repomix

Learnings (Maintainer): bekannte Probleme/Erkenntnisse zu diesem Skill in docs/skill-learnings.md → Sektion „repomix".

repomix — Repository Packer

Prerequisite: the repomix CLI must be installed once before this skill can do anything. Run repomix --version; if it errors, see Setup below.

repomix walks a directory tree, applies .gitignore and a configurable include/exclude policy, and concatenates everything into one annotated file (XML, Markdown, JSON, or plain text) sized to fit inside an LLM context window.

This skill is a thin wrapper that documents the CLI for Claude Code use. It does not ship a re-implementation — install the upstream binary once, then invoke as shown below.

Setup (one-time)

The install commands are intentionally not in this skill's allowed-tools declaration — they are session-external operations that the user runs at the shell, not commands Claude needs to issue repeatedly.

# macOS / Linux via Homebrew
brew install repomix

# Or via npm (works on any platform with Node)
npm install -g repomix

Confirm: repomix --version should print a version number.

Quick Start

# Pack the current directory into repomix-output.xml
repomix .

# Same, but write to a named file (Markdown format)
repomix . --output context.md --style markdown

# Include only certain files
repomix . --include "src/**/*.ts,README.md"

# Exclude noisy paths beyond .gitignore
repomix . --ignore "**/*.test.ts,docs/**,node_modules/**"

# Pack a specific subdirectory
repomix ./packages/core

# Pack a remote repo without cloning first (clones to temp + cleans up)
repomix --remote https://github.com/owner/repo

The output file is the artifact Claude reads. After repomix . the file repomix-output.xml (or whatever --output named) is the single source of truth for the packed view.

When to use this skill

• Bring an external repo into the current session. Claude has no access to repos outside the working directory. repomix --remote <url> produces a single file you can cat or open directly.
• Send a codebase to another LLM for comparison. A single Markdown file is far easier to upload to ChatGPT / Gemini / Claude.ai than multi-file selection.
• Code review / audit prep. One scrollable artifact beats jumping between IDE tabs when you want a holistic read.
• Onboarding a teammate. "Read this packed file, then we'll talk."

Output formats

Format	Flag	Best for
XML (default)	--style xml	LLM-friendly, explicit tags around each file
Markdown	--style markdown	Human-readable, GitHub-renderable
Plain	--style plain	Minimal envelope, when you want the raw text

Tuning the include set

# Show a file tree annotated with per-file token counts (lets you decide
# what to exclude before packing)
repomix . --token-count-tree

# Same, but only show files at or above a token threshold
repomix . --token-count-tree 1000

# Compress structure (Tree-sitter extracts key elements, drops bodies)
repomix . --compress

# Choose tokenizer model (defaults to o200k_base / GPT-4o)
repomix . --token-count-encoding cl100k_base

--compress typically saves 30-50% of tokens. Recommended for any codebase you are about to feed into an LLM session. Normal repomix . output already reports total token counts at the end — the --token-count-tree flag adds the per-file breakdown.

When NOT to use this skill

• For searching inside a codebase, use grep, rg, or the project's Explore subagent — repomix is for packing, not querying.
• For very large monorepos (>500k LOC), pack subdirectories instead of the whole tree. Even with --compress, a million-line repo will exceed any LLM's context budget.
• If you only need a handful of files, just cat or Read them directly. repomix is for whole-tree or whole-package context, not ad-hoc snippets.

Troubleshooting

Problem	Fix
command not found: repomix	Re-run installation, restart the shell
Output too large for context	Use --compress, --include, or pack a subdir
Sensitive files included	Add to .repomixignore (same syntax as .gitignore)
Want repomix to also follow custom includes	Set repomix.config.json in the repo root

For deeper configuration (config files, custom output templates, integration with CI), see the upstream README at https://github.com/yamadashy/repomix.

License

repomix itself is MIT (Copyright 2024 Kazuki Yamada). This wrapper SKILL.md is also MIT under the lars-cc-skills marketplace. See LICENSE.