win-dev-skills

WinUI agents and skills for Windows app development

An Agent Plugins 1.0 package with GitHub Copilot, Claude Code, and OpenAI Codex compatibility for building native Windows apps with WinUI 3 and the Windows App SDK. It covers the end-to-end inner loop: scaffold → design → build → run → test → package → ship.

[!WARNING] 🚧 Preview · v0.x — expect breaking changes. Skill names, on-disk layout, agent configuration, analyzer rule IDs, and CLI tool surfaces are all subject to change without notice. There is no SemVer commitment until v1.0. If you need a stable pin, install from a release tag instead of the rolling marketplace (see Pinning to a release). Outputs are suggestions, not authoritative answers — review them before committing or shipping anything they produce.

Install

The plugin requires GitHub Copilot (winget install GitHub.Copilot), Claude Code, or OpenAI Codex installed.

Git (winget install Git.Git) is required for installing pluggins.

Option A — Just ask Copilot to do it

Paste this prompt into a Copilot CLI session. It installs the plugin and sets up every prerequisite in one shot:

Install the Copilot CLI plugin "winui" from microsoft/win-dev-skills, then set up my machine for WinUI 3 development. Specifically:

1. Run: copilot plugin marketplace add microsoft/win-dev-skills
2. Run: copilot plugin install winui@win-dev-skills
3. Make sure these prerequisites are present (check first and change only what is missing or too old):
   - .NET SDK >= 8.0.100 (run `dotnet --list-sdks`; if none qualifies, `winget install --id Microsoft.DotNet.SDK.10 --exact --silent --accept-package-agreements --accept-source-agreements`)
   - WinApp CLI: must be >= 0.6.0 (parse the standalone version line from `winapp --version`); if missing, `winget install --id Microsoft.WinAppCli`; if older, `winget upgrade --id Microsoft.WinAppCli`.
   - Do not install WinUI templates separately — WinApp CLI 0.6+ installs and updates them on demand through `winapp new`.
   - Developer Mode (DWORD HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock\AllowDevelopmentWithoutDevLicense == 1) — ASK ME first before triggering UAC; if I decline, just print the elevated command for me to run later.
4. Print a short summary of what was installed vs already present, then tell me to start a new Copilot CLI, activate the "winui-dev" agent, and to ask it to build an app.

Option B — Install the plugin yourself, then ask the agent to set up the rest

If you'd rather run the plugin commands by hand:

The plugin is listed on awesome-copilot and can be installed directly:

copilot plugin install winui@awesome-copilot

Or add this repo as a marketplace and install from there:

copilot plugin marketplace add microsoft/win-dev-skills
copilot plugin install winui@win-dev-skills

claude plugin marketplace add microsoft/win-dev-skills
claude plugin install winui@win-dev-skills

Add the microsoft/win-dev-skills marketplace, then enable the winui plugin from the plugin directory.

Note: Codex doesn't have an "agents" concept, so the orchestrator agent isn't exposed there. The skills still work - invoke them by name (e.g. /winui-setup, /winui-design) and Codex will load them on demand.

Install straight from this repo - no marketplace pre-registration needed. The explicit --marketplace source clones the repo on demand, reads its marketplace manifest, and installs the winui plugin natively (Format: openclaw):

openclaw plugins install winui --marketplace microsoft/win-dev-skills
openclaw gateway restart

Or from a local clone:

git clone https://github.com/microsoft/win-dev-skills
openclaw plugins install ./win-dev-skills/plugins/winui

Verify the eight skills loaded with openclaw skills list (each shows ✓ ready).

Note: OpenClaw maps skills, not agents, so the winui-dev orchestrator agent isn't exposed there. The skills still work - ask the agent for a WinUI task and it loads the relevant skill on demand.

OpenCode loads Agent Skills natively from <name>/SKILL.md folders. Point it at the shared skills - no fork or copy needed. Link each skill into OpenCode's global skills directory (or a project's .opencode/skills/):

# One-time setup: link the shared skills into OpenCode's global skills directory
$src = "C:\path\to\win-dev-skills\plugins\winui\agent-plugin\skills"
$dst = "$env:USERPROFILE\.config\opencode\skills"
New-Item -ItemType Directory -Force $dst | Out-Null
Get-ChildItem $src -Directory | ForEach-Object {
  $link = Join-Path $dst $_.Name
  if (-not (Test-Path $link)) {
    New-Item -ItemType Junction -Path $link -Target $_.FullName | Out-Null
  }
}

Because these are junctions (not copies), git pull in the repo picks up upstream skill updates automatically.

Note: OpenCode maps skills, not agents, so the winui-dev orchestrator agent isn't exposed there. The skills still work - invoke them by name (e.g. /winui-setup, /winui-design) and OpenCode loads them on demand.

Then start a new session and run the winui-setup skill with /winui-setup.

Once setup is done, try a real task:

"Build me a WinUI 3 markdown editor with live preview and a custom title bar"

What gets installed

Tool	Minimum	Recommended	Install command
Git	2.54	2.54+	winget install Git.Git
.NET SDK	8.0.100	10.0	winget install Microsoft.DotNet.SDK.10
WinApp CLI	0.6.0	latest	winget install Microsoft.WinAppCli
Developer Mode	enabled	enabled	DWORD AllowDevelopmentWithoutDevLicense set to 1

Visual Studio is not required — these skills build and run entirely with dotnet. Neither setup path will install it; if you want it as an IDE, run:

winget install Microsoft.VisualStudio.Community --override "--add Microsoft.VisualStudio.Workload.Universal"

[!NOTE] Older Windows App SDK versions had a XAML-compiler bug under dotnet build: a malformed .xaml file produced no useful diagnostic — the build just failed with a cryptic MSB3073 (XamlCompiler.exe ... exited with code 1) and no indication of which .xaml was wrong. This is fixed in current releases — Windows App SDK ≥ 2.1.3 on the 2.x line and ≥ 1.8 on the 1.x line. If you hit a cryptic build failure with no XAML diagnostic, update the Microsoft.WindowsAppSDK NuGet package to the latest version. WinApp CLI 0.6+ builds the project directly through winapp run <project>.

Why a Copilot CLI plugin?

Modern Windows app development covers a lot of ground — XAML and Fluent Design, MVVM, MSIX packaging, code signing, Store submission, accessibility, theming, UI automation. AI agents working from generic web context tend to mix WinUI 3 with older stacks (UWP, WPF), miss the packaged-execution model, or stop short of running and verifying what they built. These skills stay in the WinUI 3 lane end-to-end — from winapp new through a signed MSIX — and pair the agent with tools that give it real, ground-truth answers instead of guesses.

The result: you ask copilot -p "create a WinUI 3 photo viewer with thumbnails and EXIF metadata", and the agent picks the right template, scaffolds the project, designs the XAML with theming and accessibility in mind, wires up MVVM correctly, builds, fixes errors with real diagnostics, launches through the right packaged-execution pipeline, and (if you ask) drives the running app through UI automation to validate it works.

What's in this repo

.github/plugin/          GitHub Copilot marketplace manifest
.claude-plugin/          Claude Code marketplace manifest
.agents/plugins/         OpenAI Codex marketplace manifest
plugins/winui/           Legacy-client compatibility package root
  .claude-plugin/        Claude Code compatibility manifest
  .codex-plugin/         OpenAI Codex compatibility manifest
  agents/                Claude Code orchestrator agent
  openclaw.plugin.json   OpenClaw compatibility manifest
  package.json           OpenClaw package metadata
  index.js               OpenClaw content-plugin entry point
  agent-plugin/          Agent Plugins 1.0 package root
    plugin.json          Portable manifest
    assets/              SVG and PNG marketplace artwork
    skills/              Portable Agent Skills (see table below)
    com.github.copilot/  Copilot-specific extension namespace
      agents/            The Copilot orchestrator agent
src/tools/             Source for the in-repo tools shipped with the skills
  winmd-cli/           Native-AOT WinRT/.NET metadata indexer (winmd.exe)
  winui-analyzer/      Microsoft.WindowsAppSDK.Analyzers Roslyn analyzer
scripts/               Helper scripts (see scripts/build-tools.ps1)

The agent: winui-dev

A focused agent for WinUI 3 / Windows App SDK / XAML / C# work. Use it for new apps, adding features, converting from WPF/Electron/web, or fixing bugs. It pulls in the skills below as needed.

The eight skills

Each skill is a focused, self-contained playbook. The agent loads winui-design and winui-dev-workflow by default — those cover most "build me a WinUI 3 app" requests end-to-end. You opt into the others when you want them, including winui-setup for one-time machine prep.

Skill	What it does
winui-dev-workflow	Build and run workflow — winapp new, project-mode winapp run, the analyzer-injecting BuildAndRun.ps1 helper, crash diagnosis, and prerequisites.
winui-design	UI design and XAML correctness — layout planning, control selection, Fluent Design, theming (Light/Dark/HighContrast), typography, spacing, brushes, accessibility, data-binding review, and grounded sample lookup with winapp find-ui.
winui-code-review	Code-quality review before committing — MVVM compliance, x:Bind correctness, accessibility, theming, security, performance. Catches what the compiler and UI tests won't.
winui-ui-testing	Automated UI testing — generates a batch test script, runs all tests in one pass, reads results. Covers element assertions, interactions, value checks (TextBox, ComboBox, ToggleSwitch), file pickers, flyouts, dialogs, persistence, accessibility audits.
winui-packaging	MSIX packaging, code signing, and distribution — release builds, certificate generation (winapp cert generate), trust, signing (winapp sign), self-contained deployment, GitHub Actions CI/CD, and Microsoft Store submission.
winui-wpf-migration	WPF → WinUI 3 migration — namespace replacement, control mapping (DataGrid → ListView, WrapPanel → ItemsRepeater, TabControl → TabView), Dispatcher → DispatcherQueue, System.Drawing → BitmapImage, MVVM conversion to CommunityToolkit.Mvvm, DynamicResource → ThemeResource.
winui-session-report	Diagnostic report on the current or a recent Copilot session. Runs only after an explicit request for session feedback, agent debugging, or a review of what happened during a build session.
winui-setup	Install and verify machine prerequisites — .NET SDK 8.0.100+, WinApp CLI 0.6+, and Developer Mode. Templates are managed on demand by winapp new. Idempotent and explicit confirmation required.

The tools we lean on