Gergely Orosz on X: "This is either brilliant or scary: Anthropic accidentally leaked the TS source code of Claude Code (which is closed source). Repos sharing the source are taken down with DMCA. BUT this repo rewrote the code using Python, and so it violates no copyright & cannot be taken down! https://t.co/uSrCDgGCAZ" / X

This is either brilliant or scary: Anthropic accidentally leaked the TS source code of Claude Code (which is closed source). Repos sharing the source are taken down with DMCA. BUT this repo rewrote the code using Python, and so it violates no copyright & cannot be taken down!

10:24 AM · Mar 31, 2026

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Gergely Orosz

@GergelyOrosz

5h

The repo: github.com/instructkr/cla The brilliance: copyright does not protect derived works. Rewriting TypeScript code in Python means copyright no longer applies. The scary thing: it can be done in trivial amount of time, with AI agents. This one was done with Codex. This can

GitHub - instructkr/claude-code: Claude Code Snapshot for Research. All original source code is the...

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You can imagine Anthropic being in a pickle: 1. Do they just leave this, and look the other way, ignoring that it's not exactly fair to transform their code and leave it up there 2. Do they claim copyright applies... but this could be bad for their own business in much bigger

Worth asking btw if code fully written with AI has copyright protection? Anthropic is big in saying most of Claude Code is generated by AI. Not 100%, but close, and the last few months pretty much all. Another interesting copyright question.

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Gergely Orosz

@GergelyOrosz

3h

Replying to @zeeg

Yes, but two things: 1. Does AI-generated code have copyright? Anthropic is big on claiming Claude Code is close to 100% AI-generated, using high-level prompts. 2. Assuming it’s copyrighted (some questions on #1 ofc!) would Anthropic try to prove it, given the obvious backlash

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This one is actually clear cut copyright violation. Changing copyrighted material does not void the IP protections and thats all they did. “Could you have implemented this without using the source code” is the easy test

Yes, but two things: 1. Does AI-generated code have copyright? Anthropic is big on claiming Claude Code is close to 100% AI-generated, using high-level prompts. 2. Assuming it’s copyrighted (some questions on #1 ofc!) would Anthropic try to prove it, given the obvious backlash

So the DMCA defense is now just "Your Honor, it's in a different language." International law scholars in ruins.

if copyright applies for derived works based on the source, that could be a coffin in the nail for training LLMs that work just like this... and Anthropic is one of the leading AI labs commercializing LLMs. So it could be tough for Anthropic to argue that copyright applies!

The pace at which he re wrote the code using Claude’s own model (assuming)

nope: used Codex!

Did they use the Claude code /batch feature to do the conversion

no, used Codex

That’s honestly both genius and a little terrifying

Turning leaked logic into a clean Python rewrite to bypass copyright is a wild loophole… Shows how fast things move in AI right now — control is an illusion if the idea is out there.

The DMCA response is the Streisand Effect in a zip file. Anthropic removes the TypeScript. The community rewrites it in Python. The code is now more distributed than before. The only thing the takedown proved is that the source maps should not have been there.

“Sir, it’s forkable”

Anthropic just had an all-time self-own. Someone on their team ran a production build of Claude Code, generated a source map (a literal blueprint of their entire codebase), and published it straight to npm for anyone to download. This is the same company that: · Told Congress

Leaked by accident. DMCA'd immediately. Rewritten in Python within hours. This is the fastest open source project in history that nobody at Anthropic intended to create

With novels, you can't use AI to translate someone's book into German, and claim it violates no copyright Why is the same not true for code?

This is wild

Leaked TS code gets DMCA'd instantly, but one dev uses AI to rewrite it all in Python in hours now it's untouchable. 40k+ forks already. Copyright vs AI agents: who wins? Anthropic's probably just gonna ignore it.

Refactoring proprietary TypeScript into Python is a flawless 'Clean-Room' reverse-engineering bypass. Under US Copyright law, Anthropic cannot DMCA the logic or the architecture. However, there is a fatal flaw in this clone. If that Python repository still contains the verbatim

The irony of a coding tool's source getting reviewed by the entire developer community in 24 hours is that it's probably the fastest security audit they'll ever get. Unplanned, but arguably useful.

Fight fire with fire I'd say. interesting times ahead.

I wonder if they really needed the source to do that, I bet Claude itself could do a decent job rewriting in Python based on the minified JS. It would be painful and lose a lot of intent but could get pretty far.

Does this mean we can fully automate clean room reverse engineering, but without even needing two separate agents, just give an agent the protected source code, and have it, while being able to directly observe the original, write a re-implementation?

Its a snapshot. Anthropic will introduce new headers or flags that will be used to disrespect non-approved requests in future versions (until the next leak, this already happened once already), and they've been squeezing third party harnesses (opencode) by default. Great lessons