claude fable 5 ships, then a us export directive takes it offline

what happened

• Anthropic released Claude Fable 5 (claude-fable-5) on June 9, 2026, calling it 'a Mythos-class model that we've made safe for general use'; Claude Mythos 5, the same underlying model with some safeguards lifted, was restricted at launch to Project Glasswing partners.[1]
• Both models are priced at $10 per million input tokens and $50 per million output tokens, with a 1M-token context window and 128K max output; the model page lists the Claude API, Amazon Bedrock, Google Cloud, Microsoft Foundry and Claude Platform on AWS.[1,2]
• Anthropic says that when Fable's classifiers detect a request related to cybersecurity, biology and chemistry, or distillation, the response is handled by Claude Opus 4.8 instead; the company reports the safeguards trigger in less than 5% of sessions on average.[1]
• On June 12, 2026 Anthropic received a US government directive to 'suspend all access to Fable 5 and Mythos 5 by any foreign national', including its own foreign-national employees, and disabled both models for all customers; its other models were not affected.[3,5]
• Anthropic says the government's letter did not provide specific details of its national security concern, and that it disagrees 'that the finding of a narrow potential jailbreak should be cause for recalling a commercial model.'[3]
• Anthropic says the controls were lifted June 30 and Fable 5 returned July 1 on the Claude Platform, Claude.ai, Claude Code and Claude Cowork, with access on AWS, Google Cloud and Microsoft Foundry to return 'as quickly as possible'.[4]
• On redeployment Anthropic added a classifier aimed at an Amazon-reported bypass technique; blocked Fable 5 requests are rerouted to Opus 4.8, and Anthropic says the classifier flags benign coding and debugging requests more often.[4]
• Anthropic released Claude Fable 5.1 (claude-fable-5-1) on September 1, 2026 at the same $10 / $50 per million token price.[6]