REA: Reverse Engineer Any App With Claude Code (Free MCP Server)

You're using some app and it does one thing really well. The search is instant, or the clipboard keeps formatting perfectly between windows, and you want that in your own product. Normally you'd guess. REA lets you ask your agent to actually find out. It's a free MCP server that hands Claude Code real reverse engineering tools, so the agent can inspect an app without its source code, explain how the feature works, show you the evidence, and then build a version for your project.

What REA does

REA stands for Reverse Engineer Anything, and the list of targets is long. Native binaries, through Hopper, Ghidra or IDA. JavaScript and Electron apps, where it recovers modules, imports, source maps, routes and IPC between processes. .NET assemblies, Android APKs via JADX, Flutter apps, Go and Rust binaries, WebAssembly, SQLite databases, firmware, saved network captures and live websites through a Chrome-family browser.

You don't need to know which tool fits which file. You ask a question in plain English, the agent calls REA over MCP, REA runs the right analysis and returns findings with the evidence attached. The agent then asks follow-ups, explains the behavior, or writes and tests an implementation. The same workflows are available as a CLI if you'd rather script it.

Setting it up

With Node.js 22.19+ installed, it's one command:

npx rea-agents setup

You pick your agents (Claude Code, Codex, Cursor, Gemini CLI and a few others are supported), review the config changes it proposes and approve them. It backs up your existing config first, which is a nice touch. Restart the agent and you can ask something like "understand how search works in the Notes app, show me the evidence, and build a similar feature for my project."

Static JavaScript and .NET analysis work out of the box. Deep native analysis needs Hopper, Ghidra or IDA. Setup can install Hopper for you with your approval, and it uses Ghidra or IDA if you already have them. If MCP servers are new to you, our guide to MCP servers for Claude Code explains how they plug in.

One practical warning from the project itself: get REA only from the official GitHub repo, rea.tools or the rea-agents npm package. A tool that runs disassemblers on your machine is exactly the kind of thing someone would clone and backdoor.

The showcases are worth a look

The project publishes case studies, and they're more convincing than any feature list. In one, REA traces Notion's clipboard bridge from the renderer, through preload and IPC, into the main process. In another, it follows a sound call in the old game DX-Ball into its stereo panning helper and reconstructs it in C, and the rebuilt version matches the original across 3,205 test cases. A third recovers the bullet-ring math from a 16-bit PC-98 game. Those are hard problems, and they show the evidence trail rather than just claiming success.

Who it's for

Developers who want to understand how a competitor or a favourite tool solves a problem. Security researchers and CTF players. People maintaining old software with no source left. Modders and game preservation folks. And honestly anyone curious about how the apps on their own machine work.

Analysis runs locally and REA doesn't upload your target, though whatever your agent sees goes to your model provider under its own data policy. Keep that in mind with anything sensitive.

A note on doing this responsibly

Understanding how something works is not the same as having the right to copy it. Software licenses often restrict reverse engineering, and the law varies by country. The repo ships a disclaimer for a reason. Using REA to learn a technique and then write your own version is a very different thing from lifting someone's code or bypassing their licensing. Stick to the first.

REA is MIT licensed and moves fast, with frequent releases, so run rea update now and then. If you build apps yourself, pair it with our free website security audit skill to see your own product the way an outsider would. For more on agents and tools, read skills vs subagents vs slash commands vs MCP.

Get REA on GitHub

REA is free and open source. The code, install steps and docs all live in the repository: morluto/rea.

View REA on GitHub →

Listed by AgentsKit. We don't maintain this project and aren't affiliated with its author. Read the code before you run anything that touches your machine or your inbox.

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