Anthropic Releases Claude Fable 5.1 and Mythos 5.1 AI Models, Cuts Cache Read Costs
AI company Anthropic has released its latest large language models, Claude Fable 5.1 and Mythos 5.1. The company simultaneously reduced the cost of cache reads by 75%.
AI company Anthropic has launched its newest large language models, Claude Fable 5.1 and Claude Mythos 5.1. Fable 5.1 is the generally available version, while Mythos 5.1 is for select cybersecurity and life sciences organizations. A key change for enterprise users is a 75% reduction in the cost of reading cached data.
The release follows recent disclosures by Anthropic regarding security incidents involving earlier Claude models. The company has since enhanced its safety measures and resumed external evaluations.
Fable 5.1 is positioned to handle complex, sustained tasks, with Anthropic reporting performance gains over previous models like Fable 5 and Opus 5. Reported improvements span coding, scientific research, and business workflow automation.
The cost reduction specifically impacts sustained agentic workloads where models frequently access stored context. This new pricing model aims to make Fable 5.1 more economical for businesses utilizing AI in long-running agent applications.