On October 8, 2024, Microsoft unveiled Microsoft.Extensions.AI in preview—a game-changing addition to the .NET ecosystem. This new set of libraries provides developers with unified abstractions for integrating AI services, enabling developers to work seamlessly with language models, embeddings, and other AI-driven functionalities without being tied to any specific provider. Let’s dive into what makes Microsoft.Extensions.AI exciting for .NET developers and how you can leverage it to build smarter applications.

What is Microsoft.Extensions.AI?

Microsoft.Extensions.AI is a set of core .NET libraries designed to standardize and simplify AI service integration. Built with extensive input from developers across the .NET community, including contributions from the Semantic Kernel team, these libraries offer a unified layer of C# abstractions for working with AI services, such as small and large language models (SLMs and LLMs), chat applications, embeddings, and middleware components.

In practical terms, Microsoft.Extensions.AI abstracts complex AI interactions into simplified interfaces like IChatClient and IEmbeddingGenerator. These interfaces can work with various AI services—whether hosted in the cloud or run locally—allowing developers to choose their preferred service provider or model without extensive rewrites.

Core Benefits of Microsoft.Extensions.AI

Microsoft.Extensions.AI has been crafted with flexibility, ease of use, and seamless integration in mind, echoing the best aspects of previous .NET abstractions, such as logging and dependency injection (DI). Here’s what developers gain from Microsoft.Extensions.AI:

1. Unified API Abstraction
   With a consistent API and shared conventions, Microsoft.Extensions.AI reduces the complexity of incorporating AI services. This means developers can integrate AI capabilities without needing to learn unique API structures or complex workarounds for each provider.
2. Flexibility Across Providers
   The abstraction layer enables .NET library authors to support AI services without binding to a single provider. Whether you’re using OpenAI, Azure AI, or even smaller providers, Microsoft.Extensions.AI enables smooth transitions and hybrid scenarios.
3. Ease of Use for Experimentation
   Experimentation becomes easier as developers can try various models and configurations without modifying the core structure of their applications. This freedom fosters innovation while retaining a consistent API that simplifies development and testing.
4. Componentization and Middleware
   Building on .NET’s modular nature, Microsoft.Extensions.AI brings componentization to AI applications. Middleware components for logging, telemetry, and caching can be seamlessly integrated, making it easier to build robust applications with powerful AI capabilities.

Key Features and Use Cases

Microsoft.Extensions.AI provides interfaces like IChatClient and IEmbeddingGenerator, designed for easy implementation by various providers and accessible to developers without requiring specialized integration. These interfaces cover essential AI use cases, including:

• Chat: The IChatClient interface allows developers to create conversational applications that can consume language models. For example, developers can integrate AI-driven customer support into apps without worrying about the underlying AI provider.
• Embeddings: For scenarios requiring semantic similarity or vector-based search, the IEmbeddingGenerator interface makes it easy to generate embeddings and add advanced search functionality.
• Middleware Support: Beyond just connecting to AI services, the library supports middleware for telemetry, caching, and logging. This gives developers a production-ready, holistic approach to AI app development.

Code Examples: Quick Start with Microsoft.Extensions.AI

Getting started with Microsoft.Extensions.AI is straightforward. Here’s a quick example to show how you can set up a chat application using OpenAI and Microsoft.Extensions.AI.

using OpenAI;
using Microsoft.Extensions.AI;

// Set up OpenAI client using Microsoft.Extensions.AI
IChatClient client =
    new OpenAIClient(Environment.GetEnvironmentVariable("OPENAI_API_KEY"))
        .AsChatClient(modelId: "gpt-4o-mini");

// Send a chat message and get a response
var response = await client.CompleteAsync("What is AI?");
Console.WriteLine(response.Message);

The above code showcases how to instantiate an AI client using Microsoft.Extensions.AI. Developers can easily switch between providers like OpenAI and Azure AI by adjusting the initialization code, thanks to the unified API abstraction.

Adopting Microsoft.Extensions.AI in Your .NET Applications

Here’s how developers across various roles can start building with Microsoft.Extensions.AI:

• Library Developers: If you maintain libraries that provide AI services, consider implementing the Microsoft.Extensions.AI interfaces to offer a plug-and-play experience for users.
• Application Developers: Experiment with the unified abstractions to integrate AI services in your applications. You’ll benefit from model portability, flexible testing, and consistent APIs.
• Ecosystem Contributors: Contribute to the .NET ecosystem by building middleware components, which could add caching, telemetry, or other useful functionalities to the AI ecosystem.

What’s Next for Microsoft.Extensions.AI?

Currently in preview, Microsoft.Extensions.AI is expected to evolve rapidly as feedback from the developer community rolls in. Microsoft is focused on continued integration with Semantic Kernel and expanding the library’s compatibility across .NET. As part of the .NET 9 release, the library is set to mature into a stable foundation for building AI applications in .NET.

Join the Future of AI in .NET

Microsoft.Extensions.AI represents a pivotal step in democratizing access to AI for .NET developers, offering a standardized approach to implementing AI in applications and libraries. Whether you’re building chatbots, embedding search functionality, or enhancing app features with AI, Microsoft.Extensions.AI brings consistency and ease of use to the table.

Try out Microsoft.Extensions.AI in preview and help shape the future of AI in the .NET ecosystem. Check out the dotnet/ai-samples GitHub repository, experiment with the sample code, and share your experiences to help refine this powerful new tool. Microsoft invites you to contribute to this ecosystem and explore the creative possibilities it brings to .NET development.