diff --git a/src/composables/useLlmProviderDirectory.ts b/src/composables/useLlmProviderDirectory.ts
index 935f48b4..3236d29e 100644
--- a/src/composables/useLlmProviderDirectory.ts
+++ b/src/composables/useLlmProviderDirectory.ts
@@ -83,6 +83,7 @@ interface UseLlmProviderDirectoryOptions {
   apiKey: Ref<string>
   baseUrl: Ref<string>
   baseUrlPreset?: Ref<string>
+  userAgent?: Ref<string>
   model: Ref<string>
   maxContextTokens?: Ref<number>
   authConnected?: Ref<boolean>
@@ -253,6 +254,7 @@ export function useLlmProviderDirectory(options: UseLlmProviderDirectoryOptions)
           api_key: normalizeValue(options.apiKey.value) || undefined,
           base_url: normalizeValue(options.baseUrl.value) || undefined,
           base_url_preset: normalizeValue(options.baseUrlPreset?.value) || undefined,
+          user_agent: normalizeValue(options.userAgent?.value) || undefined,
           force_refresh: forceRefresh,
         },
       })
diff --git a/src/composables/useSetupWizard.ts b/src/composables/useSetupWizard.ts
index 2b4cdeff..c035b956 100644
--- a/src/composables/useSetupWizard.ts
+++ b/src/composables/useSetupWizard.ts
@@ -62,6 +62,7 @@ export interface WizardData {
     apiKey: string
     baseUrl: string
     baseUrlPreset: string
+    userAgent: string
     maxContextTokens: number
     audioInputProvider: string
     audioInputApiKey: string
@@ -248,6 +249,7 @@ const wizardData = ref<WizardData>({
     apiKey: '',
     baseUrl: 'https://api.deepseek.com',
     baseUrlPreset: '',
+    userAgent: '',
     maxContextTokens: 64,
     audioInputProvider: 'openai',
     audioInputApiKey: '',
@@ -1445,6 +1447,7 @@ export function useSetupWizard() {
         LLM_API_KEY: wizardData.value.agent.apiKey,
         LLM_BASE_URL: wizardData.value.agent.baseUrl || null,
         LLM_BASE_URL_PRESET: wizardData.value.agent.baseUrlPreset || null,
+        LLM_USER_AGENT: wizardData.value.agent.userAgent || null,
         LLM_MAX_CONTEXT_TOKENS: wizardData.value.agent.maxContextTokens,
         AUDIO_INPUT_PROVIDER: wizardData.value.agent.audioInputProvider || 'openai',
         AUDIO_INPUT_API_KEY: wizardData.value.agent.audioInputApiKey || null,
@@ -1558,6 +1561,7 @@ export function useSetupWizard() {
         wizardData.value.agent.apiKey = result.data.LLM_API_KEY || ''
         wizardData.value.agent.baseUrl = result.data.LLM_BASE_URL || ''
         wizardData.value.agent.baseUrlPreset = result.data.LLM_BASE_URL_PRESET || ''
+        wizardData.value.agent.userAgent = result.data.LLM_USER_AGENT || ''
         wizardData.value.agent.maxContextTokens = result.data.LLM_MAX_CONTEXT_TOKENS || 64
         wizardData.value.agent.audioInputProvider = result.data.AUDIO_INPUT_PROVIDER || 'openai'
         wizardData.value.agent.audioInputApiKey = result.data.AUDIO_INPUT_API_KEY || ''
diff --git a/src/locales/en-US.ts b/src/locales/en-US.ts
index a5bd8e08..5d335660 100644
--- a/src/locales/en-US.ts
+++ b/src/locales/en-US.ts
@@ -1456,6 +1456,8 @@ export default {
       llmApiKeyPlaceholder: 'Please enter API key',
       llmBaseUrl: 'LLM Base URL',
       llmBaseUrlHint: 'Base URL for LLM API, used for custom API endpoints',
+      llmUserAgent: 'User-Agent',
+      llmUserAgentHint: 'User-Agent sent to OpenAI-compatible APIs. Leave empty to use the SDK default.',
       llmProviderAuth: 'Provider Authorization',
       llmProviderAuthHint:
         'Providers that support account authorization can complete sign-in here and reuse the saved auth state.',
diff --git a/src/locales/zh-CN.ts b/src/locales/zh-CN.ts
index c2f5d8ba..a86d7e1a 100644
--- a/src/locales/zh-CN.ts
+++ b/src/locales/zh-CN.ts
@@ -1448,6 +1448,8 @@ export default {
       llmApiKeyPlaceholder: '请输入API密钥',
       llmBaseUrl: 'LLM基础URL',
       llmBaseUrlHint: 'LLM API的基础URL地址，用于自定义API端点',
+      llmUserAgent: 'User-Agent',
+      llmUserAgentHint: 'OpenAI 兼容接口请求使用的 User-Agent，留空则使用 SDK 默认值',
       llmProviderAuth: '提供商授权',
       llmProviderAuthHint: '支持账号登录授权的提供商，可以直接在这里完成登录并复用授权状态。',
       llmProviderConnectedAs: '当前已连接：{label}',
diff --git a/src/locales/zh-TW.ts b/src/locales/zh-TW.ts
index 9faaf767..d78925f0 100644
--- a/src/locales/zh-TW.ts
+++ b/src/locales/zh-TW.ts
@@ -1449,6 +1449,8 @@ export default {
       llmApiKeyPlaceholder: '請輸入API密鑰',
       llmBaseUrl: 'LLM基礎URL',
       llmBaseUrlHint: 'LLM API的基礎URL地址，用於自定義API端點',
+      llmUserAgent: 'User-Agent',
+      llmUserAgentHint: 'OpenAI 兼容接口請求使用的 User-Agent，留空則使用 SDK 預設值',
       llmProviderAuth: '提供商授權',
       llmProviderAuthHint: '支援帳號登入授權的提供商，可以直接在這裡完成登入並重用授權狀態。',
       llmProviderConnectedAs: '目前已連接：{label}',
diff --git a/src/views/setting/AccountSettingSystem.vue b/src/views/setting/AccountSettingSystem.vue
index 30bdeb6e..5c92064e 100644
--- a/src/views/setting/AccountSettingSystem.vue
+++ b/src/views/setting/AccountSettingSystem.vue
@@ -58,6 +58,7 @@ const SystemSettings = ref<any>({
     LLM_API_KEY: null,
     LLM_BASE_URL: 'https://api.deepseek.com',
     LLM_BASE_URL_PRESET: null,
+    LLM_USER_AGENT: null,
     AUDIO_INPUT_PROVIDER: 'openai',
     AUDIO_INPUT_API_KEY: null,
     AUDIO_INPUT_BASE_URL: null,
@@ -214,6 +215,7 @@ type LlmSettingsSnapshot = {
   LLM_API_KEY: string
   LLM_BASE_URL: string
   LLM_BASE_URL_PRESET: string
+  LLM_USER_AGENT: string
 }
 
 let llmTestRequestId = 0
@@ -247,6 +249,13 @@ const llmBaseUrlPresetRef = computed({
   },
 })
 
+const llmUserAgentRef = computed({
+  get: () => String(SystemSettings.value.Basic.LLM_USER_AGENT ?? ''),
+  set: value => {
+    SystemSettings.value.Basic.LLM_USER_AGENT = value || ''
+  },
+})
+
 const llmModelRef = computed({
   get: () => String(SystemSettings.value.Basic.LLM_MODEL ?? ''),
   set: value => {
@@ -292,6 +301,7 @@ const {
   apiKey: llmApiKeyRef,
   baseUrl: llmBaseUrlRef,
   baseUrlPreset: llmBaseUrlPresetRef,
+  userAgent: llmUserAgentRef,
   model: llmModelRef,
   maxContextTokens: llmMaxContextRef,
 })
@@ -353,6 +363,7 @@ function buildLlmSnapshot(): LlmSettingsSnapshot {
     LLM_API_KEY: String(SystemSettings.value.Basic.LLM_API_KEY ?? ''),
     LLM_BASE_URL: String(SystemSettings.value.Basic.LLM_BASE_URL ?? ''),
     LLM_BASE_URL_PRESET: String(SystemSettings.value.Basic.LLM_BASE_URL_PRESET ?? ''),
+    LLM_USER_AGENT: String(SystemSettings.value.Basic.LLM_USER_AGENT ?? ''),
   }
 }
 
@@ -369,6 +380,7 @@ function buildLlmTestPayload(snapshot: LlmSettingsSnapshot) {
     api_key: snapshot.LLM_API_KEY.trim(),
     base_url: snapshot.LLM_BASE_URL.trim(),
     base_url_preset: snapshot.LLM_BASE_URL_PRESET.trim(),
+    user_agent: snapshot.LLM_USER_AGENT.trim(),
   }
 }
 
@@ -1205,6 +1217,15 @@ watch(currentLlmSnapshotKey, (snapshotKey, previousSnapshotKey) => {
                         prepend-inner-icon="mdi-key-variant"
                       />
                     </VCol>
+                    <VCol v-if="SystemSettings.Basic.AI_AGENT_ENABLE && showBaseUrlField" cols="12" md="6">
+                      <VTextField
+                        v-model="SystemSettings.Basic.LLM_USER_AGENT"
+                        :label="t('setting.system.llmUserAgent')"
+                        :hint="t('setting.system.llmUserAgentHint')"
+                        persistent-hint
+                        prepend-inner-icon="mdi-card-account-details-outline"
+                      />
+                    </VCol>
                     <VCol v-if="SystemSettings.Basic.AI_AGENT_ENABLE && llmProviderAuthMethods.length > 0" cols="12">
                       <VAlert type="info" variant="tonal">
                         <div class="d-flex flex-column flex-md-row justify-space-between ga-3">
diff --git a/src/views/setup/AgentSettingsStep.vue b/src/views/setup/AgentSettingsStep.vue
index c5d7fe0a..8d705b52 100644
--- a/src/views/setup/AgentSettingsStep.vue
+++ b/src/views/setup/AgentSettingsStep.vue
@@ -40,6 +40,13 @@ const baseUrlPresetRef = computed({
   },
 })
 
+const userAgentRef = computed({
+  get: () => wizardData.value.agent.userAgent,
+  set: value => {
+    wizardData.value.agent.userAgent = value || ''
+  },
+})
+
 const modelRef = computed({
   get: () => wizardData.value.agent.model,
   set: value => {
@@ -92,6 +99,7 @@ const {
   apiKey: apiKeyRef,
   baseUrl: baseUrlRef,
   baseUrlPreset: baseUrlPresetRef,
+  userAgent: userAgentRef,
   model: modelRef,
   maxContextTokens: maxContextTokensRef,
   authConnected: authConnectedRef,
@@ -349,6 +357,16 @@ onMounted(async () => {
             />
           </VCol>
 
+          <VCol v-if="showBaseUrlField" cols="12" md="6">
+            <VTextField
+              v-model="wizardData.agent.userAgent"
+              :label="t('setting.system.llmUserAgent')"
+              :hint="t('setting.system.llmUserAgentHint')"
+              persistent-hint
+              prepend-inner-icon="mdi-card-account-details-outline"
+            />
+          </VCol>
+
           <VCol v-if="providerAuthMethods.length > 0" cols="12">
             <VAlert type="info" variant="tonal">
               <div class="d-flex flex-column ga-3">