diff --git a/lib/parse_server_sdk.dart b/lib/parse_server_sdk.dart
index 0a276e93e..671c7af85 100644
--- a/lib/parse_server_sdk.dart
+++ b/lib/parse_server_sdk.dart
@@ -92,6 +92,8 @@ part 'src/utils/parse_utils.dart';
 
 part 'src/utils/parse_login_helpers.dart';
 
+part 'src/objects/parse_merge.dart';
+
 class Parse {
   ParseCoreData data;
   bool _hasBeenInitialized = false;
@@ -116,8 +118,8 @@ class Parse {
       String masterKey,
       String sessionId,
       bool autoSendSessionId,
-        SecurityContext securityContext,
-        CoreStore coreStore}) async {
+      SecurityContext securityContext,
+      CoreStore coreStore}) async {
     final String url = removeTrailingSlash(serverUrl);
 
     await ParseCoreData.init(appId, url,
@@ -147,7 +149,7 @@ class Parse {
     final ParseHTTPClient _client = client ??
         ParseHTTPClient(
             sendSessionId:
-            sendSessionIdByDefault ?? ParseCoreData().autoSendSessionId,
+                sendSessionIdByDefault ?? ParseCoreData().autoSendSessionId,
             securityContext: ParseCoreData().securityContext);
 
     const String className = 'parseBase';
diff --git a/lib/src/objects/parse_base.dart b/lib/src/objects/parse_base.dart
index 8331ee2db..01e1535bb 100644
--- a/lib/src/objects/parse_base.dart
+++ b/lib/src/objects/parse_base.dart
@@ -191,13 +191,12 @@ abstract class ParseBase {
         if (_getObjectData()[key] == value) {
           return;
         }
-        if (forceUpdate) {
-          _getObjectData()[key] = value;
-        }
+        _getObjectData()[key] =
+            ParseMergeTool().mergeWithPrevious(_unsavedChanges[key], value);
       } else {
         _getObjectData()[key] = value;
       }
-      _unsavedChanges[key] = value;
+      _unsavedChanges[key] = _getObjectData()[key];
     }
   }
 
diff --git a/lib/src/objects/parse_merge.dart b/lib/src/objects/parse_merge.dart
new file mode 100644
index 000000000..f800655de
--- /dev/null
+++ b/lib/src/objects/parse_merge.dart
@@ -0,0 +1,251 @@
+part of flutter_parse_sdk;
+
+class ParseMergeTool {
+  // merge method
+  dynamic mergeWithPrevious(dynamic previous, dynamic values) {
+    if (previous == null) {
+      return values;
+    }
+    String previousAction = 'Set';
+    if (previous is Map) {
+      previousAction = previous['__op'];
+    }
+    if (values is Map) {
+      if (values['__op'] == 'Add') {
+        values = _mergeWithPreviousAdd(previousAction, previous, values);
+      } else if (values['__op'] == 'Remove') {
+        values = _mergeWithPreviousRemove(previousAction, previous, values);
+      } else if (values['__op'] == 'Increment') {
+        values = _mergeWithPreviousIncrement(previousAction, previous, values);
+      } else if (values['__op'] == 'AddUnique') {
+        values = _mergeWithPreviousAddUnique(previousAction, previous, values);
+      } else if (values['__op'] == 'AddRelation') {
+        values =
+            _mergeWithPreviousAddRelation(previousAction, previous, values);
+      } else if (values['__op'] == 'RemoveRelation') {
+        values =
+            _mergeWithPreviousRemoveRelation(previousAction, previous, values);
+      }
+    }
+    return values;
+  }
+
+  // Add operation Merge
+  dynamic _mergeWithPreviousAdd(
+      String previousAction, dynamic previous, dynamic values) {
+    if (previousAction == 'Set') {
+      if (previous is List) {
+        return List<dynamic>.from(previous)..addAll(values['objects']);
+      } else {
+        throw 'Unable to add an item to a non-array.';
+      }
+    }
+    if (previousAction == 'Add') {
+      if (values['objects'].length == 1) {
+        previous['objects'].add(values['objects'].first);
+      } else {
+        previous['objects'].add(values['objects']);
+      }
+      values = previous;
+    }
+    if (previousAction == 'Increment') {
+      throw 'Add operation is invalid after Increment operation';
+    }
+    if (previousAction == 'Remove') {
+      throw 'Add operation is invalid after Remove operation';
+    }
+    if (previousAction == 'AddUnique') {
+      throw 'Add operation is invalid after AddUnique operation';
+    }
+    if (previousAction == 'AddRelation') {
+      throw 'Add operation is invalid after AddRelation operation';
+    }
+    if (previousAction == 'RemoveRelation') {
+      throw 'Add operation is invalid after RemoveRelation operation';
+    }
+    return values;
+  }
+
+  // Remove operation Merge
+  dynamic _mergeWithPreviousRemove(
+      String previousAction, dynamic previous, dynamic values) {
+    if (previousAction == 'Set') {
+      return previous;
+    }
+    if (previousAction == 'Remove') {
+      if (values['objects'].length == 1) {
+        previous['objects'].add(values['objects'].first);
+      } else {
+        previous['objects'].add(values['objects']);
+      }
+      values = previous;
+    }
+    if (previousAction == 'Increment') {
+      throw 'Remove operation is invalid after Increment operation';
+    }
+    if (previousAction == 'Add') {
+      throw 'Remove operation is invalid after Add operation';
+    }
+    if (previousAction == 'AddUnique') {
+      throw 'Remove operation is invalid after AddUnique operation';
+    }
+    if (previousAction == 'AddRelation') {
+      throw 'Remove operation is invalid after AddRelation operation';
+    }
+    if (previousAction == 'RemoveRelation') {
+      throw 'Remove operation is invalid after RemoveRelation operation';
+    }
+    return values;
+  }
+
+  // Increment operation Merge
+  dynamic _mergeWithPreviousIncrement(
+      String previousAction, dynamic previous, dynamic values) {
+    if (previousAction == 'Set') {
+      if (previous is num) {
+        values['amount'] += previous;
+      } else {
+        throw 'Invalid Operation';
+      }
+    }
+    if (previousAction == 'Increment') {
+      values['amount'] += previous['amount'];
+    }
+    if (previousAction == 'Add') {
+      throw 'Increment operation is invalid after Add operation';
+    }
+    if (previousAction == 'Remove') {
+      throw 'Increment operation is invalid after Remove operation';
+    }
+    if (previousAction == 'AddUnique') {
+      throw 'Increment operation is invalid after AddUnique operation';
+    }
+    if (previousAction == 'AddRelation') {
+      throw 'Increment operation is invalid after AddRelation operation';
+    }
+    if (previousAction == 'RemoveRelation') {
+      throw 'Increment operation is invalid after RemoveRelation operation';
+    }
+    return values;
+  }
+
+  // AddUnique operation Merge
+  dynamic _mergeWithPreviousAddUnique(
+      String previousAction, dynamic previous, dynamic values) {
+    if (previousAction == 'Set') {
+      if (previous is List) {
+        return _applyToValueAddUnique(previous, values['objects']);
+      } else {
+        throw 'Unable to add an item to a non-array.';
+      }
+    }
+    if (previousAction == 'AddUnique') {
+      values['objects'] =
+          _applyToValueAddUnique(previous['objects'], values['objects']);
+      return values;
+    }
+    if (previousAction == 'Add') {
+      throw 'AddUnique operation is invalid after Add operation';
+    }
+    if (previousAction == 'Remove') {
+      throw 'AddUnique operation is invalid after Reomve operation';
+    }
+    if (previousAction == 'Increment') {
+      throw 'AddUnique operation is invalid after Increment operation';
+    }
+    if (previousAction == 'AddRelation') {
+      throw 'AddUnique operation is invalid after AddRelation operation';
+    }
+    if (previousAction == 'RemoveRelation') {
+      throw 'AddUnique operation is invalid after RemoveRelation operation';
+    }
+    return values;
+  }
+
+  // AddRelation operation Merge
+  dynamic _mergeWithPreviousAddRelation(
+      String previousAction, dynamic previous, dynamic values) {
+    if (previousAction == 'AddRelation') {
+      if (values['objects'].length == 1) {
+        previous['objects'].add(values['objects'].first);
+      } else {
+        previous['objects'].add(values['objects']);
+      }
+      values = previous;
+    }
+    if (previousAction == 'Set') {
+      throw 'AddRelation operation is invalid after Set operation.';
+    }
+    if (previousAction == 'Increment') {
+      throw 'AddRelation operation is invalid after Increment operation';
+    }
+    if (previousAction == 'Add') {
+      throw 'AddRelation operation is invalid after Add operation';
+    }
+    if (previousAction == 'Remove') {
+      throw 'AddRelation operation is invalid after Remove operation';
+    }
+    if (previousAction == 'AddUnique') {
+      throw 'AddRelation operation is invalid after AddUnique operation';
+    }
+    if (previousAction == 'RemoveRelation') {
+      throw 'AddRelation operation is invalid after RemoveRelation operation';
+    }
+    return values;
+  }
+
+  // RemoveRelation operation Merge
+  dynamic _mergeWithPreviousRemoveRelation(
+      String previousAction, dynamic previous, dynamic values) {
+    if (previousAction == 'RemoveRelation') {
+      if (values['objects'].length == 1) {
+        previous['objects'].add(values['objects'].first);
+      } else {
+        previous['objects'].add(values['objects']);
+      }
+      values = previous;
+    }
+    if (previousAction == 'Set') {
+      throw 'RemoveRelation operation is invalid after Set operation.';
+    }
+    if (previousAction == 'Increment') {
+      throw 'RemoveRelation operation is invalid after Increment operation';
+    }
+    if (previousAction == 'Add') {
+      throw 'RemoveRelation operation is invalid after Add operation';
+    }
+    if (previousAction == 'Remove') {
+      throw 'RemoveRelation operation is invalid after Remove operation';
+    }
+    if (previousAction == 'AddUnique') {
+      throw 'RemoveRelation operation is invalid after AddUnique operation';
+    }
+    if (previousAction == 'AddRelation') {
+      throw 'RemoveRelation operation is invalid after AddRelation operation';
+    }
+    return values;
+  }
+
+  // service for AddUnique method
+  dynamic _applyToValueAddUnique(dynamic oldValue, dynamic newValue) {
+    for (var objectToAdd in newValue) {
+      if (objectToAdd is ParseObject && objectToAdd.objectId != null) {
+        var index = 0;
+        for (var objc in oldValue) {
+          if (objc is ParseObject && objc.objectId == objectToAdd.objectId) {
+            oldValue[index] = objectToAdd;
+            break;
+          }
+          index += 1;
+        }
+        if (index == oldValue.length) {
+          oldValue.add(objectToAdd);
+        }
+      } else if (!oldValue.contains(objectToAdd)) {
+        oldValue.add(objectToAdd);
+      }
+    }
+    print(oldValue);
+    return oldValue;
+  }
+}