Ship .NET Features With the Official dotnet/skills Plugin Set

Coding agents handle C# fine line-by-line, but they miss the .NET-specific moves: which diagnostic tool attaches to a running process, how to migrate a project off an old target framework, where MSBuild actually went wrong. dotnet/skills is the .NET team's curated set of portable skills and host-specific custom agents that fills that gap — 15 plugins, from build diagnosis to Blazor patterns, installable into Claude Code, Copilot CLI, Codex, and Cursor.

Why This Skill Matters

The 15 plugins map to the jobs a .NET developer actually does: dotnet-diag for performance investigations and incident analysis, dotnet-msbuild for build failure diagnosis and performance optimization, dotnet-nuget for dependency management and modernization, dotnet-upgrade for migrating projects across framework versions, plus dotnet-aspnetcore, dotnet-blazor, dotnet-maui, dotnet-ai, and dotnet-test among the rest. dotnet11 covers the new .NET 11 APIs and language features.

Because the skills follow the agentskills.io open standard, they work across hosts rather than locking into one vendor. The repo also publishes a Skill Value dashboard that reports token use, elapsed time, activation, and not-passed rates by plugin, skill, executor model, and judge model — so you can see whether a plugin is pulling its weight before keeping it installed.

Installation

In Claude Code or Copilot CLI:

/plugin marketplace add dotnet/skills

Then install an individual plugin and restart:

/plugin install dotnet-diag@dotnet-agent-skills

After the restart, /skills lists the available skills and /agents the custom agents; /plugin update dotnet-diag@dotnet-agent-skills updates a plugin on demand.

On Codex CLI (v0.121.0+), register the repo as a marketplace instead:

codex plugin marketplace add dotnet/skills

Then browse the dotnet-agent-skills tab in /plugins. Note one host difference the README calls out: Codex plugin installs expose the skills and any Codex-compatible MCP servers declared by the plugin, but not the repo's GitHub Copilot .agent.md files.

Real Workflow: Diagnose a Performance Complaint

1. Install the dotnet-diag plugin — its skills target .NET performance investigations, debugging, and incident analysis — then hand the agent a concrete symptom:

我们的 ASP.NET Core 服务在高峰期延迟翻了三倍。用 dotnet-diag 的 skill 排查：
先从运行中的进程收集相关诊断信息，告诉我时间花在哪里，再决定改不改代码。

2. Work through the agent's findings, letting it run the diagnostic steps against your service rather than guessing from the stack trace alone.
3. When the fix lands, ask the agent to sanity-check the change against the test plugin:

用 dotnet-test 的 skill 跑受影响的测试套件，按原因归类总结失败项。

4. Considering a larger migration? The dotnet-upgrade plugin handles moving projects across framework versions, language features, and compatibility targets — give it the project and the target version, and let it plan the migration before touching files.

Tips

• Install plugins per job, not all 15 at once — the install command takes any single plugin name, and each has a focused scope.
• Check the Skill Value dashboard before deciding what to keep — its activation and not-passed rates tell you whether a plugin is pulling its weight.
• The repo also ships reusable GitHub Agentic Workflows; gh aw add-wizard dotnet/skills/agentic-workflows@main installs the complete collection.
• On VS Code, plugin support is a preview feature you may need to enable first (chat.plugins.enabled, with the marketplace listed under chat.plugins.marketplaces).
• Cursor users can install the same plugins from the marketplace panel — the repo is a Cursor plugin marketplace too.

When Not to Use This

These skills are .NET-specific; a Rust or Go project gains nothing from them. And if you only need generic build-and-test help on a small utility project, your agent's built-in tooling is often enough — this set earns its keep on real .NET codebases where version, build, and runtime diagnostics matter.

See the leaderboard for more skills.