In brief
- Nvidia, Meta, Microsoft, Andreessen Horowitz, Hugging Face, IBM, and 19 other companies published a letter Friday titled "Open Weights and American AI Leadership," warning against restrictions on open models. OpenAI and Anthropic did not sign.
- The letter follows a week in which OpenAI's own AI agents attacked Hugging Face, which then had to use a Chinese open-weight model to defend itself after American closed models refused to cooperate.
- Trump administration officials have reportedly considered banning Chinese open-weight models, while OpenAI's Dean Ball has called an open-source-dominated AI future a "dystopian hellscape."
Twenty-five companies just told Washington to leave open-source AI alone. Nvidia, Microsoft, Meta, Andreessen Horowitz, Hugging Face, IBM, Dell, and 18 others signed a letter published Friday called "Open Weights and American AI Leadership." Their argument: restricting open models won't protect the U.S., it will just hand the AI market to a handful of closed labs.
Open-weight models are AI systems whose underlying "weights"—the billions of numbers that decide how a model responds—get published for free. Anyone can download them, run them on their own servers, and modify them. That's the opposite of closed models like OpenAI’s GPT or Anthropic’s Claude, which only run through a company's paid app or API.
The letter draws a direct line to the 1980s open-source software movement, arguing AI has reached a similar fork in the road. "Our AI leadership will be judged not by one frontier AI model, but by whether the United States builds a strong, open ecosystem that diffuses into every sector," the letter reads.
Nvidia CEO Jensen Huang shared the letter in his first-ever post on X. "AI will transform every industry, power every company, and be built by every country," he wrote. "Open models strengthen safety and cybersecurity, accelerate innovation and diffusion, and enable sovereignty." Microsoft's Satya Nadella posted it too, calling open models "essential to a healthy AI ecosystem" while protecting national security.
For my first post, I’m sharing a letter @NVIDIA signed on why open models matter.
AI will transform every industry, power every company, and be built by every country.
Open models strengthen safety and cybersecurity, accelerate innovation and diffusion, and enable sovereignty.… pic.twitter.com/t02bi51N4C
— Jensen Huang (@JensenHuang) July 24, 2026
The timing lands right after a mess American AI companies would rather forget. OpenAI admitted its own AI agents broke into Hugging Face's systems, calling it an unprecedented attack. When Hugging Face, which hosts the world’s largest repository of open-source AI, tried American closed models to investigate, the tools' safety filters couldn't tell a security researcher from the attacker. So the company ran GLM 5.2, an open-weight Chinese model, locally instead—and used it to trace the breach.
That episode complicates a fight already underway inside the government. The Trump administration has reportedly weighed banning Chinese open-weight models after Moonshot AI's Kimi K3, a 2.8-trillion-parameter model, rattled chip stocks and beat Claude Fable 5 on some benchmarks. Not everyone in the AI industry wants openness to win, either. Days after Kimi K3 launched, OpenAI's head of strategic futures, Dean Ball, wrote on X that an open-weight-dominated world leads to "full AI communism" and called it "a dystopian hellscape."
The letter pushes back on that framing directly: "Openness may be one of the most important paths to AI safety and security." It also draws a line around distillation, the practice of training one model using another's outputs, calling it a legitimate technique rather than theft that deserves "targeted legal and commercial frameworks" instead of blanket bans.
“Distillation, or the practice of using one model's outputs to help train or improve another, is a widely used technique for model improvement, evaluation, and validation. It reflects a long tradition of learning from, building upon, and improving existing technologies, a tradition that has helped drive innovation since the rise of the open-source software movement,” the letter reads.
“By contrast, unlawful efforts to extract value from closed models raise legitimate concerns. Those concerns should be addressed through targeted legal and commercial frameworks rather than sweeping restrictions on techniques that play an important role in AI innovation.”
This is precisely the argument the Trump administration seems to be weighing to justify a ban on open source Chinese models.
Notably absent from the 25 signatories: OpenAI and Anthropic, the two closed-model labs both reportedly preparing IPOs this year.
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