Microsoft Adds Anthropic Claude Models to 365 Copilot, Moving Beyond OpenAI

Microsoft on Wednesday announced that it has expanded the range of models available in Microsoft 365 Copilot, adding Anthropic’s Claude Sonnet 4 and Claude Opus 4.1 alongside the existing OpenAI options.

Organisations can enable access through the Microsoft 365 admin center. The company said customers will now be able to choose between OpenAI and Anthropic models when using Copilot’s Researcher agent or building agents in Microsoft Copilot Studio.

“Our first-of-its-kind reasoning agent can now be powered by either OpenAI’s deep reasoning models or Anthropic’s Claude Opus 4.1,” said Charles Lamanna, President, Business & Industry Copilot, in a company statement. “Whether you’re building a detailed go-to-market strategy, analysing product trends, or creating a quarterly report, you can now select your preferred model to power in-depth work.”

In Copilot Studio, users will be able to build, orchestrate, and manage agents using Anthropic models for reasoning, workflow automation, and other agentic tasks. A drop-down menu will allow switching between models from Anthropic, OpenAI, or the Azure Model Catalog without leaving the platform.

Claude in Researcher is rolling out through Microsoft’s Frontier Program to Copilot-licensed customers who opt in. Anthropic models will be hosted outside Microsoft-managed environments and subject to Anthropic’s terms and conditions.

“This is just the beginning—we’re committed to delivering model innovation at speed to empower every person with Microsoft 365 Copilot and transform business processes with agents,” Lamanna said.

The addition of Anthropic models comes as Microsoft seeks to be less dependent on OpenAI. Alongside adding large language models from more providers, Microsoft has begun testing its in-house model, MAI-1-preview.

Meanwhile, on September 11, OpenAI announced in a blog post that its nonprofit arm will now be paired with an equity stake in its Public Benefit Corporation (PBC), a valuation expected to exceed $100 billion. The company also said it has reached a Memorandum of Understanding (MoU) with Microsoft to convert its for-profit arm into a PBC, a structural shift first announced in May.

Microsoft has been a major backer of OpenAI over the past few years and has invested over $13 billion since 2019. 

Initially, the deal granted Microsoft exclusive rights to power OpenAI’s tools through its cloud platform Azure, but these restrictions have relaxed over the past few months. OpenAI is now expanding its infrastructure and cloud partnerships to include Oracle, Google, and others, breaking away from sole Azure reliance.

OpenAI recently revealed plans to spend $300 billion on projects with Oracle. This week, NVIDIA announced it will invest up to $100 billion in OpenAI as part of a joint initiative to develop hundreds of billions of dollars’ worth of new data centers.