diff --git a/web/src/services/opsService.test.ts b/web/src/services/opsService.test.ts
new file mode 100644
index 00000000..a67f1c8d
--- /dev/null
+++ b/web/src/services/opsService.test.ts
@@ -0,0 +1,91 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 { describe, expect, it, vi } from 'vitest';
+import {
+  createAlertRule,
+  listAlertRules,
+  listAuditRecords,
+  listSystemAlerts,
+  toggleAlertRule,
+  updateAlertRule,
+} from './opsService';
+
+vi.mock('../config', () => ({
+  API_BASE_URL: '/api',
+  USE_MOCK: true,
+}));
+
+describe('ops service mock data', () => {
+  it('returns copied alert rule rows', async () => {
+    const first = await listAlertRules();
+    const originalName = first[0].name;
+    first[0].name = 'mutated-rule';
+    first[0].channels.push('mutated-channel');
+
+    const second = await listAlertRules();
+    expect(second[0].name).toBe(originalName);
+    expect(second[0].channels).not.toContain('mutated-channel');
+    expect(second[0]).not.toBe(first[0]);
+  });
+
+  it('copies alert rule channels on create, update, and toggle', async () => {
+    const channels = ['email'];
+    const created = await createAlertRule({
+      name: 'created-copy-test',
+      channels,
+    });
+    channels.push('sms');
+    created.channels.push('mutated-return');
+
+    const afterCreate = (await listAlertRules()).find((rule) => rule.id === created.id);
+    expect(afterCreate?.channels).toEqual(['email']);
+
+    const updated = await updateAlertRule({
+      ...created,
+      channels: ['webhook'],
+    });
+    updated.channels.push('mutated-return');
+
+    const toggled = await toggleAlertRule(created.id, false);
+    toggled.channels.push('mutated-toggle');
+
+    const afterUpdate = (await listAlertRules()).find((rule) => rule.id === created.id);
+    expect(afterUpdate?.enabled).toBe(false);
+    expect(afterUpdate?.channels).toEqual(['webhook']);
+  });
+
+  it('returns copied system alert rows', async () => {
+    const first = await listSystemAlerts();
+    const originalTitle = first[0].title;
+    first[0].title = 'mutated-alert';
+
+    const second = await listSystemAlerts();
+    expect(second[0].title).toBe(originalTitle);
+    expect(second[0]).not.toBe(first[0]);
+  });
+
+  it('returns copied audit records', async () => {
+    const first = await listAuditRecords({ page: 1, pageSize: 1 });
+    const originalOperator = first.items[0].operator;
+    first.items[0].operator = 'mutated-operator';
+
+    const second = await listAuditRecords({ page: 1, pageSize: 1 });
+    expect(second.items[0].operator).toBe(originalOperator);
+    expect(second.items[0]).not.toBe(first.items[0]);
+  });
+});
diff --git a/web/src/services/opsService.ts b/web/src/services/opsService.ts
index 4563d72e..44113ca7 100644
--- a/web/src/services/opsService.ts
+++ b/web/src/services/opsService.ts
@@ -8,8 +8,23 @@ import { systemAlerts as mockSystemAlerts } from '../mock/dashboard';
 let auditRecordsState = mockAuditRecords as unknown as AuditRecord[];
 const alertRulesState = mockAlertRules as unknown as AlertRule[];
 
+function copyAlertRule(rule: AlertRule): AlertRule {
+  return {
+    ...rule,
+    channels: [...rule.channels],
+  };
+}
+
+function copySystemAlert(alert: SystemAlert): SystemAlert {
+  return { ...alert };
+}
+
+function copyAuditRecord(record: AuditRecord): AuditRecord {
+  return { ...record };
+}
+
 export async function listAlertRules(): Promise<AlertRule[]> {
-  if (USE_MOCK) return alertRulesState;
+  if (USE_MOCK) return alertRulesState.map(copyAlertRule);
   return opsApi.listAlertRules();
 }
 
@@ -23,14 +38,14 @@ export async function createAlertRule(data: Partial<AlertRule>): Promise<AlertRu
       threshold: 0,
       thresholdUnit: '',
       duration: '',
-      channels: [],
       enabled: true,
       lastTriggered: null,
       description: '',
       ...data,
+      channels: [...(data.channels ?? [])],
     };
     alertRulesState.push(rule);
-    return rule;
+    return copyAlertRule(rule);
   }
   return opsApi.createAlertRule(data);
 }
@@ -38,8 +53,9 @@ export async function createAlertRule(data: Partial<AlertRule>): Promise<AlertRu
 export async function updateAlertRule(data: AlertRule): Promise<AlertRule> {
   if (USE_MOCK) {
     const index = alertRulesState.findIndex((rule) => rule.id === data.id);
-    if (index >= 0) alertRulesState[index] = data;
-    return data;
+    const rule = copyAlertRule(data);
+    if (index >= 0) alertRulesState[index] = rule;
+    return copyAlertRule(rule);
   }
   return opsApi.updateAlertRule(data);
 }
@@ -49,7 +65,7 @@ export async function toggleAlertRule(id: string, enabled: boolean): Promise<Ale
     const rule = alertRulesState.find((item) => item.id === id);
     if (!rule) throw new Error(`Alert rule not found: ${id}`);
     rule.enabled = enabled;
-    return rule;
+    return copyAlertRule(rule);
   }
   return opsApi.toggleAlertRule(id, enabled);
 }
@@ -64,7 +80,7 @@ export async function deleteAlertRule(id: string): Promise<void> {
 }
 
 export async function listSystemAlerts(): Promise<SystemAlert[]> {
-  if (USE_MOCK) return mockSystemAlerts as unknown as SystemAlert[];
+  if (USE_MOCK) return (mockSystemAlerts as unknown as SystemAlert[]).map(copySystemAlert);
   return opsApi.listSystemAlerts();
 }
 
@@ -110,7 +126,7 @@ export async function listAuditRecords(params: AuditQuery = {}): Promise<PageRes
   });
   const from = (page - 1) * pageSize;
   return {
-    items: records.slice(from, from + pageSize),
+    items: records.slice(from, from + pageSize).map(copyAuditRecord),
     total: records.length,
     page,
     size: pageSize,