Anthropic to restore Fable 5 and Mythos 5 after export controls lifted

Anthropic will begin restoring access to Fable 5 and Mythos 5 on July 1, one day after the U.S. Commerce Department lifted export controls on both models. The move reverses a shutdown that had cut off access worldwide, including for U.S. users, because the original directive barred use by any foreign national, whether inside or outside the United States.

The restriction began on June 12, when Anthropic received the directive at 5:21 p.m. ET and disabled access to both models. The government did not provide specific details about the national security concern, though Anthropic believed officials were responding to a claimed jailbreak method for Fable 5. The order also swept in foreign national Anthropic employees, making a global shutdown the only way to comply.

Anthropic spent thousands of hours red-teaming the systems with the U.S. government, the UK AISI, private third parties and internal teams, and no tester found a universal jailbreak for Fable 5. The company launched Fable 5 and Mythos 5 only days before the restriction. Fable 5 was the first time it had released such an advanced model publicly. For safety, queries involving cybersecurity and biology were routed to Opus 4.8, and use of Mythos 5 required 30-day data retention for monitoring.

The restoration will unfold in stages. On June 26, the Trump administration allowed Anthropic to release Mythos 5 to a limited group of trusted partners. On June 30, the Commerce Department lifted the export controls on both models. Anthropic had priced the models at $10 per million input tokens and $50 per million output tokens.

Tech executives and investors criticized the restriction, arguing that it could give Chinese open-source model developers more time to catch up.