API reference for Windows desktop apps

Find the API surface for the Windows platform, Windows App SDK, WinUI, Win32, .NET, and app schemas.

Choose an API surface

Start with the platform or SDK that provides the capability you need.

Understand APIs and interop
Learn how Windows Runtime, Win32, COM, and .NET APIs work together in desktop apps.
Explore the Windows App SDK
Learn about the independently released SDK for modern Windows app features.
Explore the Windows SDK
Find Windows platform headers, libraries, metadata, tools, downloads, and release information.

Open the reference collection for the framework, language projection, or interoperability layer you use.

Windows App SDK APIs

Build with Windows App SDK Windows Runtime and Win32 APIs, or use the C# interop projection.
WinUI interop and bootstrapping

Find WinUI COM and C# interop APIs, or initialize the Windows App SDK runtime from unpackaged apps.
Windows SDK APIs

Use Windows Runtime, WinUI 2 for UWP, and Win32 APIs that ship with Windows.
.NET APIs, schemas, and settings

Browse .NET APIs, app schema specifications, and Windows Settings URI reference.

Continue with feature guidance, SDK downloads, or data access and interoperability support.