Index: src/MTXClient.m
==================================================================
--- src/MTXClient.m
+++ src/MTXClient.m
@@ -228,12 +228,24 @@
 			block([OFInvalidServerReplyException exception]);
 			return;
 		}
 
 		@try {
-			[_storage setNextBatch: nextBatch
-				   forDeviceID: _deviceID];
+			[_storage transactionWithBlock: ^ {
+				[_storage setNextBatch: nextBatch
+					   forDeviceID: _deviceID];
+
+				[self processRoomsSync: response[@"rooms"]];
+				[self processPresenceSync:
+				    response[@"presence"]];
+				[self processAccountDataSync:
+				    response[@"account_data"]];
+				[self processToDeviceSync:
+				    response[@"to_device"]];
+
+				return true;
+			}];
 		} @catch (id e) {
 			block(e);
 			return;
 		}
 
@@ -406,6 +418,22 @@
 		block(nil);
 	}];
 
 	objc_autoreleasePoolPop(pool);
 }
+
+- (void)processRoomsSync: (OFDictionary<OFString *, id> *)rooms
+{
+}
+
+- (void)processPresenceSync: (OFDictionary<OFString *, id> *)presence
+{
+}
+
+- (void)processAccountDataSync: (OFDictionary<OFString *, id> *)accountData
+{
+}
+
+- (void)processToDeviceSync: (OFDictionary<OFString *, id> *)toDevice
+{
+}
 @end

Index: tests/tests.m
==================================================================
--- tests/tests.m
+++ tests/tests.m
@@ -30,10 +30,11 @@
 OF_APPLICATION_DELEGATE(Tests)
 
 @implementation Tests
 {
 	MTXClient *_client;
+	OFString *_roomID;
 }
 
 - (void)applicationDidFinishLaunching
 {
 	__auto_type environment = OFApplication.environment;
@@ -104,43 +105,59 @@
 		if (exception != nil) {
 			of_log(@"Failed to join room %@: %@", room, exception);
 			[OFApplication terminateWithStatus: 1];
 		}
 
-		of_log(@"Joined room %@", roomID);
+		_roomID = [roomID copy];
+		of_log(@"Joined room %@", _roomID);
+
+		[self sync2];
+	}];
+}
+
+- (void)sync2
+{
+	[_client syncWithTimeout: 5
+			   block: ^ (id exception) {
+		if (exception != nil) {
+			of_log(@"Failed to sync: %@", exception);
+			[OFApplication terminateWithStatus: 1];
+		}
+
+		of_log(@"Synced");
 
-		[self sendMessage: roomID];
+		[self sendMessage];
 	}];
 }
 
-- (void)sendMessage: (OFString *)roomID
+- (void)sendMessage
 {
 	[_client sendMessage: @"ObjMatrix test successful!"
-		      roomID: roomID
+		      roomID: _roomID
 		       block: ^ (id exception) {
 		if (exception != nil) {
 			of_log(@"Failed to send message to room %@: %@",
-			    roomID, exception);
+			    _roomID, exception);
 			[OFApplication terminateWithStatus: 1];
 		}
 
-		of_log(@"Message sent to %@", roomID);
+		of_log(@"Message sent to %@", _roomID);
 
-		[self leaveRoom: roomID];
+		[self leaveRoom];
 	}];
 }
 
-- (void)leaveRoom: (OFString *)roomID
+- (void)leaveRoom
 {
-	[_client leaveRoom: roomID
+	[_client leaveRoom: _roomID
 		     block: ^ (id exception) {
 		if (exception != nil) {
 			of_log(@"Failed to leave room %@: %@", exception);
 			[OFApplication terminateWithStatus: 1];
 		}
 
-		of_log(@"Left room %@", roomID);
+		of_log(@"Left room %@", _roomID);
 
 		[self logOut];
 	}];
 }