--- /dev/null
+/*
+ * Copyright 2017 Google
+ *
+ * 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 <Foundation/Foundation.h>
+
+@class FIRMessagingRmqManager;
+
+/**
+ * Handle sync messages being received both via MCS and APNS.
+ */
+@interface FIRMessagingSyncMessageManager : NSObject
+
+/**
+ * Initialize sync message manager.
+ *
+ * @param rmqManager The RMQ manager on the client.
+ *
+ * @return Sync message manager.
+ */
+- (instancetype)initWithRmqManager:(FIRMessagingRmqManager *)rmqManager;
+
+/**
+ * Remove expired sync message from persistent store. Also removes messages that have
+ * been received both via APNS and MCS.
+ */
+- (void)removeExpiredSyncMessages;
+
+/**
+ * App did recive a sync message via APNS.
+ *
+ * @param message The sync message received.
+ *
+ * @return YES if the message is a duplicate of an already received sync message else NO.
+ */
+- (BOOL)didReceiveAPNSSyncMessage:(NSDictionary *)message;
+
+/**
+ * App did receive a sync message via MCS.
+ *
+ * @param message The sync message received.
+ *
+ * @return YES if the message is a duplicate of an already received sync message else NO.
+ */
+- (BOOL)didReceiveMCSSyncMessage:(NSDictionary *)message;
+
+@end