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.NET RID Catalog

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RID is short for runtime identifier. RID values are used to identify target platforms where the application runs. They're used by .NET packages to represent platform-specific assets in NuGet packages. The following values are examples of RIDs: linux-x64, win-x64, or osx-x64. For the packages with native dependencies, the RID designates on which platforms the package can be restored.

A single RID can be set in the <RuntimeIdentifier> element of your project file. Multiple RIDs can be defined as a semicolon-delimited list in the project file's <RuntimeIdentifiers> element. They're also used via the --runtime option with the following .NET CLI commands:

RIDs that represent concrete operating systems usually follow this pattern: [os].[version]-[architecture]-[additional qualifiers] where:

  • [os] is the operating/platform system moniker. For example, ubuntu.

  • [version] is the operating system version in the form of a dot-separated (.) version number. For example, 15.10.

    The version shouldn't be a marketing version, as marketing versions often represent multiple discrete versions of the operating system with varying platform API surface area.

  • [architecture] is the processor architecture. For example: x86, x64, arm, or arm64.

  • [additional qualifiers] further differentiate different platforms. For example: aot.

RID graph

The RID graph or runtime fallback graph is a list of RIDs that are compatible with each other.

These RIDs are defined in PortableRuntimeIdentifierGraph.json in the dotnet/runtime repository. In this file, you can see that all RIDs, except for the base one, contain an "#import" statement. These statements indicate compatible RIDs.

Before .NET 8, version-specific and distro-specific RIDs were regularly added to the runtime.json file, which is located in the dotnet/runtime repository. This graph is no longer updated and exists as a backwards compatibility option. Developers should use RIDs that are non-version-specific and non-distro-specific.

When NuGet restores packages, it tries to find an exact match for the specified runtime. If an exact match is not found, NuGet walks back the graph until it finds the closest compatible system according to the RID graph.

The following example is the actual entry for the osx-x64 RID:

"osx-x64": {
    "#import": [ "osx", "unix-x64" ]
}

The above RID specifies that osx-x64 imports unix-x64. So, when NuGet restores packages, it tries to find an exact match for osx-x64 in the package. If NuGet can't find the specific runtime, it can restore packages that specify unix-x64 runtimes, for example.

The following example shows a slightly bigger RID graph also defined in the runtime.json file:

    linux-arm64     linux-arm32
         |     \   /     |
         |     linux     |
         |       |       |
    unix-arm64   |    unix-x64
             \   |   /
               unix
                 |
                any

Alternatively, you can use the RidGraph tool to easily visualize the RID graph (or any subset of the graph).

All RIDs eventually map back to the root any RID.

There are some considerations about RIDs that you have to keep in mind when working with them:

  • Don't try to parse RIDs to retrieve component parts.

  • Use RIDs that are already defined for the platform.

  • The RIDs need to be specific, so don't assume anything from the actual RID value.

  • Don't build RIDs programmatically unless absolutely necessary.

    Some apps need to compute RIDs programmatically. If so, the computed RIDs must match the catalog exactly, including in casing. RIDs with different casing would cause problems when the OS is case sensitive, for example, Linux, because the value is often used when constructing things like output paths. For example, consider a custom publishing wizard in Visual Studio that relies on information from the solution configuration manager and project properties. If the solution configuration passes an invalid value, for example, ARM64 instead of arm64, it could result in an invalid RID, such as win-ARM64.

Using RIDs

To be able to use RIDs, you have to know which RIDs exist. For the latest and complete version, see the PortableRuntimeIdentifierGraph.json in the dotnet/runtime repository.

RIDs that are considered 'portable'—that is, aren't tied to a specific version or OS distribution—are the recommended choice. This means that portable RIDs should be used for both building a platform-specific application and creating a NuGet package with RID-specific assets.

Starting with .NET 8, the default behavior of the .NET SDK and runtime is to only consider non-version-specific and non-distro-specific RIDs. When restoring and building, the SDK uses a smaller portable RID graph. The RuntimeInformation.RuntimeIdentifier returns the platform for which the runtime was built. At run time, .NET finds RID-specific assets using a known set of portable RIDs. When building an application with RID-specific assets that may be ignored at runtime, the SDK will emit a warning: NETSDK1206.

Loading assets for a specific OS version or distribution

.NET no longer attempts to provide first-class support for resolving dependencies that are specific to an OS version or distribution. If your application or package needs to load different assets based on OS version or distribution, it should implement the logic to conditionally load assets.

To get information about the platform, use System.OperatingSystem APIs. On Windows and macOS, Environment.OSVersion will return the operating system version. On Linux, it may be the kernel version—to get the Linux distro name and version information, the recommended approach is to read the /etc/os-release file.

.NET provides various extension points for customizing loading logic—for example, NativeLibrary.SetDllImportResolver(Assembly, DllImportResolver), AssemblyLoadContext.ResolvingUnmanagedDll, AssemblyLoadContext.Resolving, and AppDomain.AssemblyResolve. These can be used to load the asset corresponding to the current platform.

Known RIDs

The following list shows a small subset of the most common RIDs used for each OS. For the latest and complete version, see the PortableRuntimeIdentifierGraph.json in the dotnet/runtime repository.

Windows RIDs

  • win-x64
  • win-x86
  • win-arm64

For more information, see Install .NET on Windows.

Linux RIDs

  • linux-x64 (Most desktop distributions like CentOS Stream, Debian, Fedora, Ubuntu, and derivatives)
  • linux-musl-x64 (Lightweight distributions using musl like Alpine Linux)
  • linux-musl-arm64 (Used to build Docker images for 64-bit Arm v8 and minimalistic base images)
  • linux-arm (Linux distributions running on Arm like Raspbian on Raspberry Pi Model 2+)
  • linux-arm64 (Linux distributions running on 64-bit Arm like Ubuntu Server 64-bit on Raspberry Pi Model 3+)
  • linux-bionic-arm64 (Distributions using Android's bionic libc, for example, Termux)

For more information, see .NET dependencies and requirements.

macOS RIDs

macOS RIDs use the older "OSX" branding.

  • osx-x64 (Minimum OS version is macOS 10.12 Sierra)
  • osx-arm64

For more information, see .NET dependencies and requirements.

iOS RIDs

  • ios-arm64

Android RIDs

  • android-arm64

See also