The Fable Five Test: How To Decide If Anthropic's New Claude Fable 5 Belongs In Your Stack, Or Why The 2x Price Tag Is The Smartest Move They Have Ever Made

Stephen Diaz

Published on: 10/06/2026

Anthropic released Claude Fable 5 on June 9 as the first publicly available Mythos-class model at $10/$50 per million tokens (2x Opus 4.8), with 53% on Humanity's Last Exam, GDPval Elo 1932, mandatory 30-day data retention, and free in subscription plans only through June 22. Run The Fable Five Test on your stack this week.