.NET SDK 9

.NET SDK 9 provides the dotnet command-line tools, C#/F# build support and matching .NET and ASP.NET Core runtimes for developing and testing .NET 9 applications. It suits developers maintaining projects pinned to the 9.0 SDK feature band, including console tools, libraries and web services. It is not an IDE, and it does not make Windows-only desktop frameworks available on macOS.

Installation and platform

Run the official PKG or use brew install --cask dotnet-sdk@9. The exact 9.0.318 osx-arm64 PKG is 210,084,250 bytes and targets Apple Silicon; x64 packages are separate. Microsoft's current .NET 9 support matrix lists macOS 15, 26 and 27 for Arm 64 and x64. That supported-OS list is distinct from the lowest version on which an older binary might start; the specific installer minimum was not independently inspected. No fixed RAM minimum is stated for all SDK workloads. NuGet caches, build outputs and optional workloads can require significant storage beyond the installer.

Setup and project dependencies

The installer needs administrator permission. Check dotnet --info and dotnet --list-sdks after setup, and use a repository global.json when you need a specific SDK rather than whichever newer SDK is selected. The SDK includes matching .NET and ASP.NET Core runtimes; separate runtime installers are unnecessary for ordinary SDK use. Native tools, Apple workloads, Xcode and external libraries are additional requirements for projects that use them, not bundled guarantees of this package.

Lifecycle, accounts and networking

.NET 9 is an STS release in maintenance, with support ending November 10, 2026 according to Microsoft's checked policy. Plan a supported-version migration and test compatibility rather than assuming this pinned major version receives fixes indefinitely. Local compilation does not require a Microsoft account. Package restore, workload installation, updates and cloud deployment use network services; private feeds and Azure tooling can need credentials. The CLI collects documented telemetry unless you configure the relevant opt-out controls.

License and practical risks

The SDK repository uses MIT licensing with third-party notices. The tools are available at no cost, while private packages, commercial dependencies and hosted infrastructure have their own terms and charges. Build scripts and restored packages can execute code; review unfamiliar repositories and protect feed credentials. Test servicing updates against your project and deployment runtime, because SDK selection and runtime roll-forward can affect builds or execution. The illustration is Microsoft’s Windows Visual Studio Code console-app tutorial, showing a C# project and integrated terminal. Visual Studio Code and its debugging extension are companion tools, not a bundled SDK GUI or a capture of this Mac installer or SDK patch.

Sources: Official 9.0 release metadata, Mac installation, Supported operating systems, Support lifecycle, SDK license.