GitHub, Hugging Face, Mozilla Push Back on California AI Transparency Act's Open Source Threat

GitHub has joined forces with Black Forest Labs, Hugging Face, and Mozilla to lobby for targeted changes to California's AI Transparency Act (SB 942, as amended by SB 1000). The coalition's letter—published on GitHub's developer-policy repo—zeroes in on a single provision that would force developers to revoke licenses when downstream users fail to meet certain obligations. That's a direct conflict with the fundamental premise of open source licenses, which are designed to be perpetual and irrevocable.

The problem is straightforward: if a developer releases an AI model or component under an open source license, and a downstream user modifies and deploys it without complying with the bill's transparency requirements, the current draft would require the original developer to revoke that user's license. But open source licenses don't work that way—they grant rights that cannot be unilaterally pulled. Introducing such a requirement would inject uncertainty into every dependency tree and collaborative project that touches AI.

The coalition argues that this revocation mechanism is unnecessary. Developers who directly modify and deploy AI systems are already covered by the law, and enforcement can target those actors without breaking the open source model. As an alternative, they point to the EU AI Act's Transparency Code of Practice, which acknowledges the distinct nature of open source and deems it sufficient to notify downstream users of best practices in documentation rather than impose revocable licensing.

This is a narrow but critical fight. The bill's transparency goals—labeling AI-generated content, disclosing training data—are broadly supported. But if the final text forces open source projects to adopt proprietary-style licensing or risk legal liability for downstream misuse, it could chill the collaborative development that underpins most of today's AI tooling. GitHub, Hugging Face, and Mozilla are betting that technically grounded feedback can steer the legislation toward a workable middle ground.

The full letter is available on GitHub's developer-policy repository. Developers and organizations with a stake in open source AI are encouraged to review it and contact California policymakers directly.