reverse engineer anything. (100% open-source, 200k+ stars) when you like a feature in someone else's app, you usually can't see how it was built because the source code isn't available. figuring it out used to mean hours jumping between 10+ specialized tools and reading machine code by hand. REA is an open-source MCP server that hands this work to your agent. you give it an app and a question, and the agent traces the feature down to the compiled code, explains how it works, and can build a version for your own project. how it works: REA brings the tools reverse engineers rely on, like Ghidra, IDA and JADX, under one interface that Claude Code, Codex, Cursor and other agents can call. your agent asks REA to inspect the app, and REA picks the right tool, runs it locally, and returns what it found along with the evidence behind each finding. the agent then uses those findings to dig further, explain the behavior, or write and test its own version. since every claim points back to real code, the agent works from evidence instead of guessing. what you can do with it ↳ see how a desktop app like Notion handles copy and paste, from the button you click to the code that runs behind it. ↳ look inside compiled programs and games to understand the logic they were built on. ↳ break down Android apps into readable code to see how a feature is put together. ↳ inspect how a website is structured and what it sends over the network. ↳ examine device firmware, network recordings and other files that were never meant to be read by people. in one of their showcases, it rebuilt a sound function from the old DX-Ball game that compiles back to the exact same code as the original. everything runs on your machine, and setup adds it to your agent with a single command: 𝗻𝗽𝘅 𝗿𝗲𝗮-𝗮𝗴𝗲𝗻𝘁𝘀 𝘀𝗲𝘁𝘂𝗽 it's meant for software you own or are authorized to analyze. repo: github.com/morluto/rea a while back, i wrote about two gaps in Claude Code. it only gets a summary when it reads a web page instead of the full content, and it can't see the full state of your backend. adding the right skills fixes both. REA builds on that same setup and covers one more gap, since your agent can now understand apps it never had the source code for. the full article is in the quoted post below.