Models
Anthropic launches Claude Fable 5.1 and Mythos 5.1
Anthropic launched Claude Fable 5.1 (generally available) and Mythos 5.1 (trusted-access only for cybersecurity and life sciences)—same underlying model, different safeguard tiers—aimed at coding, knowledge work, and agentic research. The company says typical token-billed workloads cost about 25% less than Fable 5 via cheaper cache reads, and up to about 45% less on highly agentic work. Enterprise Frontier Safeguards (customer-controlled storage plus misuse detection) rolls out later this fall; eligible customers keep zero data retention until then.