How I Reverse Engineered Any App with Claude Code in 10 Minutes

Author: Edwin Chen | AI Automation · Watch on YouTube

Video authored by the channel shown, not by IANIA; all rights belong to the creator. Transcript and summary generated automatically; the original-language content is preserved.

Original language: English

Original video: How I Reverse Engineered Any App with Claude Code in 10 Minutes · Channel: Edwin Chen | AI Automation · 08:13 · Watch on YouTube

Topics: AI agents, Task and workflow automation, Cybersecurity and software security, Claude Code, Privacy and data protection

Summary

The video demonstrates using the RGA repository with Claude Code to investigate how an app works and recreate its features. The presenter sets up the tool, analyzes an existing notes app’s CSV export flow, and builds a separate version of that feature. He then points the tool at his live website to see what it can learn about its design and publicly exposed information. The video also warns that reverse engineering commercial software may violate its policies or laws, and encourages caution.

Key points

RGA is presented as a tool that helps coding agents inspect apps without their source code and explain how features work.
The setup begins by running the repository’s agent setup command in a terminal and selecting a coding agent.
The presenter asks Claude to trace the notes app’s CSV export process and provide evidence for each step.
The analysis follows the export flow from the button through the app’s functions to the file being written.
Claude is asked to build its own version of the export feature rather than copy the original code.
The presenter tests the rebuilt app by adding a note and exporting it to a CSV file.
RGA is also used to produce a report about the presenter’s website, including its design and information a stranger could learn from the page.
The presenter cautions that reverse engineering commercial software may violate applicable policies or laws.

Chapters

Start	Chapter	Summary
00:00	Introducing RGA and setting it up	The presenter introduces RGA and installs it for use with a coding agent.
01:33	Tracing and rebuilding a notes app feature	Claude analyzes the notes app’s CSV export flow, then builds and tests a separate implementation.
04:36	Inspecting a live website	The presenter warns about reverse engineering commercial software before asking RGA to analyze his website.
07:13	What the analysis can reveal	The presenter describes using the website report to build another site and reflects on the risks and regulation of reverse engineering.

Quotes

work out how a feature works, and build you your own version. — 00:00

Using what you just found, build the same export feature into the project in this folder. Write your own code, don’t copy this. — 03:05

So, technically or legally, you’re not allowed to do so. — 04:36

it’s actually quite a comprehensive list by the REA repository. — 07:13

Concepts and entities

RGA, Claude Code, Codex, Hopper Disassembler, Electron, Edwin Chen | AI Automation

Full transcript (original language)

00:00 There’s a GitHub repo that blew up last week, and it passed 70,000 stars. It’s called RGA, reverse engineer any app. And it lets Claw Code or Codex open up an app that has no source code for, work out how a feature works, and build you your own version. So, in this video, I’m going to be setting up to do three builds with it start to finish. First, I’ll trace a feature inside desktop app that I built, and then I’ll rebuild that feature in my own project. And for the last one, I’m going to point it at my own live website just to see what anyone

00:31 could pull out of it. If you don’t know who I am, my name is Edan Shah. I’ve been running my own AI agency, like say I, over the past 2 years, serving more than 52 different clients worldwide. Let’s get straight to it. Okay, so the first thing you want to do is you go to github.com/Modelar/RGA. So, that is actually the GitHub repository that’s going to be powered everything that we’re going to be talking in this video. So, the first thing you actually want to do is you go to terminal. Right. And then you want to actually copy this command. Just copy MPX RGA

01:02 agent setup. And then you would just say, “Do you want to proceed?” Just click yes. And in here, you can choose which coding agent you want to set up the repository. So, I’m just going to say Claw Code. Um install Hopper for deep binary analysis. Yes. Um yes, apply. And then we’ll be waiting for it to finish installing. But like, “Hey, thank you for your interest in Hopper Disassembler. Unfortunately, I don’t actually have the license file, so just going to ignore this for now.” So, I’m just going to click just try demo.

01:33 Close this. And now it should have installed. So, now if I go to my Claw Code app, so if I go to the Claw app and then click on Claw Code, and I can just choose a folder. I already have a folder um that’s already have. So, if I go to just downloads, and then go to downloads, go to RGA demo, and then go to my notes app. I’ll click on trust workspace, and then Claw now has access to this workspace. Now, I do have the notes app already installed, so it’s basically an notes app that I can just run. Um the first prompt I actually want to

02:03 give to Claude is basically say, “Hey, use REA to find what happens when I export notes in this app.” Where is the CSS we created? Show me the evidence for each step. The app is at this directory in my downloads. REA demo notes example. So, that directory, by the way, is literally just a notes app where you can type in any notes and then you can export into a CSV. I’ve already built the app, but I haven’t actually given Claude the source code of the app. So, now you can see that it’s running a skill called {slash} reverse engineer anything, which is actually in from the

02:34 repository, right? So, now it uh then will list target app files, located tools, analyze JavaScript application, and then print out printing all the app source files with line numbers, and try to reverse engineer the entire applications. So, you can see it traces the channels, produces graphs, and actually written the CSV. It can explain how to do the entire export flow. So, it’s saying it pastes an export button, and then you click the button, calls this function, and wait for the result. Then the preload script exposes a window {dot} notes CSV, and then it goes to the

03:05 main process, and then it builds an output path, and then the CSV text is generated, and the file is written by this function, and the path is returned to this page. So, you even have the different evidence IDs, um etc. So, this is interesting because it knows exactly how to export that CSV file. So, having this knowledge now, I will ask it to reproduce the entire application. So, I’ll just say, “Using what you just found, build the same export feature into the project in this folder. Write your own code, don’t copy this. Then run it so I can click export and check the

03:35 file.” So, I’m asking it to rebuild the notes app. >> [clears throat] >> Okay, so it looks like Claude just finished building it, or at least it’s launching it. Um so, it’s launching the Electron notes app, and it’s finished building or replicating the export to CSV features from the notes app. So, if I click on the electrons, I can see that there are some sample notes here. So, I can just add a new note saying alarm, let’s say 9:00 a.m. And then I just click add. So, it will successfully added a note. If I want to export to

04:05 CSV, then it successfully exports. So, if I just click So, now if I just click on my downloads and then click on the CSV file, as you can see, it generated the Excel file with the ID, title, and the created at. So, it’s successfully mapped and reverse engineer this export CSV function. So, that was a success. So, it successfully looked at, analyzed a notes app, and then rebuilt the app with an export function. Now, of course, this is a very, very simple app, but you can easily extend it to any software you want. But, this is where you want to be

04:36 careful. If you want to, let’s say, reverse engineer commercial software like, let’s say, Notion, HubSpot, or other CRM, there are explicit policies that basically against people who try to reverse engineer. So, technically or legally, you’re not allowed to do so. Doing so will put you at your own risk of their policies. So, this is just a disclaimer. Just be careful. Don’t go crazy with it. Obviously, if you want, just you can be creative, but just got to be careful, right? And then, what I want to you want to do now is try something more more interesting. So, let me just close this

05:07 electron app and close and something much more interesting, which is try to do on my website. See if it can reverse engineer the design of my website. So, this is kind of my current website. It’s very retro design, as you can see. It’s very, very retro design. So, I wanted to see if, like, this repository can actually do the reverse engineering. So, I’ll just say, “Use REA to inspect this website page. What are the designs used? Tell me when you’ve started watching so I can click. Then write everything a stranger could learn from this page to exposure report the HTML.”

05:38 So, let’s say you really want to reference the design style from my website. This is how you can do it. And hopefully, using REA, Claude will be able to kind of reverse engineering the design principles that was used when building this website. This is pretty, pretty good. And actually written a report in here. That is actually very, very impressive. So, we’ve got a design, design fonts, colors, signature details. So, let’s see let’s see what it said. So, basically it’s saying that um the applicant data sitting a super base database that the public site can

06:10 actually reach. Now, this is kind of true, but I’ve turned on um kind of role level security. So, it does have the AON key, but unfortunately I’ve made it so they connect to not do any selection. So, this is actually confirmed this is our access on. So, because the role level security is on, normal people can’t just read from this database and therefore they can’t actually see the applicant’s detail for the coaching program. It’s good. Um the hidden base and hidden not, yeah, this is basically a 30 days. So, basically we have a 30 days um challenge and that’s soon to be

06:41 announced and this is only by selection only. So, no one can actually select. So, I’ve made the link deliberately not hidden, but I just want it’s quite complicated link. So, if you want to find it, you can find it, but I’m just not it’s not going to do anything for you. Let’s say guess post off emails. Well, I don’t mind. You can just guess my email. And then missing security headers to be embedded in other sites. Um I mean this is kind of low level, but anyways. You also have the design system in place with the typography, um the color palettes, signature details,

07:13 technology and hosting, even have the entire breakdown of the analysis, site map people can reconstruct, business information, method evidence and limits etc. So, it’s actually quite a comprehensive list by the REA repository. So, well done. I would say this is pretty good. So, there’s nothing I can change now, but obviously you can use this on any website that you want to rebuild. So, you can just ask it to write a report design report.html of a website that you really, really want to reuse and you can just ask Claude based

07:43 on that report to build your own website. So, this way you can basically rebuild any website you want, um as well as any application. So, it’s getting really scary. If it’s not regulated, right, then like I’m like, “Okay, how do you How do you actually like control what people can do?” Because a lot of reverse engineering is illegal, and how do you enforce these rules, right? So, this get becomes a very interesting topic. But anyway, I hope you guys learned something on how to use the repository. If you enjoyed this video, remember to subscribe, and if you solely you want to work with me and my team, you can use the link in the description to book a deep free discovery call with

08:13 me. If you want to get in touch with coaching program, also use the link in the description to book a free discovery call with me. And I’ll see you in the next one.