diff --git a/src/i18n/ja.ts b/src/i18n/ja.ts
index 9d5a52b..7470af2 100644
--- a/src/i18n/ja.ts
+++ b/src/i18n/ja.ts
@@ -635,7 +635,7 @@ export const jaOverrides = {
   'kernel.versions.reinstall': '再インストール',
   'kernel.versions.noBundled': 'このリリースには組み込みコアが含まれていません',
   'kernel.versions.offlineInstall': 'オフラインインストール',
-  'kernel.access.defaultKey': '既定のキー：{key}',
+  'kernel.access.firstKey': '最初のキー',
   'kernel.access.noConfiguredKey': 'キーが設定されていないため、現在はすべてのキーがデフォルトで許可されます',
   'kernel.access.connectable': '接続可能',
   'kernel.access.waiting': 'コアの起動を待っています',
diff --git a/src/i18n/resources.ts b/src/i18n/resources.ts
index f736461..24ddad3 100644
--- a/src/i18n/resources.ts
+++ b/src/i18n/resources.ts
@@ -638,7 +638,7 @@ export const zhCN = {
   'kernel.versions.reinstall': '重新安装',
   'kernel.versions.noBundled': '当前发行包未包含内置内核',
   'kernel.versions.offlineInstall': '离线安装',
-  'kernel.access.defaultKey': '默认密钥：{key}',
+  'kernel.access.firstKey': '第一个密钥',
   'kernel.access.noConfiguredKey': '未设置密钥，当前默认放行所有密钥',
   'kernel.access.connectable': '可连接',
   'kernel.access.waiting': '等待内核启动',
@@ -1345,7 +1345,7 @@ export const en: Record<MessageKey, string> = {
   'kernel.versions.reinstall': 'Reinstall',
   'kernel.versions.noBundled': 'This release does not include a bundled core',
   'kernel.versions.offlineInstall': 'Offline Install',
-  'kernel.access.defaultKey': 'Default key: {key}',
+  'kernel.access.firstKey': 'First key',
   'kernel.access.noConfiguredKey': 'No key is configured; all keys are currently allowed by default',
   'kernel.access.connectable': 'Connectable',
   'kernel.access.waiting': 'Waiting for core startup',
diff --git a/src/pages/Kernel.tsx b/src/pages/Kernel.tsx
index c89118c..593e7d0 100644
--- a/src/pages/Kernel.tsx
+++ b/src/pages/Kernel.tsx
@@ -6,7 +6,7 @@ import { type CoreStatus, useCoreRuntime } from '../coreRuntime';
 import openaiIcon from '../assets/icons/openai-light.svg';
 import claudeIcon from '../assets/icons/claude.svg';
 import geminiIcon from '../assets/icons/gemini.svg';
-import { clientApiProfiles, DEFAULT_CLIENT_API_KEY } from '../services/clientAccess';
+import { clientApiProfiles } from '../services/clientAccess';
 import packageMetadata from '../../package.json';
 import { useI18n } from '../i18n';
 import { useAppUpdate } from '../appUpdate';
@@ -138,7 +138,8 @@ export function KernelPage({ view = 'home' }: { view?: KernelView }) {
   const [installDialogOpen, setInstallDialogOpen] = useState(false);
   const [cancellingInstall, setCancellingInstall] = useState(false);
   const [copiedApiField, setCopiedApiField] = useState('');
-  const [homeApiKey, setHomeApiKey] = useState<string | null>(DEFAULT_CLIENT_API_KEY);
+  const [homeApiKey, setHomeApiKey] = useState<string | null | undefined>(undefined);
+  const [homeApiKeyError, setHomeApiKeyError] = useState(false);
   const [showHomeApiKey, setShowHomeApiKey] = useState(false);
   const [lanIpv4, setLanIpv4] = useState<string | null>(null);
   const [lanIpChecked, setLanIpChecked] = useState(false);
@@ -347,8 +348,10 @@ export function KernelPage({ view = 'home' }: { view?: KernelView }) {
     try {
       const settings = await invoke<CoreConfigSummary>('get_core_config_settings');
       setHomeApiKey(settings.apiKeys[0]?.apiKey ?? null);
+      setHomeApiKeyError(false);
     } catch {
-      setHomeApiKey(DEFAULT_CLIENT_API_KEY);
+      setHomeApiKey(undefined);
+      setHomeApiKeyError(true);
     }
   };
 
@@ -987,7 +990,7 @@ export function KernelPage({ view = 'home' }: { view?: KernelView }) {
         <div className="panel-heading client-api-heading">
           <div>
             <h2>API URL</h2>
-            {homeApiKey ? (
+            {typeof homeApiKey === 'string' ? (
               <div className="client-api-key-actions">
                 <button
                   type="button"
@@ -996,11 +999,8 @@ export function KernelPage({ view = 'home' }: { view?: KernelView }) {
                   title={showHomeApiKey ? t('config.keys.hide') : t('config.keys.show')}
                   onClick={() => setShowHomeApiKey((visible) => !visible)}
                 >
-                  <span>
-                    {t('kernel.access.defaultKey', {
-                      key: showHomeApiKey ? homeApiKey : '••••••',
-                    })}
-                  </span>
+                  <span>{t('kernel.access.firstKey')}</span>
+                  <code>{showHomeApiKey ? homeApiKey : '******'}</code>
                   {showHomeApiKey ? (
                     <EyeOff size={14} aria-hidden="true" />
                   ) : (
@@ -1027,8 +1027,12 @@ export function KernelPage({ view = 'home' }: { view?: KernelView }) {
                   )}
                 </button>
               </div>
-            ) : (
+            ) : homeApiKey === null ? (
               <p className="client-api-no-key">{t('kernel.access.noConfiguredKey')}</p>
+            ) : (
+              <p className={homeApiKeyError ? 'error' : undefined}>
+                {homeApiKeyError ? t('common.unavailable') : t('common.loading')}
+              </p>
             )}
           </div>
           <span className={`state-pill ${coreRunning ? 'success' : ''}`}>
diff --git a/src/services/clientAccess.ts b/src/services/clientAccess.ts
index 81a9033..5b6be58 100644
--- a/src/services/clientAccess.ts
+++ b/src/services/clientAccess.ts
@@ -1,7 +1,5 @@
 import { getCurrentLocale, translate } from '../i18n';
 
-export const DEFAULT_CLIENT_API_KEY = '123456';
-
 export type ClientApiProfile = {
   id: 'openai' | 'claude' | 'gemini';
   name: string;
diff --git a/src/styles.css b/src/styles.css
index 84d0447..fe47a4b 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -661,11 +661,21 @@ input:focus-visible {
 }
 
 .client-api-default-key span {
+  flex: none;
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
 }
 
+.client-api-default-key code {
+  min-width: 0;
+  overflow: hidden;
+  color: #2d2a26;
+  font-size: 12px;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
 .client-api-default-key svg {
   flex: none;
   color: #7a746c;
@@ -673,8 +683,6 @@ input:focus-visible {
 
 .client-api-default-key:hover span {
   color: #2d2a26;
-  text-decoration: underline;
-  text-underline-offset: 2px;
 }
 
 .client-api-key-copy {