diff --git a/web/src/api/client.ts b/web/src/api/client.ts
index 1e7351ff..56011165 100644
--- a/web/src/api/client.ts
+++ b/web/src/api/client.ts
@@ -40,6 +40,7 @@ import type {
   AdminLabelInput,
   LabelDefinition,
   LabelItem,
+  BatchMemberResponse,
 } from './types'
 import { ApiError } from '@/shared/lib/api-error'
 import i18n from '@/i18n/config'
@@ -702,6 +703,16 @@ export const namespaceApi = {
     })
   },
 
+  async batchAddMembers(slug: string, members: Array<{ userId: string; role: string }>): Promise<BatchMemberResponse> {
+    return fetchJson<BatchMemberResponse>(`${WEB_API_PREFIX}/namespaces/${normalizeNamespaceSlug(slug)}/members/batch`, {
+      method: 'POST',
+      headers: await ensureCsrfHeaders({
+        'Content-Type': 'application/json',
+      }),
+      body: JSON.stringify({ members }),
+    })
+  },
+
   async updateMemberRole(slug: string, userId: string, role: string): Promise<NamespaceMember> {
     return fetchJson<NamespaceMember>(
       `${WEB_API_PREFIX}/namespaces/${normalizeNamespaceSlug(slug)}/members/${encodeURIComponent(userId)}/role`,