I'm trying to integrate an interactive iOS Widget written in Swift with my Flutter app, and I'm running into issues with interactive AppIntents in my widget. My goal is to have a button in the widget that triggers an AppIntent, writes a value into Shared UserDefaults (using our app group), and then my Flutter app picks up that change.

I set my widget's deployment target to iOS 18 and I'm using Xcode 15, so I should have access to the new interactive widget APIs (like .appIntent or .buttonAction(intent:)). However, when I try to use these modifiers in my widget code, I get errors such as:

“.appIntent is not available in context” “Value of type 'Button' has no member 'appIntent'” I’ve tried cleaning the Derived Data folder, verified that the widget code is only in the widget target, and double-checked that the deployment target is correctly set for all relevant targets. Despite that, the interactive modifiers don’t work as expected.

Here's a minimal code snippet of my widget:

import WidgetKit
import SwiftUI
import AppIntents

struct SimpleAppIntent: AppIntent {
    static var title: LocalizedStringResource = "Simple Action"
    
    func perform() async throws -> some IntentResult {
        let userDefaults = UserDefaults(suiteName: "group.NSL_homescreenapp")
        userDefaults?.set("AppIntent Triggered", forKey: "flutter_action")
        WidgetCenter.shared.reloadTimelines(ofKind: "MyHomeWidget")
        return .result()
    }
}

struct MyHomeWidgetEntryView: View {
    var body: some View {
        if #available(iOS 17.0, *) {
            Button("Hard ios17") { }
                .buttonAction(intent: SimpleAppIntent())
                .buttonStyle(.bordered)
                .frame(maxWidth: .infinity)
        } else {
            Button("Hard ios irgendwas") { }
                .buttonStyle(.bordered)
                .frame(maxWidth: .infinity)
        }
    }
}

@main
struct MyHomeWidget: Widget {
    let kind: String = "MyHomeWidget"

    var body: some WidgetConfiguration {
        StaticConfiguration(kind: kind, provider: Provider()) { _ in
            MyHomeWidgetEntryView()
        }
        .configurationDisplayName("My Home Widget")
        .description("An interactive widget example using AppIntents.")
    }
}

struct Provider: TimelineProvider {
    func placeholder(in context: Context) -> SimpleEntry {
        SimpleEntry(date: Date(), message: "Placeholder")
    }
    
    func getSnapshot(in context: Context, completion: @escaping (SimpleEntry) -> Void) {
        let entry = SimpleEntry(date: Date(), message: "Snapshot")
        completion(entry)
    }
    
    func getTimeline(in context: Context, completion: @escaping (Timeline<SimpleEntry>) -> Void) {
        let entry = SimpleEntry(date: Date(), message: "Live Data")
        let timeline = Timeline(entries: [entry], policy: .atEnd)
        completion(timeline)
    }
}

struct SimpleEntry: TimelineEntry {
    let date: Date
    let message: String
}

which looks like that:

I’m confused because I’ve set everything as required: my widget target’s deployment target is iOS 18, I'm on Xcode 16.2, and I have imported AppIntents. Has anyone encountered similar issues with interactive widgets and AppIntents? Any ideas or workarounds would be appreciated!