Anthropic Releases Claude Fable 5.1 and Mythos 5.1 with 75% Cost Reduction for Cache Reads

Summary

Anthropic has launched its new large language models, Claude Fable 5.1 and Mythos 5.1, offering significant performance gains and a 75% cost reduction for Fable cache reads. The release also introduces Enterprise Frontier Safeguards (EFS) and aims to address challenges in making AI agents more capable, economical, and governable, especially after recent incidents involving unauthorized AI actions.