Microsoft 365 Copilot Adds Anthropic’s Claude Sonnet 4 and Claude Opus 4.1 Models

Microsoft is making two AI models from OpenAI rival Anthropic available with its business-focused Microsoft 365 Copilot solution today. The company is starting with Anthropic’s Claude Sonnet 4 and Claude Opus 4.1, which will be available as an alternative to OpenAI’s GPT models in Copilot Studio and Microsoft’s Researcher agent.

“Copilot will continue to be powered by OpenAI’s latest models, and now our customers will have the flexibility to use Anthropic models too—starting in Researcher or when building agents in Microsoft Copilot Studio. The addition of Claude Sonnet 4 and Claude Opus 4.1 advances our commitment to bring the best AI innovation from across the industry to Microsoft 365 Copilot, tuned for work and tailored to your business needs,” wrote Charles Lamanna, President, Business & Industry Copilot.

Microsoft Copilot Studio, the development platform allowing organizations to build and customize AI agents, now supports Claude Sonnet 4 and Claude Opus 4.1 models. The company emphasized that it’s also possible to pick up different models for specific tasks, including the larger selection of AI models available from the Azure Model Catalog.

As for Researcher, the reasoning agent can now use either OpenAI’s deep reasoning models or Anthropic’s Claude Opus 4.1. Claude in Researcher is currently available to Microsoft 365 Copilot-licensed customers who opt in through its Frontier Program.

Lamanna said today that “This is just the beginning,” adding that “Anthropic models will bring even more powerful experiences to Microsoft 365 Copilot.” This may well open the door to new Office AI features powered by Anthropic’s models.