Photoshop clone in a week: Closed source falters

Coding agents recreate commercial software from binary code and observed behavior. The open-source Photoshop clone PhotoCraft released four versions within a week. By its own assessment, it covers only a quarter to a third of professional work.

Key takeaways

Four versions in a week

What is happening in AI-assisted reverse engineering is absolutely insane, Replit CEO Amjad Masad writes on 7 October. Soon, virtually all software will effectively be open source. Reverse engineering means analyzing a finished program to understand and reproduce how it works.

PhotoCraft shows how far this goes. The project describes itself as an open-source, clean-room recreation of Adobe Photoshop in pure Rust. Here, clean room means implementation using only public specifications and observed behavior, without proprietary code. The first version appeared on 2 October, followed by three more by 7 October. Features range from layers, masks and adjustment layers to layer styles, text, vectors, brushes and PSD files.

The AGENTS.md working instructions explicitly address AI agents and contributors. They target one-to-one parity with Photoshop in menus, keyboard shortcuts, behavior and file fidelity. Sister projects such as VectorCraft and FilmCraft follow the same approach.

What is decompilation? Decompilation translates a program’s executable machine code back into readable source code. Tools such as Ghidra or IDA Pro support this process, including connections to AI models through interfaces such as GhidraMCP.

Quickly wired up does not mean finished

On 30 September, 224 of Photoshop’s 625 menu items were linked to a command. A day later, the figure was 532. This counts only whether a menu item is linked to a command, regardless of whether it behaves like the original.

The project’s assessment of actual parity is considerably more sober. It remains well below half; professionals could switch for around 25 to 35 percent of everyday work. The project sees the biggest gaps in AI features, missing tools and professional workflows.

PhotoCraft is further ahead on file fidelity. Resaving preserves the appearance of 307 of the 309 test files in the psd-tools collection. Every action can be triggered as a command through the interface, command line, a JSON control channel or an MCP server. An MCP server is an interface through which AI models operate external tools. Adobe has built such a bridge itself: in late April, it announced a connector through which Anthropic’s Claude controls multistep workflows using more than 50 professional tools from apps such as Photoshop, Illustrator, Premiere and Lightroom.

Games from machine code

For games, agents work directly on binary code. A community project is recreating the 2009 PC version of the shooter Call of Duty: Modern Warfare 2 as readable C++ from machine code. After around four weeks, 5,588 of 16,324 identified functions had been recovered, roughly a third. In mid-August, four agents worked in parallel through Claude Code. Three decompiled; the fourth checked the results. They use IDA Pro and Ghidra, with the team assigning tasks through GitHub Issues.

In early March, Piotr Migdał described on the Quesma blog how he had rebuilt the roughly 20-year-old game Chromatron for Apple Silicon and WebAssembly using Ghidra, Claude and Codex. A screenshot comparison found 307,199 of 307,200 pixels identical. He also notes that hallucinations are worse than no answer. Dedicated bridges provide access to binaries: GhidraMCP connects the analysis tool Ghidra to AI models that can decompile and automatically name functions.

Copyright limits

Without the rights holder’s consent, Section 69e of the German Copyright Act (UrhG) permits decompilation only when indispensable for an independently created program’s interoperability, meaning its ability to work with other programs. The information obtained may not be used for a program “substantially similar in its expression”.

Observation is treated differently. Under Section 69d(3) UrhG, an authorized user may observe, study and test a program to identify its underlying ideas and principles. This requires using only actions, such as loading, displaying or running it, that the user is already entitled to perform. A clean-room recreation such as PhotoCraft relies on precisely this approach.

Rights holders take action against emulators. In August, Nintendo had 401 repositories containing Switch emulators removed from GitHub. Skepticism is also growing within the community: a blog post criticizes AI-assisted game ports as empty shells. Projects such as the mGBA emulator do not accept AI-generated code.

What software vendors can learn

This development will be hard to stop. Section 69e UrhG ties permitted decompilation to interoperability; Section 69d(3) allows authorized users to observe programs. Agents accelerate precisely this observation and recreation. Menus, file formats and interface logic can be wired up in days, although PhotoCraft says true parity with the original still requires many months of work.

For vendors, this shifts what protects a product. Elements reproducible from public specifications and observed behavior, as in PhotoCraft, including interface logic and file formats, are likely to lose value as competitive moats. What never reaches the customer remains harder to replicate: server-side services, maintained data, integrations and support. Vendors hiding license checks or access keys in shipped software should assume agents will find them.

The same capability also affects security. By early February, Anthropic’s Frontier Red Team had already used Claude to find and confirm more than 500 severe vulnerabilities in open-source software. In October 2024, Google’s AI agent Big Sleep discovered a previously unknown, exploitable memory vulnerability in the SQLite database before it reached an official release. Google considers the discovery the first public example of its kind. Tools such as GhidraMCP are open source and available to defenders and attackers alike. Short patch cycles therefore matter more than hoping nobody examines the code.

Frequently asked questions

Image credit: AI-generated (October 2026)

Image source: AI-generated (October 2026)

Translated from the German original using artificial intelligence. The German version is authoritative.