Anthropic has launched a new version of its AI model, with some outlets reporting it as Claude Sonnet 4.5 and others as Claude Sonnet 4.6 or even Claude Sonnet 5. The new model is said to feature improved coding capabilities and is described as a state-of-the-art tool. There is also mention of a comparison with other models, including Opus, in terms of agentic coding benchmarks and cost-performance tradeoffs.