Anthropic Shuts Off Access to Fable 5 and Mythos 5 Models Globally After U.S. Export Restrictions

Commerce Secretary Howard Lutnick sent Anthropic CEO Dario Amodei a letter on Friday stating that the company's latest Fable 5 and Mythos 5 models are now subject to export restrictions, according to an administration official cited by the Wall Street Journal. The restrictions prohibit usage by customers outside the United States and by foreign nationals within the country.

Anthropic responded by halting access to the two models for its entire user base, not only foreign users, in order to comply with the new rule. The Wall Street Journal reported that the administration declared the models security risks in justifying the export controls.

The restrictions represent a significant escalation in U.S. government oversight of frontier AI systems. The move follows earlier White House discussions about formally assessing AI models that pose security risks, and comes amid broader efforts by top AI companies to secure Pentagon deals for classified work, according to related coverage noted by the Journal.