Anthropic Unleashes Claude Fable 5 - The Most Powerful AI Ever Released to the Public!
Anthropic launched Claude Fable 5, the first publicly available Mythos-class AI model. It sets new records in software engineering, knowledge work, and scientific research, with built-in safeguards that block high-risk queries in cybersecurity, biology, and chemistry.
The AI race just hit another gear. Anthropic on Tuesday released Claude Fable 5, the most capable AI model the company has ever made available to the public. Built on the same technology tier as its restricted Mythos models, Fable 5 brings frontier-level intelligence to everyday users with strict safety limits attached.
What Makes Fable 5 Different
Fable 5 is the first publicly accessible model in Anthropic's Mythos class, a tier that sent shockwaves through the cybersecurity world earlier this year for its superhuman ability to find and exploit software vulnerabilities. The model is state-of-the-art on nearly all tested benchmarks, excelling in software engineering, knowledge work, vision, and scientific research. The longer and more complex the task, the bigger its lead over previous models.
The real-world results are striking. During testing, payment giant Stripe reportedly used Fable 5 to complete a codebase-wide migration across 50 million lines of code in a single day. The company estimated the same task would have taken over two months of manual engineering work.
Safety First Approach
Releasing a model this powerful comes with serious risks, and Anthropic built guardrails accordingly. Queries in high-risk areas like cybersecurity, biology, chemistry, and model distillation are automatically blocked and rerouted to the less capable Claude Opus 4.8. Anthropic says these fallbacks trigger in fewer than 5% of sessions, meaning most users get the full Mythos-class experience.
Benchmarks
Pricing and Availability
Fable 5 is available now through the Claude API and enterprise plans. Through June 22, it's included in Pro, Max, Team, and Enterprise subscriptions at no extra cost. Starting June 23, the model will require usage credits, with Anthropic planning to restore it as a standard subscription feature once capacity allows.
Alongside Fable 5, approved organizations gain access to Mythos 5, an upgraded version of the restricted model that reportedly shattered performance records in drug design and molecular biology.
The Bigger Picture
The launch comes at a pivotal moment, as Anthropic prepares to enter the public markets and just days after the company urged global AI labs to coordinate a "brake pedal" on frontier AI development, warning that systems may soon achieve recursive self-improvement.
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