An artificial intelligence start-up, Legion, that uses Anthropic PBC’s AI models sued the US over a government order that the maker of Claude and Mythos keep its most advanced technology out of the hands of foreign nationals. The suit, filed on June 23 in federal court in Washington, comes less than two weeks after Anthropic disabled access to its most advanced AI models – Fable 5 and Mythos 5 – in response to the Trump administration’s export controls. Legion, a litigation-technology company based in the US, said its software development employees include Canadian nationals who work from Canada. Legion said in its filing that Anthropic shutting off access to the Fable 5 model meant the company “lost the latest tool at the centre of its development instantaneously,” calling the harm “immediate, irreparable and existential.” Defendants named in the suit include Commerce Secretary Howard Lutnick, who warned Anthropic chief executive Dario Amodei in a letter that the company would require permission from the government before exporting its Fable 5 and Mythos 5 models outside the US, or to foreign nationals in any location. An Anthropic spokesperson said the company is “grateful to the administration” for working to resolve the situation.