As AI models get more powerful, there’s also going to be a level of danger. Anthropic announced Mythos not long ago as a model that was too dangerous for public availability, but a new version of that, Claude Fable 5, is now available and, apparently, “safe for general use.”
In a post today, Anthropic explains that Claude Fable 5 is a “Mythos-class” model that’s available for public use and exceeds the capabilities of any other generally available AI model Anthropic has ever published.
Fable 5’s capabilities exceed those of any model we’ve ever made generally available. It is state-of-the-art on nearly all tested benchmarks of AI capability, showing exceptional performance in software engineering, knowledge work, vision, scientific research, and many other areas. The longer and more complex the task, the larger Fable 5’s lead over our other models.
The fear with Mythos was mainly around cybersecurity, as the model was quickly found to be able to find and use exploits in the digital world. With Fable, Anthropic says that safeguards are in place and that, if a topic comes up that Fable isn’t allowed to interact with, Claude Opus 4.8 will step into the conversation instead. Anthropic says it has tuned this “conservatively,” so it might trigger more often than you’d expect.
