Anthropic launches Claude Sonnet 4.5, its best AI model for coding

Anthropic launched Claude Sonnet 4.5 on Monday, claiming it delivers state-of-the-art coding performance that can build production-ready applications. The new AI model demonstrated remarkable capabilities during early trials, coding autonomously for up to 30 hours while building complete applications, setting up databases, purchasing domain names, and conducting security audits. This launch comes as competition heats up between Anthropic and OpenAI, with both companies rapidly releasing new models to maintain their edge in the AI coding market.