Repomix

Overview

Repomix packages entire code repositories into a single AI-friendly file. Ideal for feeding codebases to LLMs like Claude, ChatGPT, and Gemini for analysis, code review, security audits, and documentation generation.

When to Use

• Packaging codebases for AI analysis
• Creating repository snapshots for LLM context
• Analyzing third-party libraries
• Preparing security audits
• Generating documentation context
• Investigating bugs across large codebases
• Creating AI-friendly code representations

Quick Start

Check Installation

repomix --version

Install

# npm
npm install -g repomix

# Homebrew (macOS/Linux)
brew install repomix

Basic Usage

# Package current directory (generates repomix-output.xml)
repomix

# Specify output format
repomix --style markdown
repomix --style json

# Package remote repository
npx repomix --remote owner/repo

# Custom output with filters
repomix --include "src/**/*.ts" --remove-comments -o output.md

Core Capabilities

Repository Packaging

• AI-optimized format with clear delimiters
• Multiple output formats: XML, Markdown, JSON, plain text
• Git-aware processing (respects .gitignore)
• Token counting for LLM context management
• Security checks for sensitive information

Remote Repository Support

Process remote repositories without cloning:

# Shorthand
npx repomix --remote yamadashy/repomix

# Full URL
npx repomix --remote https://github.com/owner/repo

# Specific commit
npx repomix --remote https://github.com/owner/repo/commit/hash

Comment Removal

Strip comments from supported languages (HTML, CSS, JavaScript, TypeScript, Vue, Svelte, Python, PHP, Ruby, C, C#, Java, Go, Rust, Swift, Kotlin, Dart, Shell, YAML):

repomix --remove-comments

Common Use Cases

Code Review Preparation

# Package feature branch for AI review
repomix --include "src/**/*.ts" --remove-comments -o review.md --style markdown

Security Audit

# Package third-party library
npx repomix --remote vendor/library --style xml -o audit.xml

Documentation Generation

# Package docs and code
repomix --include "src/**,docs/**,*.md" --style markdown -o context.md

Bug Investigation

# Package specific modules
repomix --include "src/auth/**,src/api/**" -o debug-context.xml

Implementation Planning

# Full codebase context
repomix --remove-comments --copy

CLI Reference

File Selection

# Include specific patterns
repomix --include "src/**/*.ts,*.md"

# Additional ignore patterns
repomix -i "tests/**,*.test.js"

# Disable .gitignore rules
repomix --no-gitignore

Output Options

# Output format
repomix --style markdown  # Or xml, json, plain

# Output file path
repomix -o output.md

# Remove comments
repomix --remove-comments

# Copy to clipboard
repomix --copy

Configuration

# Use custom config file
repomix -c custom-config.json

# Initialize new config
repomix --init  # Creates repomix.config.json

Token Management

Repomix automatically calculates token counts for individual files, the entire repository, and each output format.

Typical LLM context limits:

• Claude Sonnet 4.5: ~200K tokens
• GPT-4: ~128K tokens
• GPT-3.5: ~16K tokens

Security Considerations

Repomix uses Secretlint to detect sensitive data (API keys, passwords, credentials, private keys, AWS keys).

Best practices:

1. Always review output before sharing
2. Use .repomixignore for sensitive files
3. Enable security checks for unknown codebases
4. Avoid packaging .env files
5. Check for hardcoded credentials

To disable security checks:

repomix --no-security-check

Implementation Workflow

When a user requests repository packaging:

1. Assess requirements

   • Identify target repository (local/remote)
   • Determine required output format
   • Check for sensitive data concerns

2. Configure filters

   • Set include patterns to match relevant files
   • Add ignore patterns to exclude unnecessary files
   • Enable/disable comment removal

3. Execute packaging

   • Run repomix with appropriate options
   • Monitor token count
   • Verify security checks

4. Validate output

   • Review generated file
   • Confirm no sensitive data included
   • Check token limits for target LLM

5. Deliver context

   • Provide packaged file to user
   • Include token count summary
   • Note any warnings or issues

Reference Documentation

For detailed information, see:

• Configuration Reference - Config files, include/exclude patterns, output formats, advanced options
• Usage Patterns - AI analysis workflows, security audit preparation, documentation generation, library evaluation

Additional Resources

• GitHub: https://github.com/yamadashy/repomix
• Documentation: https://repomix.com/guide/
• MCP Server: Available for AI assistant integration