Redeployed version with enhanced safety classifiers that automatically block cybersecurity tasks and revert to Opus 4.8. Available with restricted usage limits after month-long government-mandated takedown.
First public release of Anthropic's Mythos model line. Introduces extended-execution code generation with up to 12-hour continuous operation on complex specifications.
Fable 5 was shut down by government order on June 12, 2026, just 3 days after launch. Expected to return with potential access restrictions after government security review.
Anthropic is redeploying Claude Fable 5 after a month-long government-mandated takedown triggered by Amazon researchers discovering a method to bypass the model's cybersecurity safeguards. The returning version includes enhanced safety classifiers that automatically block cybersecurity tasks and revert to Opus 4.8, with restricted availability through usage credits only.
The Trump administration is close to allowing Anthropic to restore access to its Fable 5 model, which has been offline for 15 days due to national security concerns. Insiders expect restrictions could be lifted as soon as next week, though Pentagon and NSA approval is still required.
Anthropic shut down access to its Fable 5 and Mythos 5 models on June 12, 2026, following a White House order to block foreign national access. The directive came after Amazon security researchers reportedly found jailbreak methods that could expose cybersecurity vulnerabilities, though Anthropic disputes the severity of the findings.
Anthropic's Fable 5 AI model was pulled from public access Friday night after Amazon reported security vulnerabilities to the White House. The administration imposed export controls on Anthropic's Mythos-class models just days after the June 9 release.
The U.S. government ordered Anthropic to immediately shut down access to Claude Fable 5 and Claude Mythos 5 on Friday, citing national security concerns. Anthropic received the directive at 5:21 pm ET and has complied, disabling both models worldwide, but says the government received only verbal evidence of a 'potential narrow, non-universal jailbreak.'
Anthropic has released Claude Fable 5, the first publicly available version of its Mythos model line. University of Pennsylvania AI researcher Ethan Mollick reports the model can execute multi-page specifications for up to 12 hours and generate complete video games from single prompts in Claude Code.
Anthropic has released Fable 5, making capabilities from its previously restricted Mythos model available to the public. The company claims Fable 5 beats GPT-5.5, Gemini 3.1 Pro, and its own Opus 4.8 in internal testing, with pricing set at $10 per million input tokens and $50 per million output tokens after a free trial period ending June 22.
Anthropic has released Claude Fable 5, described as a 'Mythos-class' model that the company claims is safe for general use. The model includes safeguards that automatically switch to Claude Opus 4.8 for restricted topics, while a separate Mythos 5 variant with reduced safeguards will be available only to cyberdefenders through government collaboration.
Anthropic has released Claude Fable 5, its first publicly available Mythos-class model, at $10 per million input tokens and $50 per million output tokens—less than half the price of Claude Mythos Preview. The model includes safeguards that redirect sensitive queries to Claude Opus 4.8 in less than 5% of sessions.
Anthropic released Claude Fable 5, a Mythos-class model, to enterprise customers and paid subscribers two months after limiting its advanced Mythos model to select users. The new model costs $10 per million input tokens and $50 per million output tokens—twice the price of Claude Opus 4.8—and includes safeguards that block responses in high-risk areas like cybersecurity and biology.