Semantic Kernel vs the Microsoft Agent Framework: Which Should You Use in 2026?

If you’re starting an AI project on .NET in 2026, you’ve probably hit the question: Semantic Kernel or the Microsoft Agent Framework? For a while the honest answer was “it’s complicated.” Since the Agent Framework’s 1.0 GA in April 2026, it’s much simpler than it used to be. This article gives you the straight version — what to use for new work, and what to do if you already have a Semantic Kernel codebase.

For background on the framework itself, see our Microsoft Agent Framework guide.

The short answer

For new projects: use the Microsoft Agent Framework. It’s the designated successor to both Semantic Kernel and AutoGen, it’s 1.0 GA and production-ready, and it’s where Microsoft’s investment now goes. Starting new work on Semantic Kernel in 2026 means building on a foundation you’ll eventually migrate off.

For existing Semantic Kernel apps: you don’t need to panic-migrate. Semantic Kernel still works and is supported. Plan a migration deliberately, on your timeline — not as an emergency.

That’s the whole decision for most people. The rest of this article is the “why” and the “how.”

How they relate

It helps to understand the lineage, because it explains why the recommendation is what it is:

• Semantic Kernel was Microsoft’s enterprise-grade SDK for LLM apps — plugins, planners, memory, strong .NET integration, broad model support.
• AutoGen was Microsoft Research’s project for multi-agent systems, with clean agent abstractions.
• Microsoft Agent Framework is the convergence of both: AutoGen’s ergonomic agent model plus Semantic Kernel’s enterprise plumbing (state, type safety, middleware, telemetry), with new graph-based workflows on top.

So the Agent Framework isn’t a competitor to Semantic Kernel — it’s its next generation. That’s why “use the successor for new work” is the clean answer.

Feature comparison

When Semantic Kernel is still fine

Be pragmatic. Stay on Semantic Kernel a while longer if:

• You have a working production app on it — “it works and is supported” is a valid reason not to rewrite this quarter.
• You use a narrow slice (say, just prompt templates and a plugin or two) that isn’t costing you anything.
• You have no immediate need for the Agent Framework’s new capabilities (graph workflows, native MCP/A2A).

The trigger to migrate isn’t the calendar — it’s needing something the new framework does better, or reaching a natural refactor point.

How to migrate (when you’re ready)

Microsoft ships migration guidance precisely because a rewrite is the wrong approach. The sane path:

1. Start with new features. Build the next agent feature on the Agent Framework rather than porting old ones first. You learn the framework on green-field code, not under migration pressure.
2. Migrate incrementally. Both build on Microsoft.Extensions.AI’s IChatClient, so your model configuration and many abstractions carry over. Move one component at a time behind stable interfaces.
3. Follow the official migration guide, not folk wisdom — concept mappings (plugins → tools, planners → workflows) are documented and save you guesswork.
4. Lean on your tests. If you have an eval set, it’s your safety net: migrate a component, re-run the evals, confirm quality held.

Takeaway

In 2026 the decision is refreshingly clear: build new .NET agent work on the Microsoft Agent Framework — it’s the GA’d successor to both Semantic Kernel and AutoGen and where the ecosystem is going. If you’re already on Semantic Kernel, it still works; migrate deliberately, starting with new features and moving incrementally, rather than treating it as an emergency. The framework fragmentation that made this question hard is over — which is good news for everyone building on .NET.

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