The Trump administration lifted export controls on Anthropic's Claude Fable 5 AI model Tuesday evening, with access returning to customers Wednesday, restoring public access to the Mythos-class model that had been pulled for security reasons 18 days ago. Last week, the administration allowed Anthropic to restore access to Mythos 5 for a select group of government-approved organizations. Commerce Secretary Howard Lutnick said his office had "worked closely with Anthropic to analyze and approve Fable 5 to ensure alignment across the US Government and strengthen America's leadership in AI." Anthropic says it worked with the government to implement a new safeguard that blocks the jailbreak officials were worried about 99% of the time, though the safeguard could result in Fable flagging more benign requests. Commerce's Center for AI Standards and Innovation tested the model's previous and new safeguards. The U.S. government's desired role in regulating frontier AI models remains ad hoc, as OpenAI rolled out GPT-5.6 to only a small set of approved customers last week. The Trump administration faces an August deadline under a recent executive order to create standardized benchmarks for evaluating security risks of new AI models.