OpenAI and Microsoft have won a significant appeals-court ruling in a lawsuit over GitHub Copilot and OpenAI Codex, narrowing one legal route developers have used to challenge AI systems trained on publicly available source code.
Reuters reported that the U.S. Court of Appeals for the Ninth Circuit upheld the dismissal of a Digital Millennium Copyright Act claim brought by anonymous software developers who alleged that OpenAI and Microsoft misused code hosted on GitHub.
The case is Doe v. GitHub Inc., No. 24-7700, and the Ninth Circuit published its opinion on September 16.
Developers challenged missing attribution in generated code
The lawsuit began in 2022 and was brought by developers seeking to represent owners of open-source code published on GitHub.
Reuters reported that the developers alleged that Microsoft and OpenAI used GitHub repositories to train Codex and GitHub Copilot and that generated code could reproduce their work without the original copyright-management information.
The DMCA prohibits intentional removal or alteration of certain copyright-management information, such as information identifying an author or copyright owner.
The developers argued that generating similar code without that information could trigger liability under the law.
The appeals court disagreed with that theory.
Reuters reported that the court concluded Copilot and Codex generate new works that never contained the copyright-management information at issue, rather than removing the information from an existing work.
The court separated DMCA claims from copyright infringement
The distinction matters because the ruling does not establish that every form of AI-generated similarity is legally protected.
Reuters reported that the Ninth Circuit specifically distinguished the developers’ DMCA theory from traditional copyright infringement, which can turn on whether one work is substantially similar to another.
The court said it was not deciding whether similarities between AI-generated and copyrighted code could support an ordinary copyright-infringement claim.
Bloomberg Law described the decision as an appeals-court victory for OpenAI and Microsoft-owned GitHub in one of the earliest copyright-related disputes involving generative AI coding software.
Open-source licensing questions remain
The litigation is not finished.
Reuters reported that developers can continue pursuing claims that Microsoft and OpenAI breached open-source licensing terms.
That distinction is particularly important for software builders.
Open-source licenses can require attribution, copyright notices or compliance with other conditions even when source code is freely accessible. AI coding systems complicate those obligations because models can learn patterns from enormous collections of repositories and generate code without reproducing the original repository structure or metadata.
The ruling therefore resolves one legal theory without answering the larger engineering and licensing question surrounding AI-generated code.
For developer-tool companies, the signal is mixed: courts may reject attempts to stretch existing copyright-management rules around AI outputs, but open-source license obligations remain a separate risk that model providers and enterprise users still have to navigate.
