diff --git a/mobile/lib/infrastructure/repositories/sync_stream.repository.dart b/mobile/lib/infrastructure/repositories/sync_stream.repository.dart
index 067f84017..54bc01cfa 100644
--- a/mobile/lib/infrastructure/repositories/sync_stream.repository.dart
+++ b/mobile/lib/infrastructure/repositories/sync_stream.repository.dart
@@ -20,8 +20,8 @@ import 'package:immich_mobile/infrastructure/entities/user.entity.drift.dart';
 import 'package:immich_mobile/infrastructure/entities/user_metadata.entity.drift.dart';
 import 'package:immich_mobile/infrastructure/repositories/db.repository.dart';
 import 'package:logging/logging.dart';
-import 'package:openapi/api.dart' as api show AssetVisibility, AlbumUserRole;
-import 'package:openapi/api.dart' hide AssetVisibility, AlbumUserRole;
+import 'package:openapi/api.dart' as api show AssetVisibility, AlbumUserRole, UserMetadataKey;
+import 'package:openapi/api.dart' hide AssetVisibility, AlbumUserRole, UserMetadataKey;
 
 class SyncStreamRepository extends DriftDatabaseRepository {
   final Logger _logger = Logger('DriftSyncStreamRepository');
@@ -647,11 +647,11 @@ extension on api.AssetVisibility {
       };
 }
 
-extension on String {
+extension on api.UserMetadataKey {
   UserMetadataKey toUserMetadataKey() => switch (this) {
-        "onboarding" => UserMetadataKey.onboarding,
-        "preferences" => UserMetadataKey.preferences,
-        "license" => UserMetadataKey.license,
+        api.UserMetadataKey.onboarding => UserMetadataKey.onboarding,
+        api.UserMetadataKey.preferences => UserMetadataKey.preferences,
+        api.UserMetadataKey.license => UserMetadataKey.license,
         _ => throw Exception('Unknown UserMetadataKey value: $this'),
       };
 }
diff --git a/mobile/openapi/README.md b/mobile/openapi/README.md
index 62c48bf29..3181b03a4 100644
Binary files a/mobile/openapi/README.md and b/mobile/openapi/README.md differ
diff --git a/mobile/openapi/lib/api.dart b/mobile/openapi/lib/api.dart
index 8b8acc004..8c1fa1a80 100644
Binary files a/mobile/openapi/lib/api.dart and b/mobile/openapi/lib/api.dart differ
diff --git a/mobile/openapi/lib/api_client.dart b/mobile/openapi/lib/api_client.dart
index d9cae66dd..bd306cb21 100644
Binary files a/mobile/openapi/lib/api_client.dart and b/mobile/openapi/lib/api_client.dart differ
diff --git a/mobile/openapi/lib/api_helper.dart b/mobile/openapi/lib/api_helper.dart
index 1618f4a67..098d32f4f 100644
Binary files a/mobile/openapi/lib/api_helper.dart and b/mobile/openapi/lib/api_helper.dart differ
diff --git a/mobile/openapi/lib/model/sync_user_metadata_delete_v1.dart b/mobile/openapi/lib/model/sync_user_metadata_delete_v1.dart
index e9dd73329..f39acc617 100644
Binary files a/mobile/openapi/lib/model/sync_user_metadata_delete_v1.dart and b/mobile/openapi/lib/model/sync_user_metadata_delete_v1.dart differ
diff --git a/mobile/openapi/lib/model/sync_user_metadata_v1.dart b/mobile/openapi/lib/model/sync_user_metadata_v1.dart
index 0b060dc17..cf39b6d96 100644
Binary files a/mobile/openapi/lib/model/sync_user_metadata_v1.dart and b/mobile/openapi/lib/model/sync_user_metadata_v1.dart differ
diff --git a/mobile/openapi/lib/model/user_metadata_key.dart b/mobile/openapi/lib/model/user_metadata_key.dart
new file mode 100644
index 000000000..845b5ae9b
Binary files /dev/null and b/mobile/openapi/lib/model/user_metadata_key.dart differ
diff --git a/open-api/immich-openapi-specs.json b/open-api/immich-openapi-specs.json
index 53a91a401..35f84ec25 100644
--- a/open-api/immich-openapi-specs.json
+++ b/open-api/immich-openapi-specs.json
@@ -14403,7 +14403,11 @@
       "SyncUserMetadataDeleteV1": {
         "properties": {
           "key": {
-            "type": "string"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/UserMetadataKey"
+              }
+            ]
           },
           "userId": {
             "type": "string"
@@ -14418,7 +14422,11 @@
       "SyncUserMetadataV1": {
         "properties": {
           "key": {
-            "type": "string"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/UserMetadataKey"
+              }
+            ]
           },
           "userId": {
             "type": "string"
@@ -16132,6 +16140,14 @@
         ],
         "type": "object"
       },
+      "UserMetadataKey": {
+        "enum": [
+          "preferences",
+          "license",
+          "onboarding"
+        ],
+        "type": "string"
+      },
       "UserPreferencesResponseDto": {
         "properties": {
           "albums": {
diff --git a/server/src/dtos/sync.dto.ts b/server/src/dtos/sync.dto.ts
index 8614bd577..92aea8f5e 100644
--- a/server/src/dtos/sync.dto.ts
+++ b/server/src/dtos/sync.dto.ts
@@ -301,14 +301,16 @@ export class SyncAssetFaceDeleteV1 {
 @ExtraModel()
 export class SyncUserMetadataV1 {
   userId!: string;
-  key!: string;
+  @ValidateEnum({ enum: UserMetadataKey, name: 'UserMetadataKey' })
+  key!: UserMetadataKey;
   value!: UserMetadata[UserMetadataKey];
 }
 
 @ExtraModel()
 export class SyncUserMetadataDeleteV1 {
   userId!: string;
-  key!: string;
+  @ValidateEnum({ enum: UserMetadataKey, name: 'UserMetadataKey' })
+  key!: UserMetadataKey;
 }
 
 @ExtraModel()
diff --git a/server/src/schema/tables/user-metadata-audit.table.ts b/server/src/schema/tables/user-metadata-audit.table.ts
index de7d21c87..63f503ab8 100644
--- a/server/src/schema/tables/user-metadata-audit.table.ts
+++ b/server/src/schema/tables/user-metadata-audit.table.ts
@@ -1,4 +1,5 @@
 import { PrimaryGeneratedUuidV7Column } from 'src/decorators';
+import { UserMetadataKey } from 'src/enum';
 import { Column, CreateDateColumn, Generated, Table, Timestamp } from 'src/sql-tools';
 
 @Table('user_metadata_audit')
@@ -10,7 +11,7 @@ export class UserMetadataAuditTable {
   userId!: string;
 
   @Column({ indexName: 'IDX_user_metadata_audit_key' })
-  key!: string;
+  key!: UserMetadataKey;
 
   @CreateDateColumn({ default: () => 'clock_timestamp()', indexName: 'IDX_user_metadata_audit_deleted_at' })
   deletedAt!: Generated<Timestamp>;