgical Changes — Touch only what's needed. Match existing style. Don't refactor what isn't broken.
4. Goal-Driven Execution — Define verifiable success criteria. State a plan with checks.

Derived from Karpathy's observations on LLM coding pitfalls.

Active Enforcement

Beyond prompt injection, the extension actively gates tool calls that violate the guidelines:

Gate	Trigger	Guideline
Large write	write tool > 200 lines	#2 Simplicity First
Broad edit	edit tool > 5 blocks	#3 Surgical Changes

Both gates prompt for confirmation before allowing the operation through. The LLM receives the guideline-specific reason if blocked.

Commands

Command	Description
/karpathy	Toggle on/off — shows 🧠 in footer when active
/karpathy-check	Ask the LLM to self-critique its last response against all 4 guidelines

The extension is enabled by default. Use /karpathy to turn it off for trivial tasks where the caution bias isn't useful.

How it works

• before_agent_start — Appends the full guidelines to the system prompt each turn.
• tool_call — Intercepts write and edit calls, checks thresholds, prompts for confirmation.
• /karpathy-check — Sends a self-review prompt referencing the last assistant message.

License

MIT