The Crazy Way a Dev Avoided Copyright on Leaked Claude Code

#claude #ai #opensource #github

On March 31, Anthropic’s AI coding tool “Claude Code” had its entire source code suddenly leaked online.

The cause? A .map (sourcemap) file included in the npm package — the very file every developer knows all too well.

When built with Bun, the sourcemap generated by default contained the complete original TypeScript source code embedded inside it. This allowed the full source to be extracted via the sourcemap. But the real problem starts here.

Leak → Immediate Backup → DMCA Blitz

The first person to report the leak was Fried_rice.

The publicly shared ZIP file (src.zip) contained Claude Code’s full architecture, system prompts, tool implementations, unreleased feature flags (such as KAIROS, BUDDY, ULTRAPLAN, etc.), and even Undercover Mode.

realsigridjin quickly created a backup on GitHub.

However, Anthropic reacted immediately, firing off DMCA (copyright takedown) notices one after another. Repositories hosting the original code were taken down in rapid succession.

“Copyright infringement — of course they’d do that.” Up to this point, it was a standard story.

Then Came the “God-Tier Evasion”

What realsigridjin did next was on a completely different level.

He completely rewrote the same repository in Python and republished it.

Original: TypeScript (Anthropic’s official code itself)
New: Python (automatically converted and reimplemented using Codex / oh-my-codex)

The new repository (instructkr/claude-code or related clawd-code repos) has nearly identical functionality, yet can claim “this is not copyright infringement.”

What’s more, the rewrite was completed in just a few hours. It’s said that he simply handed the task to an AI agent with the instruction: “Reimplement Claude Code in Python.”

As Gergely Orosz (@gergelyorosz) accurately pointed out:

“Copyright does not protect derived works. Rewriting TypeScript code in Python means copyright no longer applies.”

(Copyright does not protect “derived works.” If you rewrite TypeScript code in Python, copyright no longer applies.)

Why Does This Bypass Copyright Infringement?

The fundamental principle of copyright law is that it protects “expression,” but not “ideas, functions, or algorithms.”

Rewriting the exact same logic from scratch in a different language = “different expression”
Even if an AI performed the automatic conversion, one can argue that “a human reviewed the specification and reimplemented it”

In other words, “translation versions” or “ports to another language” sit smack in the middle of a legal gray zone, but in practice, DMCA takedowns become extremely difficult to enforce.

In fact, this Python version is still alive and its star count is skyrocketing.

For Anthropic, this is the worst-case scenario:

Even if they DMCA the original, the “Python version” remains
Taking it down would spark a huge debate: “Are you trying to use copyright to control even AI-generated derivative works?”
It threatens the very value of the Claude/Code tools they are building

What This Means: “The Collapse of Copyright in the AI Era”

This incident made one thing crystal clear: closed-source code can no longer be protected.

Using AI agents, a 57MB TypeScript codebase can be converted to Python in just a few hours
Simply changing the language allows one to claim “this is not copyright infringement”
Developers around the world have already learned the flow: “leak → immediate rewrite → publish”

Hiding source code is rapidly becoming meaningless.

No matter how much Anthropic emphasizes “safety first,” we have entered an era where one npm publish mistake can expose the entire source, and AI can instantly generate a “legal” clone.