Anthropic unveiled Claude Sonnet 5 on July 1, 2026, describing it as the company’s most agentic model to date. The model is capable of autonomously using tools like browsers and terminals while delivering near-Opus 4.8 performance at a significantly lower cost. The release coincided with the U.S. government lifting national security restrictions on Anthropic’s Fable 5 and Mythos 5 models, enabling broader deployment of these powerful systems.
