Pattern: Frontier Capability Is Now Shipped GA With Per-Query Safety Routing Instead of Being Withheld

Anthropic·medium signal

Fable 5 makes Mythos-class capability generally available but gates it behind classifiers that route flagged cyber/bio-chem/distillation prompts down to Opus 4.8, rather than withholding the model entirely. This 'capability-with-conditional-downgrade' design lets labs release more powerful models broadly while containing the riskiest query classes. Builders should expect inconsistent capability ceilings within a single model tier depending on prompt content, and design evals to detect silent routing.