Reverse engineer any app with REA and Claude Code in 9 steps (checklist inside)

I used REA (Reverse Engineer Anything) with Claude Code on lagoslife.app, a Lagos city life game, as a case study and ended up with a working alternative. Here is the whole run in 9 steps, for educational purposes only.

1. Know what REA is. A free open source tool that lets your AI agent read how an app really works. Only install it from morluto/rea.
2. Install it. Run npx rea-agents setup, or ask Claude Code to install it for you.
3. Restart and check. Type /mcp and look for rea in the list.
4. Point it at an app. One prompt: the link and what to build.
5. Let it map the app. It reads the pages, scripts and public calls, then tells you what it found.
6. Run your new app. It starts on localhost, so you can click through it.
7. Check every screen. Compare screen by screen and note what is missing.
8. Follow up with edits until it is right. One prompt rarely builds it perfectly, so ask for one change at a time.
9. Keep going. Use it for learning and practise on your own projects.

Which app would you like to understand first? Tell me below and I will tell you how I would approach it.

Read the tutorial