The release of the powerful models shows that enterprises need to be open to different AI systems and consider governance as part of choosing models.
July 1, 2026
On the same day it made its Fable 5 and Mythos models available to customers again, Anthropic released Claude Sonnet 5 as the most agentic Sonnet model yet.
The U.S. government lifted restrictions on the two models after it shut them down on June 12 due to national security concerns, following a report by Amazon researchers who found a method to bypass Fable 5’s safeguards.
Anthropic said to get Fable 5 restored as quickly as possible, it trained an improved safety classifier that targets and blocks the jailbreaking behavior that led the government to apply export control to the models. While Mythos 5 has been restored as of June 30, it is still only available to a limited number of users.
