Anthropic slashes Claude Fable 5.1 costs up to 45% with better coding and research

anthropic released claude fable 5.1 and mythos 5.1, its most capable ai models yet. fable 5.1 delivers stronger coding performance and better text quality, with cost savings of up to 45% on complex agentic workflows. it outperforms its predecessor fable 5 and rival gpt-5.6 sol on agentic benchmarks, with scores of 52.6% on terminal-bench-science 0.1 and 55.8% on terminal-bench 4.0. the new models feature built-in watermarks and a detection api for verification. fable 5.1 is broadly available, while mythos 5.1 is restricted to special access programs.