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Supported on: iOS SDK 1.0.61+ · Android SDK 1.0.33+ · Flutter SDK 1.0.3+
The feature flags module lets you enable or disable features remotely from the AppDNA Console. Flags are evaluated locally from cached config — no network call, no latency on the hot path.

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Check a Flag

if (await AppDNA.features.isEnabled("dark_mode")) {
  enableDarkMode();
}
isEnabled() returns false by default if the flag does not exist or config has not loaded.

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Multi-Variant Flags

For flags that carry a string, integer, or JSON payload (rather than a simple on/off), read the value with getVariant: 
final variant = await AppDNA.features.getVariant("home_layout");

switch (variant) {
  case "compact":
    showCompactHome();
    break;
  case "detailed":
    showDetailedHome();
    break;
  default:
    showDefaultHome();
}
getVariant returns dynamic — cast to the type you configured in the Console.

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Module Access

final features = AppDNA.features;

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Module Methods

MethodSignatureDescription
isEnabledFuture<bool> isEnabled(String flag)Check if a feature flag is enabled
getVariantFuture<dynamic> getVariant(String flag)Get the variant payload for a multi-variant flag
onChangedvoid onChanged(Function callback)Register a callback that fires when flag values change

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Using Flags with Experiments

Gate a feature behind a flag, then run an experiment to test its impact: 
if (await AppDNA.features.isEnabled("new_workout_ui")) {
  final variant =
      await AppDNA.experiments.getVariant("workout_ui_test");

  switch (variant) {
    case "compact":
      showCompactWorkoutUI();
      break;
    case "detailed":
      showDetailedWorkoutUI();
      break;
    default:
      showDefaultWorkoutUI();
  }
} else {
  showLegacyWorkoutUI();
}

​
React to Flag Changes

Register an onChanged callback to re-render UI when the SDK receives an updated config from the server: 
AppDNA.features.onChanged(() {
  // Reload any UI that depends on feature flags.
  reloadHomeScreen();
});
The callback fires once per refresh, not per flag. Re-read the flags you care about inside the callback.

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Full Example

import 'package:appdna_sdk/appdna_sdk.dart';
import 'package:flutter/widgets.dart';

class FeatureGate {
  Future<void> checkAccess(
    String feature, {
    required VoidCallback onLocked,
    required VoidCallback onUnlocked,
  }) async {
    if (await AppDNA.features.isEnabled(feature)) {
      onUnlocked();
    } else {
      onLocked();
    }
  }
}

// Usage
final gate = FeatureGate();

await gate.checkAccess(
  "ai_suggestions",
  onLocked: () {
    AppDNA.paywall.present(
      "premium_paywall",
      context: PaywallContext(placement: "feature_gate"),
    );
  },
  onUnlocked: () {
    showAISuggestions();
  },
);

// React to remote changes
AppDNA.features.onChanged(() {
  // Re-evaluate gates when flags refresh.
});
Feature flags are managed in the Console under Settings > Feature Flags. Toggle a flag and it takes effect on the next SDK config refresh (default 5 minutes).