REA

REA, short for Reverse Engineer Anything, is a free, open source toolbox that lets AI assistants look inside software that doesn't come with its source code. You ask a plain question, such as "how does search work in this notes app?", and your assistant uses REA to open the app, trace the part that matters, explain it and show you the evidence. It can then write and test a version of that idea for your own project. It works as an MCP server for assistants like Claude Code, Codex and Cursor, and as a command-line tool you can use yourself.

How it works

Reverse engineering means working out how a program works from the finished product. Experts do it with specialist tools that take years to learn. REA gives those tools to your AI assistant in small, focused pieces.

1. You ask a question about an app, website or program, in plain words.
2. Your assistant picks the tools. It chooses from REA's toolbox and decides what to look at first.
3. REA does the looking, on your own computer. It returns short, targeted results rather than pouring a whole program into the conversation.
4. Every finding comes with evidence: where it was found, what it's based on, and what's still unknown.
5. Your assistant explains, or builds. It can answer your question, or write and test a new version of the feature for your project.

What it can look at

• Desktop apps built with web technology, like Notion, Slack or VS Code. REA maps how the screens, the background process and the computer talk to each other.
• Websites. Page structure, scripts, and what the page sends and receives, using a Chrome-family browser.
• Programs and games for Windows, Mac and Linux, down to the machine instructions. This uses Ghidra, Hopper or IDA, and even covers old DOS and console programs.
• Android apps and devices. Read an app's settings and code, or work with a connected phone or emulator.
• .NET and Go programs, which REA reads directly with no extra tools.
• Firmware from routers and other devices.
• Network traffic you've saved, and live traffic on Linux.
• And more: SQLite databases, WebAssembly files, smart-contract bytecode, crash dumps and recordings from electronics test equipment.

What makes it different

• One setup for many tools. Run npx rea-agents setup, pick your assistants, review the changes and approve them. REA backs up your settings first.
• Works with almost any assistant. Setup supports Claude Code, Claude Desktop, Codex, Cursor, Gemini CLI, Windsurf, GitHub Copilot CLI, VS Code and more than ten others. Any assistant that supports local MCP servers can use it.
• Evidence you can check. Results include where each fact came from and what REA couldn't confirm, so you can catch your assistant's mistakes.
• Rebuilds you can trust. A built-in checklist records everything a rebuilt feature must match, and marks an item done only when a test proves it.
• Watches programs as they run. Beyond reading files, REA can run a program in a terminal, record what it does, and connect to Frida, a popular tool for inspecting running apps.
• Private by design. Analysis runs on your computer and REA doesn't upload your files. Your AI assistant sees the results it's given, so your assistant's privacy rules apply to those.

Real examples

• DX-Ball, a 1990s brick-breaker game: REA traced how the game pans sound between the left and right speaker and rebuilt it in C. The rebuild matched the original in all 3,205 test cases.
• Notion's desktop app: it followed copy and paste from the button, through the app's layers, to the computer's clipboard.
• An old Japanese PC-98 game: it recovered the maths behind enemies' rings of bullets and rebuilt it in modern C++.

REA, GhidraMCP, IDA Pro MCP or Ghidra on its own?

All four help you look inside programs. The difference is how much they cover and how much they do for you.

REAThis page

Best forAsking an AI assistant about almost any kind of software

One toolbox for desktop apps, websites, programs, Android apps and more, with evidence for every finding. Uses Ghidra, Hopper or IDA underneath for compiled programs.

What it covers

Apps, websites, programs, Android, firmware and more

Open source

Yes (MIT)

Cost

Free; paid tools optional

GGhidraMCP

Best forConnecting an AI assistant to Ghidra only

A small, popular bridge that lets an assistant ask Ghidra about a program. Simple and focused, but it only covers what Ghidra does, and you set Ghidra up yourself.

What it covers

Compiled programs, through Ghidra

Open source

Yes (Apache 2.0)

Cost

Free

IIDA Pro MCP

Best forProfessionals who already use IDA

Connects an AI assistant to IDA, the industry's leading paid reverse engineering tool. Very capable, but you need an IDA licence.

What it covers

Compiled programs, through IDA

Open source

Yes (MIT); IDA itself is paid

Cost

Free plugin; IDA licence needed

GGhidra

Best forLearning reverse engineering hands-on

The free, powerful reverse engineering tool released by the US National Security Agency. You do all the work yourself in its own window, with no AI assistant involved.

What it covers

Compiled programs

Open source

Yes (Apache 2.0)

Cost

Free

A quick way to choose: want your AI assistant to investigate apps, websites and programs with one setup? Pick REA. Only need an assistant inside Ghidra? GhidraMCP is lighter. Already pay for IDA? Try IDA Pro MCP. Want to learn the craft by hand? Start with Ghidra.

What you need

• Node.js version 22.19 or newer (or 24.11 and up).
• An AI assistant that supports MCP, or just the rea command in your terminal.
• For compiled programs: Ghidra (free, needs Java 21), Hopper or IDA. Setup can install Hopper for you, with your approval. Websites, JavaScript, Electron and .NET apps don't need any of them.
• Extra tools for some jobs, such as JADX for Android apps, Frida for running apps, or TShark for network traffic. Each guide lists what it needs.
• A Mac or Linux computer works best. Many features work on Windows too, but Ghidra on Windows is still experimental.
• Plenty of memory for big programs. Large programs can take several minutes to load; 16 GB or more is a good idea.

Use it responsibly

Reverse engineering is legal in many places for security research, making software work together, preserving old software and studying programs you own. It can also break the law or a program's terms of use, depending on where you live and what you do. REA's own rules say it's for lawful research, education, compatibility, preservation and software you own or are allowed to examine. The project won't help with breaking copy protection or licence checks, making game cheats, getting into systems without permission, or copying someone else's code. If you admire a feature, use REA to understand the idea, then write your own version.

Good to know

• Brand new and changing fast. REA started in April 2026 and ships new versions every few days, sometimes with changes that break older setups. Update often with rea update.
• No independent tests yet. The examples come from the project and its contributors. Treat your assistant's conclusions as a strong lead to check, not a final answer.
• Paid tools stay paid. Hopper and IDA need their own licences. REA doesn't include them and doesn't allow cracked copies.
• Licence: MIT. Free to use, including at work. Tools it connects to keep their own licences.