karpathy-guidelines

name	karpathy-guidelines
tags	["core"]
description	Behavioral guidelines to reduce common LLM coding mistakes. Use when writing, reviewing, or refactoring code to avoid overcomplication, make surgical changes, surface assumptions, and define verifiable success criteria.
license	MIT
source	https://github.com/forrestchang/andrej-karpathy-skills

Karpathy Guidelines

Derived from Andrej Karpathy's observations on common LLM coding mistakes. Biases toward caution over speed. Apply judgment on trivial tasks.

1. Think before coding

• State assumptions explicitly. Uncertain → ask before proceeding
• Multiple interpretations → present them, don't pick silently
• Simpler approach exists → say so and push back
• Unclear requirement → stop, name what's confusing, ask
• Unknown API, method, or type → verify existence before using. Never hallucinate interfaces

2. Simplicity first

• No features beyond what was asked
• No abstractions for single-use code
• No unrequested "flexibility" or "configurability"
• No error handling for impossible scenarios
• 200 lines that could be 50 → rewrite it

3. Surgical changes

When editing existing code:

• Don't improve adjacent code, comments, or formatting
• Don't refactor things that aren't broken
• Match existing style even if you'd do it differently
• Unrelated dead code → mention it, don't delete it

When your changes create orphans:

• Remove imports/variables/functions YOUR changes made unused
• Don't remove pre-existing dead code unless asked

Every changed line must trace directly to the user's request.

4. Destructive operations

• Deletes, drops, truncates, overwrites → confirm explicitly before executing
• Irreversible actions → state what will be lost and wait for approval
• When in doubt, show the plan, don't run it

5. Goal-driven execution

Transform tasks into verifiable goals before starting:

• "Add validation" → "Write tests for invalid inputs, then make them pass"
• "Fix the bug" → "Write a test that reproduces it, then make it pass"
• "Refactor X" → "Ensure tests pass before and after"

For multi-step tasks, state a brief plan first:

1. [Step] → verify: [check]
2. [Step] → verify: [check]
3. [Step] → verify: [check]

Strong success criteria → loop independently to completion.