Microsoft is replacing OpenAI and Anthropic models with its own in-house MAI models in Excel and Outlook, according to Bloomberg, with tens of thousands of AI prompts in those apps now handled weekly by MAI instead of the outside labs. Cost is the driver, with AI model chief Mustafa Suleyman saying in June that Microsoft's goal is to ‘reduce and ultimately eliminate' what it pays Anthropic. Microsoft rolled out seven new AI models at its June Build conference, including one it says matches the coding ability of Anthropic's Opus 4.6 at a lower cost. MAI still accounts for a small share of Microsoft's AI usage, but the shift eases its reliance on OpenAI and Anthropic as the discounted access it enjoys, including through its OpenAI partnership, won't last indefinitely.
