Agents & frameworks · B-tier

Semantic Kernel

Microsoft’s open-source SDK for planners, plugins, and agents in .NET, Python, and Java.

Open Semantic Kernel Best AI agent frameworks

Best for

.NET teams adding tool-calling agents inside an existing Microsoft codebase.

What it is

Semantic Kernel is Microsoft’s open-source SDK for connecting models to plugins and planners, with first-class .NET support plus Python and Java. It fits teams already in the Microsoft stack more than greenfield JavaScript apps.

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Score breakdown

Capability 40%74
Ease 25%62
Value 20%88
Momentum 15%60

Pricing

Free

Starting price: $0

The SDK is open source. Model and Azure hosting costs are separate.

Dates

Released 2023 (year precision).

Added to StackPick 14 Oct 2026.

Alternatives

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AutoGen

Engineers who want a free multi-agent library and will write the glue.

A-tier · 89

Vercel AI SDK

TypeScript apps that need streaming chat or a small tool-calling agent.

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OpenAI Agents SDK

Agents that should stay close to OpenAI’s tools, handoffs, and tracing.

Questions

What is Semantic Kernel best for?

.NET teams adding tool-calling agents inside an existing Microsoft codebase.

How much does Semantic Kernel cost?

Free. Starting price: $0. The SDK is open source. Model and Azure hosting costs are separate.

What are alternatives to Semantic Kernel?

AutoGen, Vercel AI SDK, OpenAI Agents SDK are the alternatives we file next to it. Open a comparison when one exists.