--- /dev/null
+////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2016 Realm Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+////////////////////////////////////////////////////////////////////////////
+
+#import <Realm/RLMRealmConfiguration.h>
+
+#import "RLMSyncUtil.h"
+
+@class RLMSyncConfiguration;
+
+/// Realm configuration options related to Sync.
+@interface RLMRealmConfiguration (Sync)
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ A configuration object representing configuration state for Realms intended
+ to sync with a Realm Object Server.
+
+ This property is mutually exclusive with both `inMemoryIdentifier` and `fileURL`;
+ setting any one of the three properties will automatically nil out the other two.
+
+ @see `RLMSyncConfiguration`
+ */
+@property (nullable, nonatomic) RLMSyncConfiguration *syncConfiguration;
+
+NS_ASSUME_NONNULL_END
+
+@end