feat(analytics): Add prefetchFlags Option

packages/mixpanel_flutter/android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterPlugin.java

@@ -264,6 +264,7 @@ private void handleInitialize(MethodCall call, Result result) {
         Boolean featureFlagsEnabled = null;
         JSONObject featureFlagsContext = null;
         VariantLookupPolicy variantLookupPolicy = null;
+        Boolean prefetchFlags = null;
         if (featureFlagsMap != null) {
             Object enabledValue = featureFlagsMap.get("enabled");
             if (enabledValue instanceof Boolean) {
@@ -285,6 +286,10 @@ private void handleInitialize(MethodCall call, Result result) {
                 Map<String, Object> policyMap = (Map<String, Object>) policyValue;
                 variantLookupPolicy = parseVariantLookupPolicy(policyMap);
             }
+            Object prefetchValue = featureFlagsMap.get("prefetchFlags");
+            if (prefetchValue instanceof Boolean) {
+                prefetchFlags = (Boolean) prefetchValue;
+            }
         }
 
         // Build MixpanelOptions with feature flags configuration
@@ -304,6 +309,9 @@ private void handleInitialize(MethodCall call, Result result) {
             if (variantLookupPolicy != null) {
                 ffBuilder.variantLookupPolicy(variantLookupPolicy);
             }
+            if (prefetchFlags != null) {
+                ffBuilder.prefetchFlags(prefetchFlags);
+            }
             optionsBuilder.featureFlagOptions(ffBuilder.build());
         }
 

packages/mixpanel_flutter/lib/mixpanel_flutter.dart

@@ -317,10 +317,22 @@ class FeatureFlagsConfig {
   /// native SDK defaults and pre-persistence behavior.
   final VariantLookupPolicy variantLookupPolicy;
 
+  /// Whether to eagerly fetch flags during initialization.
+  /// When `true` (default), the SDK automatically calls `loadFlags()` during
+  /// initialization so flags are ready (or close to ready) when accessed.
+  /// When `false`, flags are fetched lazily on first access or manually via
+  /// `loadFlags()` or `identify()`.
+  ///
+  /// Setting this to `false` is useful when you want to defer the initial
+  /// fetch until after calling `identify()` to ensure flags evaluate against
+  /// the correct user identity.
+  final bool prefetchFlags;
+
   const FeatureFlagsConfig({
     this.enabled = true,
     this.context = const {},
     this.variantLookupPolicy = const VariantLookupPolicy.networkOnly(),
+    this.prefetchFlags = true,
   });
 
   /// Converts this config to a Map for serialization.
@@ -329,6 +341,7 @@ class FeatureFlagsConfig {
       'enabled': enabled,
       'context': context,
       'variantLookupPolicy': variantLookupPolicy.toMap(),
+      'prefetchFlags': prefetchFlags,
     };
   }
 }

packages/mixpanel_flutter/lib/mixpanel_flutter_web.dart

@@ -238,6 +238,9 @@ class MixpanelFlutterPlugin {
         if (persistence != null) {
           flagsConfig['persistence'] = persistence;
         }
+        // Add prefetchFlags if provided, default to true
+        bool prefetchFlags = featureFlags['prefetchFlags'] ?? true;
+        flagsConfig['prefetchFlags'] = prefetchFlags;
         initConfig['flags'] = flagsConfig.isEmpty ? true : flagsConfig;
       }
     }

packages/mixpanel_flutter/swift/Classes/SwiftMixpanelFlutterPlugin.swift

@@ -264,9 +264,11 @@ public class SwiftMixpanelFlutterPlugin: NSObject, FlutterPlugin {
            let enabled = featureFlags["enabled"] as? Bool, enabled {
             let context = featureFlags["context"] as? [String: Any] ?? [:]
             let policy = parseVariantLookupPolicy(featureFlags["variantLookupPolicy"] as? [String: Any])
+            let prefetchFlags = featureFlags["prefetchFlags"] as? Bool ?? true
             featureFlagOptions = FeatureFlagOptions(
                 enabled: true,
                 context: context,
+                prefetchFlags: prefetchFlags,
                 variantLookupPolicy: policy
             )
         }

packages/mixpanel_flutter/test/mixpanel_flutter_test.dart

@@ -1260,6 +1260,7 @@ void main() {
               'enabled': true,
               'context': {'user_tier': 'premium'},
               'variantLookupPolicy': {'policy': 'networkOnly'},
+              'prefetchFlags': true,
             },
           },
         ),
@@ -1291,6 +1292,7 @@ void main() {
               'enabled': true,
               'context': <String, dynamic>{},
               'variantLookupPolicy': {'policy': 'networkOnly'},
+              'prefetchFlags': true,
             },
           },
         ),
@@ -1325,6 +1327,7 @@ void main() {
               'enabled': false,
               'context': {'user_tier': 'premium'},
               'variantLookupPolicy': {'policy': 'networkOnly'},
+              'prefetchFlags': true,
             },
           },
         ),
@@ -1373,18 +1376,56 @@ void main() {
       expect(map['enabled'], true);
       expect(map['context'], {'key': 'value'});
       expect(map['variantLookupPolicy'], {'policy': 'networkOnly'});
+      expect(map['prefetchFlags'], true);
     });
 
     test('FeatureFlagsConfig default values', () {
       final config = FeatureFlagsConfig();
       expect(config.enabled, true);
       expect(config.context, <String, dynamic>{});
       expect(config.variantLookupPolicy, isA<NetworkOnlyPolicy>());
+      expect(config.prefetchFlags, true);
 
       final map = config.toMap();
       expect(map['enabled'], true);
       expect(map['context'], <String, dynamic>{});
       expect(map['variantLookupPolicy'], {'policy': 'networkOnly'});
+      expect(map['prefetchFlags'], true);
+    });
+
+    test('FeatureFlagsConfig with prefetchFlags false', () async {
+      _mixpanel = await Mixpanel.init(
+        "test token",
+        optOutTrackingDefault: false,
+        trackAutomaticEvents: true,
+        featureFlags: FeatureFlagsConfig(
+          enabled: true,
+          prefetchFlags: false,
+        ),
+      );
+      expect(
+        methodCall,
+        isMethodCall(
+          'initialize',
+          arguments: <String, dynamic>{
+            'token': "test token",
+            'optOutTrackingDefault': false,
+            'trackAutomaticEvents': true,
+            'mixpanelProperties': {
+              '\$lib_version': sdkVersion,
+              'mp_lib': 'flutter',
+            },
+            'superProperties': null,
+            'config': null,
+            'featureFlags': {
+              'enabled': true,
+              'context': <String, dynamic>{},
+              'variantLookupPolicy': {'policy': 'networkOnly'},
+              'prefetchFlags': false,
+            },
+          },
+        ),
+      );
     });
 
     test(