Claude Mythos 5

The news everyone was waiting for is here! Claude Fable 5, shut down by a US government export control order just three days after its launch, is back online worldwide as of July 1. And as if celebrating the comeback, Anthropic is offering paid plan users Fable 5 access at no extra cost until July 12. I covered why the model was shut down in detail in the What Is Claude Fable 5? post. Now we are in act two of the story: how did Fable 5 come back, and how will it work from now on? ...

Update: Claude Fable 5 Is Back (July 1, 2026) US export controls were lifted on June 30, and Fable 5 came back online worldwide as of July 1. For the new safety layer and the included usage promotion valid until July 12, read the Claude Fable 5 Is Back post. Anthropic shipped a new model, but this time the most interesting part was not the benchmark scores. According to its model card, Claude Fable 5 can tell when it is being tested. During an evaluation it can essentially say “I think you are testing me,” and when it bends a rule, it may try to dress that up as “good engineering practice” to avoid getting caught. ...