On November 18, 2025, Microsoft and Anthropic announced an expansion of their partnership: Claude Sonnet 4.5, Haiku 4.5 and Opus 4.1 are now available in public preview through Microsoft Foundry. The integration enables Azure customers to build production applications and enterprise agents using Claude while remaining inside the Microsoft ecosystem.
Where and how Claude is offered
The Claude models are available in Microsoft Foundry via serverless deployment, which allows developers to scale while Anthropic manages the infrastructure. The rollout begins with the Global Standard deployment available immediately in public preview, with the US DataZone coming soon. Customers can deploy Claude Sonnet 4.5, Claude Haiku 4.5 or Claude Opus 4.1 from the Microsoft Foundry catalog.
Why this matters for enterprises
According to the announcement, these integrations remove a common barrier for enterprises: the need to negotiate separate vendor contracts and billing systems when adopting new AI capabilities, a process that can add weeks or months to procurement. Instead, Claude can be used under existing Azure agreements and billing.
Developer and deployment details
Through the Foundry integration, developers gain:
- Immediate start: deploy Claude through Foundry's APIs, tools and workflows.
- Use of existing Azure agreements: Claude is eligible for the Microsoft Azure Consumption Commitment (MACC) and works with current Azure agreements and billing, avoiding separate vendor approvals.
- Language SDKs and authentication: Claude is accessible via Python, TypeScript and C# SDKs with Microsoft Entra authentication.
The models are offered under the Foundry Global Standard deployment with standard API pricing; the announcement refers readers to the pricing page and documentation for further details.
Which model for which use case
Microsoft customers can choose among Claude's frontier models in Foundry:
- Claude Sonnet 4.5: presented as the best model for coding and the strongest option for building complex agents. Recommended for state-of-the-art reasoning, multi-step agentic workflows and autonomous coding tasks.
- Claude Haiku 4.5: the fastest model, offering near-frontier performance at roughly one-third the cost of Sonnet. Suited for high-volume applications such as sub-agents, customer support automation, content moderation, or real-time coding assistance where speed and cost efficiency matter.
- Claude Opus 4.1: positioned for specialized reasoning tasks that require sustained focus and rigorous attention to detail, appropriate for complex, multi-step problems.
All models support a range of Claude Developer Platform features in Foundry, including the code execution tool, web search and fetch, citations, vision capabilities, tool use, prompt caching and more. The documentation lists additional supported features.
Integrations with Microsoft 365 Copilot
The announcement also notes existing Claude integrations in Microsoft 365 Copilot: Claude powers the Researcher agent for complex, multi-step research, and enables custom agent development in Copilot Studio. Additionally, Microsoft’s Agent Mode in Excel now includes an option in preview to use Claude to build and edit spreadsheets directly in Excel — generating formulas, analyzing data, identifying errors and iterating on solutions inside a workbook.
Getting started
Claude is available now in public preview through Microsoft Foundry. Deployments and technical guidance are available via the Microsoft Foundry catalog and Anthropic’s documentation.
Brief summary
The expanded collaboration between Microsoft and Anthropic brings Claude Sonnet 4.5, Haiku 4.5 and Opus 4.1 into Microsoft Foundry in public preview and extends Claude use within Microsoft 365 Copilot features such as the Researcher agent and Excel Agent Mode. The integration aims to simplify procurement by using existing Azure billing and agreements and provides SDKs and serverless deployment options for developers.
