diff --git a/astrbot/dashboard/server.py b/astrbot/dashboard/server.py
index eef3f37b1..91092a237 100644
--- a/astrbot/dashboard/server.py
+++ b/astrbot/dashboard/server.py
@@ -172,7 +172,12 @@ class AstrBotDashboard:
         self.app = cors(
             self.app,
             allow_origin="*",
-            allow_headers=["Authorization", "Content-Type", "X-API-Key"],
+            allow_headers=[
+                "Authorization",
+                "Content-Type",
+                "X-API-Key",
+                "Accept-Language",
+            ],
             allow_methods=["GET", "POST", "PUT", "DELETE", "OPTIONS"],
         )
 
diff --git a/dashboard/src/main.ts b/dashboard/src/main.ts
index 5f7e44991..2d7b64e82 100644
--- a/dashboard/src/main.ts
+++ b/dashboard/src/main.ts
@@ -103,7 +103,7 @@ async function initApp() {
     const headers = new Headers(
       init?.headers ||
         (typeof input !== "string" && "headers" in input
-          ? (input ).headers
+          ? input.headers
           : undefined),
     );
     if (token && !headers.has("Authorization")) {
diff --git a/dashboard/src/views/Settings.vue b/dashboard/src/views/Settings.vue
index efb94c949..04aba2694 100644
--- a/dashboard/src/views/Settings.vue
+++ b/dashboard/src/views/Settings.vue
@@ -3,10 +3,7 @@
     <!-- Proxy Settings -->
     <!-- <div class="text-h6 mb-2">{{ tm('network.title') }}</div> -->
 
-    <v-list
-      lines="two"
-      subheader
-    >
+    <v-list lines="two" subheader>
       <v-list-subheader>{{ tm("network.title") }}</v-list-subheader>
 
       <v-list-item
@@ -148,23 +145,15 @@
                   target="_blank"
                   rel="noopener noreferrer"
                 >
-                  <v-icon size="18">
-                    mdi-help-circle-outline
-                  </v-icon>
+                  <v-icon size="18"> mdi-help-circle-outline </v-icon>
                 </v-btn>
               </template>
               <span>{{ tm("apiKey.docsLink") }}</span>
             </v-tooltip>
           </div>
         </template>
-        <v-row
-          class="mt-2"
-          dense
-        >
-          <v-col
-            cols="12"
-            md="4"
-          >
+        <v-row class="mt-2" dense>
+          <v-col cols="12" md="4">
             <v-text-field
               v-model="newApiKeyName"
               :label="tm('apiKey.name')"
@@ -173,10 +162,7 @@
               hide-details
             />
           </v-col>
-          <v-col
-            cols="12"
-            md="3"
-          >
+          <v-col cols="12" md="3">
             <v-select
               v-model="newApiKeyExpiresInDays"
               :items="apiKeyExpiryOptions"
@@ -186,31 +172,18 @@
               hide-details
             />
           </v-col>
-          <v-col
-            v-if="newApiKeyExpiresInDays === 'permanent'"
-            cols="12"
-          >
-            <v-alert
-              type="warning"
-              variant="tonal"
-              density="comfortable"
-            >
+          <v-col v-if="newApiKeyExpiresInDays === 'permanent'" cols="12">
+            <v-alert type="warning" variant="tonal" density="comfortable">
               {{ tm("apiKey.permanentWarning") }}
             </v-alert>
           </v-col>
-          <v-col
-            cols="12"
-            md="5"
-            class="d-flex align-center"
-          >
+          <v-col cols="12" md="5" class="d-flex align-center">
             <v-btn
               color="primary"
               :loading="apiKeyCreating"
               @click="createApiKey"
             >
-              <v-icon class="mr-2">
-                mdi-key-plus
-              </v-icon>
+              <v-icon class="mr-2"> mdi-key-plus </v-icon>
               {{ tm("apiKey.create") }}
             </v-btn>
           </v-col>
@@ -219,10 +192,7 @@
             <div class="text-caption text-medium-emphasis mb-1">
               {{ tm("apiKey.scopes") }}
             </div>
-            <v-chip-group
-              v-model="newApiKeyScopes"
-              multiple
-            >
+            <v-chip-group v-model="newApiKeyScopes" multiple>
               <v-chip
                 v-for="scope in availableScopes"
                 :key="scope.value"
@@ -239,14 +209,8 @@
             </v-chip-group>
           </v-col>
 
-          <v-col
-            v-if="createdApiKeyPlaintext"
-            cols="12"
-          >
-            <v-alert
-              type="warning"
-              variant="tonal"
-            >
+          <v-col v-if="createdApiKeyPlaintext" cols="12">
+            <v-alert type="warning" variant="tonal">
               <div class="d-flex align-center justify-space-between flex-wrap">
                 <span>{{ tm("apiKey.plaintextHint") }}</span>
                 <v-btn
@@ -255,9 +219,8 @@
                   color="primary"
                   @click="copyCreatedApiKey"
                 >
-                  <v-icon class="mr-1">
-                    mdi-content-copy
-                  </v-icon>{{ tm("apiKey.copy") }}
+                  <v-icon class="mr-1"> mdi-content-copy </v-icon
+                  >{{ tm("apiKey.copy") }}
                 </v-btn>
               </div>
               <code style="word-break: break-all">{{
@@ -280,10 +243,7 @@
                 </tr>
               </thead>
               <tbody>
-                <tr
-                  v-for="item in apiKeys"
-                  :key="item.key_id"
-                >
+                <tr v-for="item in apiKeys" :key="item.key_id">
                   <td>{{ item.name }}</td>
                   <td>
                     <code>{{ item.key_prefix }}</code>
@@ -328,10 +288,7 @@
                   </td>
                 </tr>
                 <tr v-if="apiKeys.length === 0">
-                  <td
-                    colspan="7"
-                    class="text-center text-medium-emphasis"
-                  >
+                  <td colspan="7" class="text-center text-medium-emphasis">
                     {{ tm("apiKey.empty") }}
                   </td>
                 </tr>
@@ -345,11 +302,7 @@
         :subtitle="tm('system.migration.subtitle')"
         :title="tm('system.migration.title')"
       >
-        <v-btn
-          style="margin-top: 16px"
-          color="primary"
-          @click="startMigration"
-        >
+        <v-btn style="margin-top: 16px" color="primary" @click="startMigration">
           {{ tm("system.migration.button") }}
         </v-btn>
       </v-list-item>
@@ -371,14 +324,8 @@
       >
         <template #append />
 
-        <v-row
-          class="mt-2"
-          dense
-        >
-          <v-col
-            cols="12"
-            md="4"
-          >
+        <v-row class="mt-2" dense>
+          <v-col cols="12" md="4">
             <v-text-field
               v-model="primaryColor"
               :label="tm('style.color.primary')"
@@ -400,10 +347,7 @@
               </template>
             </v-text-field>
           </v-col>
-          <v-col
-            cols="12"
-            md="4"
-          >
+          <v-col cols="12" md="4">
             <v-text-field
               v-model="secondaryColor"
               :label="tm('style.color.secondary')"
@@ -425,18 +369,9 @@
               </template>
             </v-text-field>
           </v-col>
-          <v-col
-            cols="12"
-            md="4"
-          >
-            <v-btn
-              color="primary"
-              block
-              @click="applyThemeColors"
-            >
-              <v-icon start>
-                mdi-pencil-ruler
-              </v-icon>
+          <v-col cols="12" md="4">
+            <v-btn color="primary" block @click="applyThemeColors">
+              <v-icon start> mdi-pencil-ruler </v-icon>
               {{ t("core.common.save") }}
             </v-btn>
           </v-col>
@@ -473,10 +408,7 @@
         </div>
       </v-list-item>
 
-      <v-list-item
-        :subtitle="tm('reset.subtitle')"
-        :title="tm('reset.title')"
-      >
+      <v-list-item :subtitle="tm('reset.subtitle')" :title="tm('reset.title')">
         <div class="d-flex align-center mt-2">
           <v-btn
             color="error"
@@ -595,6 +527,12 @@ const isCustomPreset = (name) => {
 };
 
 const saveApiUrl = () => {
+  const validationError = getApiBaseUrlValidationError(apiBaseUrl.value);
+  if (validationError) {
+    toastStore.error(validationError);
+    return;
+  }
+
   apiStore.setApiBaseUrl(apiBaseUrl.value);
   window.location.reload();
 };
@@ -651,8 +589,10 @@ const autoThemeSwitcher = computed({
   get: () => customizer.autoSwitchTheme,
   set: (value) => {
     customizer.SET_AUTO_SYNC(value);
-    if (value) { customizer.APPLY_SYSTEM_THEME() }
-  }
+    if (value) {
+      customizer.APPLY_SYSTEM_THEME();
+    }
+  },
 });
 
 const wfr = ref(null);
diff --git a/dashboard/src/views/WelcomePage.vue b/dashboard/src/views/WelcomePage.vue
index 09f98012c..1cfb787ac 100644
--- a/dashboard/src/views/WelcomePage.vue
+++ b/dashboard/src/views/WelcomePage.vue
@@ -1,9 +1,6 @@
 <template>
   <div class="welcome-page">
-    <v-container
-      fluid
-      class="pa-0"
-    >
+    <v-container fluid class="pa-0">
       <v-row class="px-4 py-3 pb-6">
         <v-col cols="12">
           <h1 class="text-h1 font-weight-bold mb-2 d-flex align-center">
@@ -17,11 +14,7 @@
 
       <v-row class="px-4">
         <v-col cols="12">
-          <v-card
-            class="welcome-card pa-6"
-            elevation="0"
-            border
-          >
+          <v-card class="welcome-card pa-6" elevation="0" border>
             <div class="mb-4 text-h3 font-weight-bold">
               {{ tm("onboard.title") }}
             </div>
@@ -52,7 +45,7 @@
                   <p class="text-body-2 text-medium-emphasis mb-3">
                     {{
                       tm("onboard.step0Desc") ||
-                        "配置 AstrBot 的后端 API 地址。"
+                      "配置 AstrBot 的后端 API 地址。"
                     }}
                   </p>
                   <div class="d-flex align-center">
@@ -185,19 +178,12 @@
 
       <v-row class="px-4 mt-4">
         <v-col cols="12">
-          <v-card
-            class="welcome-card pa-6"
-            elevation="0"
-            border
-          >
+          <v-card class="welcome-card pa-6" elevation="0" border>
             <div class="mb-4 text-h3 font-weight-bold">
               {{ tm("resources.title") }}
             </div>
             <v-row>
-              <v-col
-                cols="12"
-                sm="4"
-              >
+              <v-col cols="12" sm="4">
                 <!-- GitHub Card -->
                 <v-card
                   variant="outlined"
@@ -206,12 +192,7 @@
                   target="_blank"
                 >
                   <div class="d-flex align-center mb-3">
-                    <v-icon
-                      size="32"
-                      class="mr-3"
-                    >
-                      mdi-github
-                    </v-icon>
+                    <v-icon size="32" class="mr-3"> mdi-github </v-icon>
                     <span class="text-h6 font-weight-bold">GitHub</span>
                   </div>
                   <p class="text-body-2 text-medium-emphasis mb-0">
@@ -220,10 +201,7 @@
                 </v-card>
               </v-col>
 
-              <v-col
-                cols="12"
-                sm="4"
-              >
+              <v-col cols="12" sm="4">
                 <!-- Docs Card -->
                 <v-card
                   variant="outlined"
@@ -232,10 +210,7 @@
                   target="_blank"
                 >
                   <div class="d-flex align-center mb-3">
-                    <v-icon
-                      size="32"
-                      class="mr-3"
-                    >
+                    <v-icon size="32" class="mr-3">
                       mdi-book-open-variant
                     </v-icon>
                     <span class="text-h6 font-weight-bold">{{
@@ -248,10 +223,7 @@
                 </v-card>
               </v-col>
 
-              <v-col
-                cols="12"
-                sm="4"
-              >
+              <v-col cols="12" sm="4">
                 <!-- Afdian Card -->
                 <v-card
                   variant="outlined"
@@ -260,12 +232,7 @@
                   target="_blank"
                 >
                   <div class="d-flex align-center mb-3">
-                    <v-icon
-                      size="32"
-                      class="mr-3"
-                    >
-                      mdi-hand-heart
-                    </v-icon>
+                    <v-icon size="32" class="mr-3"> mdi-hand-heart </v-icon>
                     <span class="text-h6 font-weight-bold">{{
                       tm("resources.afdianTitle")
                     }}</span>
@@ -280,16 +247,9 @@
         </v-col>
       </v-row>
 
-      <v-row
-        v-if="showAnnouncement"
-        class="px-4 mb-4"
-      >
+      <v-row v-if="showAnnouncement" class="px-4 mb-4">
         <v-col cols="12">
-          <v-card
-            class="welcome-card pa-6"
-            elevation="0"
-            border
-          >
+          <v-card class="welcome-card pa-6" elevation="0" border>
             <div class="mb-4 text-h3 font-weight-bold">
               {{ tm("announcement.title") }}
             </div>
@@ -457,32 +417,34 @@ async function loadPlatformConfigBase() {
 
 async function checkAndSaveBackend() {
   checkingBackend.value = true;
-  try {
-    // try to connect
-    const url = apiBaseUrl.value.replace(/\/+$/, "");
-    // temp set axios base url to check
-    const originalBase = axios.defaults.baseURL;
-    axios.defaults.baseURL = url;
+  const originalBase = axios.defaults.baseURL;
+  const normalizedUrl = normalizeConfiguredApiBaseUrl(apiBaseUrl.value);
+  const validationError = getApiBaseUrlValidationError(normalizedUrl);
 
+  if (validationError) {
+    backendStepState.value = "pending";
+    showError(validationError);
+    checkingBackend.value = false;
+    return;
+  }
+
+  try {
+    setApiBaseUrl(normalizedUrl);
     await axios.get("/api/stat/version");
 
-    // if success, save
-    apiStore.setApiBaseUrl(url);
+    apiStore.setApiBaseUrl(normalizedUrl);
+    apiBaseUrl.value = normalizedUrl;
     backendStepState.value = "completed";
     showSuccess("Connected to AstrBot Backend successfully!");
 
-    // load subsequent data
     await loadPlatformConfigBase();
     if ((platformConfigData.value.platform || []).length > 0) {
       platformStepState.value = "completed";
     }
-  } catch (e) {
-    showError("Failed to connect to backend: " + e);
+  } catch (error) {
+    setApiBaseUrl(originalBase);
     backendStepState.value = "pending";
-    // restore if failed (though user might want to try another)
-    // but here we just keep the axios instance dirty or reset?
-    // actually apiStore.init() logic should be used but simpler:
-    // we don't reset axios defaults here because the user might be trying to correct it.
+    showError(`Failed to connect to backend: ${error}`);
   } finally {
     checkingBackend.value = false;
   }
diff --git a/dashboard/src/views/authentication/auth/LoginPage.vue b/dashboard/src/views/authentication/auth/LoginPage.vue
index ddf13f82b..3c70a99b2 100644
--- a/dashboard/src/views/authentication/auth/LoginPage.vue
+++ b/dashboard/src/views/authentication/auth/LoginPage.vue
@@ -7,6 +7,8 @@ import { useApiStore } from "@/stores/api";
 import { useRouter } from "vue-router";
 import { useCustomizerStore } from "@/stores/customizer";
 import { useModuleI18n } from "@/i18n/composables";
+import { useToast } from "@/utils/toast";
+import { getApiBaseUrlValidationError } from "@/utils/request";
 
 const cardVisible = ref(false);
 const router = useRouter();
@@ -14,6 +16,7 @@ const authStore = useAuthStore();
 const apiStore = useApiStore();
 const customizer = useCustomizerStore();
 const { tm: t } = useModuleI18n("features/auth");
+const toast = useToast();
 
 const serverConfigDialog = ref(false);
 const apiUrl = ref(apiStore.apiBaseUrl);
@@ -23,6 +26,12 @@ const newPresetName = ref("");
 const newPresetUrl = ref("");
 
 function saveApiUrl() {
+  const validationError = getApiBaseUrlValidationError(apiUrl.value);
+  if (validationError) {
+    toast.error(validationError);
+    return;
+  }
+
   apiStore.setApiBaseUrl(apiUrl.value);
   serverConfigDialog.value = false;
   window.location.reload();
@@ -64,17 +73,14 @@ onMounted(() => {
 
 <template>
   <div class="login-page-container">
-    <v-card
-      class="login-card"
-      elevation="1"
-    >
+    <v-card class="login-card" elevation="1">
       <v-card-title>
         <div class="d-flex justify-space-between align-center w-100">
           <img
             width="80"
             src="@/assets/images/icon-no-shadow.svg"
             alt="AstrBot Logo"
-          >
+          />
           <div class="d-flex align-center gap-1">
             <LanguageSwitcher />
             <v-divider
@@ -94,16 +100,10 @@ onMounted(() => {
               size="small"
               @click="serverConfigDialog = true"
             >
-              <v-icon
-                size="18"
-                :color="'rgb(var(--v-theme-primary))'"
-              >
+              <v-icon size="18" :color="'rgb(var(--v-theme-primary))'">
                 mdi-server
               </v-icon>
-              <v-tooltip
-                activator="parent"
-                location="top"
-              >
+              <v-tooltip activator="parent" location="top">
                 {{ t("serverConfig.tooltip") }}
               </v-tooltip>
             </v-btn>
@@ -115,31 +115,27 @@ onMounted(() => {
               size="small"
               @click="toggleTheme"
             >
-              <v-icon
-                size="18"
-                :color="'rgb(var(--v-theme-primary))'"
-              >
-                {{ customizer.isDarkTheme ? 'mdi-weather-night' : 'mdi-white-balance-sunny' }}
+              <v-icon size="18" :color="'rgb(var(--v-theme-primary))'">
+                {{
+                  customizer.isDarkTheme
+                    ? "mdi-weather-night"
+                    : "mdi-white-balance-sunny"
+                }}
               </v-icon>
-              <v-tooltip
-                activator="parent"
-                location="top"
-              >
-                {{ customizer.isDarkTheme ? t('theme.switchToLight') : t('theme.switchToDark') }}
+              <v-tooltip activator="parent" location="top">
+                {{
+                  customizer.isDarkTheme
+                    ? t("theme.switchToLight")
+                    : t("theme.switchToDark")
+                }}
               </v-tooltip>
             </v-btn>
           </div>
         </div>
-        <div
-          class="ml-2"
-          style="font-size: 26px"
-        >
+        <div class="ml-2" style="font-size: 26px">
           {{ t("logo.title") }}
         </div>
-        <div
-          class="mt-2 ml-2"
-          style="font-size: 14px; color: grey"
-        >
+        <div class="mt-2 ml-2" style="font-size: 14px; color: grey">
           {{ t("logo.subtitle") }}
         </div>
       </v-card-title>
@@ -148,10 +144,7 @@ onMounted(() => {
       </v-card-text>
     </v-card>
 
-    <v-dialog
-      v-model="serverConfigDialog"
-      max-width="450"
-    >
+    <v-dialog v-model="serverConfigDialog" max-width="450">
       <v-card>
         <v-card-title>{{ t("serverConfig.title") }}</v-card-title>
         <v-card-text>
@@ -162,7 +155,7 @@ onMounted(() => {
           <div
             v-if="
               (apiStore.presets && apiStore.presets.length > 0) ||
-                apiStore.customPresets
+              apiStore.customPresets
             "
             class="mb-4"
           >
@@ -243,22 +236,11 @@ onMounted(() => {
         </v-card-text>
         <v-card-actions>
           <v-spacer />
-          <v-btn
-            variant="text"
-            @click="serverConfigDialog = false"
-          >
-            {{
-              t("serverConfig.cancel")
-            }}
+          <v-btn variant="text" @click="serverConfigDialog = false">
+            {{ t("serverConfig.cancel") }}
           </v-btn>
-          <v-btn
-            color="primary"
-            variant="flat"
-            @click="saveApiUrl"
-          >
-            {{
-              t("serverConfig.save")
-            }}
+          <v-btn color="primary" variant="flat" @click="saveApiUrl">
+            {{ t("serverConfig.save") }}
           </v-btn>
         </v-card-actions>
       </v-card>