MAI-Thinking-1

MAI-Thinking-1 is Microsoft AI's first in-house reasoning model: a 35B-active / ~1T-total sparse Mixture-of-Experts model trained from scratch without distillation from third-party models. Built with Microsoft's Hill-Climbing Machine pipeline on 30T tokens of clean licensed data, it goes toe-to-toe with Claude Opus 4.6 on SWE-Bench Pro and scores 97.0% on AIME 2025. Supports a 256K context window, function calling, and developer instructions.