Claude Opus 4.1, released on August 5, 2025, is an upgrade to the previous Claude Opus 4 model, focusing on improvements in agentic tasks, real-world coding, and reasoning capabilities. Available to paid users via Claude Code, API, Amazon Bedrock, and Google Cloud's Vertex AI at the same price as its predecessor, Opus 4.1 achieves a 74.5% performance on the SWE-bench Verified and enhances research and data analysis skills, particularly in detail tracking and agentic search. Notably, GitHub highlights improvements in multi-file code refactoring, while Rakuten Group appreciates its precision in debugging large codebases without introducing errors. Windsurf reports a significant performance increase, comparable to previous model upgrades, on a junior developer benchmark. Users are encouraged to upgrade and provide feedback as the developers continue to enhance the model, with further substantial improvements anticipated in the coming weeks.