Microsoft Partners with Anthropic to Launch Powerful C# SDK for AI Tools!

Microsoft Partners with Anthropic: Microsoft and Anthropic have joined forces to unveil an official C# SDK for the Model Context Protocol (MCP)—a major step forward in simplifying how developers integrate AI into .NET applications. As artificial intelligence becomes more central to software development, this SDK allows Microsoft developers to seamlessly embed large language models (LLMs) into their C# projects, enhancing everything from chatbots and assistants to full-scale enterprise applications.

The SDK brings the Model Context Protocol to the fingertips of .NET developers, allowing them to incorporate AI-based tools into existing apps without having to learn a new language or framework. Whether you’re building internal tools, customer-facing platforms, or interactive web services, this SDK empowers developers to move faster, innovate more efficiently, and deliver smarter applications.

This launch also highlights Microsoft’s broader commitment to open-source software, developer experience, and AI democratization. Let’s break down what this SDK means for you, how it works, and how to get started.

Microsoft Partners with Anthropic

Microsoft’s partnership with Anthropic to launch the official Model Context Protocol SDK for C# is a milestone for AI in enterprise development. It brings the best of AI technology to one of the world’s most-used programming languages, enabling smart, context-aware applications without added complexity.

For any .NET developer or team looking to bring LLMs into the mix, this SDK delivers the perfect balance of power, simplicity, and scalability. As AI becomes more embedded in how we build software, this tool will prove invaluable. Ready to build? Visit the official GitHub page to start using the MCP SDK today.

What is the Model Context Protocol (MCP)?

The Model Context Protocol (MCP) is an open interoperability standard introduced by Anthropic. It defines a structured way for AI models to communicate with external tools, APIs, and services. MCP acts as a universal protocol that allows LLMs to trigger actions, retrieve data, or exchange information with an app without hard-coded logic.

Why is this important? Previously, integrating an LLM into a traditional application involved building lots of glue code. MCP changes that by standardizing the back-and-forth messaging between your AI models and external components.

For example, with MCP:

• An AI assistant can call your internal weather API using structured parameters.
• A business bot can retrieve HR records with proper authentication.
• An agent in a customer service app can auto-generate reports using real-time data.

This approach saves time, reduces errors, and abstracts the complexity of AI integration.

Why Microsoft’s C# SDK for MCP is a Game Changer

The C# SDK for MCP fills a huge gap in the market. While many AI tools support Python or JavaScript, few cater to the C# and .NET ecosystem—used by millions of developers in enterprise environments.

With this SDK, developers can:

• Create AI-native tools using Microsoft’s established tech stack
• Extend LLMs like Anthropic’s Claude into desktop, web, and mobile apps
• Run AI servers or tool hosts that work with multiple AI providers
• Build fully operational AI agents that can understand context, call services, and generate output in real-time

This empowers teams to modernize existing C# applications with minimal changes while future-proofing them for AI-driven workflows.

Key Features of the MCP C# SDK

This SDK is rich in features and ready for serious use:

Cross-Platform Compatibility

• Built for .NET 7+ and supports Windows, macOS, and Linux environments.

NuGet Distribution

• Install in seconds using:

dotnet add package ModelContextProtocol --prerelease

Full Message Support

• Supports all MCP message types:
  • InitializeRequest
  • CallToolRequest
  • ListToolsRequest
  • FinishRequest

Asynchronous Tooling

• Build and register tools that AI models can call dynamically.
• Tools can be grouped, versioned, and hosted via REST or WebSockets.

Security-Ready

• Support for OAuth and OpenID Connect is in the roadmap, enabling enterprise authentication.
• Future versions may also support token introspection and role-based access control.

Practical Example: Building a Hello Bot with C#

Define the Tool

public class HelloTool : ITool
{
    public string Name => "hello";

    public Task<ToolResponse> CallAsync(ToolRequest request, CancellationToken cancellationToken)
    {
        var name = request.Input["name"]?.ToString();
        return Task.FromResult(new ToolResponse($"Hello, {name}!"));
    }
}

Host the Tool

Host.CreateDefaultBuilder()
    .ConfigureServices((context, services) =>
    {
        services.AddMcpServer(options =>
        {
            options.Tools.Add<HelloTool>();
        });
    })
    .Build()
    .Run();

Call from an AI Model

Once hosted, any MCP-compatible AI model can detect and invoke this tool.

Real-World Applications for the MCP SDK

C# developers can use this SDK in numerous powerful ways:

Enterprise Dashboards

• Let users ask for sales reports, inventory metrics, or customer data with natural language.

Smart Productivity Tools

• Add AI-powered assistants to apps like Outlook, Excel, or CRM platforms.

Healthcare and Legal Apps

• Build HIPAA/GDPR-compliant agents that interact securely with databases.

DevOps & Engineering

• Trigger deployments, manage logs, or summarize commits through AI agents integrated into CI/CD systems.

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Developer and Industry Reception

The launch has sparked excitement in the community. One of the early adopters, Robert Recalde, Principal Engineer at Cigna Healthcare, said:

“This SDK bridges the gap between traditional .NET development and modern AI. It’s the kind of tool that lets us innovate quickly while sticking with the language and frameworks we trust.”

Experts in the open-source space have also praised Microsoft for embracing community contributions like mcpdotnet and transforming them into production-ready solutions.

FAQs On Microsoft Partners with Anthropic

Q1: Is the SDK free?

Yes. It’s completely open-source under a permissive license. Hosted on GitHub.

Q2: Can I use it with Claude or other Anthropic models?

Yes. It’s designed to integrate directly with MCP-enabled models like Claude.

Q3: What about Azure OpenAI integration?

Not yet, but similar protocols may be supported in future Microsoft tooling.

Q4: What security features are planned?

OAuth 2.0, OpenID Connect, and enterprise-level authentication will be added in upcoming updates.

Q5: Can I deploy this in Docker or Kubernetes?

Absolutely. It’s compatible with ASP.NET Core, Azure Functions, containers, and serverless environments.