# microsoft/WindowsAppSDK

The Windows App SDK empowers all Windows desktop apps with modern Windows UI, APIs, and platform features, including back-compat support, shipped via NuGet.

Repository: https://github.com/microsoft/WindowsAppSDK
Canonical: https://ross.abutalabs.com/products/windowsappsdk
Homepage: https://docs.microsoft.com/windows/apps/windows-app-sdk/
Language: C++
License: MIT
License Family: permissive
Topics: desktop, windows, project-reunion, win32, winui, cpp, csharp, windows-app-sdk, winappsdk, windows-10, windows-11, winui3, wpf
Last push: 2026-08-26T22:25:45+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 97, longevity 100
- inputs: {"age_days": 2331, "days_push": 7, "days_rel": 20, "gap_med": 9, "n_releases_24m": 40}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4665, forks 461 (observed 2026-08-28T04:08:56.510277+00:00)

## What it is
Windows App SDK (formerly Project Reunion) is a Microsoft SDK that brings modern Windows platform APIs, WinUI 3, and Fluent Design UI to desktop apps built with Win32, WPF, WinForms, or .NET/C++. It ships via NuGet and supports Windows 10 1809 and later, including local AI/ONNX model APIs on Copilot+ PCs.

## Use cases
- build a modern Windows desktop app with WinUI 3
- add Fluent Design UI to an existing WPF or WinForms app
- run ONNX AI models locally on Windows
- use modern Windows APIs while supporting Windows 10 1809+
- distribute a desktop app without requiring MSIX packaging
- create accessible native Windows UI in C# or C++

## When to choose
- building new Windows desktop applications with modern UI
- modernizing existing Win32, WPF, or WinForms apps with current APIs
- you need back-compat across Windows 10 and 11 versions
- you want local, hardware-accelerated AI features on Windows

## When to avoid
- targeting non-Windows platforms exclusively
- building UWP-only or mobile apps
- you need a cross-platform UI framework like Flutter or Electron
- your app must run on Windows versions older than 10 1809

## Facets
- artifact type: framework
- maturity: active
- function: ui-components, mobile-framework, sdk, machine-learning
- domain: desktop-applications, web-development, developer-tools, windows
- platform: windows, cpp, dotnet, cross-platform
- tags: winui3, win32, wpf, winforms, fluent-design, nuget, project-reunion, msix, windows-11, onnx

## Member repositories
- microsoft/WindowsAppSDK (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:56.510277+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:19:25.430181+00:00, confidence not recorded.
  - readme: https://github.com/microsoft/WindowsAppSDK (fetched 2026-08-28T04:08:56.510277+00:00, sha c338ec2711c1)
  - homepage: https://docs.microsoft.com/windows/apps/windows-app-sdk/ (fetched 2026-08-29T09:03:43.727400+00:00, sha 4f7dcfabdb3e)
  - site_page: https://learn.microsoft.com/en-us/lifecycle/faq/internet-explorer-microsoft-edge (fetched 2026-08-29T09:03:43.736764+00:00, sha c363b2f43d4b)
- Data as of 2026-08-30T08:39:29.467469+00:00.