SmushSharp - Simple macOS URL Scheme Handler

A minimal C# wrapper for Smush—a tiny Objective-C shim that lets a .NET 8 app detect custom URL-scheme launches on macOS (x64).

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Prerequisites

• macOS with the Xcode command-line tools installed:

  xcode-select --install

• .NET 8 SDK (for dotnet build / pack / run).

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Compilation

Build the native shim & C# library From the src/SmushSharp folder:

dotnet build -c Release

You can find the output in bin/Release/net8.0

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Installing the NuGet package

Once you’ve packed, you can install the nuget package like this:

# from your own .NET app folder
dotnet add package SmushSharp --version 1.x.x --source .

Alternatively, you can get it from NuGet.org:

dotnet add package SmushSharp --version 1.x.x

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Usage

Register your URL scheme in your Info.plist (inside your .app bundle):

<key>CFBundleURLTypes</key>
<array>
  <dict>
    <key>CFBundleURLName</key>
    <string>com.yourcompany.yourapp</string>
    <key>CFBundleURLSchemes</key>
    <array>
      <string>your-custom-scheme</string>
    </array>
  </dict>
</array>

Call DetectLaunchUrl early in your Main:

using SmushSharp;

class Program
{
    static void Main(string[] args)
    {
        // Wait up to 1 seconds for a URL
        string? launchUrl = SmushSharp.DetectLaunchUrl(2.0);
        // Your code to handle the URL ...
    }
}

Run your app:

• Launch your app normally so that macOS can register the URL scheme. If necessary, you can manually register the URL scheme by running:

  /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -f <yourAppPath>.app

• If you now launch via open your-custom-scheme://foo, the URL will be detected by the code.

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