Overview
Bloomberg-origin reporting (July 2026): microsoft routes tens of thousands of weekly Excel and Outlook AI prompts through in-house MAI models instead of openai / anthropic, as a cost-reduction strategy. MAI remains a small share of overall usage.
Key Facts
- Scope: selected high-volume Excel/Outlook prompts (summaries, formulas, short replies)
- Complex reasoning still on third-party models
- Mustafa Suleyman (June): goal to reduce and ultimately eliminate Anthropic costs
- MAI also in github-copilot; Teams transcription model planned
- Users cannot currently see which model served a Copilot task
Directional cost strategy — not a full OpenAI partnership exit.
Related
- microsoft
- mai-thinking-1
- openai
- anthropic
- microsoft-copilot
- github-copilot
- vendor-lock-in
- llm-pricing