diff --git a/src/storage/BaseEntityService.ts b/src/storage/BaseEntityService.ts
index 3d83070..c889885 100644
--- a/src/storage/BaseEntityService.ts
+++ b/src/storage/BaseEntityService.ts
@@ -1,10 +1,10 @@
-import { ISync, EntityType, SyncStatus } from '../types/CalendarTypes';
+import { ISync, EntityType, SyncStatus, IEventBus } from '../types/CalendarTypes';
 import { IEntityService } from './IEntityService';
 import { SyncPlugin } from './SyncPlugin';
 import { IndexedDBContext } from './IndexedDBContext';
-import { IEventBus } from '../types/CalendarTypes';
 import { CoreEvents } from '../constants/CoreEvents';
 import { diff } from 'json-diff-ts';
+import { IEntitySavedPayload, IEntityDeletedPayload } from '../types/EventTypes';
 
 /**
  * BaseEntityService<T extends ISync> - Abstract base class for all entity services
@@ -171,13 +171,14 @@ export abstract class BaseEntityService<T extends ISync> implements IEntityServi
 
       request.onsuccess = () => {
         // Emit ENTITY_SAVED event
-        this.eventBus.emit(CoreEvents.ENTITY_SAVED, {
+        const payload: IEntitySavedPayload = {
           entityType: this.entityType,
           entityId,
           operation: isCreate ? 'create' : 'update',
           changes,
           timestamp: Date.now()
-        });
+        };
+        this.eventBus.emit(CoreEvents.ENTITY_SAVED, payload);
         resolve();
       };
 
@@ -201,12 +202,13 @@ export abstract class BaseEntityService<T extends ISync> implements IEntityServi
 
       request.onsuccess = () => {
         // Emit ENTITY_DELETED event
-        this.eventBus.emit(CoreEvents.ENTITY_DELETED, {
+        const payload: IEntityDeletedPayload = {
           entityType: this.entityType,
           entityId: id,
           operation: 'delete',
           timestamp: Date.now()
-        });
+        };
+        this.eventBus.emit(CoreEvents.ENTITY_DELETED, payload);
         resolve();
       };
 
diff --git a/src/storage/audit/AuditService.ts b/src/storage/audit/AuditService.ts
index 9ddbdd7..238ed87 100644
--- a/src/storage/audit/AuditService.ts
+++ b/src/storage/audit/AuditService.ts
@@ -3,6 +3,7 @@ import { IndexedDBContext } from '../IndexedDBContext';
 import { IAuditEntry } from '../../types/AuditTypes';
 import { EntityType, IEventBus } from '../../types/CalendarTypes';
 import { CoreEvents } from '../../constants/CoreEvents';
+import { IEntitySavedPayload, IEntityDeletedPayload, IAuditLoggedPayload } from '../../types/EventTypes';
 
 /**
  * AuditService - Entity service for audit entries
@@ -52,13 +53,7 @@ export class AuditService extends BaseEntityService<IAuditEntry> {
   /**
    * Handle ENTITY_SAVED event - create audit entry
    */
-  private async handleEntitySaved(payload: {
-    entityType: EntityType;
-    entityId: string;
-    operation: 'create' | 'update';
-    changes: any;
-    timestamp: number;
-  }): Promise<void> {
+  private async handleEntitySaved(payload: IEntitySavedPayload): Promise<void> {
     // Don't audit audit entries (prevent infinite loops)
     if (payload.entityType === 'Audit') return;
 
@@ -80,12 +75,7 @@ export class AuditService extends BaseEntityService<IAuditEntry> {
   /**
    * Handle ENTITY_DELETED event - create audit entry
    */
-  private async handleEntityDeleted(payload: {
-    entityType: EntityType;
-    entityId: string;
-    operation: 'delete';
-    timestamp: number;
-  }): Promise<void> {
+  private async handleEntityDeleted(payload: IEntityDeletedPayload): Promise<void> {
     // Don't audit audit entries (prevent infinite loops)
     if (payload.entityType === 'Audit') return;
 
@@ -123,13 +113,14 @@ export class AuditService extends BaseEntityService<IAuditEntry> {
 
       request.onsuccess = () => {
         // Emit AUDIT_LOGGED instead of ENTITY_SAVED
-        this.eventBus.emit(CoreEvents.AUDIT_LOGGED, {
+        const payload: IAuditLoggedPayload = {
           auditId: entity.id,
           entityType: entity.entityType,
           entityId: entity.entityId,
           operation: entity.operation,
           timestamp: entity.timestamp
-        });
+        };
+        this.eventBus.emit(CoreEvents.AUDIT_LOGGED, payload);
         resolve();
       };
 
diff --git a/src/types/EventTypes.ts b/src/types/EventTypes.ts
index 919c1b6..6b5a37e 100644
--- a/src/types/EventTypes.ts
+++ b/src/types/EventTypes.ts
@@ -3,7 +3,7 @@
  */
 
 import { IColumnBounds } from "../utils/ColumnDetectionUtils";
-import { ICalendarEvent } from "./CalendarTypes";
+import { ICalendarEvent, EntityType } from "./CalendarTypes";
 
 /**
  * Drag Event Payload Interfaces
@@ -103,4 +103,30 @@ export interface IResizeEndEventPayload {
 export interface INavButtonClickedEventPayload {
   direction: 'next' | 'previous' | 'today';
   newDate: Date;
+}
+
+// Entity saved event payload
+export interface IEntitySavedPayload {
+  entityType: EntityType;
+  entityId: string;
+  operation: 'create' | 'update';
+  changes: any;
+  timestamp: number;
+}
+
+// Entity deleted event payload
+export interface IEntityDeletedPayload {
+  entityType: EntityType;
+  entityId: string;
+  operation: 'delete';
+  timestamp: number;
+}
+
+// Audit logged event payload
+export interface IAuditLoggedPayload {
+  auditId: string;
+  entityType: EntityType;
+  entityId: string;
+  operation: 'create' | 'update' | 'delete';
+  timestamp: number;
 }
\ No newline at end of file