diff --git a/projects/poweredsoft/data/package.json b/projects/poweredsoft/data/package.json
index b277806..8ffc234 100644
--- a/projects/poweredsoft/data/package.json
+++ b/projects/poweredsoft/data/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@poweredsoft/data",
-  "version": "0.0.34",
+  "version": "0.0.35",
   "peerDependencies": {
     "rxjs": "^6.5.3"
   }
diff --git a/projects/poweredsoft/data/src/lib/IDataSource.ts b/projects/poweredsoft/data/src/lib/IDataSource.ts
index fbc73a2..2bf078b 100644
--- a/projects/poweredsoft/data/src/lib/IDataSource.ts
+++ b/projects/poweredsoft/data/src/lib/IDataSource.ts
@@ -3,6 +3,7 @@ import { ISort, IFilter, IGroup, IAggregate, IQueryExecutionResult, IQueryExecut
 import { IResolveCommandModelEvent } from "./IResolveCommandModelEvent";
 import { IDataSourceValidationError } from './IDataSourceValidationError';
 import { IDataSourceNotifyMessage } from './IDataSourceNotifyMessage';
+import { IDataSourceCommandStarted } from "./IDataSourceCommandStarted";
 
 export interface IDataSource<TModel>
 {
@@ -21,6 +22,7 @@ export interface IDataSource<TModel>
     loading$: Observable<boolean>;
     validationError$: Observable<IDataSourceValidationError>;
     notifyMessage$: Observable<IDataSourceNotifyMessage>;
+    commandStarted$: Observable<IDataSourceCommandStarted>;
 
     data: IQueryExecutionResult<TModel> & IQueryExecutionGroupResult<TModel>;