
On June 9 Anthropic launched Fable 5 and Mythos 5. Three days later the US government ordered both pulled — citing a jailbreak. Here is what actually happened and what it means.

This is a Ristretto Post [Short and Intense]: Anthropic just released its most powerful publicly available model. Here’s what changed, what it can do and what it will do to your API bill. On June 9th, Anthropic quietly dropped something that wasn’t so quiet once people started using it. Claude Fable 5 is the…

This is a Macchiato Post [Dense with a Touch]: Anthropic’s Claude Mythos was never supposed to be public news. In late March 2026, an accidental data leak first revealed the model’s existence, describing it as a “step change” in AI performance. A few weeks later, on April 7, 2026, Anthropic made it official and…