Claude Fable 5's system prompt leaked (twitter.com)

The system prompt for Claude Fable 5 has been leaked, revealing that this model is part of Anthropic's new Claude 5 family and classified as a Mythos-class model, which signifies improvements in its capabilities over previous versions. At approximately 120,000 characters, the prompt outlines the model's enhanced safety features designed to mitigate dual-use risks, making it the most advanced version widely available. Claude Fable 5 shares its underlying model with Claude Mythos 5, which lacks these safety measures and is accessible only to approved organizations. This leak is significant for the AI/ML community as it provides insight into Anthropic's approach to developing conversational AI with a focus on safety and user customization. The prompt emphasizes various features such as multi-model access, web search capabilities, and user personalization, highlighting the trend of making AI more user-friendly while balancing safety concerns. Furthermore, the clear restrictions on discussing harmful or sensitive topics suggest a commitment to ethical AI use, underscoring the ongoing dialogue around the responsibilities of AI developers in ensuring their technologies do not enable malicious behaviors.