REA (Reverse Engineer Anything): Setup Guide
REA (“Reverse Engineer Anything”) is a free, open-source (MIT) MCP server and command-line tool that lets AI coding agents inspect software without its source code — native binaries (via Hopper, Ghidra or IDA), JavaScript/Electron apps, .NET assemblies and websites. Analysis runs locally. Install with npx rea-agents setup (Node.js 22.19+, 24.11+ or 26+), pick your agent, approve the changes and restart the agent.
What REA does
REA connects an AI coding agent (for example Claude Code, Codex, Cursor, Gemini CLI or Grok Build) to reverse-engineering tools through the Model Context Protocol. You ask a question in plain language — “how does search work in this app?” — and the agent uses REA to inspect the program, returning findings with the evidence and limitations behind each conclusion.
| Target | What you get back | Needs |
|---|---|---|
| Native binaries | Pseudocode, assembly, strings, symbols, calls, references | Hopper, Ghidra or IDA |
| JavaScript / Electron | Modules, imports, source maps, routes, IPC, native add-ons | Node.js + npm only |
| .NET assemblies | Managed code triage | — |
| Websites | Page structure, scripts, network observations, screenshots | A Chrome-family browser |
| Go binaries | Compiler version, modules, build settings | Nothing extra |
Requirements
- Node.js 22.x (22.19 or later), 24.x (24.11 or later) or 26+, plus npm.
- For native analysis: an existing Ghidra or IDA install, or let setup install Hopper (asks for approval first).
- Static JavaScript/Electron analysis needs no native engine.
Install and first run
- Run
npx rea-agents setup. - Choose your agent(s), review the proposed config changes (setup backs up existing configuration) and approve.
- Restart your agent.
- Ask it something like: “Use REA to understand how search works in the Notes app and show me the evidence.”
Terminal-only use (no agent): npx -y rea-agents@latest analyze-javascript-application /absolute/path/to/app --json maps an extracted Electron app or ASAR. For regular use install the CLI with npm install --global rea-agents, then rea --help; update with rea update.
Use it responsibly
- Only analyse software you own or are allowed to inspect; licences and local law (for example anti-circumvention rules) still apply.
- “Rebuild a feature” means writing your own implementation from what you learned — not copying protected code or assets.
- REA runs locally, but your agent provider may still receive what the agent reads; check your agent’s data settings before analysing confidential software.
Frequently asked questions
Is REA free?
Yes. REA is open source under the MIT licence and installed through npm (package rea-agents).
Which AI agents work with REA?
Setup supports Claude Code, Codex, Cursor, Gemini CLI, Grok Build and other MCP-capable agents; manual MCP registration is documented for the rest.
Do I need Ghidra or IDA?
Only for native binaries. JavaScript and Electron analysis works with Node.js and npm alone; setup can optionally install Hopper with your approval.
Is reverse engineering legal?
It depends on the software licence and your country. Analyse only what you own or are permitted to inspect, and don’t copy protected code.