diff --git a/web/frontend/src/api/models.ts b/web/frontend/src/api/models.ts
index e83b0b255..6a4544c65 100644
--- a/web/frontend/src/api/models.ts
+++ b/web/frontend/src/api/models.ts
@@ -1,3 +1,5 @@
+import { refreshGatewayState } from "@/store/gateway"
+
 // API client for model list management.
 
 export interface ModelInfo {
@@ -76,11 +78,14 @@ export async function deleteModel(index: number): Promise<ModelActionResponse> {
 export async function setDefaultModel(
   modelName: string,
 ): Promise<ModelActionResponse> {
-  return request<ModelActionResponse>("/api/models/default", {
+  const response = await request<ModelActionResponse>("/api/models/default", {
     method: "POST",
     headers: { "Content-Type": "application/json" },
     body: JSON.stringify({ model_name: modelName }),
   })
+
+  void refreshGatewayState()
+  return response
 }
 
 export type { ModelsListResponse, ModelActionResponse }
diff --git a/web/frontend/src/components/channels/channel-forms/discord-form.tsx b/web/frontend/src/components/channels/channel-forms/discord-form.tsx
index ec77beaa5..300175e20 100644
--- a/web/frontend/src/components/channels/channel-forms/discord-form.tsx
+++ b/web/frontend/src/components/channels/channel-forms/discord-form.tsx
@@ -1,7 +1,7 @@
 import { useTranslation } from "react-i18next"
 
 import type { ChannelConfig } from "@/api/channels"
-import { maskedSecretPlaceholder } from "@/components/channels/channel-forms/secret-placeholder"
+import { maskedSecretPlaceholder } from "@/components/secret-placeholder"
 import { Field, KeyInput, SwitchCardField } from "@/components/shared-form"
 import { Input } from "@/components/ui/input"
 
diff --git a/web/frontend/src/components/channels/channel-forms/feishu-form.tsx b/web/frontend/src/components/channels/channel-forms/feishu-form.tsx
index 2262b7ea5..a834a65f9 100644
--- a/web/frontend/src/components/channels/channel-forms/feishu-form.tsx
+++ b/web/frontend/src/components/channels/channel-forms/feishu-form.tsx
@@ -1,7 +1,7 @@
 import { useTranslation } from "react-i18next"
 
 import type { ChannelConfig } from "@/api/channels"
-import { maskedSecretPlaceholder } from "@/components/channels/channel-forms/secret-placeholder"
+import { maskedSecretPlaceholder } from "@/components/secret-placeholder"
 import { Field, KeyInput } from "@/components/shared-form"
 import { Input } from "@/components/ui/input"
 
diff --git a/web/frontend/src/components/channels/channel-forms/generic-form.tsx b/web/frontend/src/components/channels/channel-forms/generic-form.tsx
index b120fa612..fc5a0a7fd 100644
--- a/web/frontend/src/components/channels/channel-forms/generic-form.tsx
+++ b/web/frontend/src/components/channels/channel-forms/generic-form.tsx
@@ -1,7 +1,7 @@
 import { useTranslation } from "react-i18next"
 
 import type { ChannelConfig } from "@/api/channels"
-import { maskedSecretPlaceholder } from "@/components/channels/channel-forms/secret-placeholder"
+import { maskedSecretPlaceholder } from "@/components/secret-placeholder"
 import { Field, KeyInput, SwitchCardField } from "@/components/shared-form"
 import { Input } from "@/components/ui/input"
 
diff --git a/web/frontend/src/components/channels/channel-forms/secret-placeholder.ts b/web/frontend/src/components/channels/channel-forms/secret-placeholder.ts
deleted file mode 100644
index a2d716b3c..000000000
--- a/web/frontend/src/components/channels/channel-forms/secret-placeholder.ts
+++ /dev/null
@@ -1,10 +0,0 @@
-export function maskedSecretPlaceholder(value: unknown, fallback = ""): string {
-  const secret = typeof value === "string" ? value.trim() : ""
-  if (!secret) {
-    return fallback
-  }
-
-  const prefix = secret.slice(0, Math.min(4, secret.length))
-  const suffix = secret.slice(-Math.min(3, secret.length))
-  return `${prefix}***${suffix}`
-}
diff --git a/web/frontend/src/components/channels/channel-forms/slack-form.tsx b/web/frontend/src/components/channels/channel-forms/slack-form.tsx
index b2ad7ce48..54650e842 100644
--- a/web/frontend/src/components/channels/channel-forms/slack-form.tsx
+++ b/web/frontend/src/components/channels/channel-forms/slack-form.tsx
@@ -1,7 +1,7 @@
 import { useTranslation } from "react-i18next"
 
 import type { ChannelConfig } from "@/api/channels"
-import { maskedSecretPlaceholder } from "@/components/channels/channel-forms/secret-placeholder"
+import { maskedSecretPlaceholder } from "@/components/secret-placeholder"
 import { Field, KeyInput } from "@/components/shared-form"
 import { Input } from "@/components/ui/input"
 
diff --git a/web/frontend/src/components/channels/channel-forms/telegram-form.tsx b/web/frontend/src/components/channels/channel-forms/telegram-form.tsx
index d01e7d3eb..169ddec63 100644
--- a/web/frontend/src/components/channels/channel-forms/telegram-form.tsx
+++ b/web/frontend/src/components/channels/channel-forms/telegram-form.tsx
@@ -1,7 +1,7 @@
 import { useTranslation } from "react-i18next"
 
 import type { ChannelConfig } from "@/api/channels"
-import { maskedSecretPlaceholder } from "@/components/channels/channel-forms/secret-placeholder"
+import { maskedSecretPlaceholder } from "@/components/secret-placeholder"
 import { Field, KeyInput, SwitchCardField } from "@/components/shared-form"
 import { Input } from "@/components/ui/input"
 
diff --git a/web/frontend/src/components/models/add-model-sheet.tsx b/web/frontend/src/components/models/add-model-sheet.tsx
index c61b59463..c760bc672 100644
--- a/web/frontend/src/components/models/add-model-sheet.tsx
+++ b/web/frontend/src/components/models/add-model-sheet.tsx
@@ -3,6 +3,7 @@ import { useEffect, useState } from "react"
 import { useTranslation } from "react-i18next"
 
 import { addModel, setDefaultModel } from "@/api/models"
+import { maskedSecretPlaceholder } from "@/components/secret-placeholder"
 import {
   AdvancedSection,
   Field,
@@ -54,9 +55,15 @@ interface AddModelSheetProps {
   open: boolean
   onClose: () => void
   onSaved: () => void
+  existingModelNames: string[]
 }
 
-export function AddModelSheet({ open, onClose, onSaved }: AddModelSheetProps) {
+export function AddModelSheet({
+  open,
+  onClose,
+  onSaved,
+  existingModelNames,
+}: AddModelSheetProps) {
   const { t } = useTranslation()
   const [form, setForm] = useState<AddForm>(EMPTY_ADD_FORM)
   const [saving, setSaving] = useState(false)
@@ -65,6 +72,10 @@ export function AddModelSheet({ open, onClose, onSaved }: AddModelSheetProps) {
     Partial<Record<keyof AddForm, string>>
   >({})
   const [serverError, setServerError] = useState("")
+  const apiKeyPlaceholder = maskedSecretPlaceholder(
+    form.apiKey,
+    t("models.field.apiKeyPlaceholder"),
+  )
 
   useEffect(() => {
     if (open) {
@@ -77,7 +88,12 @@ export function AddModelSheet({ open, onClose, onSaved }: AddModelSheetProps) {
 
   const validate = (): boolean => {
     const errors: Partial<Record<keyof AddForm, string>> = {}
-    if (!form.modelName.trim()) errors.modelName = t("models.add.errorRequired")
+    const modelName = form.modelName.trim()
+    if (!modelName) {
+      errors.modelName = t("models.add.errorRequired")
+    } else if (existingModelNames.some((name) => name.trim() === modelName)) {
+      errors.modelName = t("models.add.errorDuplicateModelName")
+    }
     if (!form.model.trim()) errors.model = t("models.add.errorRequired")
     setFieldErrors(errors)
     return Object.keys(errors).length === 0
@@ -178,7 +194,7 @@ export function AddModelSheet({ open, onClose, onSaved }: AddModelSheetProps) {
               <KeyInput
                 value={form.apiKey}
                 onChange={(v) => setForm((f) => ({ ...f, apiKey: v }))}
-                placeholder={t("models.field.apiKeyPlaceholder")}
+                placeholder={apiKeyPlaceholder}
               />
             </Field>
 
diff --git a/web/frontend/src/components/models/edit-model-sheet.tsx b/web/frontend/src/components/models/edit-model-sheet.tsx
index cd8d2a41c..4c77944a9 100644
--- a/web/frontend/src/components/models/edit-model-sheet.tsx
+++ b/web/frontend/src/components/models/edit-model-sheet.tsx
@@ -3,6 +3,7 @@ import { useEffect, useState } from "react"
 import { useTranslation } from "react-i18next"
 
 import { type ModelInfo, setDefaultModel, updateModel } from "@/api/models"
+import { maskedSecretPlaceholder } from "@/components/secret-placeholder"
 import {
   AdvancedSection,
   Field,
@@ -122,6 +123,12 @@ export function EditModelSheet({
   }
 
   const isOAuth = model?.auth_method === "oauth"
+  const apiKeyPlaceholder = model?.configured
+    ? maskedSecretPlaceholder(
+        model.api_key,
+        t("models.field.apiKeyPlaceholderSet"),
+      )
+    : t("models.field.apiKeyPlaceholder")
 
   return (
     <Sheet open={open} onOpenChange={(v) => !v && onClose()}>
@@ -150,11 +157,7 @@ export function EditModelSheet({
                 <KeyInput
                   value={form.apiKey}
                   onChange={(v) => setForm((f) => ({ ...f, apiKey: v }))}
-                  placeholder={
-                    model?.configured
-                      ? t("models.field.apiKeyPlaceholderSet")
-                      : t("models.field.apiKeyPlaceholder")
-                  }
+                  placeholder={apiKeyPlaceholder}
                 />
               </Field>
             )}
diff --git a/web/frontend/src/components/models/models-page.tsx b/web/frontend/src/components/models/models-page.tsx
index 839212d0f..6b207fab1 100644
--- a/web/frontend/src/components/models/models-page.tsx
+++ b/web/frontend/src/components/models/models-page.tsx
@@ -200,6 +200,7 @@ export function ModelsPage() {
         open={addOpen}
         onClose={() => setAddOpen(false)}
         onSaved={fetchModels}
+        existingModelNames={models.map((model) => model.model_name)}
       />
 
       <DeleteModelDialog
diff --git a/web/frontend/src/components/models/provider-icon.tsx b/web/frontend/src/components/models/provider-icon.tsx
index f6d6e93c6..5e2151e2d 100644
--- a/web/frontend/src/components/models/provider-icon.tsx
+++ b/web/frontend/src/components/models/provider-icon.tsx
@@ -79,7 +79,7 @@ export function ProviderIcon({
       <img
         src={iconUrl}
         alt={`${providerLabel} logo`}
-        className="size-full object-contain drop-shadow-[0_0_1px_rgba(0,0,0,0.45)]"
+        className="size-full object-contain"
         loading="lazy"
         referrerPolicy="no-referrer"
         onError={() => {
diff --git a/web/frontend/src/components/secret-placeholder.ts b/web/frontend/src/components/secret-placeholder.ts
new file mode 100644
index 000000000..c6167d78e
--- /dev/null
+++ b/web/frontend/src/components/secret-placeholder.ts
@@ -0,0 +1,16 @@
+export function maskedSecretPlaceholder(value: unknown, fallback = ""): string {
+  const secret = typeof value === "string" ? value.trim() : ""
+  if (!secret) {
+    return fallback
+  }
+
+  if (secret.length < 7) {
+    const first = secret[0]
+    const last = secret[secret.length - 1]
+    return `${first}***${last}`
+  }
+
+  const prefix = secret.slice(0, Math.min(3, secret.length))
+  const suffix = secret.slice(-Math.min(4, secret.length))
+  return `${prefix}***${suffix}`
+}
diff --git a/web/frontend/src/i18n/locales/en.json b/web/frontend/src/i18n/locales/en.json
index 402a4ca85..117abd022 100644
--- a/web/frontend/src/i18n/locales/en.json
+++ b/web/frontend/src/i18n/locales/en.json
@@ -178,6 +178,7 @@
       "modelIdPlaceholder": "e.g. openai/gpt-4o",
       "modelIdHint": "Format: protocol/model-id. Supported: openai, anthropic, gemini, groq, …",
       "errorRequired": "This field is required.",
+      "errorDuplicateModelName": "Model alias already exists. Please use a different name.",
       "saveError": "Failed to add model",
       "confirm": "Add Model"
     },
diff --git a/web/frontend/src/i18n/locales/zh.json b/web/frontend/src/i18n/locales/zh.json
index 6d6851321..d311eb114 100644
--- a/web/frontend/src/i18n/locales/zh.json
+++ b/web/frontend/src/i18n/locales/zh.json
@@ -178,6 +178,7 @@
       "modelIdPlaceholder": "例如 openai/gpt-4o",
       "modelIdHint": "格式：协议/模型ID。支持：openai、anthropic、gemini、groq 等。",
       "errorRequired": "此字段为必填项。",
+      "errorDuplicateModelName": "模型别名已存在，请使用其他名称。",
       "saveError": "添加模型失败",
       "confirm": "添加模型"
     },
diff --git a/web/frontend/src/store/gateway.ts b/web/frontend/src/store/gateway.ts
index ebe132746..89da9d7fd 100644
--- a/web/frontend/src/store/gateway.ts
+++ b/web/frontend/src/store/gateway.ts
@@ -1,4 +1,6 @@
-import { atom } from "jotai"
+import { atom, getDefaultStore } from "jotai"
+
+import { type GatewayStatusResponse, getGatewayStatus } from "@/api/gateway"
 
 export type GatewayState =
   | "running"
@@ -17,3 +19,20 @@ export const gatewayAtom = atom<GatewayStoreState>({
   status: "unknown",
   canStart: true,
 })
+
+function applyGatewayStatusToStore(data: GatewayStatusResponse) {
+  getDefaultStore().set(gatewayAtom, (prev) => ({
+    ...prev,
+    status: data.gateway_status ?? "unknown",
+    canStart: data.gateway_start_allowed ?? true,
+  }))
+}
+
+export async function refreshGatewayState() {
+  try {
+    const status = await getGatewayStatus()
+    applyGatewayStatusToStore(status)
+  } catch {
+    // Best-effort refresh only; keep current state on error.
+  }
+}