What is this?

This is a sample implementation of IMKit App with Swift/SwiftUI.

Working Environment

  • macOS 11.5
  • Swift 5.5
  • Xcode13 (beta)

Procedure to make project

  • Create new project. Bundle Identifier must contain .inputmethod. part in the String.

  • Run.

  • Remove IMKitSampleApp.swift, ContentView.swift

  • Add Swift files AppDelegate.swift and IMKitSampleInputController.swift.

    // AppDelegate.swift
    import Cocoa
    import InputMethodKit
    // necessary to launch this app
    class NSManualApplication: NSApplication {
        private let appDelegate = AppDelegate()
        override init() {
            self.delegate = appDelegate
        required init?(coder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
    class AppDelegate: NSObject, NSApplicationDelegate {
        var server = IMKServer()
        var candidatesWindow = IMKCandidates()
        func applicationDidFinishLaunching(_ notification: Notification) {
            // Insert code here to initialize your application
            server = IMKServer(name: Bundle.main.infoDictionary?["InputMethodConnectionName"] as? String, bundleIdentifier: Bundle.main.bundleIdentifier)
            candidatesWindow = IMKCandidates(server: server, panelType: kIMKSingleRowSteppingCandidatePanel, styleType: kIMKMain)
            NSLog("tried connection")
        func applicationWillTerminate(_ notification: Notification) {
            // Insert code here to tear down your application

    // IMKitSampleInputController.swift
    import Cocoa
    import InputMethodKit
    class IMKitSampleInputController: IMKInputController {
        override func inputText(_ string: String!, client sender: Any!) -> Bool {
            // get client to insert
            guard let client = sender as? IMKTextInput else {
                return false
            client.insertText(string+string, replacementRange: NSRange(location: NSNotFound, length: NSNotFound))
            return true
  • Add icon file main.tiff.

  • Modify Info.plist

    key: NSPrincipalClass  type: _  value: $(PRODUCT_MODULE_NAME).NSManualApplication
    key: InputMethodConnectionName  type: String  value: $(PRODUCT_BUNDLE_IDENTIFIER)_Connection
    key: InputMethodServerControllerClass  type: String  value: $(PRODUCT_MODULE_NAME).IMKitSampleInputController
    key: Application is background only  type: Boolean  value: YES
    key: tsInputMethodCharacterRepertoireKey  type: Array  value: [item0: String = Latn]
    key: tsInputMethodIconFileKey  type: String  value: main.tiff
  • Add entitlements

    • Go Signing & Capabilities+CapabilityApp Sandbox

    • Go IMKitSample.entitlements, add

      key: com.apple.security.temporary-exception.mach-register.global-name
      type: String
      value: $(PRODUCT_BUNDLE_IDENTIFIER)_Connection
  • Do sudo chmod -R 777 /Library/Input\ Methods on terminal.

  • Modify build settings.

    • Go Build LocationsBuild Products Path of debug → value “/Library/Input Methods`
    • Go +Add User-Defined Setting → Set key CONFIGURATION_BUILD_DIR, value /Library/Input Methods.
    • !!! DO NOT edit thinklessly, this setting is really fragile.
  • Try Run.

Trouble Shooting

I’m not expert of macOS. Please don’t ask too much, I don’t know either. It’s just my experience.

  • InputMethods says connection **Failed** all though there are no diff!

    • Open ‘Activity Monitor’ app, search the name of your InputMethods, and kill the process. Then try again.
  • print() doesn’t work!

    • Use NSLog().
  • App doesn’t run!

    • Check the path of build product file. If it isn’t at /Library/Input Methods/..., some thing went wrong.
    • Maybe build setting went wrong. Check the settings. Especially, if CONFIGURATION_BUILD_DIR=""; found, remove the line.
  • Where’s my InputMethod!?!?

    • Check English section. You would found it.


Thanks to authors!!