Claude Fable 5: Anthropic's New Mythos-Class Model (Benchmarks, Pricing & What's New)
Anthropic's first publicly available Mythos-class model, released June 9, 2026. Third-party benchmarks, pricing, context window, availability, the safety reroute to Opus 4.8, and how it compares to GPT-5.5 and Gemini 3.5.