On September 2, Anthropic made an official announcement regarding the launch of Claude Fable 5.1 and Claude Mythos 5.1. These two models are positioned as frontrunners in the global arena of coding and knowledge-based work. Claude Fable 5.1 is now accessible to all users, whereas Claude Mythos 5.1 is specifically available to the cybersecurity and life sciences sectors via a trusted access program. Notably, the cache read price for Claude Fable 5.1 has been slashed by 75%. When compared to its predecessor, Fable 5, the typical workload costs for Fable 5.1 have dropped by around 25%, with reductions reaching up to 45% for tasks involving high-agent involvement. The model achieved a score of 52.6% on the Terminal-Bench Science benchmark, showcasing its research prowess in fields like molecular design and Venus terrain modeling. Moreover, Anthropic also rolled out an enterprise-grade security mechanism that adheres to a zero-data retention policy. This ensures that data is stored within the customer's own cloud infrastructure, thereby guaranteeing utmost privacy and security.