Anthropic releases Claude Fable 5.2 and Mythos 5.2, faster and 20% cheaper than the 5.1 versions

Anthropic has released Claude Fable 5.2 and Claude Mythos 5.2, new versions of its most powerful models. The company says they improve on coding, reasoning and vision. The two are the same underlying model. Fable has strong cybersecurity and biology safeguards and is available to all users. Organizations doing beneficial cybersecurity or biomedical work can apply for Mythos through Anthropic's Life Sciences and Cyber Verification Programs. Anthropic says the models produce output up to 30% faster than the 5.1 versions. Fable 5.2 costs $8 per million input tokens and $40 per million output tokens. TNW, citing Bloomberg, says Fable 5.1 cost $10 and $50, so both prices fall by 20%. An optional fast mode generates tokens up to 2.5 times faster and costs $16 and $80. Anthropic says that in prerelease testing the models helped its engineers finish software migrations that would otherwise not have been feasible, designed three working electronic devices from scratch, and solved two open problems in black hole physics. It also says a team of 1,000 Fable 5.2 agents formalized the proof of Fermat's Last Theorem in 30 hours. These are the company's own claims. Anthropic says Claude now writes over 90% of the changes merged into its core codebase, with human guidance. For most coding and knowledge tasks, it still tells users to start with Claude Opus 5.5. The launch comes as Anthropic gets close to its stock market listing.