Repomix Skill for Claude

Repomix Skill

Repomix packs entire repositories into single, AI-friendly files. Perfect for feeding codebases to LLMs like Claude, ChatGPT, and Gemini.

When to Use

Use when:

• Packaging codebases for AI analysis
• Creating repository snapshots for LLM context
• Analyzing third-party libraries
• Preparing for 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 formatting with clear separators
• 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 with 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

Command Line Reference

File Selection

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

# Ignore additional 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 counts tokens for individual files, total repository, and per-format output.

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 secrets).

Best practices:

• Always review output before sharing
• Use .repomixignore for sensitive files
• Enable security checks for unknown codebases
• Avoid packaging .env files
• Check for hardcoded credentials

Disable security checks if needed:

repomix --no-security-check

Implementation Workflow

When user requests repository packaging:

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

• Configure Filters
• Set include patterns for relevant files
• Add ignore patterns for unnecessary files
• Enable/disable comment removal

• Execute Packaging
• Run repomix with appropriate options
• Monitor token counts
• Verify security checks

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

• 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