t1k:repomix

Field	Value
Module	`t1k-maintainer`
Version	`2.18.3`
Effort	`medium`
Tools	—

Keywords: codebase, llm-context, pack, repomix, snapshot

How to invoke

/t1k:repomix
[path] [--format xml|md|txt]

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: ~200K tokens
GPT-4: ~128K tokens
GPT-3.5: ~16K tokens

Token Count Optimization

repomix --token-count-tree
repomix --token-count-tree 1000  # Only show files/directories with 1000+ 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

Tool Size Caps + Security Guards (E6)

When invoking repomix, this skill MUST enforce the following caps on every run:

Output size cap: default --max-output-size 8MB (8 × 1024 × 1024 chars). Larger packs do not fit a single LLM context anyway. Override only when the user explicitly requests --no-output-size-cap.
Token-count guard: if the post-pack token estimate exceeds 200_000, refuse to deliver the file inline; instead write the path and report 'too large to inline; opened on disk at <path>'.
Security check is FAIL-CLOSED, not fail-open: the historical --no-security-check flag is a fail-OPEN default that ships secret-laden packs. This skill MUST pass --security-check (default), and MUST refuse --no-security-check unless the user types the literal phrase I accept secret leak risk in the same turn.
Guarded write: packed file goes to os.tmpdir()/t1k-repomix/<sha>.{xml,md,txt} first; only after the security-check passes does the skill copy to the user-specified output path. Failure path leaves nothing in the destination.

These caps protect downstream consumers (LLM context budgets) and prevent the most common failure mode (accidentally packing .env or credential files into a session).