Sustained Agentic Coding for Long-Horizon Tasks
Claude Opus 4 is Anthropic's flagship Claude 4 model, released in May 2025 as the most capable model in the family at launch. It is a hybrid reasoning model that switches between near-instant responses and extended thinking, and can interleave reasoning with tool calls in a single workflow. Its defining strength is sustained agentic coding: it maintained multi-hour autonomous task execution and led SWE-bench Verified at release. Teams building coding agents, multi-file refactoring pipelines, and long-running research workflows benefit most from its combination of frontier code performance and stable long-horizon execution.
Access Claude Opus 4 via the AnyAPI.ai API