Preparing your app to be the default translation app

Overview

In iOS and iPadOS 18.4 and later, a person can select an app other than Translate to handle text translation.

If your app provides translation service and you want it to optionally become the default translation app, you need to add an entitlement, access key, app extension, and a UI.

Add the Default Translation App entitlement to your project

Add the com.apple.developer.translation-app entitlement to the .entitlements file in your app’s Xcode project. For instructions on how to add this entitlement, see Translation.

Add the translation provider network access key to your app’s Info.plist

If your app needs to access the network in order to provide its translation services, you need to add the com.apple.developer.translation-ui-provider.network-access key to your app’s Info.plist.

To do this, perform these steps:

1. Select your app’s Info.plist file in the Xcode file navigator.

2. Add a new key and name it com.apple.developer.translation-ui-provider.network-access.

3. Set the key type to Boolean.

4. Set the key’s value to true.

Add a TranslationUIProviderExtension in your app

In the Xcode navigator, in your app’s target list, click the plus (+) and search for Translation. Click next and follow the prompts to add the app extension for Translation to your project.

Provide a translation UI to your app

The following example shows a typical workflow an app might adopt to present the translation UI to a person using their app:

import SwiftUI
import TranslationUIProvider

@main
class MyTranslationExtension: TranslationUIProviderExtension {

    var body: some TranslationUIProviderExtensionScene {
        TranslationUIProviderSelectedTextScene { context in
            MyTranslationView(context: context)
        }
    }
}

struct MyTranslationView: View {
    @State var context: TranslationUIProviderContext
    @State var translated: String = ""

    init(context c: TranslationUIProviderContext) {
        context = c
    }

    var body: some View {
        VStack(alignment: .leading) {
            Text(context.inputText ?? "")
            Text(translated)
            Button(action: translate) {
                Label("Translate", systemImage: "globe")
            }
            Button(action: replaceText) {
                Text("Replace With Translation")
            }
            .disabled(!context.allowsReplacement)
        }
    }

    // Perform the translation, leaving the UI visible.
    private func translate() {
        if let toTranslate = context.inputText, !toTranslate.characters.isEmpty {
            // Call your own, custom translation API.
            translated = String(toTranslate.characters.reversed())
        }
    }

    // Send the translation result back to the source text field, and exit.
    private func replaceText() {
        context.finish(replacingWithTranslation: AttributedString(translated))
    }
}