By Kashmira Konduparty
AI firm Anthropic has launched a public version of its highly anticipated Mythos AI model, making the technology available to a broader audience after months of restricting access due to cybersecurity concerns.
The public release is called “Claude Fable 5” and includes safety guardrails designed to prevent misuse while still offering many of the advanced capabilities that made Mythos one of the industry’s most closely watched AI systems.
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Claude Fable 5 is Anthropic’s first publicly available “Mythos-class” AI model, The Wall Street Journal reported. The model is designed to excel in software engineering, complex reasoning, analytics, scientific research and long-duration tasks. Anthropic describes it as its most powerful AI model available to general users.
Anthropic previously declined to release Mythos publicly after internal testing showed exceptional cybersecurity capabilities. The model demonstrated an ability to identify software vulnerabilities and security weaknesses at a level that raised concerns among governments, financial institutions and cybersecurity experts. Earlier versions were made available only to a limited group of vetted organizations through Anthropic’s Glasswing program.
To enable a broader rollout, Anthropic build safeguards into Fable 5. When users submit certain high-risk cybersecurity or biosecurity-related requests, the system automatically redirects those queries to the less capable Claude Opus 4.8 model. Anthropic said the measures were designed to prevent the model from being used for harmful purposes while preserving its usefulness for everyday applications.
Alongside Fable 5, Anthropic continues to offer “Claude Mythos 5,” a less restricted version available only to trusted organizations. Access remains limited to selected cybersecurity, infrastructure and research partners participating in the company’s controlled-access programs. Around 200 organizations are reported to have access to Mythos-level capabilities.
The launch reflects a broader challenge facing AI developers; balancing innovation with safety. Companies are under increasing pressure to commercialize powerful AI systems while addressing concerns about misuse, cybersecurity and national security. Anthropic’s approach is being closely watched as a potential model for future releases of frontier AI systems.
READ: Anthropic nears $1 trillion valuation ahead of possible IPO (May 29, 2026)
The release comes as Anthropic continues to expand rapidly in the competitive AI market. The company recently filed for an IPO and has emerged as one of the leading competitors to OpenAI, backed by major investments from Amazon and Google. Claude Fable 5 is expected to play a central role in the company’s next phase of growth.
With this release Anthropic is attempting to widen access to advanced AI while limiting the risks that originally kept the model behind restricted-access programs. The rollout marks one of the most significant public releases of a frontier AI system this year and highlights the industry’s continuing debate over capability versus safety.