Highly recommend adding REA to Claude Code or Codex. The name stands for 𝗥𝗲𝘃𝗲𝗿𝘀𝗲 𝗘𝗻𝗴𝗶𝗻𝗲𝗲𝗿 𝗔𝗻𝘆𝘁𝗵𝗶𝗻𝗴. See a feature you like in another app? Have your agent take it apart to see how it's built, then 𝗯𝘂𝗶𝗹𝗱 𝘆𝗼𝘂𝗿 𝗼𝘄𝗻 𝘃𝗲𝗿𝘀𝗶𝗼𝗻 in your project. It's been #1 on GitHub's daily trending two days running and is past 60K stars.

The apps on your computer are finished products. Think of a baked cake: you can taste it, but you can't see the recipe. REA hands your agent the tools made for taking software apart. It works down layer by layer, shows you where each finding comes from, and then walks you through the recipe. You can point it at desktop apps, websites and Android apps.

Ask it things like:
→ "How does this notes app show search results the moment I start typing?"
→ "Why does text copied from Notion keep its formatting when I paste it somewhere else?"
→ "How does this old game work out that ring of bullets?"
→ "Our company's 10-year-old internal tool lost its source code years ago. What is it actually doing?"

Take apart your own software and open-source code as much as you like. For anyone else's, check the terms first, since many forbid reverse engineering. Don't bring it cracking or license-bypass jobs; the model will most likely refuse anyway.

Run npx rea-agents setup in your terminal, pick your agent when it asks, and restart it. Then send this prompt to Opus 5.5 👇

"I want to use REA to figure out how a feature in some software works.
1. First ask me which app and which feature I want to study, then have me say whether it's my own, open source, or software whose terms allow reverse engineering. If I can't say, don't start.
2. Work out what kind of program it is first. If you need Hopper, Ghidra or IDA, tell me which one is missing and where to get it. Don't install it yourself.
3. Back every finding with evidence: which file, which function or address. Keep what you saw separate from what you're guessing. At the end, explain it all in words a 10-year-old could follow.
4. Once it's clear, tell me the minimum pieces I'd need to write to build something similar in my own project, without copying its code. Show me the plan first, and only start writing after I agree."

github.com/morluto/rea