Anthropic has launched a public version of its Mythos AI model called Claude Fable 5. This version comes with security guardrails in place to block its use in sensitive areas such as cybersecurity.
The AI player stated its Claude Fable 5 model is its most powerful to date on its launch on the 9th June 2026, which is two months after Anthropic first unveiled its Mythos-class model.
The limited Mythos preview sent shockwaves through the industry after the model uncovered thousands of software vulnerabilities.
Recently Anthropic expanded the reach of its Mythos AI model to an additional 150 companies across more than 15 countries.
The startup describes Fable 5 as state-of-the-art on nearly all tested benchmarks of AI capability, claiming exceptional performance across software engineering, knowledge work, vision and scientific research. The longer and more complex the task, Anthropic stated, the larger Fable 5’s lead over its other models.
Anthropic stated it has done extensive testing to ensure users cannot manipulate Fable 5 into bypassing its guidelines. Queries on restricted topics will instead receive a response from the company’s Claude Opus 4.8 model.
The AI player acknowledged the safeguards are tuned conservatively and will sometimes catch harmless requests but said they trigger on average in fewer than 5% of sessions. “With more capable models arriving in the coming months, we’re working to improve our safeguards and reduce false positives as quickly as we can”, Anthropic stated.
For a smaller group of cyber defenders and infrastructure providers, Anthropic is simultaneously launching Claude Mythos 5, which is the same underlying model as Fable 5 but with safeguards lifted in some areas.
Mythos 5 will initially be deployed through Project Glasswing in collaboration with the US government. It carries what Anthropic described as the strongest cybersecurity capabilities of any model in the world.
Users who had access to the Claude Mythos Preview will be able to upgrade to Mythos 5, with broader access planned through an expanded trusted-access programme.
Fable 5 and Mythos 5 are priced at $10 per million input tokens and $50 per million output tokens, less than half the price of Claude Mythos Preview.
The rollout comes as Anthropic, now valued at $965 billion, looks to extend the momentum which has pushed its valuation above rival OpenAI, with both startups racing toward public listings.
Source: Mobile World Live
Image Credit: Anthropic
