GoKawiilAnthropic co-founder and CEO Dario Amodei speaks on an artificial intelligence panel during Inbound 2025 Powered by HubSpot at Moscone Center on in San Francisco, Sept. 4, 2025.
Two months after Anthropic rolled out Mythos to a limited number of users, citing concerns about the artificial intelligence model's potential to do damage in the wrong hands, the company said it's ready to release an equally powerful model to the public.
Anthropic on Tuesday announced Claude Fable 5, a Mythos-class model that will be available to its enterprise customers and paid subscribers. The company said the broad release is possible because of new safeguards that block responses in specific high-risk areas, including cybersecurity and biology.
"For us, it's really around what we call 'race to the top,' being able to provide this technology in a valuable fashion, and at the same time providing the right safety guardrails so that it can do asymmetrically more benefits than harm," Dianne Penn, Anthropic's head of product management for research, told CNBC in an interview.
Anthropic captivated Wall Street and government officials in April with the unveiling of Mythos, which excels at identifying security flaws within software. The company said it did not plan to make the model generally available, and it has limited the rollout to a select group of companies as part of a cybersecurity initiative called Project Glasswing.
But with the launch of Claude Fable 5, Anthropic is honoring its stated "eventual goal" to deploy Mythos-class models at scale. It's also capitalizing on growing momentum and investor interest in its technology ahead of a potentially massive IPO, which is expected to take place as soon as this year.
Anthropic said Claude Fable 5 shows "exceptional performance" across software engineering and knowledge work tasks. On some benchmarks, it scored more than 10% higher than Claude Opus 4.8, another model the company announced late last month, according to a blog post.
Claude Fable 5 represents a "significant jump" in capability, which is why Anthropic had to implement additional guardrails to prevent misuse, Penn said. If a user asks a high-risk question, like how to make ricin, a toxin, for instance, the model will block its response and fall back to Claude Opus 4.8 to deliver a safe answer.