Today we’re launching Claude Fable 5: a Mythos-class model that we’ve made safe for general use.
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.
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.
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.
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.
Claude Mythos 5.1 and Fable 5.1: Capabilities
This is the weirdest situation in which to write a capabilities review.
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.
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.
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 is relentlessly proactive
After two days of experience with Claude Fable 5 I think the best way to describe it is relentlessly proactive. It knows a whole lot of tricks and it will …
A field guide to Claude Fable 5: Finding your unknowns | Claude | Claude by Anthropic
Practical patterns for agentic coding with Claude Fable: how to find your unknowns before, during, and after implementation, from the team at Anthropic.
Anthropic’s Mythos 5 is back
Anthropic’s Mythos 5 model, the subject of weekslong negotiations with the Trump administration, is back in action. No word yet on Fable 5.
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 #2: Cybersecurity and Project Glasswing
Anthropic is not going to release its new most capable model, Claude Mythos, to the public any time soon.
How good is Mythos?
Is Claude Mythos Preview a particularly big jump in AI capabilities?
