Claude Fable 5.2 and Mythos 5.2

Claude Fable 5.2 and Mythos 5.2 are Anthropic's upgraded frontier models built for the most demanding technical work. Key capabilities: • Stronger coding, reasoning, and vision performance • Outputs up to 30% faster than Claude 5.1 models • Lower pricing at $8 per million input tokens and $40 per million output tokens • Fable 5.2 scores 49.1% on FrontierCode 2.0, up from 32.4% • Available through the claude-fable-5-2 API ID. Fable and Mythos are the same underlying model. Fable includes strong cybersecurity and biology safeguards and is open to all users. Mythos, which omits some of those safeguards, is offered to vetted organizations. Cybersecurity and biomedical research groups can apply for Mythos access through Anthropic's Life Sciences and Cyber Verification Programs. During prerelease testing, the models helped engineers complete software migrations that were previously infeasible, design three working electronic devices from scratch, contribute to two open problems in black hole physics, and formalize the proof of Fermat's Last Theorem in 30 hours. Testers report that Fable 5.2 and Mythos 5.2 communicate more clearly than earlier versions. Faster generation and lower token prices make them practical for high-volume development and research workloads, while the benchmark gains indicate stronger performance on complex programming tasks. Improvements in vision and reasoning extend their usefulness to multi-step analysis. These models suit software engineers, researchers, financial analysts, and scientists who need reliable help with difficult coding, modeling, and analytical tasks. Developers can use them for large-scale code migrations and complex software builds. Research teams can apply them to physics, engineering, and life sciences problems. Security and biomedical organizations with verified access can use Mythos for specialized work.