Rulefy

Supercharge your Cursor AI with codebase-specific intelligence. Rulefy transforms your GitHub repositories into custom rules that teach Cursor AI how your project works, resulting in more accurate code suggestions, better refactoring, and contextually aware assistance.

Why Rulefy?

• ✅ Instant Expertise: Your AI assistant immediately understands your project conventions and architecture
• ✅ Better Suggestions: Get code completions that match your project's style and patterns
• ✅ Fewer Hallucinations: Rules constrain the AI to work within your codebase's patterns and dependencies
• ✅ Zero Learning Curve: One command to analyze your repo and generate optimized rules

Features

• 🚀 Analyze GitHub repositories or local codebases with a single command
• 🧩 Intelligently extract project structure, conventions, and patterns
• 📚 Handles large codebases that exceed the token limit for LLMs
• 🤖 Generate tailored Cursor rules using Claude AI
• 📝 Create production-ready .rules.mdc files for immediate use
• 🔧 Customize analysis with flexible configuration options

Installation

# Install globally
npm install -g rulefy

# Or use with npx (no installation required)
npx rulefy

Prerequisites

• Node.js 18 or higher
• ANTHROPIC_API_KEY environment variable set with your Anthropic API key

export ANTHROPIC_API_KEY='your-anthropic-api-key'

Usage

The basic command structure is:

rulefy <repo-url-or-path>

Examples:

# Using GitHub URL
rulefy https://github.com/fastapi/fastapi

# Using local repository path
rulefy ./my-local-project

# Rulefy with specific description as an option
rulefy --description "guidelines for extending the component using the base interface"

# Rulefy the current directory with a description
cd some/package
rulefy --description "guidelines for extending the component using the base interface"

# Specify rule type
rulefy --rule-type "agent" --description "coding standards for React components"

This will:

1. Fetch the repository content using repomix
2. Read the cursor rules guidelines
3. Generate cursor rules using Claude Sonnet 3.5
4. Save the output to a <repo-name>.rules.mdc file

Installing Rules in Cursor

After generating your rules file, you'll need to install it in Cursor:

1. Open Cursor editor
2. Go to Settings > AI > Rules
3. Click "Add Rules File" and select your generated .rules.mdc file
4. Restart Cursor to apply the new rules

For more detailed instructions, see the official Cursor documentation.

Options

Options:
  --provider <provider>    LLM provider to use (default: "claude-sonnet-3.5-latest")
  -o, --output <file>      Output file name (defaults to <repo-name>.rules.mdc)
  --guidelines <file>      Path to cursor rules guidelines file (default: "./cursorrules-guidelines.md")
  --include <patterns>     Include patterns for files (glob pattern, e.g., "**/*.py")
  --description <text>     Description of what should be rulefied
  --rule-type <type>       Type of rule to generate (auto, manual, agent, always)
  -h, --help               display help for command

How It Works

1. Repository Conversion: Uses repomix to convert GitHub repositories into a textual representation
2. Guidelines Integration: Reads cursor rules guidelines from the specified file
3. LLM Generation: Passes the repository content and guidelines to LLM with progressive summarization
4. Output: Saves the generated cursor rules to a markdown file

Example Output

The generated .rules.mdc file will contain structured guidelines for Cursor AI when working with your codebase:

# .cursorrules for my-project

## Project Overview
This project is a TypeScript application that...

## Coding Standards
- Follow TypeScript best practices with strict typing
- Use async/await for asynchronous operations
...

## File Structure Guidelines
- Place core logic in the `src/` directory
...

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Acknowledgements

This project is inspired by and builds upon the work of:

• repomix - A tool for converting repositories into textual representations
• awesome-cursorrules - A curated list of cursor rules for different projects and languages

We're grateful to these projects for their contributions to the developer tooling ecosystem.