Anthropic launches new Claude Fable 5.2, Mythos 5.2 before IPO

Anthropic has unveiled two new artificial intelligence models, Claude Fable 5.2 and Claude Mythos 5.2. The San Francisco company is sharpening its position against rival OpenAI ahead of a planned initial public offering. Fable 5.2 targets coding, reasoning and AI agent tasks. Mythos 5.2 serves approved cybersecurity and life-sciences research.

Anthropic confirms that Mythos 5.2 stays restricted to organisations cleared through its verification programmes for cybersecurity and life-sciences work. Fable 5.2 reaches a far broader base of users, and developers can call it through the Claude API as claude-fable-5-2.

Anthropic quantifies the gain at up to 30 per cent faster output than the Claude 5.1 models. The company also reports improvements in coding, reasoning and vision, and says Fable 5.2 sets a new bar in coding, finance and the sciences.

Prices have been set much lower too. The company disclosed that the pricing stands at $8 per million input tokens and $40 per million output tokens. Those rates sit below the pricing of earlier Fable and Mythos releases.

The two models share the same underlying system but Fable 5.2 adds safety measures for biology and cybersecurity. A system card published alongside the launch details safety testing for both.

Mythos sits above Opus in Anthropic's lineup. The launch follows the October rollout of Claude Haiku 5.5, which joins Opus 5.5 and Sonnet 5.5 as the smaller tiers. Anthropic recommends both new models for the most ambitious, open-ended technical work.

The launch of the latest model upgrade comes on the eve of the company's IPO roadshow, where investors are weighing enterprise demand and valuation risks. The 5.2 upgrade has come five months after the first Fable and Mythos release.