Trump Lifts Export Controls on Anthropic Claude Fable Mythos

Anthropic's Claude Fable 5 export ban has ended after 18 days, with the U.S. government clearing the model for global use again starting Wednesday. The reversal restores access across Claude.ai, Claude Code, Claude Cowork and the wider Claude platform, closing a standoff that briefly cut off users worldwide.

In Brief

• Export controls on Fable 5 and Mythos 5 lifted after 18 day shutdown
• Fable 5 returns Wednesday on Claude.ai, Claude Code, Claude Cowork and the Claude platform
• Pro, Max, Team and select Enterprise users get expanded Fable 5 access through July 7
• Mythos 5 cleared June 26 for a limited group of U.S. organizations only
• New safety classifier blocks the flagged exploit in over 99 percent of tests

What Triggered the Shutdown

The June 12 directive traced back to research from Amazon that documented a way to coax Fable 5 into producing dangerous outputs tied to software vulnerability discovery. The prohibition applied to any foreign national, a definition broad enough to include Anthropic's own researchers. Facing that constraint, the company decided the only way to comply was to pull both models offline entirely, everywhere, for everyone.

Anthropic pushed back on the idea that Fable 5 was uniquely dangerous. Its internal testing found that other mainstream models, including OpenAI's GPT-5.5, could generate the same flagged outputs. That detail matters because it suggests the underlying risk sits with the broader class of frontier models rather than one company's product.

How the Fix Cleared Government Review

Anthropic's response was a new safety classifier built specifically to catch the bypass technique Amazon had identified. In the company's own testing, it stopped the exploit more than 99 percent of the time. The Commerce Department's Center for AI Standards and Innovation reviewed both that classifier and the original guardrails, and Anthropic said the results backed up their effectiveness.

Commerce Secretary Howard Lutnick said on X that his department spent two weeks working directly with Anthropic to vet Fable 5 and align the review across the government. White House chief of staff Susie Wiles framed the resolution similarly, telling X, according to The Wall Street Journal, that the shared goal was deploying strong technology quickly and safely.

Access Rules and What Comes Next

Through July 7, subscribers on Pro, Max, Team and select Enterprise plans can use Fable 5 for up to half their weekly usage allotment before credits kick in. Any blocked requests during the transition get rerouted to Claude Opus 4.8. Anthropic also plans to restore Fable 5 on Amazon Web Services, Google Cloud and Microsoft Foundry, though it has not given a date.

Mythos 5 access is narrower for now. The government approved renewed access on June 26, but only for a limited set of U.S. organizations. Expanding that to more domestic and international partners through the Glasswing program is still being negotiated with federal officials, so how quickly Mythos 5 reaches a wider audience remains an open question.

Why the Timing Matters for Anthropic

The shutdown landed at an awkward moment. Anthropic recently filed a confidential IPO prospectus showing a $47 billion revenue run rate and a $965 billion valuation. CNBC reported that co-founder Tom Brown, not CEO Dario Amodei, led the negotiations with Washington, a shift also visible in the fact that Lutnick's correspondence was addressed directly to Brown.