An open letter signed by dozens of security experts asked the government to reverse export restrictions on Anthropic's Claude Fable 5 and Mythos 5 models.

Anthropic blocked public access to Fable 5 and Mythos 5 on Friday after the Trump administration imposed export restrictions on the models.

US Commerce Department restricts Anthropic's Fable 5 and Mythos 5 from foreign nationals, sparking European push for sovereign AI alternatives.