Anthropic announced Claude Fable 5, its most powerful widely available AI model, part of the Mythos class previously considered too dangerous for public release. The model features new safeguards that fall back to Opus 4.8 in high-risk areas.
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<p class="has-text-align-none">Anthropic just <a href="https://www.anthropic.com/news/claude-fable-5-mythos-5" data-type="link" data-id="https://www.anthropic.com/news/claude-fable-5-mythos-5">announced</a> Claude Fable 5, a new AI model it said is the most powerful model it has ever made widely available. </p>
<p class="has-text-align-none">According to the company, Fable 5 "shows exceptional performance in software engineering, knowledge work, and vision," with its lead over other models growing as tasks become longer and more complex.</p>
<p class="has-text-align-none">Fable 5 marks the first broad release from Anthropic's Mythos class of AI models, after the company said the family was so capable at cybersecurity tasks that it was <a href="https://www.theverge.com/ai-artificial-intelligence/917644/anthropic-claude-mythos-breach-humiliation">too dangerous to release publicly</a>. Anthropic said the release was "made possible by new safeguards that block responses in specific high-risk areas," with …</p>
<p><a href="https://www.theverge.com/news/946725/anthropic-releases-claude-fable-5-mythos">Read the full story at The Verge.</a></p>
# Anthropic releases its first Mythos-class model Claude Fable
Source: [https://www.theverge.com/news/946725/anthropic-releases-claude-fable-5-mythos](https://www.theverge.com/news/946725/anthropic-releases-claude-fable-5-mythos)
[](https://www.theverge.com/authors/robert-hart)
Robert Hart
is a London\-based reporter at*The Verge*covering all things AI and a Senior Tarbell Fellow\. Previously, he wrote about health, science and tech for*Forbes*\.
Anthropic just[announced](https://www.anthropic.com/news/claude-fable-5-mythos-5)Claude Fable 5, a new AI model it said is the most powerful model it has ever made widely available\.
According to the company, Fable 5 “shows exceptional performance in software engineering, knowledge work, and vision,” with its lead over other models growing as tasks become longer and more complex\.
Fable 5 marks the first broad release from Anthropic’s Mythos class of AI models, after the company said the family was so capable at cybersecurity tasks that it was[too dangerous to release publicly](https://www.theverge.com/ai-artificial-intelligence/917644/anthropic-claude-mythos-breach-humiliation)\. Anthropic said the release was “made possible by new safeguards that block responses in specific high\-risk areas,” with the system falling back to Claude Opus 4\.8 — a model it[praised](https://www.theverge.com/ai-artificial-intelligence/939094/anthropic-claude-4-8-opus-honesty-effort)for “honesty” when it launched last month\.
Anthropic singled out cybersecurity and biology as two domains where the safeguards may block responses, both areas widely considered sensitive topics for advanced AI systems\. The company said that in testing, 95 percent of Fable sessions ran entirely on Fable responses, without falling back to Opus 4\.8\.
The company is also releasing Claude Mythos 5, but provided few details on what that means\. In a blog, Anthropic said Mythos 5 is the same underlying model as Fable 5, “but with the safeguards lifted in some areas\.” For now, access appears limited to the steadily[expanding group of organizations granted access](https://www.theverge.com/ai-artificial-intelligence/941792/anthropic-claude-mythos-preview-expansion)to Claude Mythos Preview through Anthropic’s —[not entirely watertight](https://www.theverge.com/ai-artificial-intelligence/917644/anthropic-claude-mythos-breach-humiliation)— private[Project Glasswing initiative](https://www.theverge.com/ai-artificial-intelligence/908114/anthropic-project-glasswing-cybersecurity)\. Those users will be able to upgrade to Mythos 5, Anthropic said, adding that it plans to “expand access over time through a more systematic trusted\-access program\.”
Anthropic did not respond on the record to*The Verge*’s request for comment explaining how either model relates to Claude Mythos Preview or why the models are numbered “5” when there do not appear to be any previously released Mythos or Fable models\.
Pricing for both models is significantly higher than its former flagship model —[double](https://platform.claude.com/docs/en/about-claude/models/overview)rates for Claude Opus 4\.8, though it’s half what users pay for Mythos Preview — at $10 per million input tokens and $50 per million output tokens, Anthropic said\.
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- Robert Hart
Anthropic launched Claude Fable 5, a publicly accessible version of its powerful Mythos model, with safety guardrails that block responses in high-risk areas and fall back to a weaker model. The release follows Anthropic's warning about AI becoming too dangerous and its push for coordinated safety measures.
Anthropic launched Claude Fable 5, a state-of-the-art model with safety safeguards, along with Claude Mythos 5 for cyberdefense, both priced under previous models.
Anthropic releases its most powerful model, Claude Fable 5, which is of the mythical tier and introduces an automated safety review mechanism that redirects high-risk requests to Opus 4.8, balancing powerful capabilities with safety risks.
Anthropic is preparing to launch Mythos 1, a powerful AI model for cybersecurity, with preview labels appearing in Claude Code and Claude Security. The model, initially restricted, may see broader release once safeguards are in place, and a new security dashboard is being developed.
Claude Fable 5 and Claude Mythos 5 have been released by Anthropic, offering a 1 million token context window and doubled pricing compared to Opus 4.8. Fable 5 includes strict safety guardrails, while Mythos 5 lacks them. Initial impressions describe it as a powerful and capable model.