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Microsoft quietly published 99 ready-made .NET skills for AI Agents. Most .NET developers have no idea they exist 👇 These skills are official and open source. They work in Claude Code, Codex, GitHub Copilot and Cursor. A skill is a folder with instructions. Your AI agent loads it only when a task needs it. You write the steps once, and the agent follows them every time. Microsoft keeps them in the dotnet/skills repo: 14 plugins, 99 skills. A plugin is a group of related skills. You install a plugin and get all its skills at once. Here are 5 I'd install first, in this order: 𝟭. 𝗱𝗼𝘁𝗻𝗲𝘁-𝘂𝗽𝗴𝗿𝗮𝗱𝗲 Moves a project from .NET 8 to 10 and turns on nullable reference types. 𝟮. 𝗱𝗼𝘁𝗻𝗲𝘁-𝗱𝗮𝘁𝗮 The optimizing-ef-core-queries skill catches N+1 queries, picks the right tracking mode and removes common EF Core performance traps. 𝟯. 𝗱𝗼𝘁𝗻𝗲𝘁-𝗮𝘀𝗽𝗻𝗲𝘁 Builds Web API endpoints and file-upload endpoints in Minimal APIs the right way. 𝟰. 𝗱𝗼𝘁𝗻𝗲𝘁-𝘁𝗲𝘀𝘁 The biggest plugin: 22 skills to run tests, filter them and move between test frameworks. 𝟱. 𝗱𝗼𝘁𝗻𝗲𝘁-𝗮𝗶 Builds, debugs and tests MCP servers with the C# SDK. These skills know .NET. They don't know YOUR project. They can't tell where you keep your entities, that you don't use repositories, or that your handlers return Result<T>. Your own skills fill this gap: → Microsoft's skills handle general .NET tasks → Your skills handle your house rules and conventions Use both, and your AI agent knows the framework and your style. 2 tips before you install: → Don't install all 99. Every skill adds its description to the agent's context, so pick the plugins that match your stack → Name the skill in your prompt instead of letting the agent guess which one to use In my article, I explain the full setup: → What a skill is and what's inside one → How to write a description so the skill triggers at the right time → How to turn your conventions into skills: rich entities, no repositories, full features → How to use the Skill Creator to bundle your real code files → How to install Microsoft's dotnet/skills in 4 steps 👉 Read the full step-by-step guide here: ↳ https://antondevtips.com/blog/creating-claude-skills-for-dotnet-apps?utm_source=twitter&utm_medium=social&utm_campaign=newsletter&utm_content=12-11-2026
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📌 You don't read my newsletter. I explain .NET and Architecture based on my 13+ years of experience. For each topic, I present the pros, cons, and trade-offs, and you get a checklist for when to use each approach and when not to. AI won't teach you this! Every Tuesday, I send an article to 28,000 people learning to master .NET. 📌 This week's blog on New Features in .NET 11 and C# 15 (you need to read this): https://antondevtips.com/blog/new-features-in-dotnet-11-and-csharp-15?utm_source=twitter&utm_medium=social&utm_campaign=newsletter&utm_content=12-11-2026 👉 Join us (and share with your friends and colleagues) → https://antondevtips.com?utm_source=twitter&utm_medium=social&utm_campaign=newsletter&utm_content=12-11-2026
