[SMAppService] Is there any useful debug log provided by the SMAppService APIs?

then request the status, I get the value 3

I think you’re being mislead by that status value. It doesn’t mean that things have gone wrong, but rather than the system knows nothing about your agent yet. That is, status is returning information about the service as it’s installed in the system, not about your property list.

Is there an official example for these new APIs?

Not that I’m aware of. Having said that, assuming a familiarity with launchd agents, I’ve found that this API is pretty straightforward to start out with. Indeed, I just took it for a spin:

1. I created a new Mac app test project.

2. Within that, I created an agent target from the command-line tool template.

3. I changed the code to look like this:

   import Foundation
   
   func main() {
       while true {
           print("Hello Cruel World!")
           sleep(10)
       }
   }
   
   main()
   

4. I added an Embed Helper Tools build phase, per the Embed the helper tool section of Embedding a command-line tool in a sandboxed app.

5. I added a com.example.apple-samplecode.Test721737.agent.plist property list to the project.

6. I changed it to look like this:

   …
   <plist version="1.0">
   <dict>
       <key>Label</key>
       <string>com.example.apple-samplecode.Test721737.agent</string>
       <key>BundleProgram</key>
       <string>Contents/MacOS/com.example.apple-samplecode.Test721737.agent</string>
   </dict>
   </plist>
   

7. I removed it from the app’s Copy Bundle Resources build phase and added it to a new Copy Agent Property Lists build phase, targeting Contents/Library/LaunchAgents.

8. In the app I wired up a button to run this code:

   let service = SMAppService.agent(plistName: "com.example.apple-samplecode.Test721737.agent.plist")
   
   @IBAction
   private func registerAction(_ sender: Any) {
       do {
           print("will register, status: \(service.status.rawValue)")
           try service.register()
           print("did register")
       } catch {
           print("did not register, error: \(error)")
       }
   }    
   

9. I built the app. It’s structure looks like this:

   % find Test721737.app
   Test721737.app
   Test721737.app/Contents
   Test721737.app/Contents/_CodeSignature
   Test721737.app/Contents/_CodeSignature/CodeResources
   Test721737.app/Contents/MacOS
   Test721737.app/Contents/MacOS/com.example.apple-samplecode.Test721737.agent
   Test721737.app/Contents/MacOS/Test721737
   Test721737.app/Contents/Resources
   Test721737.app/Contents/Resources/MainMenu.nib
   Test721737.app/Contents/Library
   Test721737.app/Contents/Library/LaunchAgents
   Test721737.app/Contents/Library/LaunchAgents/com.example.apple-samplecode.Test721737.agent.plist
   Test721737.app/Contents/Info.plist
   Test721737.app/Contents/PkgInfo
   

10. I clicked on the button to register the agent:

    will register, status: 3
    did register
    

11. In Terminal, I saw the agent registered:

    % launchctl list | grep com.example.apple-samplecode.Test721737.agent
    -      0   com.example.apple-samplecode.Test721737.agent
    

12. The agent isn’t running because it’s configured to launch on demand, and there is no demand. I manually start it and then confirmed that it’s now running:

    % launchctl start com.example.apple-samplecode.Test721737.agent
    % launchctl list | grep com.example.apple-samplecode.Test721737.agent
    53068   0   com.example.apple-samplecode.Test721737.agent
    

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—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"