diff --git a/packages/shorebird_code_push_protocol/lib/src/messages/create_patch_artifact/create_patch_artifact_request.dart b/packages/shorebird_code_push_protocol/lib/src/messages/create_patch_artifact/create_patch_artifact_request.dart
index ecbeffe9..3878a061 100644
--- a/packages/shorebird_code_push_protocol/lib/src/messages/create_patch_artifact/create_patch_artifact_request.dart
+++ b/packages/shorebird_code_push_protocol/lib/src/messages/create_patch_artifact/create_patch_artifact_request.dart
@@ -14,6 +14,7 @@ class CreatePatchArtifactRequest {
     required this.platform,
     required this.hash,
     required this.size,
+    this.hashSignature,
   });
 
   /// Converts a Map<String, dynamic> to a [CreatePatchArtifactRequest]
@@ -32,6 +33,13 @@ class CreatePatchArtifactRequest {
   /// The hash of the artifact.
   final String hash;
 
+  /// The signature of the [hash].
+  ///
+  /// Patch code signing is an opt in feature, introduced later in the life of
+  /// the product, so when this field is null, the patch does not uses code
+  /// signing.
+  final String? hashSignature;
+
   /// The size of the artifact in bytes.
   @JsonKey(fromJson: _parseStringToInt, toJson: _parseIntToString)
   final int size;
diff --git a/packages/shorebird_code_push_protocol/lib/src/messages/create_patch_artifact/create_patch_artifact_request.g.dart b/packages/shorebird_code_push_protocol/lib/src/messages/create_patch_artifact/create_patch_artifact_request.g.dart
index ad4af47a..7db1e2ea 100644
--- a/packages/shorebird_code_push_protocol/lib/src/messages/create_patch_artifact/create_patch_artifact_request.g.dart
+++ b/packages/shorebird_code_push_protocol/lib/src/messages/create_patch_artifact/create_patch_artifact_request.g.dart
@@ -21,9 +21,11 @@ CreatePatchArtifactRequest _$CreatePatchArtifactRequestFromJson(
           hash: $checkedConvert('hash', (v) => v as String),
           size: $checkedConvert(
               'size', (v) => CreatePatchArtifactRequest._parseStringToInt(v)),
+          hashSignature: $checkedConvert('hash_signature', (v) => v as String?),
         );
         return val;
       },
+      fieldKeyMap: const {'hashSignature': 'hash_signature'},
     );
 
 Map<String, dynamic> _$CreatePatchArtifactRequestToJson(
@@ -32,6 +34,7 @@ Map<String, dynamic> _$CreatePatchArtifactRequestToJson(
       'arch': instance.arch,
       'platform': _$ReleasePlatformEnumMap[instance.platform]!,
       'hash': instance.hash,
+      'hash_signature': instance.hashSignature,
       'size': CreatePatchArtifactRequest._parseIntToString(instance.size),
     };
 
diff --git a/packages/shorebird_code_push_protocol/test/src/messages/create_patch_artifact/create_patch_artifact_request_test.dart b/packages/shorebird_code_push_protocol/test/src/messages/create_patch_artifact/create_patch_artifact_request_test.dart
index d10bb6f1..bf7a5a25 100644
--- a/packages/shorebird_code_push_protocol/test/src/messages/create_patch_artifact/create_patch_artifact_request_test.dart
+++ b/packages/shorebird_code_push_protocol/test/src/messages/create_patch_artifact/create_patch_artifact_request_test.dart
@@ -15,5 +15,23 @@ void main() {
         equals(request.toJson()),
       );
     });
+
+    group('when there is a hash signature', () {
+      test('can be (de)serialized', () {
+        const request = CreatePatchArtifactRequest(
+          arch: 'arm64',
+          platform: ReleasePlatform.android,
+          hash: '1234',
+          hashSignature: 'Shh',
+          size: 9876,
+        );
+        final instance = CreatePatchArtifactRequest.fromJson(request.toJson());
+        expect(
+          instance.toJson(),
+          equals(request.toJson()),
+        );
+        expect(instance.hashSignature, equals('Shh'));
+      });
+    });
   });
 }