Would you like to kill a boss in Skyrim with an AK-47 from Counter-Strike? Give your NPCs a genuine genius-level brain that offers unique answers instead of predefined strings of text? Run GTA V on your iPhone? Use paid software for free — and legally? People are doing all of that and more with AI right now.

A free tool that lets AI agents pull apart almost any piece of software has become the hottest project on GitHub. It is called REA, short for Reverse Engineer Anything, and its star count — GitHub's version of a bookmark — exploded from fewer than 10,000 on October 6 to more than 100,000 by Monday, October 12. REA collected more than 30,000 of those stars on October 11 alone, after sitting mostly ignored since its creation in April.

The project's rise comes amid a broader wave of AI-decompiled game mashups and ports powered by Claude Opus 5.5, ranging from Spider-Man swinging through the Gotham of Batman: Arkham City to an unofficial PC port of Fable 2. Developer Brandon Thomas has also released ArtCraft, a set of free, Rust-built alternatives to Adobe's applications built with Claude — though he describes it as a clean-room rebuild that never touches Adobe's code.

How REA works

Apps and games ship as machine code: the raw instructions a processor reads and humans basically can't. Decompiling tries to turn that back into readable code, a bit like tasting a cake and working backward to the recipe. Reverse engineering is the bigger umbrella — figuring out how something works without its blueprints, whether by watching what an app does and what data it sends, or by reading its code. REA does exactly that.

In practice, a user points an AI agent at a program, asks how one feature works, and lets it dig from what happens on screen all the way down to the binary. Instead of a specialist manually paging through disassembly, the agent plans the steps, runs the tools, and reports back what it finds. The approach works on desktop apps, Android apps, and websites.

REA hooks AI coding assistants such as Claude Code or OpenAI's Codex up to the professional tools built for that job, like Ghidra, the reverse-engineering suite the NSA released to the public in 2019 that security researchers have long relied on to dissect malware. The bridge is MCP, the Model Context Protocol, a standard Anthropic created — and other major AI labs have since adopted — so AI models can plug into outside tools, essentially a universal adapter.

The developer's readme file is far more modest than the hype, stating that REA “does not claim to recover original source code or automatically clone an application.” It doesn't even ship its own decompiler. That, in turn, is what keeps the whole operation “legal(ish)”: the developer has never read the underlying code, and simply ships a similarly coded alternative that does exactly the same, but isn't exactly the same. US courts have repeatedly held that reverse engineering a program to understand it — or to make other software work with it — can be lawful; lifting protected code or creative assets outright is a different question.

The gates are open

People are doing all sorts of strange things with REA. Some players ended up watching Spider-Man swing through the Gotham of Batman: Arkham City, and creepers fight Elden Ring boss Malenia after someone stuffed about 1,600 Minecraft items into FromSoftware's game. Another modder dropped Escape from Tarkov's guns and menus into Skyrim and called it “Escape from Skyrim lol.”

Old console exclusives are escaping their consoles too. In September, a fan used an open-source AI model and a recompilation toolkit to bring Fable 2 — the only mainline Fable game never released on PC — to Windows. The AI got it booting in about an hour, followed by a long stretch of manual fixes. Recompilation, which translates a console's machine code into a form a PC processor runs natively, has long been viewed by game preservationists as a lifeline for titles stranded on aging hardware. Another project got GTA V running fluidly on iOS, something not even Rockstar Games ever bothered doing.

gta v running natively on ios (a recent fun project of mine) pic.twitter.com/5k6w06hoLY — C22 (@c22_dev) October 9, 2026

From game mods to paid software

Using these techniques — though not the REA tools themselves — developer Brandon Thomas took the idea to software that people pay for every month, using Claude Opus 5.5 to build ArtCraft, a set of free, open-source apps written in Rust that mirror Photoshop, Illustrator, Premiere, Lightroom and other Adobe programs for Mac, Windows, and Linux.

Thomas says he snapped after Adobe charged him its cancellation fee one too many times. He isn't alone in that grudge: Adobe agreed in March to a $150 million settlement with the Justice Department, which accused the company of hiding early termination fees and making subscriptions a pain to cancel, though Adobe denied wrongdoing.

ArtCraft isn't built with REA. Thomas calls the project a clean-room rebuild, meaning the code is written from scratch using public documentation and behavior rather than the original code — same legal approach Compaq used to clone IBM's PC BIOS in the 1980s. The apps are labeled “early alpha” or “in development” on the project's site, and one pixel artist has already called the Photoshop clone “completely unusable.”

The backlash begins

Anything that runs on your own device can now be read by an AI agent with enough patience and tokens, which erodes the oldest copy protection in software: the sheer pain of reading machine code. That means cheaper clones and better game preservation, but also easier piracy and fewer places for security flaws to hide.

Studios are starting to push back. Activision has already pulled footage of an AI-decompiled Call of Duty: Modern Warfare 2, and Bethesda sent a cease-and-desist letter over an AI-made browser game called Fallout: New York.

UPDATE: Due to copyrights I had to take down this game. BUT I will have an updated version of the game up and running soon! If you want to play it now and give me feedback as I fix things just reply to this comment and I'll DM you the new link. — CHRIS FIRST (@chrisfirst) October 4, 2026

That appears to be the only defense studios have against a trend that could easily force everything open source. Takedown letters can erase individual projects, but they leave the underlying tools, like REA, sitting publicly on GitHub for the next user.

REA, meanwhile, keeps shipping, with eight releases between October 3 and October 11. Thomas has already walked back his promise to match Adobe's feature set within a month, and now says it will take months. With cease-and-desist letters arriving on one side and near-daily releases on the other, the practical limits of AI-assisted reverse engineering are being drawn in public, one project at a time.