Relicensing with AI-assisted rewrite
Posted on March 5, 2026 • 3 minutes • 529 words
Disclaimer
I am not a lawyer, nor am I an expert in copyright law or software licensing. The following post is a breakdown of recent community events and legal news; it should not be taken as legal advice regarding your own projects or dependencies.
In the world of open source, relicensing is notoriously difficult. It usually requires the unanimous consent of every person who has ever contributed a line of code, a feat nearly impossible for legacy projects. chardet , a Python character encoding detector used by requests and many others, has sat in that tension for years: as a port of Mozilla’s C++ code it was bound to the LGPL, making it a gray area for corporate users and a headache for its most famous consumer.
Recently the maintainers used Claude Code to rewrite the whole codebase and release v7.0.0 , relicensing from LGPL to MIT in the process. The original author, a2mark , saw this as a potential GPL violation:
Licensed code, when modified, must be released under the same LGPL license. Their claim that it is a “complete rewrite” is irrelevant, since they had ample exposure to the originally licensed code (i.e. this is not a “clean room” implementation). Adding a fancy code generator into the mix does not somehow grant them any additional rights.
A clean room rewrite requires a wall that AI bypasses
In traditional software law, a “clean room” rewrite requires two teams:
Team A looks at the original code and writes a functional specification
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