diff --git a/apps/web/src/app/[locale]/page.tsx b/apps/web/src/app/[locale]/page.tsx
index b558a7f4..8cf26c0c 100644
--- a/apps/web/src/app/[locale]/page.tsx
+++ b/apps/web/src/app/[locale]/page.tsx
@@ -26,6 +26,7 @@ import { HostGrid, type HostInfo, type HostService } from '@/components/infra/ho
 import { AppLayout } from '@/components/layout'
 import { PageTabs, type TabConfig } from '@/components/layout/page-tabs'
 import { LobsterLoading } from '@/components/shared/lobster-loading'
+import { ServiceTopology } from '@/components/topology'
 
 const API_BASE = process.env.NEXT_PUBLIC_API_URL ?? ''
 
@@ -736,6 +737,7 @@ export default function Home({ params }: { params: { locale: string } }) {
 
   // Sprint 5: 從 URL 讀取當前 Tab
   const [activeTabId, setActiveTabId] = useState('overview')
+  const [infraView, setInfraView] = useState<'host' | 'topo'>('host')
 
   // 每 100ms 檢查 URL query 變化（PageTabs 用 router.push 更新）
   useEffect(() => {
@@ -964,7 +966,7 @@ export default function Home({ params }: { params: { locale: string } }) {
               />
             </div>
 
-            {/* 基礎架構 Grid */}
+            {/* 基礎架構 — Toggle: 拓撲圖 / 主機網格 */}
             <div style={{
               background: '#fff',
               border: '0.5px solid #e0ddd4',
@@ -984,18 +986,49 @@ export default function Home({ params }: { params: { locale: string } }) {
               }}>
                 <div style={{ width: 6, height: 6, borderRadius: '50%', background: '#d97757', flexShrink: 0 }} />
                 {tDashboard('infrastructure')}
+                {/* Toggle 切換 */}
+                <div style={{ marginLeft: 'auto', display: 'flex', background: '#f5f4ed', borderRadius: 5, padding: 2 }}>
+                  <button
+                    onClick={() => setInfraView('host')}
+                    style={{
+                      padding: '3px 10px', borderRadius: 3, fontSize: 10, fontWeight: infraView === 'host' ? 600 : 400,
+                      cursor: 'pointer', border: 'none',
+                      background: infraView === 'host' ? '#fff' : 'transparent',
+                      color: infraView === 'host' ? '#d97757' : '#87867f',
+                      boxShadow: infraView === 'host' ? '0 1px 2px rgba(0,0,0,0.06)' : 'none',
+                    }}
+                  >主機</button>
+                  <button
+                    onClick={() => setInfraView('topo')}
+                    style={{
+                      padding: '3px 10px', borderRadius: 3, fontSize: 10, fontWeight: infraView === 'topo' ? 600 : 400,
+                      cursor: 'pointer', border: 'none',
+                      background: infraView === 'topo' ? '#fff' : 'transparent',
+                      color: infraView === 'topo' ? '#d97757' : '#87867f',
+                      boxShadow: infraView === 'topo' ? '0 1px 2px rgba(0,0,0,0.06)' : 'none',
+                    }}
+                  >拓撲</button>
+                </div>
               </div>
-              <HostGrid hosts={(() => {
-                const apiHosts = hosts.map(h =>
-                  buildHostInfo(h.ip, h.name, h.metrics?.cpu_percent ?? null, h.metrics?.memory_percent ?? null, h.services)
-                )
-                // K3s #2 (121) 若 API 未回傳，補靜態卡
-                const has121 = apiHosts.some(h => h.ip === '192.168.0.121')
-                if (!has121) {
-                  apiHosts.push(buildHostInfo('192.168.0.121', 'K3s Server #2', null, null, []))
-                }
-                return apiHosts
-              })()} />
+              {/* 主機網格 (預設) */}
+              {infraView === 'host' && (
+                <HostGrid hosts={(() => {
+                  const apiHosts = hosts.map(h =>
+                    buildHostInfo(h.ip, h.name, h.metrics?.cpu_percent ?? null, h.metrics?.memory_percent ?? null, h.services)
+                  )
+                  const has121 = apiHosts.some(h => h.ip === '192.168.0.121')
+                  if (!has121) {
+                    apiHosts.push(buildHostInfo('192.168.0.121', 'K3s Server #2', null, null, []))
+                  }
+                  return apiHosts
+                })()} />
+              )}
+              {/* 拓撲圖 (React Flow) */}
+              {infraView === 'topo' && (
+                <div style={{ height: 350 }}>
+                  <ServiceTopology mode="compact" showControls={false} showMiniMap={false} height={350} />
+                </div>
+              )}
             </div>
 
             {/* 監控工具 — figma-v2 style: 左彩色條 + 可點擊 + meta行 */}