Semantic Kernel
Microsoft's open-source SDK for integrating LLMs into .NET, Python, and Java applications. Enterprise-focused with planners, plugins, and AI agent patterns.
Semantic Kernel is Microsoft’s open-source SDK for integrating large language models into enterprise applications across .NET, Python, and Java. It provides a structured framework for combining AI services with conventional code through plugins, planners, and memory systems. For enterprise development teams working in Microsoft ecosystem languages who need a well-supported, production-ready SDK for adding AI capabilities to existing applications, Semantic Kernel is Microsoft’s official and recommended framework.
Key Features
Multi-language support. Semantic Kernel provides idiomatic SDKs for C#/.NET, Python, and Java. Unlike Python-only frameworks, this makes it the natural choice for enterprise teams working in .NET or Java who want first-class language support rather than Python wrappers.
Plugin architecture. Semantic Kernel uses a plugin system that wraps both AI prompts and native code into callable functions. Plugins can encapsulate API calls, database queries, file operations, and other business logic that the AI can invoke during task execution. This cleanly separates AI orchestration from business logic.
AI agent patterns. The framework supports agentic patterns where the AI plans and executes multi-step tasks using available plugins. Built-in planners decompose user goals into sequences of plugin calls, while agent abstractions handle tool calling, function chaining, and conversational memory.
Memory and RAG. Semantic Kernel includes a memory system that integrates with vector databases for retrieval-augmented generation. Memory connectors support Azure AI Search, Qdrant, ChromaDB, Pinecone, and other stores, providing RAG capabilities within the SDK’s framework.
Multi-provider LLM support. Connect to Azure OpenAI, OpenAI, Hugging Face, Ollama, and other providers. The abstraction layer lets you switch between cloud and local models without changing application code.
Enterprise integration. Deep integration with Azure services, Microsoft 365 Copilot extensibility, and enterprise authentication patterns make Semantic Kernel the path of least resistance for organizations already invested in the Microsoft ecosystem.
When to Use Semantic Kernel
Choose Semantic Kernel when building enterprise AI features in .NET, Java, or Python within a Microsoft-aligned technology stack. It is the right choice for teams extending Microsoft 365 with AI, organizations using Azure as their cloud platform, and developers who need structured AI orchestration in strongly typed languages.
Ecosystem Role
Semantic Kernel is Microsoft’s answer to LangChain. It targets enterprise developers rather than the ML research community. Compared to LangChain, it offers better .NET and Java support but a smaller community and fewer integrations. For Python-centric teams, LangChain or LlamaIndex may have richer ecosystems. For Microsoft-stack organizations, Semantic Kernel integrates most naturally.