Repomix

Repomix is an open-source utility that flattens a whole repository into one structured file (XML, Markdown, JSON, or plain text) optimized for ingestion by ChatGPT, Claude, Gemini, and other LLMs. Instead of pasting files one at a time or wiring up a custom RAG pipeline just to ask 'how does auth work in this project,' you run `npx repomix@latest` and hand the resulting bundle to the model. It respects .gitignore, counts tokens per file, runs Secretlint to strip secrets, and can compress code with Tree-sitter for roughly 70% token reduction.

It's aimed squarely at developers who use AI assistants for code review, refactoring, bug hunts, and onboarding into unfamiliar codebases. Pricing is the easiest part of the review: Repomix is MIT-licensed and completely free, distributed as a CLI, Node library, Docker image, and Chrome extension. There's also a hosted web UI at repomix.com for one-off packs of public repos.

It's not an AI product in the strict sense - there's no model behind it - but it sits in the daily loop of anyone pairing with a frontier LLM on a real codebase. The main caveats are the usual ones for context-packing tools: very large monorepos still blow past context windows even after compression, and you need to actually read the security-scan output rather than trusting it blindly before pasting code into a third-party model.