Anthropic unveils Claude Fable 5.2 and Mythos 5.2 AI models

Anthropic has introduced Claude Fable 5.2 and Mythos 5.2, upgraded AI models designed for coding, cybersecurity, mathematics and scientific research. The company also outlined their capabilities, pricing and access restrictions, amid reports of preparations for a potential IPO.

New Delhi: Artificial intelligence (AI) giant Anthropic has launched two upgraded models, Claude Fable 5.2 and Claude Mythos 5.2, to advance coding, mathematics, cybersecurity, robotics and scientific research, with capabilities designed to handle complex technical tasks autonomously for extended periods.

Anthropic said Claude Fable and Claude Mythos are based on the same underlying model.

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“Fable has strong cybersecurity and biology safeguards to guard against misuse, which allows us to make it available to all users. Organisations pursuing beneficial applications in cybersecurity or biomedical research can apply for access to Mythos through our recently expanded Life Sciences and Cyber Verification Programs,” the statement said.

Fable 5.2 is designed for general users, including availability through cloud platforms such as Amazon Bedrock. Mythos 5.2 offers greater access to advanced capabilities involving vulnerability discovery and sensitive scientific research, resulting in tighter access controls.

Autonomous AI operations have improved, with the models capable of working independently for hours or days, coordinating multiple AI agents and managing complex software projects.

Anthropic mentioned progress in the mathematical reasoning capabilities of its models, including a case of formalising a proof of Fermat’s Last Theorem using nearly 1,000 AI agents within 30 hours, with limited human intervention.

The models also reportedly designed three functioning electronic devices, improved performance in simulated robotics tasks and contributed to research that addressed previously unresolved theoretical physics problems related to black holes.

For both models, Anthropic has set standard pricing at $8 per million input tokens and $40 per million output tokens.

“Fable 5.2 and Mythos 5.2 also come with an optional fast mode, which speeds up token generation by up to 2.5 times. Fast mode is available for $16 per million input tokens and $80 per million output tokens,” the statement noted.

Anthropic is likely to formally start marketing its IPO from November 10, 2026, according to multiple reports, and the offering size could be as large as SpaceX’s record debut.

The reports mentioned potential investors eyeing a valuation of $1.1 trillion to $1.3 trillion, down from the $1.5 trillion to $2 trillion range discussed earlier this month.

Anthropic has filed for an initial public offering in the US, with preparations to list on the Nasdaq under the symbol “ANT”.

The San Francisco-based company’s revenue reached $16.3 billion in the six months ended June 30, 2026.