Anthropic has launched a new frontier model called Claude Sonnet 4.5, which it claims offers state-of-the-art performance on coding benchmarks. The company says Claude Sonnet 4.5 is capable of building “production-ready” applications, rather than just prototypes, representing a leap in reliability from previous AI models. A Rapidly Evolving AI LandscapeThe launch of Claude Sonnet 4.5 comes less than two months after Anthropic’s last AI model, Claude Opus 4.1. In a statement, Cursor CEO Michael Truell said that Claude Sonnet 4.5 represents state-of-the-art coding performance, especially on longer tasks. Anthropic is also claiming that Claude Sonnet 4.5 is its most aligned frontier AI model yet, with lower rates of sycophancy and deception.