The central claim has two parts: that Karpathy is barred from accessing Anthropic's most advanced model, and that the reason is his non-U.S. citizenship. Both elements are supported by available evidence.
Anthropic published a statement on June 12, 2026, saying the U.S. government had issued an export-control directive requiring it to suspend access to Fable 5 and Mythos 5 by "any foreign national, whether inside or outside the United States, including foreign national Anthropic employees." Because the directive applied to foreign nationals globally, Anthropic disabled both models for all customers to ensure compliance. XDA Developers reported the same details, noting the directive was received at 5:21 p.m. ET on Friday and that the government cited national-security concerns related to a potential jailbreak of Fable 5.
Karpathy's immigration status is the key link. He was born in Bratislava, Czechoslovakia (now Slovakia), moved to Canada as a teenager, and is described in his Wikipedia biography as a "Slovak-Canadian AI researcher." Observer's May 20, 2026, profile of his hiring by Anthropic identified him as a "Slovakian-born Canadian researcher." A widely circulated post by Andrew Curran on X stated that, according to Grok, Karpathy is an EB-1 extraordinary ability green card recipient rather than a U.S. citizen, and therefore would not be permitted to use or work on Mythos 5 or Fable 5 under the new restrictions. That post quoted directly from Anthropic's statement.
The claim's framing is accurate in substance. Karpathy is indeed barred from the restricted models, and the reason is his status as a non-U.S. citizen. The claim describes him as "a top AI scientist at Anthropic," which is consistent with his role leading pretraining research. The only minor framing issue is that the claim says he is barred from "the company's most advanced AI model," when in fact two models, Fable 5 and Mythos 5, are restricted. That does not materially change the story.
The core facts rest on Anthropic's own statement, contemporaneous reporting from XDA Developers, and Karpathy's well-documented background. The specific claim about his green card status comes from a social media post citing Grok rather than primary documentation, which prevents the evidence from being rated strong.
