o3 Pro

o3-pro focuses on correctness and step-by-step reasoning rather than flashy prose. It can absorb long prompts with documents, code, and prior chat state, then plan, call tools, verify intermediate results, and return well-structured answers. The model follows instructions tightly, produces deterministic JSON when you need schema-bound output, and integrates smoothly with retrieval so claims can be grounded in your own data. For software tasks it traces dependencies across files, explains its approach, and iterates on fixes; for analytics it decomposes questions, cites the relevant evidence you provide, and summarizes outcomes in business-ready language. Streaming keeps interactions responsive, and the same interface supports agents that orchestrate multiple tools or sub-tasks. In practice, teams pair o3-pro with a faster sibling for routine queries and reserve it for moments when accuracy and careful reasoning matter most.