Learn Microsoft Semantic Kernel in C# with this step-by-step tutorial. Build AI agents, plugins, and copilots in .NET with runnable code. Start today. If you want to add real AI capabilities to a .NET application, Semantic Kernel C# is the fastest, most production-ready route available today. Microsoft Semantic Kernel (SK) is an open-source SDK that lets you plug large language models like GPT-4o, Claude, or local models into ordinary C# code, give them tools (called plugins ), and let them plan and execute multi-step tasks. In this Semantic Kernel tutorial you will build an AI agent step by step: from a "hello world" chat completion, through function calling with your own C# methods, to a stateful copilot that can answer questions about your own data. Every example targets .NET 8 or later and uses the stable Microsoft.SemanticKernel package. You can copy the code straight into a console app and run it. What Is Microsoft Semantic Kernel and Why Use It in C#? At its...
Learn ASP.NET Core rate limiting with fixed window, sliding window, token bucket and concurrency limiters. Runnable C# examples — secure your API today. If your API is public, it will get hammered — by bots, by misconfigured clients stuck in retry loops, and occasionally by someone actively trying to knock it over. ASP.NET Core rate limiting is the built-in defense for this. Since .NET 7, the Microsoft.AspNetCore.RateLimiting middleware ships in the framework, and in 2026 with .NET 9 and .NET 10 it's mature, fast, and flexible enough that you no longer need a third-party package for most scenarios. In this guide you'll learn what rate limiting actually protects you from, how the four built-in algorithms differ (and which one to choose), and how to wire up a production-ready configuration with per-user partitions, proper 429 responses, and the pitfalls that trip up most teams. Why Rate Limiting Matters for API Security Rate limiting caps how many requests a client can...