Introducing Claude Fable 5 and Claude Mythos 5 (opens in new tab)

Claude Fable 5 and Claude Mythos 5 capabilities, API changes, and availability. --- Claude Fable 5 is Anthropic's most capable widely released model, built for the most demanding reasoning and long-horizon agentic work. Claude Mythos 5 shares the same capabilities and is available only in limited release through Project Glasswing. The headline change for integrations: Claude Fable 5 includes safety classifiers that can decline requests. Claude Mythos 5 does not include these classifiers. I...