diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index 570cc706229..5d854091647 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,9 @@
+## 26.0.0
+
+* **Breaking Change** [dart] Changes name of constructors used to create subclasses of ProxyApis to
+  `pigeon_**original_name**`.
+* [dart] Adds ProxyApi overrides classes to be used in Flutter unit tests.
+
 ## 25.5.0
 
 * [dart] Changes the default InstanceManager and its initialization to no longer make a message call
diff --git a/packages/pigeon/lib/src/ast.dart b/packages/pigeon/lib/src/ast.dart
index 116654458e5..0cf4e4cd47f 100644
--- a/packages/pigeon/lib/src/ast.dart
+++ b/packages/pigeon/lib/src/ast.dart
@@ -240,34 +240,53 @@ class AstProxyApi extends Api {
   /// `implements`.
   Iterable<AstProxyApi> apisOfInterfaces() => _recursiveFindAllInterfaceApis();
 
-  /// All methods inherited from interfaces and the interfaces of interfaces.
-  Iterable<Method> flutterMethodsFromInterfaces() sync* {
+  /// Returns a record for each method inherited from an interface and its
+  /// corresponding ProxyApi.
+  Iterable<(Method, AstProxyApi)> flutterMethodsFromInterfacesWithApis() sync* {
     for (final AstProxyApi proxyApi in apisOfInterfaces()) {
-      yield* proxyApi.methods;
+      yield* proxyApi.methods.map((Method method) => (method, proxyApi));
     }
   }
 
-  /// A list of Flutter methods inherited from the ProxyApi that this ProxyApi
-  /// `extends`.
-  ///
-  /// This also recursively checks the ProxyApi that the super class `extends`
-  /// and so on.
+  /// Returns a record for each Flutter method inherited from [superClass].
   ///
   /// This also includes methods that super classes inherited from interfaces
   /// with `implements`.
-  Iterable<Method> flutterMethodsFromSuperClasses() sync* {
+  Iterable<(Method, AstProxyApi)>
+      flutterMethodsFromSuperClassesWithApis() sync* {
     for (final AstProxyApi proxyApi in allSuperClasses().toList().reversed) {
-      yield* proxyApi.flutterMethods;
+      yield* proxyApi.flutterMethods.map((Method method) => (method, proxyApi));
     }
     if (superClass != null) {
       final Set<AstProxyApi> interfaceApisFromSuperClasses =
           superClass!.associatedProxyApi!._recursiveFindAllInterfaceApis();
       for (final AstProxyApi proxyApi in interfaceApisFromSuperClasses) {
-        yield* proxyApi.methods;
+        yield* proxyApi.methods.map((Method method) => (method, proxyApi));
       }
     }
   }
 
+  /// All methods inherited from interfaces and the interfaces of interfaces.
+  Iterable<Method> flutterMethodsFromInterfaces() sync* {
+    yield* flutterMethodsFromInterfacesWithApis().map(
+      ((Method, AstProxyApi) method) => method.$1,
+    );
+  }
+
+  /// A list of Flutter methods inherited from the ProxyApi that this ProxyApi
+  /// `extends`.
+  ///
+  /// This also recursively checks the ProxyApi that the super class `extends`
+  /// and so on.
+  ///
+  /// This also includes methods that super classes inherited from interfaces
+  /// with `implements`.
+  Iterable<Method> flutterMethodsFromSuperClasses() sync* {
+    yield* flutterMethodsFromSuperClassesWithApis().map(
+      ((Method, AstProxyApi) method) => method.$1,
+    );
+  }
+
   /// Whether the API has a method that callbacks to Dart to add a new instance
   /// to the InstanceManager.
   ///
diff --git a/packages/pigeon/lib/src/dart/dart_generator.dart b/packages/pigeon/lib/src/dart/dart_generator.dart
index 2dcb9b2efad..c87eb456cd5 100644
--- a/packages/pigeon/lib/src/dart/dart_generator.dart
+++ b/packages/pigeon/lib/src/dart/dart_generator.dart
@@ -11,6 +11,7 @@ import '../ast.dart';
 import '../functional.dart';
 import '../generator.dart';
 import '../generator_tools.dart';
+import 'proxy_api_generator_helper.dart' as proxy_api_helper;
 import 'templates.dart';
 
 /// Documentation comment open symbol.
@@ -20,14 +21,13 @@ const String _docCommentPrefix = '///';
 const String _suffixVarName = '${varNamePrefix}messageChannelSuffix';
 
 /// Name of the `InstanceManager` variable for a ProxyApi class;
-const String _instanceManagerVarName =
-    '${classMemberNamePrefix}instanceManager';
+const String instanceManagerVarName = '${classMemberNamePrefix}instanceManager';
 
 /// Name of field used for host API codec.
 const String _pigeonChannelCodec = 'pigeonChannelCodec';
 
 /// Documentation comment spec.
-const DocumentCommentSpecification _docCommentSpec =
+const DocumentCommentSpecification docCommentSpec =
     DocumentCommentSpecification(_docCommentPrefix);
 
 /// The custom codec used for all pigeon APIs.
@@ -38,6 +38,10 @@ const String _pigeonMethodChannelCodec = 'pigeonMethodCodec';
 
 const String _overflowClassName = '_PigeonCodecOverflow';
 
+/// Name of the overrides class for overriding constructors and static members
+/// of proxy APIs.
+const String proxyApiOverridesClassName = '${proxyApiClassNamePrefix}Overrides';
+
 /// Options that control how Dart code will be generated.
 class DartOptions {
   /// Constructor for DartOptions.
@@ -120,6 +124,11 @@ class DartGenerator extends StructuredGenerator<InternalDartOptions> {
   /// Instantiates a Dart Generator.
   const DartGenerator();
 
+  // Formatter used to format code from `code_builder`.
+  DartFormatter get _formatter {
+    return DartFormatter(languageVersion: Version(3, 6, 0));
+  }
+
   @override
   void writeFilePrologue(
     InternalDartOptions generatorOptions,
@@ -155,7 +164,7 @@ class DartGenerator extends StructuredGenerator<InternalDartOptions> {
     indent.newln();
 
     indent.writeln(
-        "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer${root.containsProxyApi ? ', immutable, protected' : ''};");
+        "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer${root.containsProxyApi ? ', immutable, protected, visibleForTesting' : ''};");
     indent.writeln("import 'package:flutter/services.dart';");
     if (root.containsProxyApi) {
       indent.writeln(
@@ -174,12 +183,12 @@ class DartGenerator extends StructuredGenerator<InternalDartOptions> {
   }) {
     indent.newln();
     addDocumentationComments(
-        indent, anEnum.documentationComments, _docCommentSpec);
+        indent, anEnum.documentationComments, docCommentSpec);
     indent.write('enum ${anEnum.name} ');
     indent.addScoped('{', '}', () {
       for (final EnumMember member in anEnum.members) {
         addDocumentationComments(
-            indent, member.documentationComments, _docCommentSpec);
+            indent, member.documentationComments, docCommentSpec);
         indent.writeln('${member.name},');
       }
     });
@@ -195,7 +204,7 @@ class DartGenerator extends StructuredGenerator<InternalDartOptions> {
   }) {
     indent.newln();
     addDocumentationComments(
-        indent, classDefinition.documentationComments, _docCommentSpec);
+        indent, classDefinition.documentationComments, docCommentSpec);
     final String sealed = classDefinition.isSealed ? 'sealed ' : '';
     final String implements = classDefinition.superClassName != null
         ? 'extends ${classDefinition.superClassName} '
@@ -211,9 +220,9 @@ class DartGenerator extends StructuredGenerator<InternalDartOptions> {
       for (final NamedType field
           in getFieldsInSerializationOrder(classDefinition)) {
         addDocumentationComments(
-            indent, field.documentationComments, _docCommentSpec);
+            indent, field.documentationComments, docCommentSpec);
 
-        final String datatype = _addGenericTypesNullable(field.type);
+        final String datatype = addGenericTypesNullable(field.type);
         indent.writeln('$datatype ${field.name};');
         indent.newln();
       }
@@ -500,8 +509,7 @@ class DartGenerator extends StructuredGenerator<InternalDartOptions> {
     required String dartPackageName,
   }) {
     indent.newln();
-    addDocumentationComments(
-        indent, api.documentationComments, _docCommentSpec);
+    addDocumentationComments(indent, api.documentationComments, docCommentSpec);
 
     indent.write('abstract class ${api.name} ');
     indent.addScoped('{', '}', () {
@@ -514,12 +522,12 @@ class DartGenerator extends StructuredGenerator<InternalDartOptions> {
       indent.newln();
       for (final Method func in api.methods) {
         addDocumentationComments(
-            indent, func.documentationComments, _docCommentSpec);
+            indent, func.documentationComments, docCommentSpec);
 
         final bool isAsync = func.isAsynchronous;
         final String returnType = isAsync
-            ? 'Future<${_addGenericTypesNullable(func.returnType)}>'
-            : _addGenericTypesNullable(func.returnType);
+            ? 'Future<${addGenericTypesNullable(func.returnType)}>'
+            : addGenericTypesNullable(func.returnType);
         final String argSignature =
             _getMethodParameterSignature(func.parameters);
         indent.writeln('$returnType ${func.name}($argSignature);');
@@ -576,8 +584,7 @@ class DartGenerator extends StructuredGenerator<InternalDartOptions> {
   }) {
     indent.newln();
     bool first = true;
-    addDocumentationComments(
-        indent, api.documentationComments, _docCommentSpec);
+    addDocumentationComments(indent, api.documentationComments, docCommentSpec);
     indent.write('class ${api.name} ');
     indent.addScoped('{', '}', () {
       indent.format('''
@@ -623,8 +630,7 @@ final BinaryMessenger? ${varNamePrefix}binaryMessenger;
     required String dartPackageName,
   }) {
     indent.newln();
-    addDocumentationComments(
-        indent, api.documentationComments, _docCommentSpec);
+    addDocumentationComments(indent, api.documentationComments, docCommentSpec);
     for (final Method func in api.methods) {
       indent.format('''
       Stream<${func.returnType.baseName}> ${func.name}(${_getMethodParameterSignature(func.parameters, addTrailingComma: true)} {String instanceName = ''}) {
@@ -896,7 +902,7 @@ final BinaryMessenger? ${varNamePrefix}binaryMessenger;
           ),
         )
         ..docs.addAll(
-          asDocumentationComments(api.documentationComments, _docCommentSpec),
+          asDocumentationComments(api.documentationComments, docCommentSpec),
         )
         ..constructors.addAll(_proxyApiConstructors(
           api.constructors,
@@ -906,8 +912,10 @@ final BinaryMessenger? ${varNamePrefix}binaryMessenger;
           codecInstanceName: codecInstanceName,
           superClassApi: api.superClass?.associatedProxyApi,
           unattachedFields: api.unattachedFields,
-          flutterMethodsFromSuperClasses: api.flutterMethodsFromSuperClasses(),
-          flutterMethodsFromInterfaces: api.flutterMethodsFromInterfaces(),
+          flutterMethodsFromSuperClasses:
+              api.flutterMethodsFromSuperClassesWithApis(),
+          flutterMethodsFromInterfaces:
+              api.flutterMethodsFromInterfacesWithApis(),
           declaredFlutterMethods: api.flutterMethods,
         ))
         ..constructors.add(
@@ -916,8 +924,9 @@ final BinaryMessenger? ${varNamePrefix}binaryMessenger;
             superClassApi: api.superClass?.associatedProxyApi,
             unattachedFields: api.unattachedFields,
             flutterMethodsFromSuperClasses:
-                api.flutterMethodsFromSuperClasses(),
-            flutterMethodsFromInterfaces: api.flutterMethodsFromInterfaces(),
+                api.flutterMethodsFromSuperClassesWithApis(),
+            flutterMethodsFromInterfaces:
+                api.flutterMethodsFromInterfacesWithApis(),
             declaredFlutterMethods: api.flutterMethods,
           ),
         )
@@ -937,6 +946,10 @@ final BinaryMessenger? ${varNamePrefix}binaryMessenger;
         ))
         ..fields.addAll(_proxyApiInterfaceApiFields(api.apisOfInterfaces()))
         ..fields.addAll(_proxyApiAttachedFields(api.attachedFields))
+        ..methods.addAll(proxy_api_helper.staticAttachedFieldsGetters(
+          api.attachedFields.where((ApiField field) => field.isStatic),
+          apiName: api.name,
+        ))
         ..methods.add(
           _proxyApiSetUpMessageHandlerMethod(
             flutterMethods: api.flutterMethods,
@@ -967,17 +980,17 @@ final BinaryMessenger? ${varNamePrefix}binaryMessenger;
           _proxyApiCopyMethod(
             apiName: api.name,
             unattachedFields: api.unattachedFields,
-            declaredAndInheritedFlutterMethods: api
-                .flutterMethodsFromSuperClasses()
-                .followedBy(api.flutterMethodsFromInterfaces())
-                .followedBy(api.flutterMethods),
+            flutterMethodsFromSuperClasses:
+                api.flutterMethodsFromSuperClassesWithApis(),
+            flutterMethodsFromInterfaces:
+                api.flutterMethodsFromInterfacesWithApis(),
+            declaredFlutterMethods: api.flutterMethods,
           ),
         ),
     );
 
     final cb.DartEmitter emitter = cb.DartEmitter(useNullSafetySyntax: true);
-    indent.format(DartFormatter(languageVersion: Version(3, 6, 0))
-        .format('${proxyApi.accept(emitter)}'));
+    indent.format(_formatter.format('${proxyApi.accept(emitter)}'));
   }
 
   /// Generates Dart source code for test support libraries based on the given AST
@@ -1080,6 +1093,13 @@ final BinaryMessenger? ${varNamePrefix}binaryMessenger;
     if (root.classes.isNotEmpty) {
       _writeDeepEquals(indent);
     }
+    if (root.containsProxyApi) {
+      proxy_api_helper.writeProxyApiPigeonOverrides(
+        indent,
+        formatter: _formatter,
+        proxyApis: root.apis.whereType(),
+      );
+    }
   }
 
   /// Writes [wrapResponse] method.
@@ -1189,10 +1209,10 @@ if (wrapped == null) {
     required String channelName,
     required bool addSuffixVariable,
   }) {
-    addDocumentationComments(indent, documentationComments, _docCommentSpec);
+    addDocumentationComments(indent, documentationComments, docCommentSpec);
     final String argSignature = _getMethodParameterSignature(parameters);
     indent.write(
-      'Future<${_addGenericTypesNullable(returnType)}> $name($argSignature) async ',
+      'Future<${addGenericTypesNullable(returnType)}> $name($argSignature) async ',
     );
     indent.addScoped('{', '}', () {
       _writeHostMethodMessageCall(
@@ -1217,7 +1237,7 @@ if (wrapped == null) {
     if (parameters.isNotEmpty) {
       final Iterable<String> argExpressions =
           indexMap(parameters, (int index, NamedType type) {
-        final String name = _getParameterName(index, type);
+        final String name = getParameterName(index, type);
         return name;
       });
       sendArgument = '<Object?>[${argExpressions.join(', ')}]';
@@ -1334,7 +1354,7 @@ if (${varNamePrefix}replyList == null) {
           '$messageHandlerSetterWithOpeningParentheses(Object? message) async ',
         );
         indent.addScoped('{', '});', () {
-          final String returnTypeString = _addGenericTypesNullable(returnType);
+          final String returnTypeString = addGenericTypesNullable(returnType);
           final bool isAsync = isAsynchronous;
           const String emptyReturnStatement =
               'return wrapResponse(empty: true);';
@@ -1416,8 +1436,12 @@ if (${varNamePrefix}replyList == null) {
     return 'api.$methodName(${safeArgumentNames.join(', ')})';
   }
 
-  /// Converts Constructors from the pigeon AST to a `code_builder` Constructor
+  /// Converts Constructors from the pigeon AST to `code_builder` Constructors
   /// for a ProxyApi.
+  ///
+  /// Creates a factory constructor that can return an overrideable static
+  /// method for testing and a constructor that calls to the native
+  /// API implementation
   Iterable<cb.Constructor> _proxyApiConstructors(
     Iterable<Constructor> constructors, {
     required String apiName,
@@ -1426,8 +1450,8 @@ if (${varNamePrefix}replyList == null) {
     required String codecInstanceName,
     required AstProxyApi? superClassApi,
     required Iterable<ApiField> unattachedFields,
-    required Iterable<Method> flutterMethodsFromSuperClasses,
-    required Iterable<Method> flutterMethodsFromInterfaces,
+    required Iterable<(Method, AstProxyApi)> flutterMethodsFromSuperClasses,
+    required Iterable<(Method, AstProxyApi)> flutterMethodsFromInterfaces,
     required Iterable<Method> declaredFlutterMethods,
   }) sync* {
     final cb.Parameter binaryMessengerParameter = cb.Parameter(
@@ -1436,13 +1460,86 @@ if (${varNamePrefix}replyList == null) {
         ..named = true
         ..toSuper = true,
     );
-    final cb.Parameter instanceManagerParameter = cb.Parameter(
-      (cb.ParameterBuilder builder) => builder
-        ..name = _instanceManagerVarName
-        ..named = true
-        ..toSuper = true,
-    );
+
     for (final Constructor constructor in constructors) {
+      final String? factoryConstructorName =
+          constructor.name.isNotEmpty ? constructor.name : null;
+      final String constructorName =
+          '$classMemberNamePrefix${constructor.name.isNotEmpty ? constructor.name : 'new'}';
+      final String overridesConstructorName = constructor.name.isNotEmpty
+          ? '${toLowerCamelCase(apiName)}_${constructor.name}'
+          : '${toLowerCamelCase(apiName)}_new';
+
+      // Factory constructor that forwards the parameters to the overrides class
+      // or to the constructor yielded below this one.
+      yield cb.Constructor(
+        (cb.ConstructorBuilder builder) {
+          final Iterable<cb.Parameter> parameters =
+              proxy_api_helper.asConstructorParameters(
+            apiName: apiName,
+            parameters: constructor.parameters,
+            unattachedFields: unattachedFields,
+            flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
+            flutterMethodsFromInterfaces: flutterMethodsFromInterfaces,
+            declaredFlutterMethods: declaredFlutterMethods,
+          );
+          final Iterable<cb.Parameter> parametersWithoutMessengerAndManager =
+              proxy_api_helper.asConstructorParameters(
+            apiName: apiName,
+            parameters: constructor.parameters,
+            unattachedFields: unattachedFields,
+            flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
+            flutterMethodsFromInterfaces: flutterMethodsFromInterfaces,
+            declaredFlutterMethods: declaredFlutterMethods,
+            includeBinaryMessengerAndInstanceManager: false,
+          );
+          builder
+            ..name = factoryConstructorName
+            ..factory = true
+            ..docs.addAll(asDocumentationComments(
+              constructor.documentationComments,
+              docCommentSpec,
+            ))
+            ..optionalParameters.addAll(parameters)
+            ..body = cb.Block(
+              (cb.BlockBuilder builder) {
+                final Map<String, cb.Expression> forwardedParams =
+                    <String, cb.Expression>{
+                  for (final cb.Parameter parameter in parameters)
+                    parameter.name: cb.refer(parameter.name)
+                };
+                final Map<String, cb.Expression>
+                    forwardedParamsWithoutMessengerAndManager =
+                    <String, cb.Expression>{
+                  for (final cb.Parameter parameter
+                      in parametersWithoutMessengerAndManager)
+                    parameter.name: cb.refer(parameter.name)
+                };
+
+                builder.statements.addAll(<cb.Code>[
+                  cb.Code(
+                      'if ($proxyApiOverridesClassName.$overridesConstructorName != null) {'),
+                  cb.CodeExpression(
+                    cb.Code(
+                        '$proxyApiOverridesClassName.$overridesConstructorName!'),
+                  )
+                      .call(
+                        <cb.Expression>[],
+                        forwardedParamsWithoutMessengerAndManager,
+                      )
+                      .returned
+                      .statement,
+                  const cb.Code('}'),
+                  cb.CodeExpression(cb.Code('$apiName.$constructorName'))
+                      .call(<cb.Expression>[], forwardedParams)
+                      .returned
+                      .statement,
+                ]);
+              },
+            );
+        },
+      );
+
       yield cb.Constructor(
         (cb.ConstructorBuilder builder) {
           final String channelName = makeChannelNameWithStrings(
@@ -1453,52 +1550,22 @@ if (${varNamePrefix}replyList == null) {
             dartPackageName: dartPackageName,
           );
           builder
-            ..name = constructor.name.isNotEmpty ? constructor.name : null
+            ..name = constructorName
+            ..annotations.add(cb.refer('protected'))
             ..docs.addAll(asDocumentationComments(
               constructor.documentationComments,
-              _docCommentSpec,
+              docCommentSpec,
+            ))
+            ..optionalParameters
+                .addAll(proxy_api_helper.asConstructorParameters(
+              apiName: apiName,
+              parameters: constructor.parameters,
+              unattachedFields: unattachedFields,
+              flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
+              flutterMethodsFromInterfaces: flutterMethodsFromInterfaces,
+              declaredFlutterMethods: declaredFlutterMethods,
+              defineType: false,
             ))
-            ..optionalParameters.addAll(
-              <cb.Parameter>[
-                binaryMessengerParameter,
-                instanceManagerParameter,
-                for (final ApiField field in unattachedFields)
-                  cb.Parameter(
-                    (cb.ParameterBuilder builder) => builder
-                      ..name = field.name
-                      ..named = true
-                      ..toThis = true
-                      ..required = !field.type.isNullable,
-                  ),
-                for (final Method method in flutterMethodsFromSuperClasses)
-                  cb.Parameter(
-                    (cb.ParameterBuilder builder) => builder
-                      ..name = method.name
-                      ..named = true
-                      ..toSuper = true
-                      ..required = method.isRequired,
-                  ),
-                for (final Method method in flutterMethodsFromInterfaces
-                    .followedBy(declaredFlutterMethods))
-                  cb.Parameter(
-                    (cb.ParameterBuilder builder) => builder
-                      ..name = method.name
-                      ..named = true
-                      ..toThis = true
-                      ..required = method.isRequired,
-                  ),
-                ...indexMap(
-                  constructor.parameters,
-                  (int index, NamedType parameter) => cb.Parameter(
-                    (cb.ParameterBuilder builder) => builder
-                      ..name = _getParameterName(index, parameter)
-                      ..type = _refer(parameter.type)
-                      ..named = true
-                      ..required = !parameter.type.isNullable,
-                  ),
-                )
-              ],
-            )
             ..initializers.addAll(
               <cb.Code>[
                 if (superClassApi != null)
@@ -1534,7 +1601,7 @@ if (${varNamePrefix}replyList == null) {
 
                 builder.statements.addAll(<cb.Code>[
                   const cb.Code(
-                    'final int ${varNamePrefix}instanceIdentifier = $_instanceManagerVarName.addDartCreatedInstance(this);',
+                    'final int ${varNamePrefix}instanceIdentifier = $instanceManagerVarName.addDartCreatedInstance(this);',
                   ),
                   cb.Code('final $codecName $_pigeonChannelCodec =\n'
                       '    $codecInstanceName;'),
@@ -1560,22 +1627,10 @@ if (${varNamePrefix}replyList == null) {
     required String apiName,
     required AstProxyApi? superClassApi,
     required Iterable<ApiField> unattachedFields,
-    required Iterable<Method> flutterMethodsFromSuperClasses,
-    required Iterable<Method> flutterMethodsFromInterfaces,
+    required Iterable<(Method, AstProxyApi)> flutterMethodsFromSuperClasses,
+    required Iterable<(Method, AstProxyApi)> flutterMethodsFromInterfaces,
     required Iterable<Method> declaredFlutterMethods,
   }) {
-    final cb.Parameter binaryMessengerParameter = cb.Parameter(
-      (cb.ParameterBuilder builder) => builder
-        ..name = '${classMemberNamePrefix}binaryMessenger'
-        ..named = true
-        ..toSuper = true,
-    );
-    final cb.Parameter instanceManagerParameter = cb.Parameter(
-      (cb.ParameterBuilder builder) => builder
-        ..name = _instanceManagerVarName
-        ..named = true
-        ..toSuper = true,
-    );
     return cb.Constructor(
       (cb.ConstructorBuilder builder) => builder
         ..name = '${classMemberNamePrefix}detached'
@@ -1586,35 +1641,15 @@ if (${varNamePrefix}replyList == null) {
           '/// create copies for an [$dartInstanceManagerClassName].',
         ])
         ..annotations.add(cb.refer('protected'))
-        ..optionalParameters.addAll(<cb.Parameter>[
-          binaryMessengerParameter,
-          instanceManagerParameter,
-          for (final ApiField field in unattachedFields)
-            cb.Parameter(
-              (cb.ParameterBuilder builder) => builder
-                ..name = field.name
-                ..named = true
-                ..toThis = true
-                ..required = !field.type.isNullable,
-            ),
-          for (final Method method in flutterMethodsFromSuperClasses)
-            cb.Parameter(
-              (cb.ParameterBuilder builder) => builder
-                ..name = method.name
-                ..named = true
-                ..toSuper = true
-                ..required = method.isRequired,
-            ),
-          for (final Method method in flutterMethodsFromInterfaces
-              .followedBy(declaredFlutterMethods))
-            cb.Parameter(
-              (cb.ParameterBuilder builder) => builder
-                ..name = method.name
-                ..named = true
-                ..toThis = true
-                ..required = method.isRequired,
-            ),
-        ])
+        ..optionalParameters.addAll(proxy_api_helper.asConstructorParameters(
+          apiName: apiName,
+          parameters: <Parameter>[],
+          unattachedFields: unattachedFields,
+          flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
+          flutterMethodsFromInterfaces: flutterMethodsFromInterfaces,
+          declaredFlutterMethods: declaredFlutterMethods,
+          defineType: false,
+        ))
         ..initializers.addAll(<cb.Code>[
           if (superClassApi != null)
             const cb.Code('super.${classMemberNamePrefix}detached()'),
@@ -1633,7 +1668,7 @@ if (${varNamePrefix}replyList == null) {
         ..type = cb.refer(codecName)
         ..late = true
         ..modifier = cb.FieldModifier.final$
-        ..assignment = cb.Code('$codecName($_instanceManagerVarName)'),
+        ..assignment = cb.Code('$codecName($instanceManagerVarName)'),
     );
   }
 
@@ -1646,11 +1681,11 @@ if (${varNamePrefix}replyList == null) {
       yield cb.Field(
         (cb.FieldBuilder builder) => builder
           ..name = field.name
-          ..type = cb.refer(_addGenericTypesNullable(field.type))
+          ..type = cb.refer(addGenericTypesNullable(field.type))
           ..modifier = cb.FieldModifier.final$
           ..docs.addAll(asDocumentationComments(
             field.documentationComments,
-            _docCommentSpec,
+            docCommentSpec,
           )),
       );
     }
@@ -1694,27 +1729,10 @@ if (${varNamePrefix}replyList == null) {
                 'release the associated Native object manually.',
               ],
             ],
-            _docCommentSpec,
+            docCommentSpec,
           ))
-          ..type = cb.FunctionType(
-            (cb.FunctionTypeBuilder builder) => builder
-              ..returnType = _refer(
-                method.returnType,
-                asFuture: method.isAsynchronous,
-              )
-              ..isNullable = !method.isRequired
-              ..requiredParameters.addAll(<cb.Reference>[
-                cb.refer('$apiName ${classMemberNamePrefix}instance'),
-                ...indexMap(
-                  method.parameters,
-                  (int index, NamedType parameter) {
-                    return cb.refer(
-                      '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
-                    );
-                  },
-                ),
-              ]),
-          ),
+          ..type =
+              proxy_api_helper.methodAsFunctionType(method, apiName: apiName),
       );
     }
   }
@@ -1739,11 +1757,11 @@ if (${varNamePrefix}replyList == null) {
             ..annotations.add(cb.refer('override'))
             ..docs.addAll(asDocumentationComments(
               method.documentationComments,
-              _docCommentSpec,
+              docCommentSpec,
             ))
             ..type = cb.FunctionType(
               (cb.FunctionTypeBuilder builder) => builder
-                ..returnType = _refer(
+                ..returnType = refer(
                   method.returnType,
                   asFuture: method.isAsynchronous,
                 )
@@ -1756,7 +1774,7 @@ if (${varNamePrefix}replyList == null) {
                     method.parameters,
                     (int index, NamedType parameter) {
                       return cb.refer(
-                        '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
+                        '${addGenericTypesNullable(parameter.type)} ${getParameterName(index, parameter)}',
                       );
                     },
                   ),
@@ -1781,14 +1799,14 @@ if (${varNamePrefix}replyList == null) {
     for (final ApiField field in fields) {
       yield cb.Field(
         (cb.FieldBuilder builder) => builder
-          ..name = field.name
-          ..type = cb.refer(_addGenericTypesNullable(field.type))
+          ..name = '${field.isStatic ? '_' : ''}${field.name}'
+          ..type = cb.refer(addGenericTypesNullable(field.type))
           ..modifier = cb.FieldModifier.final$
           ..static = field.isStatic
           ..late = !field.isStatic
           ..docs.addAll(asDocumentationComments(
             field.documentationComments,
-            _docCommentSpec,
+            docCommentSpec,
           ))
           ..assignment = cb.Code('$varNamePrefix${field.name}()'),
       );
@@ -1834,7 +1852,7 @@ if (${varNamePrefix}replyList == null) {
           ),
           cb.Parameter(
             (cb.ParameterBuilder builder) => builder
-              ..name = _instanceManagerVarName
+              ..name = instanceManagerVarName
               ..named = true
               ..type = cb.refer('$dartInstanceManagerClassName?'),
           ),
@@ -1852,7 +1870,7 @@ if (${varNamePrefix}replyList == null) {
                         unattachedFields,
                         (int index, ApiField field) {
                           return cb.refer(
-                            '${_addGenericTypesNullable(field.type)} ${_getParameterName(index, field)}',
+                            '${addGenericTypesNullable(field.type)} ${getParameterName(index, field)}',
                           );
                         },
                       ),
@@ -1865,7 +1883,7 @@ if (${varNamePrefix}replyList == null) {
                 ..name = method.name
                 ..type = cb.FunctionType(
                   (cb.FunctionTypeBuilder builder) => builder
-                    ..returnType = _refer(
+                    ..returnType = refer(
                       method.returnType,
                       asFuture: method.isAsynchronous,
                     )
@@ -1876,7 +1894,7 @@ if (${varNamePrefix}replyList == null) {
                         method.parameters,
                         (int index, NamedType parameter) {
                           return cb.refer(
-                            '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
+                            '${addGenericTypesNullable(parameter.type)} ${getParameterName(index, parameter)}',
                           );
                         },
                       ),
@@ -1887,7 +1905,7 @@ if (${varNamePrefix}replyList == null) {
         ..body = cb.Block.of(<cb.Code>[
           if (hasAnyMessageHandlers) ...<cb.Code>[
             cb.Code(
-              'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $dartInstanceManagerClassName.instance);',
+              'final $codecName $_pigeonChannelCodec = $codecName($instanceManagerVarName ?? $dartInstanceManagerClassName.instance);',
             ),
             const cb.Code(
               'final BinaryMessenger? binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
@@ -1935,12 +1953,12 @@ if (${varNamePrefix}replyList == null) {
                       return '${parameter.name}: $safeArgName,\n';
                     },
                   ).skip(1).join();
-                  return '($_instanceManagerVarName ?? $dartInstanceManagerClassName.instance)\n'
+                  return '($instanceManagerVarName ?? $dartInstanceManagerClassName.instance)\n'
                       '    .addHostCreatedInstance(\n'
                       '  $methodName?.call(${safeArgumentNames.skip(1).join(',')}) ??\n'
                       '      $apiName.${classMemberNamePrefix}detached('
                       '        ${classMemberNamePrefix}binaryMessenger: ${classMemberNamePrefix}binaryMessenger,\n'
-                      '        $_instanceManagerVarName: $_instanceManagerVarName,\n'
+                      '        $instanceManagerVarName: $instanceManagerVarName,\n'
                       '        $argsAsNamedParams\n'
                       '      ),\n'
                       '  ${safeArgumentNames.first},\n'
@@ -2012,7 +2030,7 @@ if (${varNamePrefix}replyList == null) {
     for (final ApiField field in fields) {
       yield cb.Method(
         (cb.MethodBuilder builder) {
-          final String type = _addGenericTypesNullable(field.type);
+          final String type = addGenericTypesNullable(field.type);
           const String instanceName = '${varNamePrefix}instance';
           const String identifierInstanceName =
               '${varNamePrefix}instanceIdentifier';
@@ -2064,7 +2082,7 @@ if (${varNamePrefix}replyList == null) {
                       'final BinaryMessenger? ${varNamePrefix}binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
                     ),
                     const cb.Code(
-                      'final int $identifierInstanceName = $_instanceManagerVarName.addDartCreatedInstance($instanceName);',
+                      'final int $identifierInstanceName = $instanceManagerVarName.addDartCreatedInstance($instanceName);',
                     ),
                   ] else ...<cb.Code>[
                     cb.Code(
@@ -2105,6 +2123,16 @@ if (${varNamePrefix}replyList == null) {
   }) sync* {
     for (final Method method in methods) {
       assert(method.location == ApiLocation.host);
+      final Iterable<cb.Parameter> parameters = indexMap(
+        method.parameters,
+        (int index, NamedType parameter) => cb.Parameter(
+          (cb.ParameterBuilder builder) => builder
+            ..name = getParameterName(index, parameter)
+            ..type = cb.refer(
+              addGenericTypesNullable(parameter.type),
+            ),
+        ),
+      );
       yield cb.Method(
         (cb.MethodBuilder builder) => builder
           ..name = method.name
@@ -2112,21 +2140,10 @@ if (${varNamePrefix}replyList == null) {
           ..modifier = cb.MethodModifier.async
           ..docs.addAll(asDocumentationComments(
             method.documentationComments,
-            _docCommentSpec,
+            docCommentSpec,
           ))
-          ..returns = _refer(method.returnType, asFuture: true)
-          ..requiredParameters.addAll(
-            indexMap(
-              method.parameters,
-              (int index, NamedType parameter) => cb.Parameter(
-                (cb.ParameterBuilder builder) => builder
-                  ..name = _getParameterName(index, parameter)
-                  ..type = cb.refer(
-                    _addGenericTypesNullable(parameter.type),
-                  ),
-              ),
-            ),
-          )
+          ..returns = refer(method.returnType, asFuture: true)
+          ..requiredParameters.addAll(parameters)
           ..optionalParameters.addAll(<cb.Parameter>[
             if (method.isStatic) ...<cb.Parameter>[
               cb.Parameter(
@@ -2137,7 +2154,7 @@ if (${varNamePrefix}replyList == null) {
               ),
               cb.Parameter(
                 (cb.ParameterBuilder builder) => builder
-                  ..name = _instanceManagerVarName
+                  ..name = instanceManagerVarName
                   ..type = cb.refer('$dartInstanceManagerClassName?'),
               ),
             ],
@@ -2167,12 +2184,28 @@ if (${varNamePrefix}replyList == null) {
                 returnType: method.returnType,
               );
               builder.statements.addAll(<cb.Code>[
+                if (method.isStatic) ...<cb.Code>[
+                  cb.Code(
+                    'if ($proxyApiOverridesClassName.${toLowerCamelCase(apiName)}_${method.name} != null) {',
+                  ),
+                  cb.CodeExpression(
+                    cb.Code(
+                      '$proxyApiOverridesClassName.${toLowerCamelCase(apiName)}_${method.name}!',
+                    ),
+                  )
+                      .call(parameters.map(
+                        (cb.Parameter parameter) => cb.refer(parameter.name),
+                      ))
+                      .returned
+                      .statement,
+                  const cb.Code('}'),
+                ],
                 if (!method.isStatic)
                   cb.Code('final $codecName $_pigeonChannelCodec =\n'
                       '    $codecInstanceName;')
                 else
                   cb.Code(
-                    'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $dartInstanceManagerClassName.instance);',
+                    'final $codecName $_pigeonChannelCodec = $codecName($instanceManagerVarName ?? $dartInstanceManagerClassName.instance);',
                   ),
                 const cb.Code(
                   'final BinaryMessenger? ${varNamePrefix}binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
@@ -2193,8 +2226,19 @@ if (${varNamePrefix}replyList == null) {
   cb.Method _proxyApiCopyMethod({
     required String apiName,
     required Iterable<ApiField> unattachedFields,
-    required Iterable<Method> declaredAndInheritedFlutterMethods,
+    required Iterable<(Method, AstProxyApi)> flutterMethodsFromSuperClasses,
+    required Iterable<(Method, AstProxyApi)> flutterMethodsFromInterfaces,
+    required Iterable<Method> declaredFlutterMethods,
   }) {
+    final Iterable<cb.Parameter> parameters =
+        proxy_api_helper.asConstructorParameters(
+      apiName: apiName,
+      parameters: <Parameter>[],
+      unattachedFields: unattachedFields,
+      flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
+      flutterMethodsFromInterfaces: flutterMethodsFromInterfaces,
+      declaredFlutterMethods: declaredFlutterMethods,
+    );
     return cb.Method(
       (cb.MethodBuilder builder) => builder
         ..name = '${classMemberNamePrefix}copy'
@@ -2206,14 +2250,8 @@ if (${varNamePrefix}replyList == null) {
               .call(
                 <cb.Expression>[],
                 <String, cb.Expression>{
-                  '${classMemberNamePrefix}binaryMessenger':
-                      cb.refer('${classMemberNamePrefix}binaryMessenger'),
-                  _instanceManagerVarName: cb.refer(_instanceManagerVarName),
-                  for (final ApiField field in unattachedFields)
-                    field.name: cb.refer(field.name),
-                  for (final Method method
-                      in declaredAndInheritedFlutterMethods)
-                    method.name: cb.refer(method.name),
+                  for (final cb.Parameter parameter in parameters)
+                    parameter.name: cb.refer(parameter.name)
                 },
               )
               .returned
@@ -2223,8 +2261,9 @@ if (${varNamePrefix}replyList == null) {
   }
 }
 
-cb.Reference _refer(TypeDeclaration type, {bool asFuture = false}) {
-  final String symbol = _addGenericTypesNullable(type);
+/// Converts a [TypeDeclaration] to a `code_builder` Reference.
+cb.Reference refer(TypeDeclaration type, {bool asFuture = false}) {
+  final String symbol = addGenericTypesNullable(type);
   return cb.refer(asFuture ? 'Future<$symbol>' : symbol);
 }
 
@@ -2255,11 +2294,11 @@ String _getSafeArgumentName(int count, NamedType field) =>
     field.name.isEmpty ? 'arg$count' : 'arg_${field.name}';
 
 /// Generates a parameter name if one isn't defined.
-String _getParameterName(int count, NamedType field) =>
+String getParameterName(int count, NamedType field) =>
     field.name.isEmpty ? 'arg$count' : field.name;
 
 /// Generates the parameters code for [func]
-/// Example: (func, _getParameterName) -> 'String? foo, int bar'
+/// Example: (func, getParameterName) -> 'String? foo, int bar'
 String _getMethodParameterSignature(
   Iterable<Parameter> parameters, {
   bool addTrailingComma = false,
@@ -2281,7 +2320,7 @@ String _getMethodParameterSignature(
   String getParameterString(Parameter p) {
     final String required = p.isRequired && !p.isPositional ? 'required ' : '';
 
-    final String type = _addGenericTypesNullable(p.type);
+    final String type = addGenericTypesNullable(p.type);
 
     final String defaultValue =
         p.defaultValue == null ? '' : ' = ${p.defaultValue}';
@@ -2350,7 +2389,9 @@ String _addGenericTypes(TypeDeclaration type) {
   }
 }
 
-String _addGenericTypesNullable(TypeDeclaration type) {
+/// Converts the type signature of a [TypeDeclaration] that include generic
+/// types.
+String addGenericTypesNullable(TypeDeclaration type) {
   final String genericType = _addGenericTypes(type);
   return type.isNullable ? '$genericType?' : genericType;
 }
diff --git a/packages/pigeon/lib/src/dart/proxy_api_generator_helper.dart b/packages/pigeon/lib/src/dart/proxy_api_generator_helper.dart
new file mode 100644
index 00000000000..ca89ce6a034
--- /dev/null
+++ b/packages/pigeon/lib/src/dart/proxy_api_generator_helper.dart
@@ -0,0 +1,332 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:code_builder/code_builder.dart' as cb;
+import 'package:collection/collection.dart';
+import 'package:dart_style/dart_style.dart';
+
+import '../ast.dart';
+import '../generator_tools.dart';
+import 'dart_generator.dart';
+import 'templates.dart';
+
+/// Converts fields and methods of a [AstProxyApi] constructor to the
+/// `code_builder` Parameters.
+Iterable<cb.Parameter> asConstructorParameters({
+  required String apiName,
+  required Iterable<Parameter> parameters,
+  required Iterable<ApiField> unattachedFields,
+  required Iterable<(Method, AstProxyApi)> flutterMethodsFromSuperClasses,
+  required Iterable<(Method, AstProxyApi)> flutterMethodsFromInterfaces,
+  required Iterable<Method> declaredFlutterMethods,
+  bool defineType = true,
+  bool includeBinaryMessengerAndInstanceManager = true,
+}) sync* {
+  if (includeBinaryMessengerAndInstanceManager) {
+    yield cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = '${classMemberNamePrefix}binaryMessenger'
+        ..named = true
+        ..type = defineType ? cb.refer('BinaryMessenger?') : null
+        ..toSuper = !defineType
+        ..required = false,
+    );
+    yield cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = instanceManagerVarName
+        ..named = true
+        ..type = defineType ? cb.refer('$dartInstanceManagerClassName?') : null
+        ..toSuper = !defineType
+        ..required = false,
+    );
+  }
+
+  for (final ApiField field in unattachedFields) {
+    yield cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = field.name
+        ..named = true
+        ..type =
+            defineType ? cb.refer(addGenericTypesNullable(field.type)) : null
+        ..toThis = !defineType
+        ..required = !field.type.isNullable,
+    );
+  }
+
+  for (final (Method method, AstProxyApi api)
+      in flutterMethodsFromSuperClasses) {
+    yield cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = method.name
+        ..named = true
+        ..type =
+            defineType ? methodAsFunctionType(method, apiName: api.name) : null
+        ..toSuper = !defineType
+        ..required = method.isRequired,
+    );
+  }
+
+  for (final (Method method, AstProxyApi api) in flutterMethodsFromInterfaces) {
+    yield cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = method.name
+        ..named = true
+        ..type =
+            defineType ? methodAsFunctionType(method, apiName: api.name) : null
+        ..toThis = !defineType
+        ..required = method.isRequired,
+    );
+  }
+
+  for (final Method method in declaredFlutterMethods) {
+    yield cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = method.name
+        ..named = true
+        ..type =
+            defineType ? methodAsFunctionType(method, apiName: apiName) : null
+        ..toThis = !defineType
+        ..required = method.isRequired,
+    );
+  }
+
+  yield* parameters.mapIndexed(
+    (int index, NamedType parameter) => cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = getParameterName(index, parameter)
+        ..type = refer(parameter.type)
+        ..named = true
+        ..required = !parameter.type.isNullable,
+    ),
+  );
+}
+
+/// Converts all the constructors of a ProxyApi into fields that are used to
+/// override the corresponding factory constructor of the generated Dart class.
+Iterable<cb.Field> overridesClassConstructors(
+  Iterable<AstProxyApi> proxyApis,
+) sync* {
+  for (final AstProxyApi api in proxyApis) {
+    final String lowerCamelCaseApiName = toLowerCamelCase(api.name);
+
+    for (final Constructor constructor in api.constructors) {
+      yield cb.Field(
+        (cb.FieldBuilder builder) {
+          final String constructorName =
+              constructor.name.isEmpty ? 'new' : constructor.name;
+          final Iterable<cb.Parameter> parameters = asConstructorParameters(
+            apiName: api.name,
+            parameters: constructor.parameters,
+            unattachedFields: api.unattachedFields,
+            flutterMethodsFromSuperClasses:
+                api.flutterMethodsFromSuperClassesWithApis(),
+            flutterMethodsFromInterfaces:
+                api.flutterMethodsFromInterfacesWithApis(),
+            declaredFlutterMethods: api.flutterMethods,
+            includeBinaryMessengerAndInstanceManager: false,
+          );
+          builder
+            ..name = constructor.name.isEmpty
+                ? '${lowerCamelCaseApiName}_new'
+                : '${lowerCamelCaseApiName}_${constructor.name}'
+            ..static = true
+            ..docs.add('/// Overrides [${api.name}.$constructorName].')
+            ..type = cb.FunctionType(
+              (cb.FunctionTypeBuilder builder) => builder
+                ..returnType = cb.refer(api.name)
+                ..isNullable = true
+                ..namedRequiredParameters.addAll(<String, cb.Reference>{
+                  for (final cb.Parameter parameter in parameters
+                      .where((cb.Parameter parameter) => parameter.required))
+                    parameter.name: parameter.type!,
+                })
+                ..namedParameters.addAll(<String, cb.Reference>{
+                  for (final cb.Parameter parameter in parameters
+                      .where((cb.Parameter parameter) => !parameter.required))
+                    parameter.name: parameter.type!,
+                }),
+            );
+        },
+      );
+    }
+  }
+}
+
+/// Converts all the static fields of a ProxyApi into fields that are used to
+/// override the corresponding static field of the generated Dart class.
+Iterable<cb.Field> overridesClassStaticFields(
+  Iterable<AstProxyApi> proxyApis,
+) sync* {
+  for (final AstProxyApi api in proxyApis) {
+    final String lowerCamelCaseApiName = toLowerCamelCase(api.name);
+
+    for (final ApiField field
+        in api.fields.where((ApiField field) => field.isStatic)) {
+      yield cb.Field((cb.FieldBuilder builder) {
+        builder
+          ..name = '${lowerCamelCaseApiName}_${field.name}'
+          ..static = true
+          ..docs.add('/// Overrides [${api.name}.${field.name}].')
+          ..type = cb.refer('${field.type.baseName}?');
+      });
+    }
+  }
+}
+
+/// Converts all the static methods of a ProxyApi into fields that are used to
+/// override the corresponding static method of the generated Dart class.
+Iterable<cb.Field> overridesClassStaticMethods(
+  Iterable<AstProxyApi> proxyApis,
+) sync* {
+  for (final AstProxyApi api in proxyApis) {
+    final String lowerCamelCaseApiName = toLowerCamelCase(api.name);
+
+    for (final Method method
+        in api.hostMethods.where((Method method) => method.isStatic)) {
+      yield cb.Field((cb.FieldBuilder builder) {
+        builder
+          ..name = '${lowerCamelCaseApiName}_${method.name}'
+          ..static = true
+          ..docs.add('/// Overrides [${api.name}.${method.name}].')
+          ..type = cb.FunctionType((cb.FunctionTypeBuilder builder) {
+            builder
+              ..isNullable = true
+              ..returnType = refer(method.returnType, asFuture: true)
+              ..requiredParameters.addAll(<cb.Reference>[
+                for (final Parameter parameter in method.parameters)
+                  refer(parameter.type),
+              ]);
+          });
+      });
+    }
+  }
+}
+
+/// Creates the reset method for the `PigeonOverrides` class that sets all
+/// overrideable methods to null.
+cb.Method overridesClassResetMethod(
+  Iterable<AstProxyApi> proxyApis,
+) {
+  return cb.Method.returnsVoid((cb.MethodBuilder builder) {
+    builder
+      ..name = '${classMemberNamePrefix}reset'
+      ..static = true
+      ..docs.addAll(<String>[
+        '/// Sets all overridden ProxyApi class members to null.',
+      ])
+      ..body = cb.Block.of(<cb.Code>[
+        for (final AstProxyApi api in proxyApis) ...<cb.Code>[
+          for (final Constructor constructor in api.constructors)
+            cb.Code(
+              '${toLowerCamelCase(api.name)}_${constructor.name.isEmpty ? 'new' : constructor.name} = null;',
+            ),
+          for (final ApiField attachedField
+              in api.fields.where((ApiField field) => field.isStatic))
+            cb.Code(
+              '${toLowerCamelCase(api.name)}_${attachedField.name} = null;',
+            ),
+          for (final Method staticMethod
+              in api.methods.where((Method method) => method.isStatic))
+            cb.Code(
+              '${toLowerCamelCase(api.name)}_${staticMethod.name} = null;',
+            ),
+        ],
+      ]);
+  });
+}
+
+/// Converts a method to a `code_builder` FunctionType with all parameters as
+/// positional arguments.
+cb.FunctionType methodAsFunctionType(
+  Method method, {
+  required String apiName,
+}) {
+  return cb.FunctionType(
+    (cb.FunctionTypeBuilder builder) => builder
+      ..returnType = refer(
+        method.returnType,
+        asFuture: method.isAsynchronous,
+      )
+      ..isNullable = !method.isRequired
+      ..requiredParameters.addAll(<cb.Reference>[
+        if (method.location == ApiLocation.flutter)
+          cb.refer('$apiName ${classMemberNamePrefix}instance'),
+        ...method.parameters.mapIndexed(
+          (int index, NamedType parameter) {
+            return cb.refer(
+              '${addGenericTypesNullable(parameter.type)} ${getParameterName(index, parameter)}',
+            );
+          },
+        )
+      ]),
+  );
+}
+
+/// Converts static attached Fields from the pigeon AST to `code_builder`
+/// Method.
+///
+/// Static attached fields return an overrideable test value or returns the
+/// private static instance.
+///
+/// Example Output:
+///
+/// ```dart
+/// static MyClass get instance => PigeonMyClassOverrides.instance ?? _instance;
+/// ```
+Iterable<cb.Method> staticAttachedFieldsGetters(
+  Iterable<ApiField> fields, {
+  required String apiName,
+}) sync* {
+  for (final ApiField field in fields) {
+    yield cb.Method((cb.MethodBuilder builder) => builder
+      ..name = field.name
+      ..type = cb.MethodType.getter
+      ..static = true
+      ..returns = cb.refer(addGenericTypesNullable(field.type))
+      ..docs.addAll(asDocumentationComments(
+        field.documentationComments,
+        docCommentSpec,
+      ))
+      ..lambda = true
+      ..body = cb.Code(
+        '$proxyApiOverridesClassName.${toLowerCamelCase(apiName)}_${field.name} ?? _${field.name}',
+      ));
+  }
+}
+
+/// Write the `PigeonOverrides` class that provides overrides for constructors
+/// and static members of each generated Dart class of a ProxyApi.
+void writeProxyApiPigeonOverrides(
+  Indent indent, {
+  required DartFormatter formatter,
+  required Iterable<AstProxyApi> proxyApis,
+}) {
+  final cb.Class proxyApiOverrides = cb.Class(
+    (cb.ClassBuilder builder) => builder
+      ..name = proxyApiOverridesClassName
+      ..annotations.add(cb.refer('visibleForTesting'))
+      ..docs.addAll(<String>[
+        '/// Provides overrides for the constructors and static members of each proxy',
+        '/// API.',
+        '///',
+        '/// This is only intended to be used with unit tests to prevent errors from',
+        '/// making message calls in a unit test.',
+        '///',
+        '/// See [$proxyApiOverridesClassName.${classMemberNamePrefix}reset] to set all overrides back to null.',
+      ])
+      ..fields.addAll(
+        overridesClassConstructors(proxyApis),
+      )
+      ..fields.addAll(
+        overridesClassStaticFields(proxyApis),
+      )
+      ..fields.addAll(overridesClassStaticMethods(proxyApis))
+      ..methods.add(
+        overridesClassResetMethod(proxyApis),
+      ),
+  );
+
+  final cb.DartEmitter emitter = cb.DartEmitter(useNullSafetySyntax: true);
+  indent.format(formatter.format('${proxyApiOverrides.accept(emitter)}'));
+}
diff --git a/packages/pigeon/lib/src/generator_tools.dart b/packages/pigeon/lib/src/generator_tools.dart
index 8528dd70df8..51d2500e9de 100644
--- a/packages/pigeon/lib/src/generator_tools.dart
+++ b/packages/pigeon/lib/src/generator_tools.dart
@@ -15,7 +15,7 @@ import 'generator.dart';
 /// The current version of pigeon.
 ///
 /// This must match the version in pubspec.yaml.
-const String pigeonVersion = '25.5.0';
+const String pigeonVersion = '26.0.0';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
index 4f6b8593aed..214476f8f53 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
@@ -11,7 +11,7 @@ import 'dart:io' show Platform;
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
 import 'package:flutter/foundation.dart'
-    show ReadBuffer, WriteBuffer, immutable, protected;
+    show ReadBuffer, WriteBuffer, immutable, protected, visibleForTesting;
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart' show WidgetsFlutterBinding;
 
@@ -33,6 +33,286 @@ List<Object?> wrapResponse(
   return <Object?>[error.code, error.message, error.details];
 }
 
+/// Provides overrides for the constructors and static members of each proxy
+/// API.
+///
+/// This is only intended to be used with unit tests to prevent errors from
+/// making message calls in a unit test.
+///
+/// See [PigeonOverrides.pigeon_reset] to set all overrides back to null.
+@visibleForTesting
+class PigeonOverrides {
+  /// Overrides [ProxyApiTestClass.new].
+  static ProxyApiTestClass Function({
+    required bool aBool,
+    required int anInt,
+    required double aDouble,
+    required String aString,
+    required Uint8List aUint8List,
+    required List<Object?> aList,
+    required Map<String?, Object?> aMap,
+    required ProxyApiTestEnum anEnum,
+    required ProxyApiSuperClass aProxyApi,
+    required bool Function(
+      ProxyApiTestClass pigeon_instance,
+      bool aBool,
+    ) flutterEchoBool,
+    required int Function(
+      ProxyApiTestClass pigeon_instance,
+      int anInt,
+    ) flutterEchoInt,
+    required double Function(
+      ProxyApiTestClass pigeon_instance,
+      double aDouble,
+    ) flutterEchoDouble,
+    required String Function(
+      ProxyApiTestClass pigeon_instance,
+      String aString,
+    ) flutterEchoString,
+    required Uint8List Function(
+      ProxyApiTestClass pigeon_instance,
+      Uint8List aList,
+    ) flutterEchoUint8List,
+    required List<Object?> Function(
+      ProxyApiTestClass pigeon_instance,
+      List<Object?> aList,
+    ) flutterEchoList,
+    required List<ProxyApiTestClass?> Function(
+      ProxyApiTestClass pigeon_instance,
+      List<ProxyApiTestClass?> aList,
+    ) flutterEchoProxyApiList,
+    required Map<String?, Object?> Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, Object?> aMap,
+    ) flutterEchoMap,
+    required Map<String?, ProxyApiTestClass?> Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, ProxyApiTestClass?> aMap,
+    ) flutterEchoProxyApiMap,
+    required ProxyApiTestEnum Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiTestEnum anEnum,
+    ) flutterEchoEnum,
+    required ProxyApiSuperClass Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiSuperClass aProxyApi,
+    ) flutterEchoProxyApi,
+    required Future<String> Function(
+      ProxyApiTestClass pigeon_instance,
+      String aString,
+    ) flutterEchoAsyncString,
+    required bool boolParam,
+    required int intParam,
+    required double doubleParam,
+    required String stringParam,
+    required Uint8List aUint8ListParam,
+    required List<Object?> listParam,
+    required Map<String?, Object?> mapParam,
+    required ProxyApiTestEnum enumParam,
+    required ProxyApiSuperClass proxyApiParam,
+    bool? aNullableBool,
+    int? aNullableInt,
+    double? aNullableDouble,
+    String? aNullableString,
+    Uint8List? aNullableUint8List,
+    List<Object?>? aNullableList,
+    Map<String?, Object?>? aNullableMap,
+    ProxyApiTestEnum? aNullableEnum,
+    ProxyApiSuperClass? aNullableProxyApi,
+    void Function(ProxyApiInterface pigeon_instance)? anInterfaceMethod,
+    void Function(ProxyApiTestClass pigeon_instance)? flutterNoop,
+    Object? Function(ProxyApiTestClass pigeon_instance)? flutterThrowError,
+    void Function(ProxyApiTestClass pigeon_instance)? flutterThrowErrorFromVoid,
+    bool? Function(
+      ProxyApiTestClass pigeon_instance,
+      bool? aBool,
+    )? flutterEchoNullableBool,
+    int? Function(
+      ProxyApiTestClass pigeon_instance,
+      int? anInt,
+    )? flutterEchoNullableInt,
+    double? Function(
+      ProxyApiTestClass pigeon_instance,
+      double? aDouble,
+    )? flutterEchoNullableDouble,
+    String? Function(
+      ProxyApiTestClass pigeon_instance,
+      String? aString,
+    )? flutterEchoNullableString,
+    Uint8List? Function(
+      ProxyApiTestClass pigeon_instance,
+      Uint8List? aList,
+    )? flutterEchoNullableUint8List,
+    List<Object?>? Function(
+      ProxyApiTestClass pigeon_instance,
+      List<Object?>? aList,
+    )? flutterEchoNullableList,
+    Map<String?, Object?>? Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, Object?>? aMap,
+    )? flutterEchoNullableMap,
+    ProxyApiTestEnum? Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiTestEnum? anEnum,
+    )? flutterEchoNullableEnum,
+    ProxyApiSuperClass? Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiSuperClass? aProxyApi,
+    )? flutterEchoNullableProxyApi,
+    Future<void> Function(ProxyApiTestClass pigeon_instance)? flutterNoopAsync,
+    bool? nullableBoolParam,
+    int? nullableIntParam,
+    double? nullableDoubleParam,
+    String? nullableStringParam,
+    Uint8List? nullableUint8ListParam,
+    List<Object?>? nullableListParam,
+    Map<String?, Object?>? nullableMapParam,
+    ProxyApiTestEnum? nullableEnumParam,
+    ProxyApiSuperClass? nullableProxyApiParam,
+  })? proxyApiTestClass_new;
+
+  /// Overrides [ProxyApiTestClass.namedConstructor].
+  static ProxyApiTestClass Function({
+    required bool aBool,
+    required int anInt,
+    required double aDouble,
+    required String aString,
+    required Uint8List aUint8List,
+    required List<Object?> aList,
+    required Map<String?, Object?> aMap,
+    required ProxyApiTestEnum anEnum,
+    required ProxyApiSuperClass aProxyApi,
+    required bool Function(
+      ProxyApiTestClass pigeon_instance,
+      bool aBool,
+    ) flutterEchoBool,
+    required int Function(
+      ProxyApiTestClass pigeon_instance,
+      int anInt,
+    ) flutterEchoInt,
+    required double Function(
+      ProxyApiTestClass pigeon_instance,
+      double aDouble,
+    ) flutterEchoDouble,
+    required String Function(
+      ProxyApiTestClass pigeon_instance,
+      String aString,
+    ) flutterEchoString,
+    required Uint8List Function(
+      ProxyApiTestClass pigeon_instance,
+      Uint8List aList,
+    ) flutterEchoUint8List,
+    required List<Object?> Function(
+      ProxyApiTestClass pigeon_instance,
+      List<Object?> aList,
+    ) flutterEchoList,
+    required List<ProxyApiTestClass?> Function(
+      ProxyApiTestClass pigeon_instance,
+      List<ProxyApiTestClass?> aList,
+    ) flutterEchoProxyApiList,
+    required Map<String?, Object?> Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, Object?> aMap,
+    ) flutterEchoMap,
+    required Map<String?, ProxyApiTestClass?> Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, ProxyApiTestClass?> aMap,
+    ) flutterEchoProxyApiMap,
+    required ProxyApiTestEnum Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiTestEnum anEnum,
+    ) flutterEchoEnum,
+    required ProxyApiSuperClass Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiSuperClass aProxyApi,
+    ) flutterEchoProxyApi,
+    required Future<String> Function(
+      ProxyApiTestClass pigeon_instance,
+      String aString,
+    ) flutterEchoAsyncString,
+    bool? aNullableBool,
+    int? aNullableInt,
+    double? aNullableDouble,
+    String? aNullableString,
+    Uint8List? aNullableUint8List,
+    List<Object?>? aNullableList,
+    Map<String?, Object?>? aNullableMap,
+    ProxyApiTestEnum? aNullableEnum,
+    ProxyApiSuperClass? aNullableProxyApi,
+    void Function(ProxyApiInterface pigeon_instance)? anInterfaceMethod,
+    void Function(ProxyApiTestClass pigeon_instance)? flutterNoop,
+    Object? Function(ProxyApiTestClass pigeon_instance)? flutterThrowError,
+    void Function(ProxyApiTestClass pigeon_instance)? flutterThrowErrorFromVoid,
+    bool? Function(
+      ProxyApiTestClass pigeon_instance,
+      bool? aBool,
+    )? flutterEchoNullableBool,
+    int? Function(
+      ProxyApiTestClass pigeon_instance,
+      int? anInt,
+    )? flutterEchoNullableInt,
+    double? Function(
+      ProxyApiTestClass pigeon_instance,
+      double? aDouble,
+    )? flutterEchoNullableDouble,
+    String? Function(
+      ProxyApiTestClass pigeon_instance,
+      String? aString,
+    )? flutterEchoNullableString,
+    Uint8List? Function(
+      ProxyApiTestClass pigeon_instance,
+      Uint8List? aList,
+    )? flutterEchoNullableUint8List,
+    List<Object?>? Function(
+      ProxyApiTestClass pigeon_instance,
+      List<Object?>? aList,
+    )? flutterEchoNullableList,
+    Map<String?, Object?>? Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, Object?>? aMap,
+    )? flutterEchoNullableMap,
+    ProxyApiTestEnum? Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiTestEnum? anEnum,
+    )? flutterEchoNullableEnum,
+    ProxyApiSuperClass? Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiSuperClass? aProxyApi,
+    )? flutterEchoNullableProxyApi,
+    Future<void> Function(ProxyApiTestClass pigeon_instance)? flutterNoopAsync,
+  })? proxyApiTestClass_namedConstructor;
+
+  /// Overrides [ProxyApiSuperClass.new].
+  static ProxyApiSuperClass Function()? proxyApiSuperClass_new;
+
+  /// Overrides [ClassWithApiRequirement.new].
+  static ClassWithApiRequirement Function()? classWithApiRequirement_new;
+
+  /// Overrides [ProxyApiTestClass.staticAttachedField].
+  static ProxyApiSuperClass? proxyApiTestClass_staticAttachedField;
+
+  /// Overrides [ProxyApiTestClass.staticNoop].
+  static Future<void> Function()? proxyApiTestClass_staticNoop;
+
+  /// Overrides [ProxyApiTestClass.echoStaticString].
+  static Future<String> Function(String)? proxyApiTestClass_echoStaticString;
+
+  /// Overrides [ProxyApiTestClass.staticAsyncNoop].
+  static Future<void> Function()? proxyApiTestClass_staticAsyncNoop;
+
+  /// Sets all overridden ProxyApi class members to null.
+  static void pigeon_reset() {
+    proxyApiTestClass_new = null;
+    proxyApiTestClass_namedConstructor = null;
+    proxyApiTestClass_staticAttachedField = null;
+    proxyApiTestClass_staticNoop = null;
+    proxyApiTestClass_echoStaticString = null;
+    proxyApiTestClass_staticAsyncNoop = null;
+    proxyApiSuperClass_new = null;
+    classWithApiRequirement_new = null;
+  }
+}
+
 /// An immutable object that serves as the base class for all ProxyApis and
 /// can provide functional copies of itself.
 ///
@@ -453,7 +733,271 @@ class _PigeonCodec extends StandardMessageCodec {
 /// implement in platform_tests integration tests.
 class ProxyApiTestClass extends ProxyApiSuperClass
     implements ProxyApiInterface {
-  ProxyApiTestClass({
+  factory ProxyApiTestClass({
+    BinaryMessenger? pigeon_binaryMessenger,
+    PigeonInstanceManager? pigeon_instanceManager,
+    required bool aBool,
+    required int anInt,
+    required double aDouble,
+    required String aString,
+    required Uint8List aUint8List,
+    required List<Object?> aList,
+    required Map<String?, Object?> aMap,
+    required ProxyApiTestEnum anEnum,
+    required ProxyApiSuperClass aProxyApi,
+    bool? aNullableBool,
+    int? aNullableInt,
+    double? aNullableDouble,
+    String? aNullableString,
+    Uint8List? aNullableUint8List,
+    List<Object?>? aNullableList,
+    Map<String?, Object?>? aNullableMap,
+    ProxyApiTestEnum? aNullableEnum,
+    ProxyApiSuperClass? aNullableProxyApi,
+    void Function(ProxyApiInterface pigeon_instance)? anInterfaceMethod,
+    void Function(ProxyApiTestClass pigeon_instance)? flutterNoop,
+    Object? Function(ProxyApiTestClass pigeon_instance)? flutterThrowError,
+    void Function(ProxyApiTestClass pigeon_instance)? flutterThrowErrorFromVoid,
+    required bool Function(
+      ProxyApiTestClass pigeon_instance,
+      bool aBool,
+    ) flutterEchoBool,
+    required int Function(
+      ProxyApiTestClass pigeon_instance,
+      int anInt,
+    ) flutterEchoInt,
+    required double Function(
+      ProxyApiTestClass pigeon_instance,
+      double aDouble,
+    ) flutterEchoDouble,
+    required String Function(
+      ProxyApiTestClass pigeon_instance,
+      String aString,
+    ) flutterEchoString,
+    required Uint8List Function(
+      ProxyApiTestClass pigeon_instance,
+      Uint8List aList,
+    ) flutterEchoUint8List,
+    required List<Object?> Function(
+      ProxyApiTestClass pigeon_instance,
+      List<Object?> aList,
+    ) flutterEchoList,
+    required List<ProxyApiTestClass?> Function(
+      ProxyApiTestClass pigeon_instance,
+      List<ProxyApiTestClass?> aList,
+    ) flutterEchoProxyApiList,
+    required Map<String?, Object?> Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, Object?> aMap,
+    ) flutterEchoMap,
+    required Map<String?, ProxyApiTestClass?> Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, ProxyApiTestClass?> aMap,
+    ) flutterEchoProxyApiMap,
+    required ProxyApiTestEnum Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiTestEnum anEnum,
+    ) flutterEchoEnum,
+    required ProxyApiSuperClass Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiSuperClass aProxyApi,
+    ) flutterEchoProxyApi,
+    bool? Function(
+      ProxyApiTestClass pigeon_instance,
+      bool? aBool,
+    )? flutterEchoNullableBool,
+    int? Function(
+      ProxyApiTestClass pigeon_instance,
+      int? anInt,
+    )? flutterEchoNullableInt,
+    double? Function(
+      ProxyApiTestClass pigeon_instance,
+      double? aDouble,
+    )? flutterEchoNullableDouble,
+    String? Function(
+      ProxyApiTestClass pigeon_instance,
+      String? aString,
+    )? flutterEchoNullableString,
+    Uint8List? Function(
+      ProxyApiTestClass pigeon_instance,
+      Uint8List? aList,
+    )? flutterEchoNullableUint8List,
+    List<Object?>? Function(
+      ProxyApiTestClass pigeon_instance,
+      List<Object?>? aList,
+    )? flutterEchoNullableList,
+    Map<String?, Object?>? Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, Object?>? aMap,
+    )? flutterEchoNullableMap,
+    ProxyApiTestEnum? Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiTestEnum? anEnum,
+    )? flutterEchoNullableEnum,
+    ProxyApiSuperClass? Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiSuperClass? aProxyApi,
+    )? flutterEchoNullableProxyApi,
+    Future<void> Function(ProxyApiTestClass pigeon_instance)? flutterNoopAsync,
+    required Future<String> Function(
+      ProxyApiTestClass pigeon_instance,
+      String aString,
+    ) flutterEchoAsyncString,
+    required bool boolParam,
+    required int intParam,
+    required double doubleParam,
+    required String stringParam,
+    required Uint8List aUint8ListParam,
+    required List<Object?> listParam,
+    required Map<String?, Object?> mapParam,
+    required ProxyApiTestEnum enumParam,
+    required ProxyApiSuperClass proxyApiParam,
+    bool? nullableBoolParam,
+    int? nullableIntParam,
+    double? nullableDoubleParam,
+    String? nullableStringParam,
+    Uint8List? nullableUint8ListParam,
+    List<Object?>? nullableListParam,
+    Map<String?, Object?>? nullableMapParam,
+    ProxyApiTestEnum? nullableEnumParam,
+    ProxyApiSuperClass? nullableProxyApiParam,
+  }) {
+    if (PigeonOverrides.proxyApiTestClass_new != null) {
+      return PigeonOverrides.proxyApiTestClass_new!(
+        aBool: aBool,
+        anInt: anInt,
+        aDouble: aDouble,
+        aString: aString,
+        aUint8List: aUint8List,
+        aList: aList,
+        aMap: aMap,
+        anEnum: anEnum,
+        aProxyApi: aProxyApi,
+        aNullableBool: aNullableBool,
+        aNullableInt: aNullableInt,
+        aNullableDouble: aNullableDouble,
+        aNullableString: aNullableString,
+        aNullableUint8List: aNullableUint8List,
+        aNullableList: aNullableList,
+        aNullableMap: aNullableMap,
+        aNullableEnum: aNullableEnum,
+        aNullableProxyApi: aNullableProxyApi,
+        anInterfaceMethod: anInterfaceMethod,
+        flutterNoop: flutterNoop,
+        flutterThrowError: flutterThrowError,
+        flutterThrowErrorFromVoid: flutterThrowErrorFromVoid,
+        flutterEchoBool: flutterEchoBool,
+        flutterEchoInt: flutterEchoInt,
+        flutterEchoDouble: flutterEchoDouble,
+        flutterEchoString: flutterEchoString,
+        flutterEchoUint8List: flutterEchoUint8List,
+        flutterEchoList: flutterEchoList,
+        flutterEchoProxyApiList: flutterEchoProxyApiList,
+        flutterEchoMap: flutterEchoMap,
+        flutterEchoProxyApiMap: flutterEchoProxyApiMap,
+        flutterEchoEnum: flutterEchoEnum,
+        flutterEchoProxyApi: flutterEchoProxyApi,
+        flutterEchoNullableBool: flutterEchoNullableBool,
+        flutterEchoNullableInt: flutterEchoNullableInt,
+        flutterEchoNullableDouble: flutterEchoNullableDouble,
+        flutterEchoNullableString: flutterEchoNullableString,
+        flutterEchoNullableUint8List: flutterEchoNullableUint8List,
+        flutterEchoNullableList: flutterEchoNullableList,
+        flutterEchoNullableMap: flutterEchoNullableMap,
+        flutterEchoNullableEnum: flutterEchoNullableEnum,
+        flutterEchoNullableProxyApi: flutterEchoNullableProxyApi,
+        flutterNoopAsync: flutterNoopAsync,
+        flutterEchoAsyncString: flutterEchoAsyncString,
+        boolParam: boolParam,
+        intParam: intParam,
+        doubleParam: doubleParam,
+        stringParam: stringParam,
+        aUint8ListParam: aUint8ListParam,
+        listParam: listParam,
+        mapParam: mapParam,
+        enumParam: enumParam,
+        proxyApiParam: proxyApiParam,
+        nullableBoolParam: nullableBoolParam,
+        nullableIntParam: nullableIntParam,
+        nullableDoubleParam: nullableDoubleParam,
+        nullableStringParam: nullableStringParam,
+        nullableUint8ListParam: nullableUint8ListParam,
+        nullableListParam: nullableListParam,
+        nullableMapParam: nullableMapParam,
+        nullableEnumParam: nullableEnumParam,
+        nullableProxyApiParam: nullableProxyApiParam,
+      );
+    }
+    return ProxyApiTestClass.pigeon_new(
+      pigeon_binaryMessenger: pigeon_binaryMessenger,
+      pigeon_instanceManager: pigeon_instanceManager,
+      aBool: aBool,
+      anInt: anInt,
+      aDouble: aDouble,
+      aString: aString,
+      aUint8List: aUint8List,
+      aList: aList,
+      aMap: aMap,
+      anEnum: anEnum,
+      aProxyApi: aProxyApi,
+      aNullableBool: aNullableBool,
+      aNullableInt: aNullableInt,
+      aNullableDouble: aNullableDouble,
+      aNullableString: aNullableString,
+      aNullableUint8List: aNullableUint8List,
+      aNullableList: aNullableList,
+      aNullableMap: aNullableMap,
+      aNullableEnum: aNullableEnum,
+      aNullableProxyApi: aNullableProxyApi,
+      anInterfaceMethod: anInterfaceMethod,
+      flutterNoop: flutterNoop,
+      flutterThrowError: flutterThrowError,
+      flutterThrowErrorFromVoid: flutterThrowErrorFromVoid,
+      flutterEchoBool: flutterEchoBool,
+      flutterEchoInt: flutterEchoInt,
+      flutterEchoDouble: flutterEchoDouble,
+      flutterEchoString: flutterEchoString,
+      flutterEchoUint8List: flutterEchoUint8List,
+      flutterEchoList: flutterEchoList,
+      flutterEchoProxyApiList: flutterEchoProxyApiList,
+      flutterEchoMap: flutterEchoMap,
+      flutterEchoProxyApiMap: flutterEchoProxyApiMap,
+      flutterEchoEnum: flutterEchoEnum,
+      flutterEchoProxyApi: flutterEchoProxyApi,
+      flutterEchoNullableBool: flutterEchoNullableBool,
+      flutterEchoNullableInt: flutterEchoNullableInt,
+      flutterEchoNullableDouble: flutterEchoNullableDouble,
+      flutterEchoNullableString: flutterEchoNullableString,
+      flutterEchoNullableUint8List: flutterEchoNullableUint8List,
+      flutterEchoNullableList: flutterEchoNullableList,
+      flutterEchoNullableMap: flutterEchoNullableMap,
+      flutterEchoNullableEnum: flutterEchoNullableEnum,
+      flutterEchoNullableProxyApi: flutterEchoNullableProxyApi,
+      flutterNoopAsync: flutterNoopAsync,
+      flutterEchoAsyncString: flutterEchoAsyncString,
+      boolParam: boolParam,
+      intParam: intParam,
+      doubleParam: doubleParam,
+      stringParam: stringParam,
+      aUint8ListParam: aUint8ListParam,
+      listParam: listParam,
+      mapParam: mapParam,
+      enumParam: enumParam,
+      proxyApiParam: proxyApiParam,
+      nullableBoolParam: nullableBoolParam,
+      nullableIntParam: nullableIntParam,
+      nullableDoubleParam: nullableDoubleParam,
+      nullableStringParam: nullableStringParam,
+      nullableUint8ListParam: nullableUint8ListParam,
+      nullableListParam: nullableListParam,
+      nullableMapParam: nullableMapParam,
+      nullableEnumParam: nullableEnumParam,
+      nullableProxyApiParam: nullableProxyApiParam,
+    );
+  }
+
+  @protected
+  ProxyApiTestClass.pigeon_new({
     super.pigeon_binaryMessenger,
     super.pigeon_instanceManager,
     required this.aBool,
@@ -589,7 +1133,217 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     }();
   }
 
-  ProxyApiTestClass.namedConstructor({
+  factory ProxyApiTestClass.namedConstructor({
+    BinaryMessenger? pigeon_binaryMessenger,
+    PigeonInstanceManager? pigeon_instanceManager,
+    required bool aBool,
+    required int anInt,
+    required double aDouble,
+    required String aString,
+    required Uint8List aUint8List,
+    required List<Object?> aList,
+    required Map<String?, Object?> aMap,
+    required ProxyApiTestEnum anEnum,
+    required ProxyApiSuperClass aProxyApi,
+    bool? aNullableBool,
+    int? aNullableInt,
+    double? aNullableDouble,
+    String? aNullableString,
+    Uint8List? aNullableUint8List,
+    List<Object?>? aNullableList,
+    Map<String?, Object?>? aNullableMap,
+    ProxyApiTestEnum? aNullableEnum,
+    ProxyApiSuperClass? aNullableProxyApi,
+    void Function(ProxyApiInterface pigeon_instance)? anInterfaceMethod,
+    void Function(ProxyApiTestClass pigeon_instance)? flutterNoop,
+    Object? Function(ProxyApiTestClass pigeon_instance)? flutterThrowError,
+    void Function(ProxyApiTestClass pigeon_instance)? flutterThrowErrorFromVoid,
+    required bool Function(
+      ProxyApiTestClass pigeon_instance,
+      bool aBool,
+    ) flutterEchoBool,
+    required int Function(
+      ProxyApiTestClass pigeon_instance,
+      int anInt,
+    ) flutterEchoInt,
+    required double Function(
+      ProxyApiTestClass pigeon_instance,
+      double aDouble,
+    ) flutterEchoDouble,
+    required String Function(
+      ProxyApiTestClass pigeon_instance,
+      String aString,
+    ) flutterEchoString,
+    required Uint8List Function(
+      ProxyApiTestClass pigeon_instance,
+      Uint8List aList,
+    ) flutterEchoUint8List,
+    required List<Object?> Function(
+      ProxyApiTestClass pigeon_instance,
+      List<Object?> aList,
+    ) flutterEchoList,
+    required List<ProxyApiTestClass?> Function(
+      ProxyApiTestClass pigeon_instance,
+      List<ProxyApiTestClass?> aList,
+    ) flutterEchoProxyApiList,
+    required Map<String?, Object?> Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, Object?> aMap,
+    ) flutterEchoMap,
+    required Map<String?, ProxyApiTestClass?> Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, ProxyApiTestClass?> aMap,
+    ) flutterEchoProxyApiMap,
+    required ProxyApiTestEnum Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiTestEnum anEnum,
+    ) flutterEchoEnum,
+    required ProxyApiSuperClass Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiSuperClass aProxyApi,
+    ) flutterEchoProxyApi,
+    bool? Function(
+      ProxyApiTestClass pigeon_instance,
+      bool? aBool,
+    )? flutterEchoNullableBool,
+    int? Function(
+      ProxyApiTestClass pigeon_instance,
+      int? anInt,
+    )? flutterEchoNullableInt,
+    double? Function(
+      ProxyApiTestClass pigeon_instance,
+      double? aDouble,
+    )? flutterEchoNullableDouble,
+    String? Function(
+      ProxyApiTestClass pigeon_instance,
+      String? aString,
+    )? flutterEchoNullableString,
+    Uint8List? Function(
+      ProxyApiTestClass pigeon_instance,
+      Uint8List? aList,
+    )? flutterEchoNullableUint8List,
+    List<Object?>? Function(
+      ProxyApiTestClass pigeon_instance,
+      List<Object?>? aList,
+    )? flutterEchoNullableList,
+    Map<String?, Object?>? Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, Object?>? aMap,
+    )? flutterEchoNullableMap,
+    ProxyApiTestEnum? Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiTestEnum? anEnum,
+    )? flutterEchoNullableEnum,
+    ProxyApiSuperClass? Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiSuperClass? aProxyApi,
+    )? flutterEchoNullableProxyApi,
+    Future<void> Function(ProxyApiTestClass pigeon_instance)? flutterNoopAsync,
+    required Future<String> Function(
+      ProxyApiTestClass pigeon_instance,
+      String aString,
+    ) flutterEchoAsyncString,
+  }) {
+    if (PigeonOverrides.proxyApiTestClass_namedConstructor != null) {
+      return PigeonOverrides.proxyApiTestClass_namedConstructor!(
+        aBool: aBool,
+        anInt: anInt,
+        aDouble: aDouble,
+        aString: aString,
+        aUint8List: aUint8List,
+        aList: aList,
+        aMap: aMap,
+        anEnum: anEnum,
+        aProxyApi: aProxyApi,
+        aNullableBool: aNullableBool,
+        aNullableInt: aNullableInt,
+        aNullableDouble: aNullableDouble,
+        aNullableString: aNullableString,
+        aNullableUint8List: aNullableUint8List,
+        aNullableList: aNullableList,
+        aNullableMap: aNullableMap,
+        aNullableEnum: aNullableEnum,
+        aNullableProxyApi: aNullableProxyApi,
+        anInterfaceMethod: anInterfaceMethod,
+        flutterNoop: flutterNoop,
+        flutterThrowError: flutterThrowError,
+        flutterThrowErrorFromVoid: flutterThrowErrorFromVoid,
+        flutterEchoBool: flutterEchoBool,
+        flutterEchoInt: flutterEchoInt,
+        flutterEchoDouble: flutterEchoDouble,
+        flutterEchoString: flutterEchoString,
+        flutterEchoUint8List: flutterEchoUint8List,
+        flutterEchoList: flutterEchoList,
+        flutterEchoProxyApiList: flutterEchoProxyApiList,
+        flutterEchoMap: flutterEchoMap,
+        flutterEchoProxyApiMap: flutterEchoProxyApiMap,
+        flutterEchoEnum: flutterEchoEnum,
+        flutterEchoProxyApi: flutterEchoProxyApi,
+        flutterEchoNullableBool: flutterEchoNullableBool,
+        flutterEchoNullableInt: flutterEchoNullableInt,
+        flutterEchoNullableDouble: flutterEchoNullableDouble,
+        flutterEchoNullableString: flutterEchoNullableString,
+        flutterEchoNullableUint8List: flutterEchoNullableUint8List,
+        flutterEchoNullableList: flutterEchoNullableList,
+        flutterEchoNullableMap: flutterEchoNullableMap,
+        flutterEchoNullableEnum: flutterEchoNullableEnum,
+        flutterEchoNullableProxyApi: flutterEchoNullableProxyApi,
+        flutterNoopAsync: flutterNoopAsync,
+        flutterEchoAsyncString: flutterEchoAsyncString,
+      );
+    }
+    return ProxyApiTestClass.pigeon_namedConstructor(
+      pigeon_binaryMessenger: pigeon_binaryMessenger,
+      pigeon_instanceManager: pigeon_instanceManager,
+      aBool: aBool,
+      anInt: anInt,
+      aDouble: aDouble,
+      aString: aString,
+      aUint8List: aUint8List,
+      aList: aList,
+      aMap: aMap,
+      anEnum: anEnum,
+      aProxyApi: aProxyApi,
+      aNullableBool: aNullableBool,
+      aNullableInt: aNullableInt,
+      aNullableDouble: aNullableDouble,
+      aNullableString: aNullableString,
+      aNullableUint8List: aNullableUint8List,
+      aNullableList: aNullableList,
+      aNullableMap: aNullableMap,
+      aNullableEnum: aNullableEnum,
+      aNullableProxyApi: aNullableProxyApi,
+      anInterfaceMethod: anInterfaceMethod,
+      flutterNoop: flutterNoop,
+      flutterThrowError: flutterThrowError,
+      flutterThrowErrorFromVoid: flutterThrowErrorFromVoid,
+      flutterEchoBool: flutterEchoBool,
+      flutterEchoInt: flutterEchoInt,
+      flutterEchoDouble: flutterEchoDouble,
+      flutterEchoString: flutterEchoString,
+      flutterEchoUint8List: flutterEchoUint8List,
+      flutterEchoList: flutterEchoList,
+      flutterEchoProxyApiList: flutterEchoProxyApiList,
+      flutterEchoMap: flutterEchoMap,
+      flutterEchoProxyApiMap: flutterEchoProxyApiMap,
+      flutterEchoEnum: flutterEchoEnum,
+      flutterEchoProxyApi: flutterEchoProxyApi,
+      flutterEchoNullableBool: flutterEchoNullableBool,
+      flutterEchoNullableInt: flutterEchoNullableInt,
+      flutterEchoNullableDouble: flutterEchoNullableDouble,
+      flutterEchoNullableString: flutterEchoNullableString,
+      flutterEchoNullableUint8List: flutterEchoNullableUint8List,
+      flutterEchoNullableList: flutterEchoNullableList,
+      flutterEchoNullableMap: flutterEchoNullableMap,
+      flutterEchoNullableEnum: flutterEchoNullableEnum,
+      flutterEchoNullableProxyApi: flutterEchoNullableProxyApi,
+      flutterNoopAsync: flutterNoopAsync,
+      flutterEchoAsyncString: flutterEchoAsyncString,
+    );
+  }
+
+  @protected
+  ProxyApiTestClass.pigeon_namedConstructor({
     super.pigeon_binaryMessenger,
     super.pigeon_instanceManager,
     required this.aBool,
@@ -1382,9 +2136,13 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   late final ProxyApiSuperClass attachedField = pigeonVar_attachedField();
 
-  static final ProxyApiSuperClass staticAttachedField =
+  static final ProxyApiSuperClass _staticAttachedField =
       pigeonVar_staticAttachedField();
 
+  static ProxyApiSuperClass get staticAttachedField =>
+      PigeonOverrides.proxyApiTestClass_staticAttachedField ??
+      _staticAttachedField;
+
   static void pigeon_setUpMessageHandlers({
     bool pigeon_clearHandlers = false,
     BinaryMessenger? pigeon_binaryMessenger,
@@ -4003,6 +4761,9 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     BinaryMessenger? pigeon_binaryMessenger,
     PigeonInstanceManager? pigeon_instanceManager,
   }) async {
+    if (PigeonOverrides.proxyApiTestClass_staticNoop != null) {
+      return PigeonOverrides.proxyApiTestClass_staticNoop!();
+    }
     final _PigeonInternalProxyApiBaseCodec pigeonChannelCodec =
         _PigeonInternalProxyApiBaseCodec(
             pigeon_instanceManager ?? PigeonInstanceManager.instance);
@@ -4036,6 +4797,9 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     BinaryMessenger? pigeon_binaryMessenger,
     PigeonInstanceManager? pigeon_instanceManager,
   }) async {
+    if (PigeonOverrides.proxyApiTestClass_echoStaticString != null) {
+      return PigeonOverrides.proxyApiTestClass_echoStaticString!(aString);
+    }
     final _PigeonInternalProxyApiBaseCodec pigeonChannelCodec =
         _PigeonInternalProxyApiBaseCodec(
             pigeon_instanceManager ?? PigeonInstanceManager.instance);
@@ -4074,6 +4838,9 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     BinaryMessenger? pigeon_binaryMessenger,
     PigeonInstanceManager? pigeon_instanceManager,
   }) async {
+    if (PigeonOverrides.proxyApiTestClass_staticAsyncNoop != null) {
+      return PigeonOverrides.proxyApiTestClass_staticAsyncNoop!();
+    }
     final _PigeonInternalProxyApiBaseCodec pigeonChannelCodec =
         _PigeonInternalProxyApiBaseCodec(
             pigeon_instanceManager ?? PigeonInstanceManager.instance);
@@ -4955,7 +5722,21 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
 /// ProxyApi to serve as a super class to the core ProxyApi class.
 class ProxyApiSuperClass extends PigeonInternalProxyApiBaseClass {
-  ProxyApiSuperClass({
+  factory ProxyApiSuperClass({
+    BinaryMessenger? pigeon_binaryMessenger,
+    PigeonInstanceManager? pigeon_instanceManager,
+  }) {
+    if (PigeonOverrides.proxyApiSuperClass_new != null) {
+      return PigeonOverrides.proxyApiSuperClass_new!();
+    }
+    return ProxyApiSuperClass.pigeon_new(
+      pigeon_binaryMessenger: pigeon_binaryMessenger,
+      pigeon_instanceManager: pigeon_instanceManager,
+    );
+  }
+
+  @protected
+  ProxyApiSuperClass.pigeon_new({
     super.pigeon_binaryMessenger,
     super.pigeon_instanceManager,
   }) {
@@ -5219,7 +6000,21 @@ class ProxyApiInterface extends PigeonInternalProxyApiBaseClass {
 }
 
 class ClassWithApiRequirement extends PigeonInternalProxyApiBaseClass {
-  ClassWithApiRequirement({
+  factory ClassWithApiRequirement({
+    BinaryMessenger? pigeon_binaryMessenger,
+    PigeonInstanceManager? pigeon_instanceManager,
+  }) {
+    if (PigeonOverrides.classWithApiRequirement_new != null) {
+      return PigeonOverrides.classWithApiRequirement_new!();
+    }
+    return ClassWithApiRequirement.pigeon_new(
+      pigeon_binaryMessenger: pigeon_binaryMessenger,
+      pigeon_instanceManager: pigeon_instanceManager,
+    );
+  }
+
+  @protected
+  ClassWithApiRequirement.pigeon_new({
     super.pigeon_binaryMessenger,
     super.pigeon_instanceManager,
   }) {
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/test/proxy_api_overrides_test.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/test/proxy_api_overrides_test.dart
new file mode 100644
index 00000000000..d3a1967d11b
--- /dev/null
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/test/proxy_api_overrides_test.dart
@@ -0,0 +1,65 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shared_test_plugin_code/src/generated/proxy_api_tests.gen.dart';
+
+void main() {
+  test('can override ProxyApi constructors', () {
+    PigeonOverrides.pigeon_reset();
+
+    final ProxyApiSuperClass instance = ProxyApiSuperClass.pigeon_detached();
+    PigeonOverrides.proxyApiSuperClass_new = () => instance;
+
+    expect(ProxyApiSuperClass(), instance);
+  });
+
+  test('can override ProxyApi static attached fields', () {
+    PigeonOverrides.pigeon_reset();
+
+    final ProxyApiSuperClass instance = ProxyApiSuperClass.pigeon_detached();
+    PigeonOverrides.proxyApiTestClass_staticAttachedField = instance;
+
+    expect(ProxyApiTestClass.staticAttachedField, instance);
+  });
+
+  test('can override ProxyApi static methods', () async {
+    PigeonOverrides.pigeon_reset();
+
+    PigeonOverrides.proxyApiTestClass_echoStaticString = (String value) async {
+      return value;
+    };
+
+    const String value = 'testString';
+    expect(await ProxyApiTestClass.echoStaticString(value), value);
+  });
+
+  test('pigeon_reset sets constructor overrides to null', () {
+    PigeonOverrides.proxyApiSuperClass_new =
+        () => ProxyApiSuperClass.pigeon_detached();
+
+    PigeonOverrides.pigeon_reset();
+    expect(
+      PigeonOverrides.proxyApiSuperClass_new,
+      isNull,
+    );
+  });
+
+  test('pigeon_reset sets attached field overrides to null', () {
+    PigeonOverrides.proxyApiTestClass_staticAttachedField =
+        ProxyApiSuperClass.pigeon_detached();
+
+    PigeonOverrides.pigeon_reset();
+    expect(PigeonOverrides.proxyApiTestClass_staticAttachedField, isNull);
+  });
+
+  test('pigeon_reset sets static method overrides to null', () {
+    PigeonOverrides.proxyApiTestClass_echoStaticString = (String value) async {
+      return value;
+    };
+
+    PigeonOverrides.pigeon_reset();
+    expect(PigeonOverrides.proxyApiTestClass_echoStaticString, isNull);
+  });
+}
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index fc25e430e75..0c2d643267e 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+pigeon%22
-version: 25.5.0 # This must match the version in lib/src/generator_tools.dart
+version: 26.0.0 # This must match the version in lib/src/generator_tools.dart
 
 environment:
   sdk: ^3.6.0
diff --git a/packages/pigeon/test/dart/proxy_api_test.dart b/packages/pigeon/test/dart/proxy_api_test.dart
index ac72dfb07f1..d1bc8761065 100644
--- a/packages/pigeon/test/dart/proxy_api_test.dart
+++ b/packages/pigeon/test/dart/proxy_api_test.dart
@@ -98,7 +98,13 @@ void main() {
       expect(
         collapsedCode,
         contains(
-          r'Api.name({ super.pigeon_binaryMessenger, super.pigeon_instanceManager, required this.someField, this.doSomethingElse, required Input input, })',
+          r'factory Api.name({ BinaryMessenger? pigeon_binaryMessenger, PigeonInstanceManager? pigeon_instanceManager, required int someField, String Function( Api pigeon_instance, Input input, )? doSomethingElse, required Input input, })',
+        ),
+      );
+      expect(
+        collapsedCode,
+        contains(
+          r'Api.pigeon_name({ super.pigeon_binaryMessenger, super.pigeon_instanceManager, required this.someField, this.doSomethingElse, required Input input, })',
         ),
       );
       expect(
@@ -459,7 +465,14 @@ void main() {
         expect(
           collapsedCode,
           contains(
-            r'Api({ super.pigeon_binaryMessenger, '
+            r'factory Api({ BinaryMessenger? pigeon_binaryMessenger, '
+            r'PigeonInstanceManager? pigeon_instanceManager, })',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'Api.pigeon_new({ super.pigeon_binaryMessenger, '
             r'super.pigeon_instanceManager, })',
           ),
         );
@@ -565,7 +578,20 @@ void main() {
         expect(
           collapsedCode,
           contains(
-            r'Api.name({ super.pigeon_binaryMessenger, '
+            r'factory Api.name({ BinaryMessenger? pigeon_binaryMessenger, '
+            r'PigeonInstanceManager? pigeon_instanceManager, '
+            r'required int validType, '
+            r'required AnEnum enumType, '
+            r'required Api2 proxyApiType, '
+            r'int? nullableValidType, '
+            r'AnEnum? nullableEnumType, '
+            r'Api2? nullableProxyApiType, })',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'Api.pigeon_name({ super.pigeon_binaryMessenger, '
             r'super.pigeon_instanceManager, '
             r'required int validType, '
             r'required AnEnum enumType, '
@@ -675,7 +701,20 @@ void main() {
         expect(
           collapsedCode,
           contains(
-            r'Api.name({ super.pigeon_binaryMessenger, '
+            r'factory Api.name({ BinaryMessenger? pigeon_binaryMessenger, '
+            r'PigeonInstanceManager? pigeon_instanceManager, '
+            r'required int validType, '
+            r'required AnEnum enumType, '
+            r'required Api2 proxyApiType, '
+            r'int? nullableValidType, '
+            r'AnEnum? nullableEnumType, '
+            r'Api2? nullableProxyApiType, })',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'Api.pigeon_name({ super.pigeon_binaryMessenger, '
             r'super.pigeon_instanceManager, '
             r'required this.validType, '
             r'required this.enumType, '
@@ -806,7 +845,11 @@ void main() {
         final String code = sink.toString();
         expect(code, contains('class Api'));
         expect(
-            code, contains(r'static final Api2 aField = pigeonVar_aField();'));
+            code,
+            contains(
+                r'static Api2 get aField => PigeonOverrides.api_aField ?? _aField;'));
+        expect(
+            code, contains(r'static final Api2 _aField = pigeonVar_aField();'));
         expect(code, contains(r'static Api2 pigeonVar_aField()'));
       });
     });