Building macOS apps with Flutter

This page discusses considerations unique to building macOS apps with Flutter, including shell integration and distribution of macOS apps through the Apple Store.

Integrating with macOS look and feel

While you can use any visual style or theme you choose to build a macOS app, you might want to adapt your app to more fully align with the macOS look and feel. Flutter includes the Cupertino widget set, which provides a set of widgets for the current iOS design language. Many of these widgets, including sliders, switches and segmented controls, are also appropriate for use on macOS.

Alternatively, you might find the macos_ui package a good fit for your needs. This package provides widgets and themes that implement the macOS design language, including a MacosWindow frame and scaffold, toolbars, pulldown and pop-up buttons, and modal dialogs.

Building macOS apps

To distribute your macOS application, you can either distribute it through the macOS App Store, or you can distribute the .app itself, perhaps from your own website. As of macOS 10.14.5, you need to notarize your macOS application before distributing it outside of the macOS App Store.

The first step in both of the above processes involves working with your application inside of Xcode. To be able to compile your application from inside of Xcode you first need to build the application for release using the flutter build command, then open the Flutter macOS Runner application.

flutter build macos
open macos/Runner.xcworkspace

Once inside of Xcode, follow either Apple’s documentation on notarizing macOS Applications, or on distributing an application through the App Store. You should also read through the macOS-specific support section below to understand how entitlements, the App Sandbox, and the Hardened Runtime impact your distributable application.

Build and release a macOS app provides a more detailed step-by-step walkthrough.

Entitlements and the App Sandbox

macOS builds are configured by default to be signed, and sandboxed with App Sandbox. This means that if you want to confer specific capabilities or services on your macOS app, such as the following:

  • Accessing the internet
  • Capturing movies and images from the built-in camera
  • Accessing files

Then you must set up specific entitlements in Xcode. The following section tells you how to do this.

Setting up entitlements

Managing sandbox settings is done in the macos/Runner/*.entitlements files. When editing these files, you shouldn’t remove the original Runner-DebugProfile.entitlements exceptions (that support incoming network connections and JIT), as they’re necessary for the debug and profile modes to function correctly.

If you’re used to managing entitlement files through the Xcode capabilities UI, be aware that the capabilities editor updates only one of the two files or, in some cases, it creates a whole new entitlements file and switches the project to use it for all configurations. Either scenario causes issues. We recommend that you edit the files directly. Unless you have a very specific reason, you should always make identical changes to both files.

If you keep the App Sandbox enabled (which is required if you plan to distribute your application in the App Store), you need to manage entitlements for your application when you add certain plugins or other native functionality. For instance, using the file_chooser plugin requires adding either the com.apple.security.files.user-selected.read-only or com.apple.security.files.user-selected.read-write entitlement. Another common entitlement is com.apple.security.network.client, which you must add if you make any network requests.

Without the com.apple.security.network.client entitlement, for example, network requests fail with a message such as:

flutter: SocketException: Connection failed
(OS Error: Operation not permitted, errno = 1),
address = example.com, port = 443

For more information on these topics, see App Sandbox and Entitlements on the Apple Developer site.

Hardened Runtime

If you choose to distribute your application outside of the App Store, you need to notarize your application for compatibility with macOS 10.15+. This requires enabling the Hardened Runtime option. Once you have enabled it, you need a valid signing certificate in order to build.

By default, the entitlements file allows JIT for debug builds but, as with App Sandbox, you might need to manage other entitlements. If you have both App Sandbox and Hardened Runtime enabled, you might need to add multiple entitlements for the same resource. For instance, microphone access would require both com.apple.security.device.audio-input (for Hardened Runtime) and com.apple.security.device.microphone (for App Sandbox).

For more information on this topic, see Hardened Runtime on the Apple Developer site.