Microsoft and Anthropic have announced an expanded partnership that integrates Anthropic’s Claude models—Sonnet 4.5, Haiku 4.5, and Opus 4.1—into Microsoft Foundry and Microsoft 365 Copilot. The models are now available in public preview, allowing Azure customers to build production applications and enterprise agents using Claude within Microsoft’s infrastructure. This integration simplifies procurement by aligning with existing Azure agreements and billing systems, eliminating the need for separate vendor contracts. Developers can deploy Claude through Foundry’s APIs and SDKs in Python, TypeScript, and C#, using Microsoft Entra authentication. In Microsoft 365 Copilot, Claude powers the Researcher agent and is now available in Excel’s Agent Mode to assist with data analysis, formula generation, and error detection. The rollout begins globally with a U.S. DataZone coming soon, offering scalable, serverless deployment and access to Claude’s full suite of developer tools and capabilities.