Claude Fable 5: The first Mythos model is powerful, expensive, and heavily filtered

In three linesAnthropic releases Claude Fable 5, first Mythos-class model. Leads benchmarks (SWE-bench Verified 95%), but costs 2× more than Opus 4.8 (10-50$/M tokens). Strict safety filters block 9% of requests; mandatory 30-day data retention policy.

Summary generated by Claude — human-verified