Anthropic releases Fable 5.1 and Mythos 5.1 with lower costs and updated safeguards

Anthropic has introduced its latest artificial intelligence models, Claude Fable 5.1 and Mythos 5.1. The release aims to address recurring customer criticisms regarding operational costs, data retention policies, and overly restrictive safety guardrails.

Pricing and Performance Updates

The newly released Claude Fable 5.1 delivers stronger performance compared to its predecessor while reducing typical costs by roughly 25 percent. For complex agentic workflows, the price reduction can reach up to 45 percent, primarily due to lowered pricing structures for cached data that has already been processed and stored.

Early evaluations from enterprise users indicate notable improvements in coding capabilities and conversational tone. Additionally, testing suggests that Mythos 5.1 achieves comparable benchmark results at lower reasoning settings than previous iterations.