Microsoft announced MAI-Thinking-1, a 35B reasoning model available to select early partners, and MAI-Code-1-Flash, a 5B coding model rolling out to GitHub Copilot individual users in VS Code. Simon Willison highlights their relatively small parameter counts and Microsoft's claim that MAI-Thinking-1 was preferred to Sonnet 4.6 in internal blind evaluations. He also questions what Microsoft's clean and appropriately licensed training data claims mean in practice.
Microsoft announced several in-house AI models at Build 2026, including its new flagship reasoning model, MAI-Thinking-1. The launch marks a significant expansion of Microsoft's model-development efforts after it introduced its first internal models last year. Previously reliant on OpenAI models, Microsoft is building more independent capabilities as the companies loosen ties through a renegotiated agreement.