Semantic Kernel: Microsoft's Multi-Agent SDK
Semantic Kernel is Microsoft's open-source SDK for AI agents. Per the official GitHub repo, it is "a model-agnostic SDK that empowers developers to build, orchestrate, and deploy AI agents and multi-agent systems." It is one of the few agent SDKs with first-class support for C#, Python, and Java. MIT licensed.
2026 transition note
The Semantic Kernel GitHub repo now states: "Semantic Kernel is now Microsoft Agent Framework (MAF)." Microsoft Agent Framework is positioned as the enterprise successor with production-ready 1.0 status. Existing Semantic Kernel projects still work, and the Python SDK continues to ship (1.42.0 on May 14, 2026), but new enterprise work is being directed to Microsoft Agent Framework. Track both before committing.
The 30-second version
- What: Microsoft's open-source AI agent SDK for C#, Python, and Java
- Who: enterprises in the Microsoft stack or on Java
- Price: free (MIT)
- Best at: multi-agent systems inside Azure, Microsoft 365, or .NET environments
- Verdict: pick Semantic Kernel for Microsoft-stack enterprise, but track Microsoft Agent Framework for the long-term path
What Semantic Kernel actually is
Semantic Kernel is Microsoft's answer to the LangChain category. The SDK is model-agnostic, so you can plug in OpenAI, Azure OpenAI, Hugging Face, NVidia, or other providers. The framework supports tool calling, plugins, agent loops, and multi-agent systems where specialist agents collaborate on complex workflows.
The differentiator is Microsoft-stack integration. Semantic Kernel runs natively in C# (.NET 10.0 or higher), Python (3.10 or higher), and Java (JDK 17 or higher). If your enterprise ships agents inside an existing .NET, Azure Functions, or Java microservice, Semantic Kernel slots in without bridging two languages.
The 2026 shift is significant. Microsoft has consolidated its agent strategy into Microsoft Agent Framework, with Semantic Kernel positioned as a precursor. For most new enterprise projects, evaluate Agent Framework first. Existing Semantic Kernel deployments remain supported.
Key capabilities
- C#, Python, and Java SDKs (multi-language unique in the category)
- Model flexibility: OpenAI, Azure OpenAI, Hugging Face, NVidia, custom providers
- Multi-agent systems: orchestrate collaborating specialist agents
- Plugin model for tool calling
- Enterprise-grade observability, security, stable APIs
- Open source under MIT license
- Latest Python SDK: 1.42.0 (May 14, 2026)
Pricing
Semantic Kernel is free under the MIT license. You pay for LLM API calls and any Azure or other infrastructure you deploy the agents on. No first-party paid product for the SDK itself; Microsoft monetizes via Azure consumption of compatible services.
Who Semantic Kernel fits
- Enterprises building agents inside Azure or .NET environments
- Java shops that need a serious agent SDK (rare in the category)
- Microsoft Enterprise Agreement customers who want vendor-aligned tooling
- Teams building multi-language stacks across C#, Python, and Java
Who Semantic Kernel does not fit
- New enterprise projects in 2026 (evaluate Microsoft Agent Framework first)
- Solo developers and small teams (LangChain ecosystem is more community-friendly)
- Anyone outside the Microsoft or Java enterprise context
Semantic Kernel vs LangChain and Microsoft Agent Framework
| Axis | Semantic Kernel | LangChain | MS Agent Framework |
|---|---|---|---|
| Maintainer | Microsoft | LangChain Inc. | Microsoft (successor) |
| Languages | C#, Python, Java | Python + JavaScript | .NET + Python |
| 2026 status | Consolidating into MAF | Active, expanding | v1.0, recommended path |
| Multi-agent native | Yes | Via LangGraph | Yes (core) |
| Best for | Existing MS-stack work | General-purpose | New enterprise + Azure work |
Pros and cons
Pros:
- Best agent SDK for the Microsoft stack and Java shops
- Multi-language support is rare in the category
- Microsoft enterprise support and SLAs once you go through Azure
Cons:
- 2026 consolidation into Microsoft Agent Framework creates uncertainty for new projects
- Smaller community than LangChain
- Documentation and tutorials lag the most-used open-source frameworks
How I'd think about Semantic Kernel on SellerShorts
I would not recommend a SellerShorts tool builder pick Semantic Kernel for a fresh project in 2026. The framework is solid but the consolidation note on the official GitHub means new enterprise work should evaluate Microsoft Agent Framework first. For a Microsoft-stack enterprise with an existing Semantic Kernel investment, keep shipping. For a new build, see the Microsoft Copilot Studio page (no-code) or wait for our coverage of Microsoft Agent Framework.
Try Semantic Kernel
Get Semantic Kernel on GitHub
Open source, MIT licensed. Best evaluated alongside Microsoft Agent Framework before committing to new work.
Building Amazon-specific agents? See the Amazon AI hub.
Frequently asked questions
What is Semantic Kernel?
Semantic Kernel is Microsoft's model-agnostic SDK for building, orchestrating, and deploying AI agents and multi-agent systems. It supports C# (.NET 10.0+), Python (3.10+), and Java (JDK 17+). MIT licensed.
Is Semantic Kernel still active in 2026?
Yes, but with a major shift. The Semantic Kernel GitHub repo notes that 'Semantic Kernel is now Microsoft Agent Framework (MAF),' positioning Agent Framework as the enterprise successor at version 1.0. The Semantic Kernel SDKs still ship (Python 1.42.0 released May 14, 2026), but new enterprise work is being directed at Microsoft Agent Framework.
Semantic Kernel vs LangChain: which should I pick?
Pick Semantic Kernel if you live in the Microsoft stack (.NET, Azure, Microsoft 365) or your enterprise mandates a Microsoft-supported SDK. Pick LangChain if you are language-agnostic, want the widest community, and value LangSmith observability.
Why does Semantic Kernel support Java?
Most agent frameworks ignore Java because the AI dev community is Python-first. Microsoft built for the enterprises that ship in Java (banks, insurance, large healthcare). If your enterprise has a Java-only mandate, Semantic Kernel is one of the few serious options.