forrestchang / andrej-karpathy-skills

What This Repo Claims

Four behavioral principles for Claude Code, derived from Andrej Karpathy's observations on how LLMs fail during coding:

1. Think Before Coding — stop assuming, ask clarifying questions first 2. Simplicity First — minimum code that solves the problem, nothing extra 3. Surgical Changes — don't touch code you weren't asked to touch 4. Goal-Driven Execution — work toward success criteria, not just instructions

Two install methods: a Claude Code plugin (global, all projects) or a per-project CLAUDE.md file.

What I Tested

Tested the plugin install method (Option A — global scope) on a clean macOS user with no prior Claude Code configuration.

Environment:

• macOS, MacBook Pro 14-inch M4 Pro, 24GB RAM
• Claude Code 2.1.119
• Fresh user account — no existing CLAUDE.md, no prior Claude Code history

Same prompt, same empty directory, before and after plugin install:

> "I need to build a user authentication system. Just start building it."

This is a deliberately vague, imperative prompt — exactly the behavior the repo targets.

Results

Before plugin:

Claude Code responded immediately:

> "Empty directory. I'll build a Node.js/Express authentication system with JWT, bcrypt, and SQLite."

Then ran npm install without asking a single question. Stack choice, database, auth method — all decided silently.

After plugin (user scope install):

Same prompt, same directory. Claude Code responded:

> "The directory is empty. Before I start building, I need a few quick decisions: > 1. Language/framework — Node.js (Express), Python (FastAPI/Flask), or something else? > 2. Database — PostgreSQL, SQLite, MongoDB? > 3. Auth method — username/password with JWT, sessions, OAuth, or all three? > 4. Scope — just the backend API, or a full-stack app with a frontend? > What are you working with?"

No code written. No assumptions made. Complete reversal of behavior.

Install Experience

Plugin install followed README exactly: /plugin marketplace add forrestchang/andrej-karpathy-skills /plugin install andrej-karpathy-skills@karpathy-skills /reload-plugins

Three commands. No errors. Worked first time.

What I Did Not Test

This review directly tested Principle 1: Think Before Coding. The other three principles — Simplicity First, Surgical Changes, Goal-Driven Execution — require longer coding sessions to verify meaningfully. A single session is not enough to confirm whether Claude Code writes less bloated code or avoids touching unrelated files over time.

The verdict reflects what was tested. The untested principles may work as claimed — but this review cannot confirm them.

Verdict: Solid

The install works. The core claim is real and immediately verifiable. One prompt was enough to see a measurable behavior change in Claude Code.

93.9k stars. 9.1k forks. The attention is deserved for what it does — just understand that "Think Before Coding" is the principle you can verify in 5 minutes. The rest requires sustained use to evaluate.

Worth installing. Takes 3 commands and 30 seconds.