diff --git a/codegen/end_to_end_test/test/operation/variables_test.dart b/codegen/end_to_end_test/test/operation/variables_test.dart
index f0d0a9ea..e3227c6d 100644
--- a/codegen/end_to_end_test/test/operation/variables_test.dart
+++ b/codegen/end_to_end_test/test/operation/variables_test.dart
@@ -1,8 +1,7 @@
-import "package:test/test.dart";
-
 import 'package:end_to_end_test/graphql/__generated__/schema.schema.gql.dart';
-import 'package:end_to_end_test/variables/__generated__/human_with_args.var.gql.dart';
 import 'package:end_to_end_test/variables/__generated__/create_review.var.gql.dart';
+import 'package:end_to_end_test/variables/__generated__/human_with_args.var.gql.dart';
+import "package:test/test.dart";
 
 void main() {
   group("Basic Args", () {
diff --git a/codegen/end_to_end_test/test/schema/input_test.dart b/codegen/end_to_end_test/test/schema/input_test.dart
index 1d9bf6f6..9dcb1d7c 100644
--- a/codegen/end_to_end_test/test/schema/input_test.dart
+++ b/codegen/end_to_end_test/test/schema/input_test.dart
@@ -1,6 +1,5 @@
-import "package:test/test.dart";
-
 import 'package:end_to_end_test/graphql/__generated__/schema.schema.gql.dart';
+import "package:test/test.dart";
 
 void main() {
   group("Inputs", () {
diff --git a/codegen/end_to_end_test/test/schema/scalars_test.dart b/codegen/end_to_end_test/test/schema/scalars_test.dart
index 5224ac69..5a18b244 100644
--- a/codegen/end_to_end_test/test/schema/scalars_test.dart
+++ b/codegen/end_to_end_test/test/schema/scalars_test.dart
@@ -1,11 +1,10 @@
-import "package:test/test.dart";
-
+import 'package:end_to_end_test/custom_field.dart';
+import 'package:end_to_end_test/custom_field_serializer.dart';
 import 'package:end_to_end_test/graphql/__generated__/schema.schema.gql.dart';
 import 'package:end_to_end_test/graphql/__generated__/serializers.gql.dart';
 import 'package:end_to_end_test/scalars/__generated__/review_with_date.data.gql.dart';
 import 'package:end_to_end_test/scalars/__generated__/review_with_date.var.gql.dart';
-import 'package:end_to_end_test/custom_field.dart';
-import 'package:end_to_end_test/custom_field_serializer.dart';
+import "package:test/test.dart";
 
 void main() {
   group("Custom scalars from non-standard dart types", () {
diff --git a/codegen/gql_build/README.md b/codegen/gql_build/README.md
index 86acaf98..7ce876c6 100644
--- a/codegen/gql_build/README.md
+++ b/codegen/gql_build/README.md
@@ -63,6 +63,20 @@ new enum values are added to the schema and the client has not updated to the ne
 `global_enum_fallbacks`: \[bool\] Add a generated fallback value for each enum value (except for ones that have a custom fallback value specified in the enum_fallbacks map).
 Defaults to false.
 
+`when_extensions`: [Map\] whether to enable the `when`/`maybeWhen` extension on the generated data classes
+from inline fragment spreads with type conditions. 
+Supported keys are `when` and `maybeWhen`, and the values are booleans indicating whether to enable 
+generation of the extension method not.
+
+
+Example:
+
+```yaml
+when_extensions:
+  when: true # enable the `when` extension method
+  maybeWhen: true  # enable the `maybeWhen` extension method
+```
+
 Example:
 
 ```yaml
diff --git a/codegen/gql_build/lib/src/schema_builder.dart b/codegen/gql_build/lib/src/schema_builder.dart
index b7054dd5..d85096f9 100644
--- a/codegen/gql_build/lib/src/schema_builder.dart
+++ b/codegen/gql_build/lib/src/schema_builder.dart
@@ -2,6 +2,7 @@ import "dart:async";
 
 import "package:build/build.dart";
 import "package:code_builder/code_builder.dart";
+import "package:gql_build/src/allocators/gql_allocator.dart";
 import "package:gql_code_builder/schema.dart";
 import "package:path/path.dart";
 
@@ -14,11 +15,8 @@ class SchemaBuilder implements Builder {
   final EnumFallbackConfig enumFallbackConfig;
   final bool generatePossibleTypesMap;
 
-  SchemaBuilder(
-    this.typeOverrides,
-    this.enumFallbackConfig,
-    this.generatePossibleTypesMap,
-  );
+  SchemaBuilder(this.typeOverrides, this.enumFallbackConfig,
+      this.generatePossibleTypesMap);
 
   @override
   Map<String, List<String>> get buildExtensions => {
@@ -34,19 +32,20 @@ class SchemaBuilder implements Builder {
         .uri
         .path;
 
-    final library = buildSchemaLibrary(
-      doc,
-      basename(generatedPartUrl),
-      typeOverrides,
-      enumFallbackConfig,
-      generatePossibleTypesMap: generatePossibleTypesMap,
+    final schemaUrl =
+        outputAssetId(buildStep.inputId, schemaExtension).uri.toString();
+    final allocator = GqlAllocator(
+      buildStep.inputId.uri.toString(),
+      outputAssetId(buildStep.inputId, schemaExtension).uri.toString(),
+      schemaUrl,
     );
 
+    final library = buildSchemaLibrary(
+        doc, basename(generatedPartUrl), typeOverrides, enumFallbackConfig,
+        generatePossibleTypesMap: generatePossibleTypesMap,
+        allocator: allocator);
+
     return writeDocument(
-      library,
-      buildStep,
-      schemaExtension,
-      outputAssetId(buildStep.inputId, schemaExtension).uri.toString(),
-    );
+        library, buildStep, schemaExtension, schemaUrl, allocator);
   }
 }
diff --git a/codegen/gql_build/lib/src/serializer_builder.dart b/codegen/gql_build/lib/src/serializer_builder.dart
index 22028a04..16d60280 100644
--- a/codegen/gql_build/lib/src/serializer_builder.dart
+++ b/codegen/gql_build/lib/src/serializer_builder.dart
@@ -42,6 +42,14 @@ class SerializerBuilder implements Builder {
 
   @override
   FutureOr<void> build(BuildStep buildStep) async {
+    final allocator = PickAllocator(
+      doNotPick: ["package:built_value/serializer.dart"],
+      include: [
+        "package:built_collection/built_collection.dart",
+        ...typeOverrides.values.map((ref) => ref.url).whereType<String>()
+      ],
+    );
+
     /// BuiltValue classes with serializers. These will be added automatically
     /// using `@SerializersFor`.
     final builtClasses =
@@ -102,13 +110,7 @@ class SerializerBuilder implements Builder {
     );
 
     final _emitter = DartEmitter(
-      allocator: PickAllocator(
-        doNotPick: ["package:built_value/serializer.dart"],
-        include: [
-          "package:built_collection/built_collection.dart",
-          ...typeOverrides.values.map((ref) => ref.url).whereType<String>()
-        ],
-      ),
+      allocator: allocator,
       orderDirectives: true,
       useNullSafetySyntax: true,
     );
diff --git a/codegen/gql_build/lib/src/utils/writer.dart b/codegen/gql_build/lib/src/utils/writer.dart
index a1285154..ba901931 100644
--- a/codegen/gql_build/lib/src/utils/writer.dart
+++ b/codegen/gql_build/lib/src/utils/writer.dart
@@ -14,18 +14,21 @@ Future<void> writeDocument(
   BuildStep buildStep,
   String extension, [
   String? schemaUrl,
+  Allocator? allocator,
 ]) {
   if (library.body.isEmpty) return Future.value(null);
 
+  allocator ??= GqlAllocator(
+    buildStep.inputId.uri.toString(),
+    outputAssetId(buildStep.inputId, extension).uri.toString(),
+    schemaUrl,
+  );
+
   final generatedAsset = outputAssetId(buildStep.inputId, extension);
 
   final genSrc = _dartfmt.format("${library.accept(
     DartEmitter(
-      allocator: GqlAllocator(
-        buildStep.inputId.uri.toString(),
-        generatedAsset.uri.toString(),
-        schemaUrl,
-      ),
+      allocator: allocator,
       orderDirectives: true,
       useNullSafetySyntax: true,
     ),
diff --git a/codegen/gql_build/lib/src/var_builder.dart b/codegen/gql_build/lib/src/var_builder.dart
index 74ba44dc..8733b6b5 100644
--- a/codegen/gql_build/lib/src/var_builder.dart
+++ b/codegen/gql_build/lib/src/var_builder.dart
@@ -2,6 +2,7 @@ import "dart:async";
 
 import "package:build/build.dart";
 import "package:code_builder/code_builder.dart";
+import "package:gql_build/src/allocators/gql_allocator.dart";
 import "package:gql_code_builder/var.dart";
 import "package:path/path.dart";
 
@@ -34,18 +35,22 @@ class VarBuilder implements Builder {
         .uri
         .path;
 
-    final library = buildVarLibrary(
-      doc,
-      addTypenames(schema),
-      basename(generatedPartUrl),
-      typeOverrides,
+    final schemaUrl = outputAssetId(schemaId, schemaExtension).uri.toString();
+    final allocator = GqlAllocator(
+      buildStep.inputId.uri.toString(),
+      outputAssetId(buildStep.inputId, schemaExtension).uri.toString(),
+      schemaUrl,
     );
 
+    final library = buildVarLibrary(doc, addTypenames(schema),
+        basename(generatedPartUrl), typeOverrides, allocator);
+
     return writeDocument(
       library,
       buildStep,
       varExtension,
-      outputAssetId(schemaId, schemaExtension).uri.toString(),
+      schemaUrl,
+      allocator,
     );
   }
 }
diff --git a/codegen/gql_code_builder/lib/schema.dart b/codegen/gql_code_builder/lib/schema.dart
index 61a57957..99da105a 100644
--- a/codegen/gql_code_builder/lib/schema.dart
+++ b/codegen/gql_code_builder/lib/schema.dart
@@ -7,17 +7,14 @@ import "package:gql_code_builder/src/utils/possible_types.dart";
 
 export "package:gql_code_builder/src/config/enum_fallback_config.dart";
 
-Library buildSchemaLibrary(
-  SourceNode schemaSource,
-  String partUrl,
-  Map<String, Reference> typeOverrides,
-  EnumFallbackConfig enumFallbackConfig, {
-  bool generatePossibleTypesMap = false,
-}) {
+Library buildSchemaLibrary(SourceNode schemaSource, String partUrl,
+    Map<String, Reference> typeOverrides, EnumFallbackConfig enumFallbackConfig,
+    {bool generatePossibleTypesMap = false, Allocator? allocator}) {
   final lib = buildSchema(
     schemaSource,
     typeOverrides,
     enumFallbackConfig,
+    allocator ?? Allocator(),
   ) as Library;
 
   final Code? possibleTypes;
diff --git a/codegen/gql_code_builder/lib/src/built_class.dart b/codegen/gql_code_builder/lib/src/built_class.dart
index 631ba97b..9b92906e 100644
--- a/codegen/gql_code_builder/lib/src/built_class.dart
+++ b/codegen/gql_code_builder/lib/src/built_class.dart
@@ -11,6 +11,7 @@ Class builtClass({
   Map<String, Expression>? initializers,
   Map<String, SourceSelections> superclassSelections = const {},
   List<Method> methods = const [],
+  bool hasCustomSerializer = false,
 }) {
   final className = builtClassName(name);
   return Class(
@@ -76,10 +77,11 @@ Class builtClass({
               ).code,
           ),
         if (getters != null) ...getters,
-        // Serlialization methods
-        buildSerializerGetter(className).rebuild(
-          (b) => b..body = Code("_\$${toCamelCase(className)}Serializer"),
-        ),
+        // Serialization methods
+        if (!hasCustomSerializer)
+          buildSerializerGetter(className).rebuild(
+            (b) => b..body = Code("_\$${toCamelCase(className)}Serializer"),
+          ),
         buildToJsonGetter(
           className,
           isOverride: superclassSelections.isNotEmpty,
diff --git a/codegen/gql_code_builder/lib/src/common.dart b/codegen/gql_code_builder/lib/src/common.dart
index 7cbcd01a..3df0ea8b 100644
--- a/codegen/gql_code_builder/lib/src/common.dart
+++ b/codegen/gql_code_builder/lib/src/common.dart
@@ -93,9 +93,6 @@ Reference _typeRef(TypeNode type, Map<String, Reference> typeMap) {
       (b) => b
         ..url = ref.url
         ..symbol = ref.symbol
-
-        /// TODO: remove `inList` check
-        /// https://github.com/google/built_value.dart/issues/1011#issuecomment-804843573
         ..isNullable = !type.isNonNull,
     );
   } else if (type is ListTypeNode) {
diff --git a/codegen/gql_code_builder/lib/src/schema.dart b/codegen/gql_code_builder/lib/src/schema.dart
index aa9eb78b..0b9d5f23 100644
--- a/codegen/gql_code_builder/lib/src/schema.dart
+++ b/codegen/gql_code_builder/lib/src/schema.dart
@@ -1,5 +1,6 @@
 import "package:code_builder/code_builder.dart";
 import "package:gql/ast.dart";
+import "package:gql_code_builder/var.dart";
 
 import "./schema/enum.dart";
 import "./schema/input.dart";
@@ -12,69 +13,67 @@ Spec? buildSchema(
   SourceNode schemaSource,
   Map<String, Reference> typeOverrides,
   EnumFallbackConfig enumFallbackConfig,
+  Allocator allocator,
 ) =>
-    schemaSource.document.accept(
-      _SchemaBuilderVisitor(
-        schemaSource,
-        typeOverrides,
-        enumFallbackConfig,
-      ),
-    );
+    schemaSource.document
+        .accept(
+          _SchemaBuilderVisitor(
+            schemaSource,
+            typeOverrides,
+            enumFallbackConfig,
+            allocator,
+          ),
+        )
+        ?.first;
 
-class _SchemaBuilderVisitor extends SimpleVisitor<Spec?> {
+class _SchemaBuilderVisitor extends SimpleVisitor<List<Spec>?> {
   final SourceNode schemaSource;
   final Map<String, Reference> typeOverrides;
   final EnumFallbackConfig enumFallbackConfig;
+  final Allocator allocator;
 
-  _SchemaBuilderVisitor(
-    this.schemaSource,
-    this.typeOverrides,
-    this.enumFallbackConfig,
-  );
-
-  Spec? _acceptOne(
-    Node? node,
-  ) =>
-      node != null ? node.accept(this) : literalNull;
-
-  List<Spec?> _acceptMany(
-    List<Node> nodes,
-  ) =>
-      nodes.map(_acceptOne).toList(
-            growable: false,
-          );
+  _SchemaBuilderVisitor(this.schemaSource, this.typeOverrides,
+      this.enumFallbackConfig, this.allocator);
 
   @override
-  Spec visitDocumentNode(
+  List<Spec> visitDocumentNode(
     DocumentNode node,
   ) =>
-      Library(
-        (b) => b.body.addAll(
-          _acceptMany(node.definitions).whereType<Spec>(),
-        ),
-      );
+      [
+        Library(
+          (b) => b.body.addAll(
+            node.definitions.expand(
+              (node) => node.accept(this) ?? [],
+            ),
+          ),
+        )
+      ];
 
   @override
-  Spec visitInputObjectTypeDefinitionNode(
+  List<Spec> visitInputObjectTypeDefinitionNode(
     InputObjectTypeDefinitionNode node,
-  ) =>
-      buildInputClass(
-        node,
-        schemaSource,
-        typeOverrides,
-      );
+  ) {
+    final inputClass = buildInputClass(
+      node,
+      schemaSource,
+      typeOverrides,
+    );
+    final serializer = nullAwareJsonSerializerClass(
+        inputClass, allocator, schemaSource, typeOverrides);
+    return [inputClass, serializer];
+  }
 
   @override
-  Spec? visitScalarTypeDefinitionNode(
+  List<Spec> visitScalarTypeDefinitionNode(
     ScalarTypeDefinitionNode node,
   ) =>
       typeOverrides.containsKey(node.name.value)
-          ? null
-          : buildScalarClass(node);
+          ? []
+          : [buildScalarClass(node)];
 
   @override
-  Spec visitEnumTypeDefinitionNode(
+  List<Spec> visitEnumTypeDefinitionNode(
     EnumTypeDefinitionNode node,
   ) =>
-      buildEnumClass(node, enumFallbackConfig);
+      [buildEnumClass(node, enumFallbackConfig)];
 }
diff --git a/codegen/gql_code_builder/lib/src/schema/input.dart b/codegen/gql_code_builder/lib/src/schema/input.dart
index bce9faa7..7fff98d7 100644
--- a/codegen/gql_code_builder/lib/src/schema/input.dart
+++ b/codegen/gql_code_builder/lib/src/schema/input.dart
@@ -1,5 +1,6 @@
 import "package:code_builder/code_builder.dart";
 import "package:gql/ast.dart";
+import "package:gql_code_builder/var.dart";
 
 import "../../source.dart";
 import "../built_class.dart";
@@ -8,17 +9,20 @@ import "../common.dart";
 List<Class> buildInputClasses(
   SourceNode schemaSource,
   Map<String, Reference> typeOverrides,
+  Allocator allocator,
 ) =>
     schemaSource.document.definitions
         .whereType<InputObjectTypeDefinitionNode>()
-        .map(
-          (InputObjectTypeDefinitionNode node) => buildInputClass(
-            node,
-            schemaSource,
-            typeOverrides,
-          ),
-        )
-        .toList();
+        .expand((InputObjectTypeDefinitionNode node) {
+      final inputClass = buildInputClass(
+        node,
+        schemaSource,
+        typeOverrides,
+      );
+      final serializer = nullAwareJsonSerializerClass(
+          inputClass, allocator, schemaSource, typeOverrides);
+      return [inputClass, serializer];
+    }).toList();
 
 Class buildInputClass(
   InputObjectTypeDefinitionNode node,
@@ -35,4 +39,8 @@ Class buildInputClass(
           typeOverrides: typeOverrides,
         ),
       ),
+      hasCustomSerializer: true,
+      methods: [
+        nullAwareJsonSerializerField(node, "G${node.name.value}"),
+      ],
     );
diff --git a/codegen/gql_code_builder/lib/var.dart b/codegen/gql_code_builder/lib/var.dart
index 80f553c7..13396672 100644
--- a/codegen/gql_code_builder/lib/var.dart
+++ b/codegen/gql_code_builder/lib/var.dart
@@ -1,4 +1,5 @@
 import "package:code_builder/code_builder.dart";
+import "package:collection/collection.dart";
 import "package:gql/ast.dart";
 
 import "./source.dart";
@@ -11,22 +12,37 @@ Library buildVarLibrary(
   SourceNode schemaSource,
   String partUrl,
   Map<String, Reference> typeOverrides,
+  bool serializeNulls,
+  Allocator allocator,
 ) {
   final operationVarClasses = docSource.document.definitions
       .whereType<OperationDefinitionNode>()
-      .map(
-        (op) => builtClass(
-          name: "${op.name!.value}Vars",
-          getters: op.variableDefinitions.map<Method>(
-            (node) => buildGetter(
-              nameNode: node.variable.name,
-              typeNode: node.type,
-              schemaSource: schemaSource,
-              typeOverrides: typeOverrides,
-            ),
-          ),
-        ),
-      )
+      .map((op) => serializeNulls
+          ? builtClass(
+              name: "${op.name!.value}Vars",
+              getters: op.variableDefinitions.map<Method>(
+                (node) => buildGetter(
+                  nameNode: node.variable.name,
+                  typeNode: node.type,
+                  schemaSource: schemaSource,
+                  typeOverrides: typeOverrides,
+                ),
+              ),
+              hasCustomSerializer: true,
+              methods: [
+                  nullAwareJsonSerializerField(op, "G${op.name!.value}Vars"),
+                ])
+          : builtClass(
+              name: "${op.name!.value}Vars",
+              getters: op.variableDefinitions.map<Method>(
+                (node) => buildGetter(
+                  nameNode: node.variable.name,
+                  typeNode: node.type,
+                  schemaSource: schemaSource,
+                  typeOverrides: typeOverrides,
+                ),
+              ),
+            ))
       .toList();
 
   Map<String, FragmentDefinitionNode> _fragmentMap(SourceNode source) => {
@@ -54,6 +70,10 @@ Library buildVarLibrary(
           typeOverrides: typeOverrides,
         ),
       ),
+      hasCustomSerializer: true,
+      methods: [
+        nullAwareJsonSerializerField(frag, "G${frag.name.value}Vars"),
+      ],
     );
   }).toList();
 
@@ -63,6 +83,216 @@ Library buildVarLibrary(
       ..body.addAll([
         ...operationVarClasses,
         ...fragmentVarClasses,
+        for (var op in operationVarClasses)
+          nullAwareJsonSerializerClass(
+            op,
+            allocator,
+            schemaSource,
+            typeOverrides,
+          ),
+        for (var frag in fragmentVarClasses)
+          nullAwareJsonSerializerClass(
+            frag,
+            allocator,
+            schemaSource,
+            typeOverrides,
+          ),
       ]),
   );
 }
+
+Method nullAwareJsonSerializerField(Node op, String className) =>
+    Method((b) => b
+      ..annotations.add(CodeExpression(
+          Code("BuiltValueSerializer(custom: true, serializeNulls: true)")))
+      ..static = true
+      ..type = MethodType.getter
+      ..lambda = true
+      ..returns = TypeReference((b2) => b2
+        ..symbol = "Serializer"
+        ..url = "package:built_value/serializer.dart"
+        ..types.add(refer(className)))
+      ..name = "serializer"
+      ..body = Code("${className}Serializer()"));
+
+Class nullAwareJsonSerializerClass(
+  Class base,
+  Allocator allocator,
+  SourceNode schemaSource,
+  Map<String, Reference> typeOverrides,
+) =>
+    Class((b) => b
+      ..name = "${base.name}Serializer"
+      ..extend = TypeReference((b) => b
+        ..symbol = "StructuredSerializer"
+        ..url = "package:built_value/serializer.dart"
+        ..types.add(refer(base.name)))
+      ..fields.addAll([
+        Field(
+          (b) => b
+            ..name = "wireName"
+            ..modifier = FieldModifier.final$
+            ..type = refer("String")
+            ..assignment = (literalString(base.name)).code,
+        ),
+        Field((b) => b
+          ..name = "types"
+          ..modifier = FieldModifier.final$
+          ..type = TypeReference((b2) => b2..symbol = "Iterable<Type>")
+          ..assignment = Code("const [${base.name}, _\$${base.name}]"))
+      ])
+      ..methods.addAll([
+        Method((b) => b
+          ..name = "serialize"
+          ..returns = refer("Iterable<Object?>")
+          ..requiredParameters.add(Parameter((b) => b
+            ..name = "serializers"
+            ..type =
+                refer("Serializers", "package:built_value/serializer.dart")))
+          ..requiredParameters.add(Parameter((b) => b
+            ..name = "object"
+            ..type = refer(base.name)))
+          ..optionalParameters.add(Parameter((b) => b
+            ..name = "specifiedType"
+            ..named = true
+            ..type = refer("FullType", "package:built_value/serializer.dart")
+            ..defaultTo = Code("FullType.unspecified")))
+          ..body =
+              _serializerBody(base, allocator, schemaSource, typeOverrides)),
+        Method((b) => b
+          ..name = "deserialize"
+          ..returns = refer(base.name)
+          ..requiredParameters.add(Parameter((b) => b
+            ..name = "serializers"
+            ..type =
+                refer("Serializers", "package:built_value/serializer.dart")))
+          ..requiredParameters.add(Parameter((b) => b
+            ..name = "serialized"
+            ..type = refer("Iterable<Object?>")))
+          ..optionalParameters.add(Parameter((b) => b
+            ..name = "specifiedType"
+            ..named = true
+            ..type = refer("FullType", "package:built_value/serializer.dart")
+            ..defaultTo = Code("FullType.unspecified")))
+          ..body =
+              _deserializerBody(base, allocator, schemaSource, typeOverrides)),
+      ]));
+
+Code _serializerBody(Class base, Allocator allocator, SourceNode schemaSource,
+    Map<String, Reference> typeOverrides) {
+  final vars = <Code>[];
+
+  for (final field in base.methods
+      .where((field) => !field.static && field.type == MethodType.getter)) {
+    final statements = <Code>[];
+
+    statements.add(Code("result.add('${_getWireName(field)}');"));
+    statements.add(Code(
+        "result.add(serializers.serialize(object.${field.name}, specifiedType: const ${_generateFullType(field.returns as TypeReference, allocator)}));"));
+
+    vars.add(Block.of(statements));
+  }
+
+  final body = Block.of([
+    Code("final result = <Object?>[];"),
+    ...vars,
+    Code("return result;"),
+  ]);
+
+  return body;
+}
+
+Code _deserializerBody(Class base, Allocator allocator, SourceNode schemaSource,
+        Map<String, Reference> typeOverrides) =>
+    Code("""final builder =  ${base.name}Builder();
+      final iterator = serialized.iterator;
+      while (iterator.moveNext()) {
+        final key = iterator.current as String;
+        iterator.moveNext();
+        final Object? value = iterator.current;
+        switch (key) {
+          ${_generateFieldDeserializers(
+      base,
+      allocator,
+      schemaSource,
+      typeOverrides,
+    )}
+        }
+      }
+      return builder.build();
+    """);
+
+String _generateFieldDeserializers(
+  Class clazz,
+  Allocator allocator,
+  SourceNode schemaSource,
+  Map<String, Reference> typeOverrides,
+) =>
+    clazz.methods
+        .where((field) => field.type == MethodType.getter && !field.static)
+        .map((field) {
+      final type = field.returns!;
+
+      final fullType = _generateFullType(type as TypeReference, allocator);
+
+      final typeDefNode = getTypeDefinitionNode(
+          schemaSource.document, type.symbol.substring(1));
+
+      print(typeDefNode.runtimeType.toString() +
+          " " +
+          (typeDefNode?.name.value.toString() ?? ""));
+
+      //TODO this feels flaky, find a better way
+      final isBuilder = type.url != null &&
+          (typeDefNode is! ScalarTypeDefinitionNode &&
+              typeDefNode is! EnumTypeDefinitionNode);
+
+      /// TODO check for wireName
+
+      var base = """
+case '${_getWireName(field)}':
+  var fieldValue = serializers.deserialize(
+      value, specifiedType: const $fullType) as ${_generateTypeCast(type, allocator)};""";
+
+      if (isBuilder) {
+        base += """
+        builder.${field.name}.replace(fieldValue);
+      """;
+      } else {
+        base += """
+        builder.${field.name} = ${"fieldValue"};
+      """;
+      }
+
+      return base +
+          """
+break;
+""";
+    }).join();
+
+Code _generateFullType(TypeReference ref, Allocator allocator) {
+  if (ref.types.isEmpty) {
+    return Code("FullType(${allocator.allocate(ref)})");
+  } else {
+    return Code(
+        "FullType(${allocator.allocate(ref)}, [${ref.types.map((t) => _generateFullType(t as TypeReference, allocator)).join(",")}])");
+  }
+}
+
+String _generateTypeCast(TypeReference ref, Allocator allocator) {
+  if (ref.types.isEmpty) {
+    return allocator.allocate(ref);
+  } else {
+    return "${allocator.allocate(ref)}<${ref.types.map((t) => _generateTypeCast(t as TypeReference, allocator)).join(",")}>";
+  }
+}
+
+String _getWireName(Method m) {
+  final annotation = m.annotations.firstWhereOrNull(
+          (a) => a is InvokeExpression && a.name == "BuiltValueField")
+      as InvokeExpression?;
+  if (annotation == null) return m.name!;
+  return (annotation.namedArguments["wireName"] as LiteralExpression?)
+          ?.literal ??
+      m.name!;
+}
diff --git a/gql/lib/src/operation/definitions/selections.dart b/gql/lib/src/operation/definitions/selections.dart
index eab6af9e..451607aa 100644
--- a/gql/lib/src/operation/definitions/selections.dart
+++ b/gql/lib/src/operation/definitions/selections.dart
@@ -56,7 +56,6 @@ abstract class Selection extends ExecutableWithResolver {
 
   static Selection fromNode(
     SelectionNode astNode, [
-
     /// The [schemaType] of the containing element
     TypeDefinition? schemaType,
     GetExecutableType? getType,
diff --git a/links/gql_link/lib/src/link.dart b/links/gql_link/lib/src/link.dart
index 2e1f355c..73af9085 100644
--- a/links/gql_link/lib/src/link.dart
+++ b/links/gql_link/lib/src/link.dart
@@ -89,7 +89,6 @@ abstract class Link {
   Stream<Response> request(
     /// An incoming [Request]
     Request request, [
-
     /// Function that invokes the [request] function of
     ///   the next [Link]
     ///