It's very easy to get lost in the world of AI developments. What were once mighty AI models not intended for general use are now being rolled out for everyone to use on a daily basis. And there are no signs of development slowing down any time soon.

You may have heard of Claude Mythos, a powerful LLM that wasn't meant to be used by regular users. Due to its focus on cyber security, giving everyone the keys to this mighty AI would have been detrimental. However, it was still functionality superior to other models. Now, Anthropic has revealed Claude Fable 5, a Mythos-class model designed for general use.

Claude Fable 5 delivers Mythos-grade AI at no additional cost

But only for a short time

Over on the Anthropic blog, the company has revealed the general use of Claude Fable 5. This model is designed to be a version of its mighty Mythos model but without the same cyber security focus. That way, people can take advantage of the smartest LLM Anthropic has without handing over the controls to people who will use it for evil.

Of course, just because Fable 5 isn't designed for cyber security purposes, doesn't mean bad actors won't try using it to develop malware anyway. Fortunately, Anthropic thought of this:

We’ve therefore launched the model with safeguards that mean queries on some topics will instead receive a response from our next-most-capable model, Claude Opus 4.8. To release the model both safely and quickly, we’ve tuned these safeguards conservatively—they’ll sometimes catch harmless requests, though they trigger, on average, in less than 5% of sessions.

Here's the good news: Anthropic has made Claude Fable 5 available for Pro, Max, Team, and seat-based Enterprise plans at no extra cost. The bad news is that it'll go away again on June 23rd and require usage credits to continue use, so get your testing in now. If things look up in the future, Anthropic says it will re-add Fable 5 to the paid plans at no additional cost.