How to Use REA GitHub to Reverse Engineer Anything in Claude Code

0:00In 1982, a [music] tiny company called Compact reverse engineered IBM's PC. They never saw IBM's code. They figured it out by taking the machine apart and studying how the pieces fit. That one move built the entire cheap laptop industry, the one you're probably watching this on. 40 years later, apps are the new lock boxes. You pay Adobe $720 a year because you can't look inside and figure out how theirs is built. But last month, one developer

0:28finally broke that pattern using Claude. Then he rebuilt all seven of Adobe's flagship apps and gave them away free. Here's [music] the thing. Every app on your computer is a locked box. The company keeps the real code in their office. You get the finished product and you have to trust what it does. Can't learn from it. Can't customize it. When something breaks, you wait for them to fix it. And when they raise prices next year, you pay more. That's always been the deal. [music] You rent the app, they own the knowledge. But the app itself is

0:59sitting right there on your drive. Everything it does is inside that [music] file. You just can't read what it says. Which is exactly what that developer figured out how to do. He pointed Claude at Adobe's apps, had it read what was inside them, and asked a simple question. [music] How does this part work? Claude explained it in plain English. Then he had Claude build the

1:20same thing from scratch in his own code. Do that for every feature and you've got a working copy legally because none of Adobe's actual code made it in. Just the understanding of how it works. [music] And Adobe wasn't a one-off. He turned around and did it to Microsoft Next. [music] Free versions of Word, Excel, and PowerPoint. 13 free apps now from one person. Reverse engineering built

1:44half the tech world you use every day. Compact in the 80s, Linux in the '90s, half the open-source movement. What changed last month is who gets to do it. Today, I'm giving Claude that exact power. By the end of this video, my Claude, the same Claude code sitting on my computer, will be able to open almost any app on my machine, look inside it, and explain to me in plain English how it works. Any .exe, any desktop app, even apps from companies that would never show you their code. And then it builds me four apps, a dashboard, and a real installer. And the best part, I

2:19didn't write a single line of code to set this up. I typed two sentences into Claude. That's the whole setup. I'll show you both of them.

2:32The tool that makes this possible is called REA. It stands for reverse engineer Anything. It's a free open-source project on GitHub. And think of it as a forensics kit for software. 213 tools that open up Windows programs, Mac apps, even the apps behind websites. On its own, it's just a toolbox on a shelf. It comes alive when you plug it into your AI. The AI becomes the detective. Rea is its kit. You ask in

3:00plain English, how does this app work? And the AI picks the right tool, digs in, and reports back with proof. I'm not doing any of this setup myself. I have someone for that. For this entire build, I'm using Claude code. And if you don't have a Claude subscription, you're not locked out. Freebuff is completely free, ad supported, no credit card. You install it and start working. Google's anti-gravity is free, too, and runs on Gemini 3. Rea works with anti-gravity the same way, so the prompts in this video don't change. I'm using Claude Code because for long jobs like this one, it's the strongest senior dev of

3:36the bunch. Open claude code in any folder and paste this. Install rea. Clone the GitHub repo github.com/morluto/rea and install all the requirements and dependencies to work along with the tools and MCP. Press enter. That's the entire install. You'll see the word MCP flash across the screen. All it means is a plug. It plugs tools straight into

4:00Claude with a manual on how to use them. A new attachment snapped onto the drill. At the end, Claude runs the project's own health check. They literally call it the doctor. And you want it green. Everything installed, everything connected, 213 tools ready. Now, a real world moment. When I ran this, the doctor came back with one complaint.

4:22Here's what I did about it. Nothing. Claude read the warning, found the missing piece, put it in place, and ran the doctor again. Green. It diagnosed and fixed its own install while I watched. That's the pattern for the whole video. If anything looks broken, you don't troubleshoot. You paste the error into Claude and say, "Fix it." That's how non-coders do technical setups. Now, last step, close code completely and open it again. Claude loads its new tools when it starts up, like restarting your phone after an update. When it comes back, the detective has the kit. Right now, Claude can look inside the easy stuff, websites and apps built with web technology like

5:02Slack or VS Code. But most apps on your computer aren't built that way. The big ones, Photoshop, Office, Chrome itself, are written in a language your processor speaks, not one humans can read. For those, Claude needs one more tool. Here's what's different about serious apps. .exe files, the stuff written for raw speed. When a company builds those, the code gets translated into machine code. Pure ones and zeros for your processor. Opening one in a text editor looks like someone shredded a book into confetti. To turn that confetti back into readable pages, [music] you need a decompiler. And the best free one on earth comes from, I'm not joking, the

5:41NSA, the National Security Agency. This is the tool their own analysts use to pick apart software. And in 2019, they open sourced it. It's called Gedra, and it costs nothing. Rea is built to use Gedra as its engine. So Claude offered to set it up and I said yes. Install Gedra. Yes. Set up Gedra as AA's native analysis engine on this machine. Press enter and watch it work. Cloud checked what my computer was missing. Download the free pieces from their official sources about half a gigabyte. So give it a few minutes. Made sure nothing had been tampered with on the way. Connected Gedra to Rea and ran the doctor one more

6:22time. Nine checks, nine green. Restart claude code one more time and the setup is officially done. Two sentences typed. That's it. So in plain English, here's what's under the hood. Rea, the forensics kit. 213 tools that look inside software. Gedra, the decoder ring, turns ones and zeros back into readable code. Rea's app reader reads apps built with web technology like Slack or VS Code with no extra engine needed. ARA's website engine, the X-ray, opens a website in a Chrome browser and scans everything, the layout, the code,

6:59what the page loads, and screenshots. Four tools, one detective. Now, we point it at something and see if it actually works. Claude ran the first test itself. It picked a real Windows system file, a little tool called wear.exe that ships inside every copy of Windows. Compiled machine code. No source code available. Exactly the kind of file that used to take an expert to read. And then the results landed. An inventory of what's inside the program with evidence attached to every finding. A file that was confetti 10 minutes ago laid out like a table of contents. So what do you actually do with this power? The artcraft play. See a feature you love in

7:39some app and say, "Study how this works, then build a version of it for my project. Understand it, then recreate it." That's the loop the Artcraft developer says he used for his free Photoshop alternative and it's now sitting in your chat box. And if you're thinking about websites, Rea's website engine x-rays them. It opens the page in a real browser, scans the layout and the code and everything the page loads, takes screenshots, and Claude rebuilds the template from that. For legal reasons, it only copies the template, the layout and the structure, not the

8:12images, not the videos, not the logo. Those belong to the site's owner. You drop in your own. But the real test for me wasn't wear.exe or a website. It was whether Claude could take apart an app we built ourselves. Not a toy, something packaged like the real thing. So Claude built a tiny word processor of our own. Open page. Packed it exactly the way a

8:33real app ships and let take it apart. Load the reverse engineer anything. Rea skill. I want a short live demo of Rea's capabilities using a small original app we built ourselves as the target. The rest of the prompt asks for a tiny word processor called open page. Then to map it, trace save document and compare version one with version two. Working only from the packaged app file, Rea mapped how the app is built, followed save into the part of the app that handles saving, and spotted that the app never checks which window is asking it to save or open a file, a weak spot worth fixing. We added find and replace

9:13as version two and Rea listed what changed and marked three things it couldn't be sure about and where it couldn't prove something like the button click itself, it said. So, quick note before we do. Legally, you can't copy an entire app. And if you ask your AI to, it'll probably refuse. Mine did when I asked for an exact copy of Office. What you can do is study how an app works, then rebuild the features in your own

9:39code. That's the approach we took next. Claude rebuilt the everyday features from scratch without copying a line of Microsoft's code. I asked Claude how close we could honestly get to Office. The answer, about 70 to 85% of what most people do every day, but only around 10% of Office's full feature list because Office has 30 years of features baked

10:02in. I like that it didn't oversell it. We named the apps. Pros for documents, cells for spreadsheets, Deck for presentations, Jotbook for notes. The suite is Paperlite. And I gave Claude one big grief. That last line matters most. Claude can't just say done. It has to prove it. For design, I gave it a skill called impeccable, like hiring a design director. Before each app, it showed me a few layout options and I picked one. A clean Swiss grid style for the whole suite. Focus sheet for jotbook. Sheet strip for cells. Talk timeline for deck, one line each. Pick a layout. Build cells with the sheet strip

10:42layout. Build deck with the talk timeline layout. After every app, a second AI reviewer checked the screens and sent back a list of fixes. Claude fixed them, all of them. And Claude tested everything itself. It opened each app, typed, clicked, saved real Word and Excel files, opened them again, and checked the PowerPoint files it saved. When pasting into cells didn't work, it caught that itself and fixed it. I

11:08mostly watched and picked layouts. Here's what's under the hood in plain English. Electron makes it a real desktop program. The same framework as VS Code and Slack. Tiptap is the typing engine. The formula engine in cells Claude wrote from scratch. About a 100 functions like sum and VLOOKUP. Free libraries do the file work. Exceljs for Excel, docx and mammoth for word, pptx genjs to save powerpoint and chart.js draws the charts. All free, all open source. None of it Microsoft's. What we ended up with documents, spreadsheets with formulas and charts, presentations with a timeline view of your talk, and notebooks that save themselves, opening and saving real Word and Excel files,

11:53saving PowerPoint files. So now I've got four apps, which is great until you realize you're juggling four separate windows. I wanted one home for all of it. So one line, the dashboard. Now make a dashboard and put all the four apps in one space. Claude came back with three layouts. I picked one called continue stage. Here's the idea. Whatever you touch last gets the big stage. Not a thumbnail, not a file name, the real slide, the real page, the real spreadsheet with a continue button right there. The other three apps sit beside it. Your newest work in each and a new button ready to go. And my favorite

12:32part, just rest your mouse on anything and it jumps onto the stage. Now, at this point, I had to ask the obvious question. Is this actually a desktop app? Claude said yes. Its own window, works offline, your files never leave your computer. But there was one catch. I was still opening it from the terminal. And nobody wants to open a terminal just to write a letter. So

12:55Claude offered to make a real installer. I said yes. Package the installer. Package Paperlite as a Windows installer.exe exe with a start menu entry. And it went a step further. It designed an icon, a white P with a tiny fourcolor square in the corner, one color for each app. Then it built the installer. Double click, pick a folder, done. Paperlite sits in your start menu with an uninstaller like any other program. I had Claude run it on my own PC and it opens straight from the start menu. So, how was every app actually built and checked? Claude put a plan on screen for each one. Seven or eight

13:34steps. Pick the layout, build it, test it, fix what broke, design review. The testing was automatic. Claude opened each app, typed, clicked, saved files. I didn't touch a thing. Then I went in and tested every app by hand myself. Opened CSV files in cells, exported PDFs, tried to break it. One heads up, if you try the installer, it isn't signed. That needs a paid certificate. So, Windows might warn you the first time. Click more info, then run anyway. And let's keep it real about what doesn't work yet. Deck can save PowerPoint files, but it can't open them. And really complex Word files lose a bit of formatting when

14:13you open them. Funny thing is, Claude called this before we wrote a single line of code. And for a free Office suite built in about a day, I'll take that trade every time. That's the build. Now, before you take Rea and point it at every app on your drive, two quick things. First, the legal line in one sentence. Study software you own or are allowed to examine for learning, research, or building something compatible. That's the lane Compact drove in. That's the lane Artcraft drives in. It's protected in most places. What's not okay is copying someone's actual code into your product

14:49or breaking licenses and protections. Understand the recipe. Don't photocopy the cookbook. That's exactly why Paperlite is built from scratch instead of copied. Second, a practical note. The first look at any new program is slow. Gibbra reads the whole file and it can look stuck for a few minutes. It's not. After that first pass, everything is instant. So, let's add up what just happened. One developer with Claude reverse engineered Adobe's entire creative suite and gave it away free. 13 apps and counting. Today, with two sentences typed into a chat box, you gave your own clot that same ability, 213 analysis tools, plus the NSA's own decompiler running entirely on your

15:34machine, showing receipts for every claim. Then, with one big brief and a few oneline picks, it built us our own free Office suite. Four apps, a dashboard, a real installer. The apps on your computer just stopped being blackboxes. If you want to try this, every prompt from the video is inside my free staying ahead WhatsApp community. Links in the description. Join, grab the prompts, run your own investigation. And if there's a workflow you'd want me to break down next or an app you want me to point this at first, drop it in the comments. Our team will try to pick the

16:08next video based on what you ask for. Catch you in the next