Enterprise AI
Microsoft Launches Copilot Cowork Powered by Anthropic’s Claude
Redmond’s new agentic AI for Microsoft 365 executes multi-step tasks across Office apps — and despite a multi-billion-dollar OpenAI partnership, it runs on Anthropic’s model.
Microsoft announced Copilot Cowork on Monday, an agentic AI system built into Microsoft 365 that can autonomously execute multi-step tasks across the entire Office suite — building PowerPoint presentations from raw data, pulling and formatting Excel analyses, scheduling meetings based on email context, and chaining these operations together without user intervention between steps. The product ships as part of the new $99-per-user-per-month Microsoft 365 E7 licensing tier, the company’s most expensive enterprise subscription ever.
The technical architecture is what makes this announcement extraordinary: despite Microsoft’s $13 billion investment in OpenAI and years of integrating GPT models across its product line, the company chose Anthropic’s Claude as the reasoning engine for its flagship agentic product. Microsoft described the collaboration as a “close partnership with Anthropic” focused on building agents that can operate safely within enterprise environments, suggesting that Claude’s constitutional AI approach and instruction-following reliability won out over GPT in Microsoft’s own internal evaluations for autonomous task execution.
The strategic implications extend far beyond a single product launch. Microsoft’s willingness to use a competitor’s model for its highest-value enterprise feature signals that the AI provider market is becoming genuinely multi-model — even for companies with deep exclusive partnerships. For Anthropic, landing the centerpiece feature of Microsoft’s enterprise stack validates the company’s commercial viability in a way no benchmark ever could. For OpenAI, it raises uncomfortable questions about why its largest investor and distribution partner looked elsewhere for the product that matters most.