This is the weirdest situation in which to write a capabilities review.
Claude Mythos #3: Capabilities and Additions
To round out coverage of Mythos, today covers capabilities other than cyber, and anything else additional not covered by the first two posts, including new reactions and details.
Claude Fable 5 and Claude Mythos 5
Today we’re launching Claude Fable 5: a Mythos-class model that we’ve made safe for general use.
Claude Fable 5.1 and Mythos 5.1: The System Card
At the time of its release Claude Fable 5.1 was, by a healthy margin, the most capable publicly available AI model in the world.
Claude Fable 5 and Mythos 5: Capabilities
Only three days after the release of Claude Fable 5, Anthropic was forced by the United States Government to make it unavailable, when a jailbreak was brought to its attention, rather than the previous situation of ‘yes obviously experts can jailbreak anything if they care enough’ and ‘yes obviously you can ask Fable to fix your code.’
Claude Fable 5 and Mythos 5: The System Card
First things first: Claude Fable 5 is the new best publicly available model.
Anthropic releases Claude Fable, a version of Mythos, days after warning AI is becoming too dangerous
Anthropic is releasing Claude Fable 5, its first Mythos-class model available to the public. The model comes with guardrails that block responses in high-risk areas like cybersecurity and biology.
How good is Mythos?
Is Claude Mythos Preview a particularly big jump in AI capabilities?
Anthropic disables access to Fable 5 and Mythos 5 to comply with government directive
Anthropic said it disabled access to its Fable 5 and Mythos 5 models to comply with an export control directive from the U.S. government.
Three Labs With a Plan and A Memorandum
The big story today is the release of Claude Fable 5, the version of Claude Mythos that Anthropic believes they can safely distribute to the people.
Claude Opus 5 Is Highly Capable, But Is No Mythos
Claude Opus 5 is a weirder than usual release to evaluate, for two reasons.
Claude Mythos Preview \ red.anthropic.com
Earlier today we announced Claude Mythos Preview, a new general-purpose language model. This model performs strongly across the board, but it is strikingly capable at computer security tasks. In response, we have launched Project Glasswing, an effort to use Mythos Preview to help secure the world’s most critical software, and to prepare the industry for the practices we all will need to adopt to keep ahead of cyberattackers.
Introducing Claude Fable 5.1 on AWS | Amazon Web Services
Claude Fable 5.1 is now available on Amazon Bedrock and Claude Platform on AWS. This post covers Claude Fable 5.1's improvements, the Enterprise Frontier Safeguards for keeping your data in a cloud environment you control, and how to start building with the model on Amazon Bedrock.
Redeploying Claude Fable 5
Anthropic is redeploying Claude Fable 5 starting July 1 following the lifting of export controls, with updated cybersecurity safeguards and a new industry jailbreak framework.
Introducing Claude Fable 5.1 and Claude Mythos 5.1
Our most advanced models for coding and knowledge work. Their research capabilities also offer an early glimpse of how AI models will contribute to scientific progress.
