Anthropic releases Claude 5.1 with 25% lower costs and zero data retention

eugeneyan · x · 2026-09-02

Anthropic launched Claude Fable 5.1 and Mythos 5.1, sharing the same model with differing safeguards. Fable 5.1 cuts costs by 25% for typical workloads (up to 45% for agentic flows) via cheaper cache reads. The new Enterprise Frontier Safeguards (EFS) enables customer-controlled data storage for zero retention, available immediately as a temporary policy. Safety features reduce cybersecurity false positives by 60%, while autonomous research performance on Terminal-Bench-Science 0.1 jumps from 25% to 53.6%.

Related event: Anthropic Releases Claude Fable 5.1 and Mythos 5.1 with Better Benchmarks and 75% Cheaper Caching(60 posts)→

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