Relationship Between Claude Code Skills and Cursor Rules: A Complete Guide

Claude Code skills and Cursor rules are mirrored configurations that enforce the same behavioral guidelines—Claude uses CLAUDE.md packaged as a plugin, while Cursor uses .cursor/rules/karpathy-guidelines.mdc with alwaysApply: true.

The multica-ai/andrej-karpathy-skills repository distributes Andrej Karpathy’s four coding principles in dual formats to ensure seamless integration across AI-assisted development environments. Understanding the relationship between Claude Code skills and Cursor rules helps teams maintain consistent code quality standards regardless of their preferred editor.

How the Two Formats Mirror Each Other

Both implementations encode identical behavioral constraints derived from Karpathy’s methodology: Think Before Coding, Simplicity First, Surgical Changes, and Goal-Driven Execution. The repository maintains strict parity between the two files to prevent environment-specific drift.

Claude Code Implementation

Claude Code consumes the guidelines through CLAUDE.md, which serves as the master document for the forrestchang/andrej-karpathy-skills plugin. When installed via the marketplace, the plugin exposes the skill under the identifier karpathy-guidelines, making the principles available during code generation, review, and refactoring sessions.

Source location: CLAUDE.md (repository root)

Cursor Implementation

Cursor implements the same constraints through .cursor/rules/karpathy-guidelines.mdc, located in the repository’s .cursor/rules/ directory. The file includes the alwaysApply: true directive, ensuring the rules activate automatically when the repository opens in Cursor without requiring manual configuration.

Source location: .cursor/rules/karpathy-guidelines.mdc

Installation and Configuration

Installing the Claude Code Skill

Add the plugin from within Claude Code to enable the guidelines across your sessions:

/plugin marketplace add forrestchang/andrej-karpathy-skills
/plugin install andrej-karpathy-skills@karpathy-skills

Once installed, the skill karpathy-guidelines becomes available for every Claude Code interaction, enforcing the four principles during AI-assisted coding.

Enabling Cursor Rules (Zero Configuration)

Opening the repository in Cursor automatically activates the rules:

1. Clone or open the repository folder in Cursor.
2. Navigate to Settings → Rules to verify that karpathy-guidelines appears with the status always applied.

To apply these rules to a different project, copy the rule file manually:

mkdir -p .cursor/rules
cp path/to/karpathy-guidelines.mdc .cursor/rules/

Synchronization Strategy

The repository requires manual synchronization between CLAUDE.md and .cursor/rules/karpathy-guidelines.mdc whenever the four principles undergo modification. The README.md and CURSOR.md files explicitly instruct contributors to maintain parity between these artifacts.

Manual Sync Workflow

After editing the principles in CLAUDE.md, propagate changes to the Cursor rule:

# Overwrite the Cursor rule with the updated Claude guidelines

cp CLAUDE.md .cursor/rules/karpathy-guidelines.mdc

Automated Synchronization Script

Create a bash script to ensure consistency before committing:

#!/usr/bin/env bash

# sync-guidelines.sh – maintain parity between Claude and Cursor formats

cp CLAUDE.md .cursor/rules/karpathy-guidelines.mdc
echo "Synchronized karpathy-guidelines to Cursor rules"

Execute this script prior to each commit to prevent environment-specific drift.

Key Differences in Usage

While the underlying principles remain identical, the interaction models differ:

• Claude Code: Skills are explicitly invoked during conversations. The karpathy-guidelines skill surfaces contextually when Claude generates or reviews code, but users can reference it explicitly for specific guidance.

• Cursor: Rules are implicitly enforced during editing. The .mdc file operates continuously in the background, constraining AI-generated suggestions without requiring explicit user prompts.

Summary

• The multica-ai/andrej-karpathy-skills repository provides identical coding principles in two formats: CLAUDE.md for Claude Code and .cursor/rules/karpathy-guidelines.mdc for Cursor.
• Claude Code implements these as a marketplace plugin skill (karpathy-guidelines) that users can invoke during sessions.
• Cursor implements these as always-on rules that apply automatically when the repository opens.
• Contributors must synchronize changes between CLAUDE.md and the Cursor rule file to maintain consistency across environments.

Frequently Asked Questions

What is the difference between a Claude Code skill and a Cursor rule?

A Claude Code skill is a packaged plugin installed via the marketplace that exposes specific guidelines or capabilities during conversational AI sessions. A Cursor rule is a file-based configuration stored in .cursor/rules/ that automatically constrains AI behavior during editing without requiring explicit user invocation. Both achieve the same behavioral outcome but differ in activation mechanisms.

How do I install the karpathy-guidelines in my development environment?

For Claude Code, run /plugin marketplace add forrestchang/andrej-karpathy-skills and /plugin install andrej-karpathy-skills@karpathy-skills within your Claude Code session. For Cursor, simply open the repository containing .cursor/rules/karpathy-guidelines.mdc; the rule applies automatically due to the alwaysApply: true directive.

Why does the repository maintain two separate files for the same guidelines?

The repository maintains CLAUDE.md and .cursor/rules/karpathy-guidelines.mdc as mirrored artifacts because Claude Code and Cursor consume configuration through incompatible formats. Claude Code requires markdown-based skill definitions installable via its plugin marketplace, while Cursor requires .mdc rule files stored in a specific directory structure. Maintaining both ensures the Karpathy coding principles work out-of-the-box regardless of which AI editor a developer chooses.

What happens if I only update one file and not the other?

If you update CLAUDE.md without synchronizing .cursor/rules/karpathy-guidelines.mdc, Claude Code users will see updated principles while Cursor users will continue following outdated guidelines. This creates environment-specific drift where the same repository enforces different coding standards depending on the AI editor used. The repository documentation explicitly warns against this and recommends using the sync-guidelines.sh script or manual cp command to maintain parity.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}