fix(gemini): 第三方上游 API Key 与 Vertex 不再套用 AI Studio 等级和模拟配额

- 按 base_url 判定上游：非官方地址的 Gemini API Key 账号视为第三方上游
- 第三方上游与 Vertex 不返回本地模拟配额，隐藏等级与配额说明；
  账号列表中第三方上游按普通 Key 账号展示今日统计与额度进度条，
  Vertex 显示 vertex 徽章与今日统计
- 第三方上游的 429 只认显式重试时长，否则走全局 429 兜底冷却，
  不按每日配额冷却到 PST 午夜
- 创建账号：第三方 Base URL 不显示 AI Studio 等级选项，也不写入 tier_id；
  API 密钥卡片标题与说明不再限定 AI Studio，免费层说明只在官方 Base URL 下显示；
  OAuth 等级回退下拉只在 OAuth 表单显示

backend/internal/service/account.go

@@ -339,6 +339,13 @@ func (a *Account) IsGeminiGoogleOne() bool {
 	return a.Platform == PlatformGemini && a.Type == AccountTypeOAuth && a.GeminiOAuthType() == "google_one"
 }
 
+// IsGeminiThirdPartyAPIKey reports whether a Gemini API Key account points at a
+// non-Google base URL. Such upstreams carry no AI Studio tier or daily quota.
+func (a *Account) IsGeminiThirdPartyAPIKey() bool {
+	return a != nil && a.Platform == PlatformGemini && a.Type == AccountTypeAPIKey &&
+		!isOfficialGeminiAPIBaseURL(a.GetCredential("base_url"))
+}
+
 func (a *Account) CanGetUsage() bool {
 	return a.Type == AccountTypeOAuth
 }

backend/internal/service/gemini_error_policy_test.go

@@ -677,6 +677,72 @@ func TestHandleGeminiUpstreamError_APIKeyFallbackStillPSTMidnight(t *testing.T)
 	require.WithinDuration(t, expected, repo.lastRateLimitReset, 5*time.Second)
 }
 
+// 第三方上游 API Key 的 429 不套用 AI Studio 每日配额语义：只认显式重试时长，
+// 否则走全局 429 兜底冷却（未配置时默认 5 秒）。
+func TestHandleGeminiUpstreamError_ThirdPartyAPIKey429(t *testing.T) {
+	const relayBaseURL = "https://relay.example.com"
+	tests := []struct {
+		name       string
+		baseURL    string
+		body       string
+		expectWait time.Duration
+		pstNight   bool
+	}{
+		{
+			name:       "no_reset_time_uses_global_fallback",
+			baseURL:    relayBaseURL,
+			body:       `{"error":{"code":429,"message":"You have exhausted your capacity on this model. Your quota will reset after 6h53m10s."}}`,
+			expectWait: defaultRateLimit429CooldownSeconds * time.Second,
+		},
+		{
+			name:       "daily_quota_message_not_treated_as_pst_midnight",
+			baseURL:    relayBaseURL,
+			body:       `{"error":{"code":429,"message":"Quota exceeded for metric: generate_content_free_tier_requests, limit: 50 per day"}}`,
+			expectWait: defaultRateLimit429CooldownSeconds * time.Second,
+		},
+		{
+			name:       "explicit_quota_reset_delay_respected",
+			baseURL:    relayBaseURL,
+			body:       `{"error":{"code":429,"message":"rate limit","details":[{"metadata":{"quotaResetDelay":"42s"}}]}}`,
+			expectWait: 42 * time.Second,
+		},
+		{
+			name:     "official_base_url_keeps_pst_midnight",
+			baseURL:  "https://generativelanguage.googleapis.com/",
+			body:     `{"error":{"code":429,"message":"rate limit"}}`,
+			pstNight: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			repo := &rateLimit429AccountRepoStub{}
+			svc := &GeminiMessagesCompatService{
+				accountRepo:      repo,
+				rateLimitService: NewRateLimitService(repo, nil, &config.Config{}, nil, nil),
+			}
+			account := &Account{
+				ID:          700,
+				Platform:    PlatformGemini,
+				Type:        AccountTypeAPIKey,
+				Credentials: map[string]any{"base_url": tt.baseURL},
+			}
+
+			before := time.Now()
+			svc.handleGeminiUpstreamError(context.Background(), account, http.StatusTooManyRequests, http.Header{}, []byte(tt.body))
+
+			require.Equal(t, 1, repo.rateLimitCalls)
+			require.Equal(t, int64(700), repo.lastRateLimitID)
+			if tt.pstNight {
+				expected := time.Unix(*nextGeminiDailyResetUnix(), 0)
+				require.WithinDuration(t, expected, repo.lastRateLimitReset, 5*time.Second)
+				return
+			}
+			require.WithinDuration(t, before.Add(tt.expectWait), repo.lastRateLimitReset, 2*time.Second)
+		})
+	}
+}
+
 type geminiErrorPolicyRepo struct {
 	mockAccountRepoForGemini
 	setErrorCalls            int

backend/internal/service/gemini_messages_compat_service.go

@@ -3159,6 +3159,10 @@ func (s *GeminiMessagesCompatService) handleGeminiUpstreamError(ctx context.Cont
 	if account.IsPoolMode() && !account.IsCustomErrorCodesEnabled() {
 		return
 	}
+	if account.IsGeminiThirdPartyAPIKey() {
+		s.handleGeminiThirdParty429(ctx, account, body)
+		return
+	}
 
 	oauthType := account.GeminiOAuthType()
 	tierID := account.GeminiTierID()
@@ -3207,16 +3211,36 @@ func (s *GeminiMessagesCompatService) handleGeminiUpstreamError(ctx context.Cont
 		account.ID, resetTime, oauthType, tierID)
 }
 
+// handleGeminiThirdParty429 处理第三方上游的 429：不套用 AI Studio 每日配额语义，
+// 只认响应里显式给出的重试时间，否则走全局 429 兜底冷却。
+func (s *GeminiMessagesCompatService) handleGeminiThirdParty429(ctx context.Context, account *Account, body []byte) {
+	if resetAt := parseGeminiRetryDelayResetTime(body); resetAt != nil {
+		resetTime := time.Unix(*resetAt, 0)
+		_ = s.accountRepo.SetRateLimited(ctx, account.ID, resetTime)
+		logger.LegacyPrintf("service.gemini_messages_compat", "[Gemini 429] Account %d (third-party API Key) rate limited until %v", account.ID, resetTime)
+		return
+	}
+	if s.rateLimitService != nil {
+		s.rateLimitService.apply429FallbackRateLimit(ctx, account, "gemini_third_party_no_reset_time")
+		return
+	}
+	_ = s.accountRepo.SetRateLimited(ctx, account.ID, time.Now().Add(defaultRateLimit429CooldownSeconds*time.Second))
+}
+
 // ParseGeminiRateLimitResetTime 解析 Gemini 格式的 429 响应，返回重置时间的 Unix 时间戳
 func ParseGeminiRateLimitResetTime(body []byte) *int64 {
-	// 第一阶段：gjson 结构化提取
 	errMsg := gjson.GetBytes(body, "error.message").String()
 	if looksLikeGeminiDailyQuota(errMsg) {
 		if ts := nextGeminiDailyResetUnix(); ts != nil {
 			return ts
 		}
 	}
+	return parseGeminiRetryDelayResetTime(body)
+}
 
+// parseGeminiRetryDelayResetTime 只解析响应里显式给出的重试时长，返回重置时间的 Unix 时间戳。
+func parseGeminiRetryDelayResetTime(body []byte) *int64 {
+	// 第一阶段：gjson 结构化提取
 	// 遍历 error.details 查找 quotaResetDelay（AI Studio）或 RetryInfo.retryDelay（Vertex）
 	var found *int64
 	gjson.GetBytes(body, "error.details").ForEach(func(_, detail gjson.Result) bool {

backend/internal/service/gemini_quota.go

@@ -373,6 +373,10 @@ func geminiQuotaTierKeyForAccount(account *Account) string {
 	if account == nil || account.Platform != PlatformGemini {
 		return ""
 	}
+	// 本地模拟配额只适用于按 Google 账号等级限额的通道；第三方上游与 Vertex 按量付费不套用。
+	if account.IsGeminiThirdPartyAPIKey() || account.IsVertexServiceAccount() {
+		return ""
+	}
 
 	// Note: GeminiOAuthType() already defaults legacy (project_id present) to code_assist.
 	oauthType := strings.ToLower(strings.TrimSpace(account.GeminiOAuthType()))

backend/internal/service/gemini_quota_test.go

@@ -0,0 +1,80 @@
+//go:build unit
+
+package service
+
+import (
+	"context"
+	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/config"
+	"github.com/stretchr/testify/require"
+)
+
+func TestAccountIsGeminiThirdPartyAPIKey(t *testing.T) {
+	tests := []struct {
+		name     string
+		account  *Account
+		expected bool
+	}{
+		{"nil_account", nil, false},
+		{"empty_base_url_is_official", geminiQuotaAPIKeyAccount(""), false},
+		{"official_base_url", geminiQuotaAPIKeyAccount("https://generativelanguage.googleapis.com"), false},
+		{"official_base_url_trailing_slash", geminiQuotaAPIKeyAccount("https://generativelanguage.googleapis.com/"), false},
+		{"official_host_over_http", geminiQuotaAPIKeyAccount("http://generativelanguage.googleapis.com"), true},
+		{"official_host_with_path_prefix", geminiQuotaAPIKeyAccount("https://generativelanguage.googleapis.com/proxy"), true},
+		{"relay_base_url", geminiQuotaAPIKeyAccount("https://relay.example.com"), true},
+		{"oauth_account", &Account{Platform: PlatformGemini, Type: AccountTypeOAuth, Credentials: map[string]any{"base_url": "https://relay.example.com"}}, false},
+		{"vertex_service_account", &Account{Platform: PlatformGemini, Type: AccountTypeServiceAccount}, false},
+		{"non_gemini_platform", &Account{Platform: PlatformOpenAI, Type: AccountTypeAPIKey, Credentials: map[string]any{"base_url": "https://relay.example.com"}}, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			require.Equal(t, tt.expected, tt.account.IsGeminiThirdPartyAPIKey())
+		})
+	}
+}
+
+func TestGeminiQuotaService_QuotaForAccountSkipsThirdPartyAndVertex(t *testing.T) {
+	svc := NewGeminiQuotaService(&config.Config{}, nil)
+	ctx := context.Background()
+
+	quota, ok := svc.QuotaForAccount(ctx, geminiQuotaAPIKeyAccount(""))
+	require.True(t, ok)
+	require.Equal(t, int64(50), quota.ProRPD)
+
+	paid := geminiQuotaAPIKeyAccount("https://generativelanguage.googleapis.com")
+	paid.Credentials["tier_id"] = GeminiTierAIStudioPaid
+	quota, ok = svc.QuotaForAccount(ctx, paid)
+	require.True(t, ok)
+	require.Equal(t, int64(-1), quota.ProRPD)
+
+	relay := geminiQuotaAPIKeyAccount("https://relay.example.com")
+	relay.Credentials["tier_id"] = GeminiTierAIStudioFree
+	_, ok = svc.QuotaForAccount(ctx, relay)
+	require.False(t, ok, "第三方上游不套用 AI Studio 模拟配额")
+
+	vertex := &Account{
+		Platform:    PlatformGemini,
+		Type:        AccountTypeServiceAccount,
+		Credentials: map[string]any{"project_id": "my-project", "tier_id": "vertex"},
+	}
+	_, ok = svc.QuotaForAccount(ctx, vertex)
+	require.False(t, ok, "Vertex 按量付费不套用模拟配额")
+
+	googleOne := &Account{
+		Platform:    PlatformGemini,
+		Type:        AccountTypeOAuth,
+		Credentials: map[string]any{"oauth_type": "google_one", "tier_id": GeminiTierGoogleOneFree},
+	}
+	quota, ok = svc.QuotaForAccount(ctx, googleOne)
+	require.True(t, ok)
+	require.Positive(t, quota.SharedRPD)
+}
+
+func geminiQuotaAPIKeyAccount(baseURL string) *Account {
+	credentials := map[string]any{}
+	if baseURL != "" {
+		credentials["base_url"] = baseURL
+	}
+	return &Account{Platform: PlatformGemini, Type: AccountTypeAPIKey, Credentials: credentials}
+}

frontend/src/components/account/AccountUsageCell.vue

@@ -489,6 +489,7 @@
         </span>
         <!-- Help icon -->
         <span
+          v-if="showGeminiQuotaPolicy"
           class="group relative cursor-help"
         >
           <svg
@@ -579,7 +580,7 @@
           </p>
         </div>
         <!-- AI Studio Client OAuth: show unlimited flow (no usage tracking) -->
-        <div v-else class="text-xs text-gray-400">
+        <div v-else-if="!showGeminiTodayStats" class="text-xs text-gray-400">
           {{ t('admin.accounts.gemini.rateLimit.unlimited') }}
         </div>
       </div>
@@ -594,7 +595,7 @@
   <!-- Non-OAuth/Setup-Token accounts -->
   <div ref="rootRef" v-else>
     <!-- Gemini API Key accounts: show quota info -->
-    <AccountQuotaInfo v-if="account.platform === 'gemini'" :account="account" />
+    <AccountQuotaInfo v-if="account.platform === 'gemini' && !isGeminiThirdPartyApiKey" :account="account" />
     <!-- Key/Bedrock accounts: show today stats + optional quota bars -->
     <div v-else class="space-y-1">
       <OllamaCloudUsageCell
@@ -682,6 +683,7 @@ import type { Account, AccountUsageInfo, GeminiCredentials, WindowStats } from '
 import { buildOpenAIUsageRefreshKey } from '@/utils/accountUsageRefresh'
 import { enqueueUsageRequest } from '@/utils/usageLoadQueue'
 import { formatCompactNumber } from '@/utils/format'
+import { isOfficialGeminiBaseUrl } from '@/utils/geminiExplicitCache'
 import UsageProgressBar from './UsageProgressBar.vue'
 import AccountQuotaInfo from './AccountQuotaInfo.vue'
 import ClaudeResetCreditsCell from './ClaudeResetCreditsCell.vue'
@@ -753,10 +755,22 @@ let desktopViewportMediaQuery: MediaQueryList | null = null
 let desktopViewportListener: ((event: MediaQueryListEvent) => void) | null = null
 let visibilityObserver: IntersectionObserver | null = null
 
+// Gemini 第三方上游 API Key：没有 AI Studio 等级与本地模拟配额
+const isGeminiThirdPartyApiKey = computed(() => {
+  if (props.account.platform !== 'gemini' || props.account.type !== 'apikey') return false
+  const creds = props.account.credentials as GeminiCredentials | undefined
+  return !isOfficialGeminiBaseUrl(creds?.base_url)
+})
+
+const isGeminiVertex = computed(() => {
+  return props.account.platform === 'gemini' && props.account.type === 'service_account'
+})
+
 // Show usage windows for OAuth and Setup Token accounts
 const showUsageWindows = computed(() => {
   // Gemini: we can always compute local usage windows from DB logs (simulated quotas).
-  if (props.account.platform === 'gemini') return true
+  // 第三方上游 API Key 没有模拟配额，按普通 Key 账号展示今日统计与额度进度条。
+  if (props.account.platform === 'gemini') return !isGeminiThirdPartyApiKey.value
   // 多协议 API Key 供应商：apikey 账号也有滚动用量窗口（coding plan / 订阅）或余额，
   // 由 CNProviderQuotaCell / CNProviderBalanceCell 自行探测与展示。
   if (isMultiProtocolApiKeyPlatform(props.account.platform)) {
@@ -770,7 +784,7 @@ const shouldFetchUsage = computed(() => {
     return props.account.type === 'oauth' || props.account.type === 'setup-token'
   }
   if (props.account.platform === 'gemini') {
-    return true
+    return !isGeminiThirdPartyApiKey.value && !isGeminiVertex.value
   }
   if (props.account.platform === 'antigravity') {
     return props.account.type === 'oauth'
@@ -791,8 +805,9 @@ const cnBalanceCellVisible = computed(() => cnBalanceCellVisibleFn(props.account
 
 const isBatchManaged = computed(() => typeof props.requestBatchedUsage === 'function')
 
+// Vertex 没有本地模拟配额，用量窗口展示今日统计
 const showGeminiTodayStats = computed(() => {
-  return props.account.platform === 'gemini' && props.account.type === 'service_account'
+  return isGeminiVertex.value
 })
 
 const geminiUsageAvailable = computed(() => {
@@ -956,6 +971,10 @@ const geminiOAuthType = computed(() => {
   return (creds?.oauth_type || '').trim() || null
 })
 
+const showGeminiQuotaPolicy = computed(() => {
+  return !isGeminiVertex.value
+})
+
 // Gemini 是否为 Code Assist OAuth
 const isGeminiCodeAssist = computed(() => {
   if (props.account.platform !== 'gemini') return false
@@ -963,9 +982,10 @@ const isGeminiCodeAssist = computed(() => {
   return creds?.oauth_type === 'code_assist' || (!creds?.oauth_type && !!creds?.project_id)
 })
 
-const geminiChannelShort = computed((): 'ai studio' | 'gcp' | 'google one' | 'client' | null => {
+const geminiChannelShort = computed((): 'ai studio' | 'vertex' | 'gcp' | 'google one' | 'client' | null => {
   if (props.account.platform !== 'gemini') return null
 
+  if (isGeminiVertex.value) return 'vertex'
   // API Key accounts are AI Studio.
   if (props.account.type === 'apikey') return 'ai studio'
 
@@ -979,6 +999,7 @@ const geminiChannelShort = computed((): 'ai studio' | 'gcp' | 'google one' | 'cl
 
 const geminiUserLevel = computed((): string | null => {
   if (props.account.platform !== 'gemini') return null
+  if (isGeminiVertex.value) return null
 
   const tier = (geminiTier.value || '').toString().trim()
   const tierLower = tier.toLowerCase()
@@ -1036,7 +1057,7 @@ const geminiTierClass = computed(() => {
   const channel = geminiChannelShort.value
   const level = geminiUserLevel.value
 
-  if (channel === 'client' || channel === 'ai studio') {
+  if (channel === 'client' || channel === 'ai studio' || channel === 'vertex') {
     return 'bg-blue-100 text-blue-600 dark:bg-blue-900/40 dark:text-blue-300'
   }
 

frontend/src/components/account/CreateAccountModal.vue

@@ -840,7 +840,8 @@
         </div>
 
         <div
-          v-if="accountCategory === 'apikey'"
+          v-if="accountCategory === 'apikey' && isOfficialGeminiBaseUrl(apiKeyBaseUrl)"
+          data-testid="gemini-apikey-note"
           class="mt-3 rounded-lg border border-purple-200 bg-purple-50 px-3 py-2 text-xs text-purple-800 dark:border-purple-800/40 dark:bg-purple-900/20 dark:text-purple-200"
         >
           <p>{{ t('admin.accounts.gemini.accountType.apiKeyNote') }}</p>
@@ -1068,7 +1069,7 @@
         </div>
 
         <!-- Tier selection (used as fallback when auto-detection is unavailable/fails) -->
-        <div v-if="accountCategory !== 'service_account'" class="mt-4">
+        <div v-if="accountCategory === 'oauth-based'" class="mt-4" data-testid="gemini-oauth-tier">
           <label class="input-label">{{ t('admin.accounts.gemini.tier.label') }}</label>
           <div class="mt-2">
             <select
@@ -1579,9 +1580,9 @@
         </div>
 
         <!-- Gemini API Key tier selection -->
-        <div v-if="form.platform === 'gemini'">
+        <div v-if="form.platform === 'gemini' && isOfficialGeminiBaseUrl(apiKeyBaseUrl)">
           <label class="input-label">{{ t('admin.accounts.gemini.tier.label') }}</label>
-          <select v-model="geminiTierAIStudio" class="input">
+          <select v-model="geminiTierAIStudio" class="input" data-testid="gemini-apikey-tier">
             <option value="aistudio_free">{{ t('admin.accounts.gemini.tier.aiStudio.free') }}</option>
             <option value="aistudio_paid">{{ t('admin.accounts.gemini.tier.aiStudio.paid') }}</option>
           </select>
@@ -6061,7 +6062,7 @@ const handleSubmit = async () => {
     base_url: apiKeyBaseUrl.value.trim() || defaultBaseUrl,
     api_key: apiKeyValue.value.trim()
   }
-  if (form.platform === 'gemini') {
+  if (form.platform === 'gemini' && isOfficialGeminiBaseUrl(apiKeyBaseUrl.value)) {
     credentials.tier_id = geminiTierAIStudio.value
   }
 

frontend/src/components/account/__tests__/AccountUsageCell.spec.ts

@@ -1709,6 +1709,101 @@ describe('AccountUsageCell', () => {
 		expect(wrapper.text()).toContain('0')
 		expect(wrapper.text()).toContain('A $0.00')
 		expect(wrapper.text()).toContain('U $0.00')
+		expect(wrapper.text()).toContain('vertex')
+		expect(wrapper.text()).not.toContain('admin.accounts.gemini.quotaPolicy.title')
+		expect(wrapper.text()).not.toContain('admin.accounts.gemini.rateLimit.unlimited')
+		expect(getUsage).not.toHaveBeenCalled()
+  })
+
+  it('Gemini 第三方上游 API Key 按普通 Key 账号展示今日统计与额度，不显示 Gemini 徽章', async () => {
+    const wrapper = mount(AccountUsageCell, {
+      props: {
+        account: makeAccount({
+          id: 4002,
+          platform: 'gemini',
+          type: 'apikey',
+          credentials: {
+            base_url: 'https://relay.example.com/gemini',
+            api_key: 'sk-relay',
+            tier_id: 'aistudio_free'
+          },
+          extra: {},
+          quota_daily_limit: 10,
+          quota_daily_used: 2.5
+        }),
+        todayStats: {
+          requests: 123,
+          tokens: 2300000,
+          cost: 1.79,
+          standard_cost: 1.79,
+          user_cost: 0
+        }
+      },
+      global: {
+        stubs: {
+          UsageProgressBar: true,
+          AccountQuotaInfo: true
+        }
+      }
+    })
+
+    await flushPromises()
+
+    const text = wrapper.text()
+    expect(text).not.toContain('api key')
+    expect(text).not.toContain('ai studio')
+    expect(text).not.toContain('free')
+    expect(text).not.toContain('relay.example.com')
+    expect(wrapper.find('account-quota-info-stub').exists()).toBe(false)
+    expect(text).toContain('123 req')
+    expect(text).toContain('A $1.79')
+    expect(text).toContain('U $0.00')
+    const bars = wrapper.findAll('usage-progress-bar-stub')
+    expect(bars.map((bar) => bar.attributes('label'))).toEqual(['1d'])
+    expect(text).not.toContain('admin.accounts.gemini.quotaPolicy.title')
+    expect(text).not.toContain('admin.accounts.gemini.quotaPolicy.simulatedNote')
+    expect(text).not.toContain('admin.accounts.gemini.rateLimit.unlimited')
+    expect(getUsage).not.toHaveBeenCalled()
+  })
+
+  it('Gemini 官方 API Key 保留 AI Studio 等级与模拟配额', async () => {
+    getUsage.mockResolvedValue({
+      gemini_pro_daily: {
+        utilization: 20,
+        resets_at: '2026-10-11T07:00:00Z',
+        remaining_seconds: 3600
+      }
+    })
+
+    const wrapper = mount(AccountUsageCell, {
+      props: {
+        account: makeAccount({
+          id: 4003,
+          platform: 'gemini',
+          type: 'apikey',
+          credentials: {
+            base_url: 'https://generativelanguage.googleapis.com',
+            api_key: 'AIza-official',
+            tier_id: 'aistudio_paid'
+          },
+          extra: {}
+        })
+      },
+      global: {
+        stubs: {
+          UsageProgressBar: true,
+          AccountQuotaInfo: true
+        }
+      }
+    })
+
+    await flushPromises()
+
+    const text = wrapper.text()
+    expect(text).toContain('ai studio paid')
+    expect(text).toContain('admin.accounts.gemini.quotaPolicy.title')
+    expect(text).toContain('admin.accounts.gemini.quotaPolicy.simulatedNote')
+    expect(getUsage).toHaveBeenCalledWith(4003)
   })
 
   it('Anthropic OAuth 会渲染 7d F (Fable) 进度条，且 7d S 逻辑保留', async () => {

frontend/src/components/account/__tests__/CreateAccountModal.spec.ts

@@ -931,6 +931,58 @@ describe('CreateAccountModal gemini explicit cache upstream switch', () => {
       explicit_cache_upstream_max_ttl_seconds: 1800
     })
   })
+
+  it('only offers the AI Studio tier for the official base url', async () => {
+    const wrapper = mountModal()
+    await selectButtonByText(wrapper, 'Gemini')
+    await selectButtonByText(wrapper, 'admin.accounts.gemini.accountType.apiKeyTitle')
+    expect(wrapper.find('[data-testid="gemini-oauth-tier"]').exists()).toBe(false)
+    expect(wrapper.find('[data-testid="gemini-apikey-note"]').exists()).toBe(true)
+    await wrapper.get('[data-testid="gemini-apikey-tier"]').setValue('aistudio_paid')
+
+    const baseUrlInput = wrapper
+      .findAll('form#create-account-form input[type="text"]')
+      .find((input) => (input.element as HTMLInputElement).value === 'https://generativelanguage.googleapis.com')
+    expect(baseUrlInput).toBeDefined()
+    await baseUrlInput!.setValue('https://upstream.example.com')
+    expect(wrapper.find('[data-testid="gemini-apikey-tier"]').exists()).toBe(false)
+    expect(wrapper.find('[data-testid="gemini-apikey-note"]').exists()).toBe(false)
+
+    await wrapper.get('form#create-account-form input[type="text"]').setValue('gemini relay')
+    await wrapper.get('form#create-account-form input[type="password"]').setValue('sk-upstream')
+    await wrapper.get('form#create-account-form').trigger('submit.prevent')
+    await flushPromises()
+
+    expect(createAccountMock).toHaveBeenCalledTimes(1)
+    const credentials = createAccountMock.mock.calls[0]?.[0]?.credentials
+    expect(credentials).toMatchObject({ base_url: 'https://upstream.example.com' })
+    expect(credentials).not.toHaveProperty('tier_id')
+  })
+
+  it('shows the OAuth tier fallback only on the OAuth form', async () => {
+    const wrapper = mountModal()
+    await selectButtonByText(wrapper, 'Gemini')
+    await selectButtonByText(wrapper, 'admin.accounts.gemini.accountType.oauthTitle')
+    expect(wrapper.find('[data-testid="gemini-oauth-tier"]').exists()).toBe(true)
+    expect(wrapper.find('[data-testid="gemini-apikey-note"]').exists()).toBe(false)
+  })
+
+  it('keeps the selected AI Studio tier for the official base url', async () => {
+    const wrapper = mountModal()
+    await selectButtonByText(wrapper, 'Gemini')
+    await selectButtonByText(wrapper, 'admin.accounts.gemini.accountType.apiKeyTitle')
+    await wrapper.get('[data-testid="gemini-apikey-tier"]').setValue('aistudio_paid')
+    await wrapper.get('form#create-account-form input[type="text"]').setValue('gemini official')
+    await wrapper.get('form#create-account-form input[type="password"]').setValue('AIza-official')
+    await wrapper.get('form#create-account-form').trigger('submit.prevent')
+    await flushPromises()
+
+    expect(createAccountMock).toHaveBeenCalledTimes(1)
+    expect(createAccountMock.mock.calls[0]?.[0]?.credentials).toMatchObject({
+      base_url: 'https://generativelanguage.googleapis.com',
+      tier_id: 'aistudio_paid'
+    })
+  })
 })
 
 describe('CreateAccountModal Vertex API key auth', () => {

frontend/src/i18n/locales/en/admin/accounts.ts

@@ -1445,8 +1445,8 @@ export default {
         accountType: {
           oauthTitle: 'OAuth (Gemini)',
           oauthDesc: 'Authorize with your Google account and choose an OAuth type.',
-          apiKeyTitle: 'API Key (AI Studio)',
+          apiKeyTitle: 'API Key',
-          apiKeyDesc: 'Fastest setup. Use an AIza API key.',
+          apiKeyDesc: 'An official AI Studio key, or a Gemini-compatible third-party upstream.',
           apiKeyNote:
             'Best for light testing. Free tier has strict rate limits and data may be used for training.',
           apiKeyLink: 'Get API Key',

frontend/src/i18n/locales/zh/admin/accounts.ts

@@ -1536,8 +1536,8 @@ export default {
         accountType: {
           oauthTitle: 'OAuth 授权（Gemini）',
           oauthDesc: '使用 Google 账号授权，并选择 OAuth 子类型。',
-          apiKeyTitle: 'API 密钥（AI Studio）',
+          apiKeyTitle: 'API 密钥',
-          apiKeyDesc: '最快接入方式，使用 AIza API Key。',
+          apiKeyDesc: 'AI Studio 官方 Key，或兼容 Gemini 协议的第三方上游。',
           apiKeyNote: '适合轻量测试。免费层限流严格，数据可能用于训练。',
           apiKeyLink: '获取 API Key',
           quotaLink: '配额说明'

frontend/src/types/index.ts

@@ -1010,6 +1010,7 @@ export interface ProxyQualityCheckResult {
 export interface GeminiCredentials {
   // API Key authentication
   api_key?: string
+  base_url?: string
 
   // OAuth authentication
   access_token?: string