On Monday, Anthropic announced Opus 4.5, the latest version of its flagship model. It’s the last of Anthropic’s 4.5 series of models to be released, following the launch of Sonnet 4.5 in September and Haiku 4.5 in October. As expected, the new version of Opus has state-of-the-art performance on a range of benchmarks, including coding benchmarks (SWE-Bench and Terminal-bench), tool use (tau2-bench and MCP Atlas) and general problem solving (ARC-AGI 2, GPQA Diamond). Notably, Opus 4.5 is the first...