
Anthropic pitched its new Claude Fable 5.1 and Mythos 5.1 release as a massive win for enterprise budgets. The headlines scream about a 75% cost reduction for cache reads. Executives see a $0.25 per million token rate and assume autonomous agents finally became cheap. This assumption creates a dangerous trap. The era of toy chatbots has ended. We now face long-running autonomous agents capable of consuming millions of tokens over hours-long runs. Cheap caching only masks the brutal truth. If you deploy these highly capable models without strict architectural boundaries, you invite financial and security chaos. The threat shifts from simple prompt engineering to system-level vulnerability. When an agent possesses the intelligence to rewrite its own environment, unchecked access transforms...








