Repomix

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: 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

Disable security checks if needed:

repomix --no-security-check

Implementation Workflow

When user requests repository packaging:

1. Assess Requirements

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

2. Configure Filters

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

3. Execute Packaging

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

4. Validate Output

• Review generated file
• Confirm no sensitive data
• 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

Configuration Reference

Detailed configuration options for Repomix.

Configuration File

Create repomix.config.json in project root:

{
  "output": {
    "filePath": "repomix-output.xml",
    "style": "xml",
    "removeComments": false,
    "showLineNumbers": true,
    "copyToClipboard": false
  },
  "include": ["**/*"],
  "ignore": {
    "useGitignore": true,
    "useDefaultPatterns": true,
    "customPatterns": ["additional-folder", "**/*.log", "**/tmp/**"]
  },
  "security": {
    "enableSecurityCheck": true
  }
}

Output Options

• filePath: Output file path (default: repomix-output.xml)
• style: Format - xml, markdown, json, plain (default: xml)
• removeComments: Strip comments (default: false). Supports HTML, CSS, JS/TS, Vue, Svelte, Python, PHP, Ruby, C, C#, Java, Go, Rust, Swift, Kotlin, Dart, Shell, YAML
• showLineNumbers: Include line numbers (default: true)
• copyToClipboard: Auto-copy output (default: false)

Include/Ignore

• include: Glob patterns for files to include (default: ["**/*"])
• useGitignore: Respect .gitignore (default: true)
• useDefaultPatterns: Use default ignore patterns (default: true)
• customPatterns: Additional ignore patterns (same format as .gitignore)

Security

• enableSecurityCheck: Scan for sensitive data with Secretlint (default: true)
• Detects: API keys, passwords, credentials, private keys, AWS secrets, DB connections

Glob Patterns

Wildcards:

• * - Any chars except /
• ** - Any chars including /
• ? - Single char
• [abc] - Char from set
• {js,ts} - Either extension

Examples:

• **/*.ts - All TypeScript
• src/** - Specific dir
• **/*.{js,jsx,ts,tsx} - Multiple extensions
• !**/*.test.ts - Exclude tests

CLI Options

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

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

# Disable .gitignore
repomix --no-gitignore

# Disable defaults
repomix --no-default-patterns

.repomixignore File

Create .repomixignore for Repomix-specific patterns (same format as .gitignore):

# Build artifacts
dist/
build/
*.min.js
out/

# Test files
**/*.test.ts
**/*.spec.ts
coverage/
__tests__/

# Dependencies
node_modules/
vendor/
packages/*/node_modules/

# Large files
*.mp4
*.zip
*.tar.gz
*.iso

# Sensitive files
.env*
secrets/
*.key
*.pem

# IDE files
.vscode/
.idea/
*.swp

# Logs
logs/
**/*.log

Pattern Precedence

Order (highest to lowest priority): 1. CLI ignore patterns (-i) 2. .repomixignore file 3. Custom patterns in config 4. .gitignore (if enabled) 5. Default patterns (if enabled)

Pattern Examples

TypeScript:

{"include": ["**/*.ts", "**/*.tsx"], "ignore": {"customPatterns": ["**/*.test.ts", "dist/"]}}

React:

{"include": ["src/**/*.{js,jsx,ts,tsx}", "*.md"], "ignore": {"customPatterns": ["build/"]}}

Monorepo:

{"include": ["packages/*/src/**"], "ignore": {"customPatterns": ["packages/*/dist/"]}}

Output Formats

XML (Default)

repomix --style xml

Structured AI consumption. Features: tags, hierarchy, metadata, AI-optimized separators. Use for: LLMs, structured analysis, programmatic parsing.

Markdown

repomix --style markdown

Human-readable with syntax highlighting. Features: syntax highlighting, headers, TOC. Use for: documentation, code review, sharing.

JSON

repomix --style json

Programmatic processing. Features: structured data, easy parsing, metadata. Use for: API integration, custom tooling, data analysis.

Plain Text

repomix --style plain

Simple concatenation. Features: no formatting, minimal overhead. Use for: simple analysis, minimal processing.

Advanced Options

# Verbose - show processing details
repomix --verbose

# Custom config file
repomix -c /path/to/custom-config.json

# Initialize config
repomix --init

# Disable line numbers - smaller output
repomix --no-line-numbers

Performance

Worker Threads: Parallel processing handles large codebases efficiently (e.g., facebook/react: 29x faster, 123s → 4s)

Optimization:

# Exclude unnecessary files
repomix -i "node_modules/**,dist/**,*.min.js"

# Specific directories only
repomix --include "src/**/*.ts"

# Remove comments, disable line numbers
repomix --remove-comments --no-line-numbers

Usage Patterns

Practical workflows and patterns for using Repomix in different scenarios.

AI Analysis Workflows

Full Repository

repomix --remove-comments --style markdown -o full-repo.md

Use: New codebase, architecture review, complete LLM context, planning Tips: Remove comments, use markdown, check token limits, review before sharing

Focused Module

repomix --include "src/auth/**,src/api/**" -o modules.xml

Use: Feature analysis, debugging specific areas, targeted refactoring Tips: Include related files only, stay within token limits, use XML for AI

Incremental Analysis

git checkout feature-branch && repomix --include "src/**" -o feature.xml
git checkout main && repomix --include "src/**" -o main.xml

Use: Feature branch review, change impact, before/after comparison, migration planning

Cross-Repository

npx repomix --remote org/repo1 -o repo1.xml
npx repomix --remote org/repo2 -o repo2.xml

Use: Microservices, library comparisons, consistency checks, integration analysis

Security Audit

Third-Party Library

npx repomix --remote vendor/library --style xml -o audit.xml

Workflow: Package library → enable security checks → review vulnerabilities → check suspicious patterns → AI analysis Check for: API keys, hardcoded credentials, network calls, obfuscation, malicious patterns

Pre-Deployment

repomix --include "src/**,config/**" --style xml -o pre-deploy-audit.xml

Checklist: No sensitive data, no test credentials, env vars correct, security practices, no debug code

Dependency Audit

repomix --include "**/package.json,**/package-lock.json" -o deps.md --style markdown
repomix --include "node_modules/suspicious-package/**" -o dep-audit.xml

Use: Suspicious dependency, security advisory, license compliance, vulnerability assessment

Compliance

repomix --include "src/**,LICENSE,README.md,docs/**" --style markdown -o compliance.md

Include: Source, licenses, docs, configs. Exclude: Test data, dependencies

Documentation

Doc Context

repomix --include "src/**,docs/**,*.md" --style markdown -o doc-context.md

Use: API docs, architecture docs, user guides, onboarding Tips: Include existing docs, include source, use markdown

API Documentation

repomix --include "src/api/**,src/routes/**,src/controllers/**" --remove-comments -o api-context.xml

Include: Routes, controllers, schemas, middleware Workflow: Package → AI → OpenAPI/Swagger → endpoint docs → examples

Architecture

repomix --include "src/**/*.ts,*.md" -i "**/*.test.ts" --style markdown -o architecture.md

Focus: Module structure, dependencies, design patterns, data flow

Examples

repomix --include "examples/**,demos/**,*.example.js" --style markdown -o examples.md

Library Evaluation

Quick Assessment

npx repomix --remote owner/library --style markdown -o library-eval.md

Evaluate: Code quality, architecture, dependencies, tests, docs, maintenance

Feature Comparison

npx repomix --remote owner/lib-a --style xml -o lib-a.xml
npx repomix --remote owner/lib-b --style xml -o lib-b.xml

Compare: Features, API design, performance, bundle size, dependencies, maintenance

Integration Feasibility

npx repomix --remote vendor/library --include "src/**,*.md" -o library.xml
repomix --include "src/integrations/**" -o our-integrations.xml

Analyze compatibility between target library and your integration points

Migration Planning

repomix --include "node_modules/old-lib/**" -o old-lib.xml
npx repomix --remote owner/new-lib -o new-lib.xml

Compare current vs target library, analyze usage patterns

Workflow Integration

CI/CD

# GitHub Actions
- name: Generate Snapshot
  run: |
    npm install -g repomix
    repomix --style markdown -o release-snapshot.md
- name: Upload Artifact
  uses: actions/upload-artifact@v3
  with: {name: repo-snapshot, path: release-snapshot.md}

Use: Release docs, compliance archives, change tracking, audit trails

Git Hooks

#!/bin/bash
# .git/hooks/pre-commit
git diff --cached --name-only > staged-files.txt
repomix --include "$(cat staged-files.txt | tr '\n' ',')" -o .context/latest.xml

IDE (VS Code)

{"version": "2.0.0", "tasks": [{"label": "Package for AI", "type": "shell", "command": "repomix --include 'src/**' --remove-comments --copy"}]}

Claude Code

repomix --style markdown --copy  # Then paste into Claude

Language-Specific Patterns

TypeScript

repomix --include "**/*.ts,**/*.tsx" --remove-comments --no-line-numbers

Exclude: **/*.test.ts, dist/, coverage/

React

repomix --include "src/**/*.{js,jsx,ts,tsx},public/**" -i "build/,*.test.*"

Include: Components, hooks, utils, public assets

Node.js Backend

repomix --include "src/**/*.js,config/**" -i "node_modules/,logs/,tmp/"

Focus: Routes, controllers, models, middleware, configs

Python

repomix --include "**/*.py,requirements.txt,*.md" -i "**/__pycache__/,venv/"

Exclude: __pycache__/, *.pyc, venv/, .pytest_cache/

Monorepo

repomix --include "packages/*/src/**" -i "packages/*/node_modules/,packages/*/dist/"

Consider: Package-specific patterns, shared deps, cross-package refs, workspace structure

Troubleshooting

Output Too Large

Problem: Exceeds LLM token limits Fix:

repomix -i "node_modules/**,dist/**,coverage/**" --include "src/core/**" --remove-comments --no-line-numbers

Missing Files

Problem: Expected files not included Debug:

cat .gitignore .repomixignore  # Check ignore patterns
repomix --no-gitignore --no-default-patterns --verbose

Sensitive Data Warnings

Problem: Security scanner flags secrets Actions: Review files → add to .repomixignore → remove sensitive data → use env vars

repomix --no-security-check  # Use carefully for false positives

Performance Issues

Problem: Slow on large repo Optimize:

repomix --include "src/**/*.ts" -i "node_modules/**,dist/**,vendor/**"

Remote Access

Problem: Cannot access remote repo Fix:

npx repomix --remote https://github.com/owner/repo  # Full URL
npx repomix --remote https://github.com/owner/repo/commit/abc123  # Specific commit
# For private: clone first, run locally

Best Practices

Planning: Define scope → identify files → check token limits → consider security

Execution: Start broad, refine narrow → use appropriate format → enable security checks → monitor tokens

Review: Verify no sensitive data → check completeness → validate format → test with LLM

Iteration: Refine patterns → adjust format → optimize tokens → document patterns