diff --git a/packages/shorebird_code_push_protocol/lib/src/messages/messages.dart b/packages/shorebird_code_push_protocol/lib/src/messages/messages.dart
index 89311ef6..a5d6e434 100644
--- a/packages/shorebird_code_push_protocol/lib/src/messages/messages.dart
+++ b/packages/shorebird_code_push_protocol/lib/src/messages/messages.dart
@@ -13,6 +13,7 @@ export 'get_organizations/get_organizations.dart';
 export 'get_release_artifacts/get_release_artifacts.dart';
 export 'get_release_patches/get_release_patches.dart';
 export 'get_releases/get_releases.dart';
+export 'patch_check/patch_check.dart';
 export 'promote_patch/promote_patch.dart';
 export 'update_app_collaborator/update_app_collaborator.dart';
 export 'update_patch/update_patch.dart';
diff --git a/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check.dart b/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check.dart
new file mode 100644
index 00000000..3bb2106f
--- /dev/null
+++ b/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check.dart
@@ -0,0 +1,2 @@
+export 'patch_check_request.dart';
+export 'patch_check_response.dart';
diff --git a/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_request.dart b/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_request.dart
new file mode 100644
index 00000000..ce0c42f7
--- /dev/null
+++ b/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_request.dart
@@ -0,0 +1,52 @@
+import 'package:json_annotation/json_annotation.dart';
+import 'package:shorebird_code_push_protocol/shorebird_code_push_protocol.dart';
+
+part 'patch_check_request.g.dart';
+
+/// {@template patch_check_request}
+/// The request body for POST /api/v1/patches/check
+/// {@endtemplate}
+@JsonSerializable()
+class PatchCheckRequest {
+  /// {@macro patch_check_request}
+  const PatchCheckRequest({
+    required this.releaseVersion,
+    required this.patchNumber,
+    required this.patchHash,
+    required this.platform,
+    required this.arch,
+    required this.appId,
+    required this.channel,
+  });
+
+  /// Converts a `Map<String, dynamic>` to a [PatchCheckRequest]
+  factory PatchCheckRequest.fromJson(Map<String, dynamic> json) =>
+      _$PatchCheckRequestFromJson(json);
+
+  /// Converts a [PatchCheckRequest] to a `Map<String, dynamic>`
+  Map<String, dynamic> toJson() => _$PatchCheckRequestToJson(this);
+
+  /// The release version of the app.
+  final String releaseVersion;
+
+  /// The highest patch number that the client has downloaded.
+  /// If provided, the server will only return patches with a higher patch
+  ///   number.
+  /// If not provided, the server will provide the latest available patch.
+  final int? patchNumber;
+
+  /// The current patch hash of the app.
+  final String? patchHash;
+
+  /// The platform of the app.
+  final ReleasePlatform platform;
+
+  /// The architecture of the app.
+  final String arch;
+
+  /// The ID of the app.
+  final String appId;
+
+  /// The channel of the app.
+  final String channel;
+}
diff --git a/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_request.g.dart b/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_request.g.dart
new file mode 100644
index 00000000..a9e732bb
--- /dev/null
+++ b/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_request.g.dart
@@ -0,0 +1,56 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+// ignore_for_file: implicit_dynamic_parameter, require_trailing_commas, cast_nullable_to_non_nullable, lines_longer_than_80_chars, unnecessary_lambdas
+
+part of 'patch_check_request.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+PatchCheckRequest _$PatchCheckRequestFromJson(
+  Map<String, dynamic> json,
+) => $checkedCreate(
+  'PatchCheckRequest',
+  json,
+  ($checkedConvert) {
+    final val = PatchCheckRequest(
+      releaseVersion: $checkedConvert('release_version', (v) => v as String),
+      patchNumber: $checkedConvert('patch_number', (v) => (v as num?)?.toInt()),
+      patchHash: $checkedConvert('patch_hash', (v) => v as String?),
+      platform: $checkedConvert(
+        'platform',
+        (v) => $enumDecode(_$ReleasePlatformEnumMap, v),
+      ),
+      arch: $checkedConvert('arch', (v) => v as String),
+      appId: $checkedConvert('app_id', (v) => v as String),
+      channel: $checkedConvert('channel', (v) => v as String),
+    );
+    return val;
+  },
+  fieldKeyMap: const {
+    'releaseVersion': 'release_version',
+    'patchNumber': 'patch_number',
+    'patchHash': 'patch_hash',
+    'appId': 'app_id',
+  },
+);
+
+Map<String, dynamic> _$PatchCheckRequestToJson(PatchCheckRequest instance) =>
+    <String, dynamic>{
+      'release_version': instance.releaseVersion,
+      'patch_number': instance.patchNumber,
+      'patch_hash': instance.patchHash,
+      'platform': _$ReleasePlatformEnumMap[instance.platform]!,
+      'arch': instance.arch,
+      'app_id': instance.appId,
+      'channel': instance.channel,
+    };
+
+const _$ReleasePlatformEnumMap = {
+  ReleasePlatform.android: 'android',
+  ReleasePlatform.ios: 'ios',
+  ReleasePlatform.linux: 'linux',
+  ReleasePlatform.macos: 'macos',
+  ReleasePlatform.windows: 'windows',
+};
diff --git a/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_response.dart b/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_response.dart
new file mode 100644
index 00000000..c4dffd67
--- /dev/null
+++ b/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_response.dart
@@ -0,0 +1,75 @@
+import 'package:equatable/equatable.dart';
+import 'package:json_annotation/json_annotation.dart';
+
+part 'patch_check_response.g.dart';
+
+/// {@template patch_check_response}
+/// The response body for POST /api/v1/patches/check
+/// {@endtemplate}
+@JsonSerializable()
+class PatchCheckResponse extends Equatable {
+  /// {@macro patch_check_response}
+  const PatchCheckResponse({
+    required this.patchAvailable,
+    this.patch,
+    this.rolledBackPatchNumbers,
+  });
+
+  /// Converts a `Map<String, dynamic>` to a [PatchCheckResponse]
+  factory PatchCheckResponse.fromJson(Map<String, dynamic> json) =>
+      _$PatchCheckResponseFromJson(json);
+
+  /// Converts a [PatchCheckResponse] to a `Map<String, dynamic>`
+  Map<String, dynamic> toJson() => _$PatchCheckResponseToJson(this);
+
+  /// Whether a patch is available.
+  final bool patchAvailable;
+
+  /// The patch metadata.
+  final PatchCheckMetadata? patch;
+
+  /// The numbers of all patches that have been rolled back for the current
+  /// release.
+  final List<int>? rolledBackPatchNumbers;
+
+  @override
+  List<Object?> get props => [patchAvailable, patch, rolledBackPatchNumbers];
+}
+
+/// {@template patch_check_metadata}
+/// Patch metadata represents the contents of an update (patch) for a specific
+/// platform and architecture.
+/// {@endtemplate}
+@JsonSerializable()
+class PatchCheckMetadata extends Equatable {
+  /// {@macro patch_check_metadata}
+  const PatchCheckMetadata({
+    required this.number,
+    required this.downloadUrl,
+    required this.hash,
+    required this.hashSignature,
+  });
+
+  /// Converts a `Map<String, dynamic>` to an [PatchCheckMetadata]
+  factory PatchCheckMetadata.fromJson(Map<String, dynamic> json) =>
+      _$PatchCheckMetadataFromJson(json);
+
+  /// Converts an [PatchCheckMetadata] to a `Map<String, dynamic>`
+  Map<String, dynamic> toJson() => _$PatchCheckMetadataToJson(this);
+
+  /// The patch number associated with the artifact.
+  final int number;
+
+  /// The URL of the artifact.
+  final String downloadUrl;
+
+  /// The hash of the artifact.
+  final String hash;
+
+  /// The signature of the [hash].
+  @JsonKey(includeIfNull: false)
+  final String? hashSignature;
+
+  @override
+  List<Object?> get props => [number, downloadUrl, hash, hashSignature];
+}
diff --git a/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_response.g.dart b/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_response.g.dart
new file mode 100644
index 00000000..a5b07417
--- /dev/null
+++ b/packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_response.g.dart
@@ -0,0 +1,71 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+// ignore_for_file: implicit_dynamic_parameter, require_trailing_commas, cast_nullable_to_non_nullable, lines_longer_than_80_chars, unnecessary_lambdas
+
+part of 'patch_check_response.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+PatchCheckResponse _$PatchCheckResponseFromJson(Map<String, dynamic> json) =>
+    $checkedCreate(
+      'PatchCheckResponse',
+      json,
+      ($checkedConvert) {
+        final val = PatchCheckResponse(
+          patchAvailable: $checkedConvert('patch_available', (v) => v as bool),
+          patch: $checkedConvert(
+            'patch',
+            (v) =>
+                v == null
+                    ? null
+                    : PatchCheckMetadata.fromJson(v as Map<String, dynamic>),
+          ),
+          rolledBackPatchNumbers: $checkedConvert(
+            'rolled_back_patch_numbers',
+            (v) =>
+                (v as List<dynamic>?)?.map((e) => (e as num).toInt()).toList(),
+          ),
+        );
+        return val;
+      },
+      fieldKeyMap: const {
+        'patchAvailable': 'patch_available',
+        'rolledBackPatchNumbers': 'rolled_back_patch_numbers',
+      },
+    );
+
+Map<String, dynamic> _$PatchCheckResponseToJson(PatchCheckResponse instance) =>
+    <String, dynamic>{
+      'patch_available': instance.patchAvailable,
+      'patch': instance.patch?.toJson(),
+      'rolled_back_patch_numbers': instance.rolledBackPatchNumbers,
+    };
+
+PatchCheckMetadata _$PatchCheckMetadataFromJson(Map<String, dynamic> json) =>
+    $checkedCreate(
+      'PatchCheckMetadata',
+      json,
+      ($checkedConvert) {
+        final val = PatchCheckMetadata(
+          number: $checkedConvert('number', (v) => (v as num).toInt()),
+          downloadUrl: $checkedConvert('download_url', (v) => v as String),
+          hash: $checkedConvert('hash', (v) => v as String),
+          hashSignature: $checkedConvert('hash_signature', (v) => v as String?),
+        );
+        return val;
+      },
+      fieldKeyMap: const {
+        'downloadUrl': 'download_url',
+        'hashSignature': 'hash_signature',
+      },
+    );
+
+Map<String, dynamic> _$PatchCheckMetadataToJson(PatchCheckMetadata instance) =>
+    <String, dynamic>{
+      'number': instance.number,
+      'download_url': instance.downloadUrl,
+      'hash': instance.hash,
+      if (instance.hashSignature case final value?) 'hash_signature': value,
+    };
diff --git a/packages/shorebird_code_push_protocol/test/src/messages/patch_check/patch_check_request_test.dart b/packages/shorebird_code_push_protocol/test/src/messages/patch_check/patch_check_request_test.dart
new file mode 100644
index 00000000..ad0aef73
--- /dev/null
+++ b/packages/shorebird_code_push_protocol/test/src/messages/patch_check/patch_check_request_test.dart
@@ -0,0 +1,22 @@
+import 'package:shorebird_code_push_protocol/shorebird_code_push_protocol.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group(PatchCheckRequest, () {
+    test('can be (de)serialized', () {
+      const request = PatchCheckRequest(
+        releaseVersion: '1',
+        patchNumber: 2,
+        patchHash: '3',
+        platform: ReleasePlatform.android,
+        arch: 'arm64',
+        appId: 'app_123',
+        channel: 'channel_123',
+      );
+      expect(
+        PatchCheckRequest.fromJson(request.toJson()).toJson(),
+        equals(request.toJson()),
+      );
+    });
+  });
+}
diff --git a/packages/shorebird_code_push_protocol/test/src/messages/patch_check/patch_check_response_test.dart b/packages/shorebird_code_push_protocol/test/src/messages/patch_check/patch_check_response_test.dart
new file mode 100644
index 00000000..56f47d51
--- /dev/null
+++ b/packages/shorebird_code_push_protocol/test/src/messages/patch_check/patch_check_response_test.dart
@@ -0,0 +1,129 @@
+import 'package:shorebird_code_push_protocol/shorebird_code_push_protocol.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group(PatchCheckResponse, () {
+    test('uses value equality', () {
+      expect(
+        // Ignoring for value quality testing.
+        // ignore: prefer_const_constructors
+        PatchCheckResponse(patchAvailable: true),
+        // Ignoring for value quality testing.
+        // ignore: prefer_const_constructors
+        equals(PatchCheckResponse(patchAvailable: true)),
+      );
+    });
+
+    test('can be (de)serialized', () {
+      const response = PatchCheckResponse(patchAvailable: true);
+      expect(
+        PatchCheckResponse.fromJson(response.toJson()).toJson(),
+        equals(response.toJson()),
+      );
+    });
+
+    test('can be serialized to json without patch metadata', () {
+      const response = PatchCheckResponse(patchAvailable: true);
+      expect(response.toJson(), {
+        'patch_available': true,
+        'patch': null,
+        'rolled_back_patch_numbers': null,
+      });
+    });
+
+    test('PatchCheckMetadata uses value equality', () {
+      expect(
+        // Ignoring for value quality testing.
+        // ignore: prefer_const_constructors
+        PatchCheckMetadata(
+          number: 1,
+          downloadUrl: 'https://download.com',
+          hash: '1234',
+          hashSignature: null,
+        ),
+        equals(
+          // Ignoring for value quality testing.
+          // ignore: prefer_const_constructors
+          PatchCheckMetadata(
+            number: 1,
+            downloadUrl: 'https://download.com',
+            hash: '1234',
+            hashSignature: null,
+          ),
+        ),
+      );
+    });
+
+    test('PatchCheckMetadata can be (de)serialized', () {
+      const metadata = PatchCheckMetadata(
+        number: 1,
+        downloadUrl: 'https://download.com',
+        hash: '1234',
+        hashSignature: null,
+      );
+      expect(
+        PatchCheckMetadata.fromJson(metadata.toJson()).toJson(),
+        equals(metadata.toJson()),
+      );
+    });
+
+    test('can be serialized to json with patch metadata', () {
+      const response = PatchCheckResponse(
+        patchAvailable: true,
+        patch: PatchCheckMetadata(
+          number: 1,
+          downloadUrl: 'https://download.com',
+          hash: '1234',
+          hashSignature: null,
+        ),
+      );
+      expect(response.toJson(), {
+        'patch_available': true,
+        'patch': {
+          'number': 1,
+          'download_url': 'https://download.com',
+          'hash': '1234',
+        },
+        'rolled_back_patch_numbers': null,
+      });
+    });
+
+    group('when there is a hash signature', () {
+      test('includes the signature', () {
+        const response = PatchCheckResponse(
+          patchAvailable: true,
+          patch: PatchCheckMetadata(
+            number: 1,
+            downloadUrl: 'https://download.com',
+            hash: '1234',
+            hashSignature: 'signature',
+          ),
+        );
+        expect(response.toJson(), {
+          'patch_available': true,
+          'patch': {
+            'number': 1,
+            'download_url': 'https://download.com',
+            'hash': '1234',
+            'hash_signature': 'signature',
+          },
+          'rolled_back_patch_numbers': null,
+        });
+      });
+    });
+
+    group('when rolled back patch numbers are provided', () {
+      test('includes the rolled back patch numbers', () {
+        const response = PatchCheckResponse(
+          patchAvailable: true,
+          rolledBackPatchNumbers: [1, 2, 3],
+        );
+        expect(response.toJson(), {
+          'patch_available': true,
+          'patch': null,
+          'rolled_back_patch_numbers': [1, 2, 3],
+        });
+      });
+    });
+  });
+}