Claude Opus 4.1

Claude Opus 4.1 is designed as a high-performance model focused on complex agentic tasks, real-world software engineering, and deep data analysis. It serves as an evolution of the Opus 4 architecture, specifically engineered to improve accuracy in multi-file code refactoring and bug resolution. By achieving a 74.5% score on the SWE-bench Verified benchmark, the model demonstrates a refined ability to pinpoint exact corrections within large codebases while minimizing unnecessary adjustments or the introduction of new errors. Its design intent centers on providing a reliable, detail-oriented assistant for professional developers and researchers who require high-fidelity output in technical workflows.

The model benefits from advancements in hybrid reasoning, allowing users to balance rapid response times with more deliberate, step-by-step thinking processes. Developers can leverage adjustable thinking budgets via the API to optimize performance and cost-efficiency for specific tasks. Beyond its coding capabilities, the model has been refined to excel in long-horizon, tool-assisted research, enabling it to synthesize information across diverse data sources with greater precision. As part of a broader development roadmap, this iteration maintains a consistent safety profile while providing a seamless upgrade path for existing users, positioning it as a robust solution for complex, multi-step agentic operations.