diff --git a/backend/cmd/server/wire_gen.go b/backend/cmd/server/wire_gen.go
index f767bbea..dea46561 100644
--- a/backend/cmd/server/wire_gen.go
+++ b/backend/cmd/server/wire_gen.go
@@ -145,13 +145,14 @@ func initializeApplication(buildInfo handler.BuildInfo) (*Application, error) {
 	accountUsageService := service.NewAccountUsageService(accountRepository, usageLogRepository, claudeUsageFetcher, geminiQuotaService, antigravityQuotaFetcher, usageCache, identityCache, tlsFingerprintProfileService)
 	oAuthRefreshAPI := service.ProvideOAuthRefreshAPI(accountRepository, geminiTokenCache)
 	geminiTokenProvider := service.ProvideGeminiTokenProvider(accountRepository, geminiTokenCache, geminiOAuthService, oAuthRefreshAPI)
+	claudeTokenProvider := service.ProvideClaudeTokenProvider(accountRepository, geminiTokenCache, oAuthService, oAuthRefreshAPI)
 	gatewayCache := repository.NewGatewayCache(redisClient)
 	schedulerOutboxRepository := repository.NewSchedulerOutboxRepository(db)
 	schedulerSnapshotService := service.ProvideSchedulerSnapshotService(schedulerCache, schedulerOutboxRepository, accountRepository, groupRepository, configConfig)
 	antigravityTokenProvider := service.ProvideAntigravityTokenProvider(accountRepository, geminiTokenCache, antigravityOAuthService, oAuthRefreshAPI, tempUnschedCache)
 	internal500CounterCache := repository.NewInternal500CounterCache(redisClient)
 	antigravityGatewayService := service.NewAntigravityGatewayService(accountRepository, gatewayCache, schedulerSnapshotService, antigravityTokenProvider, rateLimitService, httpUpstream, settingService, internal500CounterCache)
-	accountTestService := service.NewAccountTestService(accountRepository, geminiTokenProvider, antigravityGatewayService, httpUpstream, configConfig, tlsFingerprintProfileService)
+	accountTestService := service.NewAccountTestService(accountRepository, geminiTokenProvider, claudeTokenProvider, antigravityGatewayService, httpUpstream, configConfig, tlsFingerprintProfileService)
 	crsSyncService := service.NewCRSSyncService(accountRepository, proxyRepository, oAuthService, openAIOAuthService, geminiOAuthService, configConfig)
 	accountHandler := admin.NewAccountHandler(adminService, oAuthService, openAIOAuthService, geminiOAuthService, antigravityOAuthService, rateLimitService, accountUsageService, accountTestService, concurrencyService, crsSyncService, sessionLimitCache, rpmCache, compositeTokenCacheInvalidator)
 	adminAnnouncementHandler := admin.NewAnnouncementHandler(announcementService)
@@ -178,7 +179,6 @@ func initializeApplication(buildInfo handler.BuildInfo) (*Application, error) {
 	billingService := service.NewBillingService(configConfig, pricingService)
 	identityService := service.NewIdentityService(identityCache)
 	deferredService := service.ProvideDeferredService(accountRepository, timingWheelService)
-	claudeTokenProvider := service.ProvideClaudeTokenProvider(accountRepository, geminiTokenCache, oAuthService, oAuthRefreshAPI)
 	digestSessionStore := service.NewDigestSessionStore()
 	channelRepository := repository.NewChannelRepository(db)
 	channelService := service.NewChannelService(channelRepository, groupRepository, apiKeyAuthCacheInvalidator, pricingService)
diff --git a/backend/internal/domain/constants.go b/backend/internal/domain/constants.go
index a57f7067..27c543dd 100644
--- a/backend/internal/domain/constants.go
+++ b/backend/internal/domain/constants.go
@@ -26,11 +26,12 @@ const (
 
 // Account type constants
 const (
-	AccountTypeOAuth      = "oauth"       // OAuth类型账号（full scope: profile + inference）
-	AccountTypeSetupToken = "setup-token" // Setup Token类型账号（inference only scope）
-	AccountTypeAPIKey     = "apikey"      // API Key类型账号
-	AccountTypeUpstream   = "upstream"    // 上游透传类型账号（通过 Base URL + API Key 连接上游）
-	AccountTypeBedrock    = "bedrock"     // AWS Bedrock 类型账号（通过 SigV4 签名或 API Key 连接 Bedrock，由 credentials.auth_mode 区分）
+	AccountTypeOAuth          = "oauth"           // OAuth类型账号（full scope: profile + inference）
+	AccountTypeSetupToken     = "setup-token"     // Setup Token类型账号（inference only scope）
+	AccountTypeAPIKey         = "apikey"          // API Key类型账号
+	AccountTypeUpstream       = "upstream"        // 上游透传类型账号（通过 Base URL + API Key 连接上游）
+	AccountTypeBedrock        = "bedrock"         // AWS Bedrock 类型账号（通过 SigV4 签名或 API Key 连接 Bedrock，由 credentials.auth_mode 区分）
+	AccountTypeServiceAccount = "service_account" // Google Service Account 类型账号（用于 Vertex AI）
 )
 
 // Redeem type constants
diff --git a/backend/internal/handler/admin/account_handler.go b/backend/internal/handler/admin/account_handler.go
index 7454451a..e69e056f 100644
--- a/backend/internal/handler/admin/account_handler.go
+++ b/backend/internal/handler/admin/account_handler.go
@@ -98,7 +98,7 @@ type CreateAccountRequest struct {
 	Name                    string         `json:"name" binding:"required"`
 	Notes                   *string        `json:"notes"`
 	Platform                string         `json:"platform" binding:"required"`
-	Type                    string         `json:"type" binding:"required,oneof=oauth setup-token apikey upstream bedrock"`
+	Type                    string         `json:"type" binding:"required,oneof=oauth setup-token apikey upstream bedrock service_account"`
 	Credentials             map[string]any `json:"credentials" binding:"required"`
 	Extra                   map[string]any `json:"extra"`
 	ProxyID                 *int64         `json:"proxy_id"`
@@ -117,7 +117,7 @@ type CreateAccountRequest struct {
 type UpdateAccountRequest struct {
 	Name                    string         `json:"name"`
 	Notes                   *string        `json:"notes"`
-	Type                    string         `json:"type" binding:"omitempty,oneof=oauth setup-token apikey upstream bedrock"`
+	Type                    string         `json:"type" binding:"omitempty,oneof=oauth setup-token apikey upstream bedrock service_account"`
 	Credentials             map[string]any `json:"credentials"`
 	Extra                   map[string]any `json:"extra"`
 	ProxyID                 *int64         `json:"proxy_id"`
diff --git a/backend/internal/service/account_test_service.go b/backend/internal/service/account_test_service.go
index c0bbc6dc..aa657e0e 100644
--- a/backend/internal/service/account_test_service.go
+++ b/backend/internal/service/account_test_service.go
@@ -64,6 +64,7 @@ func isOpenAIImageModel(model string) bool {
 type AccountTestService struct {
 	accountRepo               AccountRepository
 	geminiTokenProvider       *GeminiTokenProvider
+	claudeTokenProvider       *ClaudeTokenProvider
 	antigravityGatewayService *AntigravityGatewayService
 	httpUpstream              HTTPUpstream
 	cfg                       *config.Config
@@ -74,6 +75,7 @@ type AccountTestService struct {
 func NewAccountTestService(
 	accountRepo AccountRepository,
 	geminiTokenProvider *GeminiTokenProvider,
+	claudeTokenProvider *ClaudeTokenProvider,
 	antigravityGatewayService *AntigravityGatewayService,
 	httpUpstream HTTPUpstream,
 	cfg *config.Config,
@@ -82,6 +84,7 @@ func NewAccountTestService(
 	return &AccountTestService{
 		accountRepo:               accountRepo,
 		geminiTokenProvider:       geminiTokenProvider,
+		claudeTokenProvider:       claudeTokenProvider,
 		antigravityGatewayService: antigravityGatewayService,
 		httpUpstream:              httpUpstream,
 		cfg:                       cfg,
@@ -210,6 +213,9 @@ func (s *AccountTestService) testClaudeAccountConnection(c *gin.Context, account
 	if account.IsBedrock() {
 		return s.testBedrockAccountConnection(c, ctx, account, testModelID)
 	}
+	if account.Type == AccountTypeServiceAccount {
+		return s.testClaudeVertexServiceAccountConnection(c, ctx, account, testModelID)
+	}
 
 	// Determine authentication method and API URL
 	var authToken string
@@ -313,6 +319,74 @@ func (s *AccountTestService) testClaudeAccountConnection(c *gin.Context, account
 	return s.processClaudeStream(c, resp.Body)
 }
 
+func (s *AccountTestService) testClaudeVertexServiceAccountConnection(c *gin.Context, ctx context.Context, account *Account, testModelID string) error {
+	if mappedModel, matched := account.ResolveMappedModel(testModelID); matched {
+		testModelID = mappedModel
+	} else {
+		testModelID = normalizeVertexAnthropicModelID(claude.NormalizeModelID(testModelID))
+	}
+
+	c.Writer.Header().Set("Content-Type", "text/event-stream")
+	c.Writer.Header().Set("Cache-Control", "no-cache")
+	c.Writer.Header().Set("Connection", "keep-alive")
+	c.Writer.Header().Set("X-Accel-Buffering", "no")
+	c.Writer.Flush()
+
+	payload, err := createTestPayload(testModelID)
+	if err != nil {
+		return s.sendErrorAndEnd(c, "Failed to create test payload")
+	}
+	payloadBytes, _ := json.Marshal(payload)
+	vertexBody, err := buildVertexAnthropicRequestBody(payloadBytes)
+	if err != nil {
+		return s.sendErrorAndEnd(c, fmt.Sprintf("Failed to create Vertex request body: %s", err.Error()))
+	}
+
+	if s.claudeTokenProvider == nil {
+		return s.sendErrorAndEnd(c, "Claude token provider not configured")
+	}
+	accessToken, err := s.claudeTokenProvider.GetAccessToken(ctx, account)
+	if err != nil {
+		return s.sendErrorAndEnd(c, fmt.Sprintf("Failed to get service account access token: %s", err.Error()))
+	}
+
+	fullURL, err := buildVertexAnthropicURL(account.VertexProjectID(), account.VertexLocation(testModelID), testModelID, true)
+	if err != nil {
+		return s.sendErrorAndEnd(c, fmt.Sprintf("Failed to build Vertex URL: %s", err.Error()))
+	}
+
+	s.sendEvent(c, TestEvent{Type: "test_start", Model: testModelID})
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, fullURL, bytes.NewReader(vertexBody))
+	if err != nil {
+		return s.sendErrorAndEnd(c, "Failed to create request")
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+accessToken)
+
+	proxyURL := ""
+	if account.ProxyID != nil && account.Proxy != nil {
+		proxyURL = account.Proxy.URL()
+	}
+
+	resp, err := s.httpUpstream.DoWithTLS(req, proxyURL, account.ID, account.Concurrency, s.tlsFPProfileService.ResolveTLSProfile(account))
+	if err != nil {
+		return s.sendErrorAndEnd(c, fmt.Sprintf("Request failed: %s", err.Error()))
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		errMsg := fmt.Sprintf("API returned %d: %s", resp.StatusCode, string(body))
+		if resp.StatusCode == http.StatusForbidden {
+			_ = s.accountRepo.SetError(ctx, account.ID, errMsg)
+		}
+		return s.sendErrorAndEnd(c, errMsg)
+	}
+
+	return s.processClaudeStream(c, resp.Body)
+}
+
 // testBedrockAccountConnection tests a Bedrock (SigV4 or API Key) account using non-streaming invoke
 func (s *AccountTestService) testBedrockAccountConnection(c *gin.Context, ctx context.Context, account *Account, testModelID string) error {
 	region := bedrockRuntimeRegion(account)
@@ -711,8 +785,8 @@ func (s *AccountTestService) testGeminiAccountConnection(c *gin.Context, account
 		testModelID = geminicli.DefaultTestModel
 	}
 
-	// For API Key accounts with model mapping, map the model
-	if account.Type == AccountTypeAPIKey {
+	// For static upstream credentials with model mapping, map the model
+	if account.Type == AccountTypeAPIKey || account.Type == AccountTypeServiceAccount {
 		mapping := account.GetModelMapping()
 		if len(mapping) > 0 {
 			if mappedModel, exists := mapping[testModelID]; exists {
@@ -740,6 +814,8 @@ func (s *AccountTestService) testGeminiAccountConnection(c *gin.Context, account
 		req, err = s.buildGeminiAPIKeyRequest(ctx, account, testModelID, payload)
 	case AccountTypeOAuth:
 		req, err = s.buildGeminiOAuthRequest(ctx, account, testModelID, payload)
+	case AccountTypeServiceAccount:
+		req, err = s.buildGeminiServiceAccountRequest(ctx, account, testModelID, payload)
 	default:
 		return s.sendErrorAndEnd(c, fmt.Sprintf("Unsupported account type: %s", account.Type))
 	}
@@ -893,6 +969,27 @@ func (s *AccountTestService) buildGeminiOAuthRequest(ctx context.Context, accoun
 	return s.buildCodeAssistRequest(ctx, accessToken, projectID, modelID, payload)
 }
 
+func (s *AccountTestService) buildGeminiServiceAccountRequest(ctx context.Context, account *Account, modelID string, payload []byte) (*http.Request, error) {
+	if s.geminiTokenProvider == nil {
+		return nil, fmt.Errorf("gemini token provider not configured")
+	}
+	accessToken, err := s.geminiTokenProvider.GetAccessToken(ctx, account)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get service account access token: %w", err)
+	}
+	fullURL, err := buildVertexGeminiURL(account.VertexProjectID(), account.VertexLocation(modelID), modelID, "streamGenerateContent", true)
+	if err != nil {
+		return nil, err
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, fullURL, bytes.NewReader(payload))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+accessToken)
+	return req, nil
+}
+
 // buildCodeAssistRequest builds request for Google Code Assist API (used by Gemini CLI and Antigravity)
 func (s *AccountTestService) buildCodeAssistRequest(ctx context.Context, accessToken, projectID, modelID string, payload []byte) (*http.Request, error) {
 	var inner map[string]any
diff --git a/backend/internal/service/claude_token_provider.go b/backend/internal/service/claude_token_provider.go
index 82fa31c4..9292979f 100644
--- a/backend/internal/service/claude_token_provider.go
+++ b/backend/internal/service/claude_token_provider.go
@@ -17,7 +17,7 @@ const (
 // ClaudeTokenCache token cache interface.
 type ClaudeTokenCache = GeminiTokenCache
 
-// ClaudeTokenProvider manages access_token for Claude OAuth accounts.
+// ClaudeTokenProvider manages access_token for Claude OAuth and Vertex service account accounts.
 type ClaudeTokenProvider struct {
 	accountRepo   AccountRepository
 	tokenCache    ClaudeTokenCache
@@ -56,8 +56,11 @@ func (p *ClaudeTokenProvider) GetAccessToken(ctx context.Context, account *Accou
 	if account == nil {
 		return "", errors.New("account is nil")
 	}
-	if account.Platform != PlatformAnthropic || account.Type != AccountTypeOAuth {
-		return "", errors.New("not an anthropic oauth account")
+	if account.Platform != PlatformAnthropic || (account.Type != AccountTypeOAuth && account.Type != AccountTypeServiceAccount) {
+		return "", errors.New("not an anthropic oauth or service account")
+	}
+	if account.Type == AccountTypeServiceAccount {
+		return p.getServiceAccountAccessToken(ctx, account)
 	}
 
 	cacheKey := ClaudeTokenCacheKey(account)
@@ -157,3 +160,42 @@ func (p *ClaudeTokenProvider) GetAccessToken(ctx context.Context, account *Accou
 
 	return accessToken, nil
 }
+
+func (p *ClaudeTokenProvider) getServiceAccountAccessToken(ctx context.Context, account *Account) (string, error) {
+	key, err := parseVertexServiceAccountKey(account)
+	if err != nil {
+		return "", err
+	}
+	cacheKey := vertexServiceAccountCacheKey(account, key)
+
+	if p.tokenCache != nil {
+		if token, err := p.tokenCache.GetAccessToken(ctx, cacheKey); err == nil && strings.TrimSpace(token) != "" {
+			return token, nil
+		}
+	}
+
+	locked := false
+	if p.tokenCache != nil {
+		var lockErr error
+		locked, lockErr = p.tokenCache.AcquireRefreshLock(ctx, cacheKey, 30*time.Second)
+		if lockErr == nil && locked {
+			defer func() { _ = p.tokenCache.ReleaseRefreshLock(ctx, cacheKey) }()
+		} else if lockErr != nil {
+			slog.Warn("vertex_service_account_token_lock_failed", "account_id", account.ID, "error", lockErr)
+		} else {
+			time.Sleep(claudeLockWaitTime)
+			if token, err := p.tokenCache.GetAccessToken(ctx, cacheKey); err == nil && strings.TrimSpace(token) != "" {
+				return token, nil
+			}
+		}
+	}
+
+	accessToken, ttl, err := exchangeVertexServiceAccountToken(ctx, key)
+	if err != nil {
+		return "", err
+	}
+	if p.tokenCache != nil {
+		_ = p.tokenCache.SetAccessToken(ctx, cacheKey, accessToken, ttl)
+	}
+	return accessToken, nil
+}
diff --git a/backend/internal/service/claude_token_provider_test.go b/backend/internal/service/claude_token_provider_test.go
index 3e21f6f4..d4a4a14a 100644
--- a/backend/internal/service/claude_token_provider_test.go
+++ b/backend/internal/service/claude_token_provider_test.go
@@ -137,7 +137,7 @@ func (p *testClaudeTokenProvider) GetAccessToken(ctx context.Context, account *A
 		return "", errors.New("account is nil")
 	}
 	if account.Platform != PlatformAnthropic || account.Type != AccountTypeOAuth {
-		return "", errors.New("not an anthropic oauth account")
+		return "", errors.New("not an anthropic oauth or service account")
 	}
 
 	cacheKey := ClaudeTokenCacheKey(account)
@@ -371,7 +371,7 @@ func TestClaudeTokenProvider_WrongPlatform(t *testing.T) {
 
 	token, err := provider.GetAccessToken(context.Background(), account)
 	require.Error(t, err)
-	require.Contains(t, err.Error(), "not an anthropic oauth account")
+	require.Contains(t, err.Error(), "not an anthropic oauth or service account")
 	require.Empty(t, token)
 }
 
@@ -385,7 +385,7 @@ func TestClaudeTokenProvider_WrongAccountType(t *testing.T) {
 
 	token, err := provider.GetAccessToken(context.Background(), account)
 	require.Error(t, err)
-	require.Contains(t, err.Error(), "not an anthropic oauth account")
+	require.Contains(t, err.Error(), "not an anthropic oauth or service account")
 	require.Empty(t, token)
 }
 
@@ -399,7 +399,7 @@ func TestClaudeTokenProvider_SetupTokenType(t *testing.T) {
 
 	token, err := provider.GetAccessToken(context.Background(), account)
 	require.Error(t, err)
-	require.Contains(t, err.Error(), "not an anthropic oauth account")
+	require.Contains(t, err.Error(), "not an anthropic oauth or service account")
 	require.Empty(t, token)
 }
 
diff --git a/backend/internal/service/domain_constants.go b/backend/internal/service/domain_constants.go
index 04037987..e3d3a872 100644
--- a/backend/internal/service/domain_constants.go
+++ b/backend/internal/service/domain_constants.go
@@ -36,11 +36,12 @@ const (
 
 // Account type constants
 const (
-	AccountTypeOAuth      = domain.AccountTypeOAuth      // OAuth类型账号（full scope: profile + inference）
-	AccountTypeSetupToken = domain.AccountTypeSetupToken // Setup Token类型账号（inference only scope）
-	AccountTypeAPIKey     = domain.AccountTypeAPIKey     // API Key类型账号
-	AccountTypeUpstream   = domain.AccountTypeUpstream   // 上游透传类型账号（通过 Base URL + API Key 连接上游）
-	AccountTypeBedrock    = domain.AccountTypeBedrock    // AWS Bedrock 类型账号（通过 SigV4 签名或 API Key 连接 Bedrock，由 credentials.auth_mode 区分）
+	AccountTypeOAuth          = domain.AccountTypeOAuth          // OAuth类型账号（full scope: profile + inference）
+	AccountTypeSetupToken     = domain.AccountTypeSetupToken     // Setup Token类型账号（inference only scope）
+	AccountTypeAPIKey         = domain.AccountTypeAPIKey         // API Key类型账号
+	AccountTypeUpstream       = domain.AccountTypeUpstream       // 上游透传类型账号（通过 Base URL + API Key 连接上游）
+	AccountTypeBedrock        = domain.AccountTypeBedrock        // AWS Bedrock 类型账号（通过 SigV4 签名或 API Key 连接 Bedrock，由 credentials.auth_mode 区分）
+	AccountTypeServiceAccount = domain.AccountTypeServiceAccount // Google Service Account 类型账号（用于 Vertex AI）
 )
 
 // Redeem type constants
diff --git a/backend/internal/service/gateway_anthropic_vertex_service_account_test.go b/backend/internal/service/gateway_anthropic_vertex_service_account_test.go
new file mode 100644
index 00000000..aa779805
--- /dev/null
+++ b/backend/internal/service/gateway_anthropic_vertex_service_account_test.go
@@ -0,0 +1,68 @@
+package service
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/require"
+	"github.com/tidwall/gjson"
+)
+
+func TestGatewayService_BuildAnthropicVertexServiceAccountRequest(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = httptest.NewRequest(http.MethodPost, "/v1/messages", nil)
+	c.Request.Header.Set("Authorization", "Bearer inbound-token")
+	c.Request.Header.Set("X-Api-Key", "inbound-api-key")
+	c.Request.Header.Set("Anthropic-Version", "2023-06-01")
+	c.Request.Header.Set("Anthropic-Beta", "interleaved-thinking-2025-05-14")
+
+	account := &Account{
+		ID:       301,
+		Platform: PlatformAnthropic,
+		Type:     AccountTypeServiceAccount,
+		Credentials: map[string]any{
+			"project_id": "vertex-proj",
+			"location":   "us-east5",
+		},
+	}
+	body := []byte(`{"model":"claude-sonnet-4-5","stream":false,"max_tokens":32,"messages":[{"role":"user","content":"hello"}]}`)
+
+	svc := &GatewayService{}
+	req, err := svc.buildUpstreamRequest(
+		context.Background(),
+		c,
+		account,
+		body,
+		"vertex-token",
+		"service_account",
+		"claude-sonnet-4-5@20250929",
+		false,
+		false,
+	)
+	require.NoError(t, err)
+	require.Equal(t, "https://us-east5-aiplatform.googleapis.com/v1/projects/vertex-proj/locations/us-east5/publishers/anthropic/models/claude-sonnet-4-5@20250929:rawPredict", req.URL.String())
+	require.Equal(t, "Bearer vertex-token", getHeaderRaw(req.Header, "authorization"))
+	require.Empty(t, getHeaderRaw(req.Header, "x-api-key"))
+	require.Empty(t, getHeaderRaw(req.Header, "anthropic-version"))
+	require.Equal(t, "interleaved-thinking-2025-05-14", getHeaderRaw(req.Header, "anthropic-beta"))
+
+	got := readRequestBodyForTest(t, req)
+	require.Equal(t, "", gjson.GetBytes(got, "model").String())
+	require.Equal(t, vertexAnthropicVersion, gjson.GetBytes(got, "anthropic_version").String())
+	require.Equal(t, "hello", gjson.GetBytes(got, "messages.0.content").String())
+}
+
+func readRequestBodyForTest(t *testing.T, req *http.Request) []byte {
+	t.Helper()
+	require.NotNil(t, req.Body)
+	body, err := io.ReadAll(req.Body)
+	require.NoError(t, err)
+	return body
+}
diff --git a/backend/internal/service/gateway_service.go b/backend/internal/service/gateway_service.go
index 6be19ba6..75725753 100644
--- a/backend/internal/service/gateway_service.go
+++ b/backend/internal/service/gateway_service.go
@@ -3597,7 +3597,11 @@ func (s *GatewayService) isModelSupportedByAccount(account *Account, requestedMo
 	}
 	// OAuth/SetupToken 账号使用 Anthropic 标准映射（短ID → 长ID）
 	if account.Platform == PlatformAnthropic && account.Type != AccountTypeAPIKey {
-		requestedModel = claude.NormalizeModelID(requestedModel)
+		if account.Type == AccountTypeServiceAccount {
+			requestedModel = normalizeVertexAnthropicModelID(claude.NormalizeModelID(requestedModel))
+		} else {
+			requestedModel = claude.NormalizeModelID(requestedModel)
+		}
 	}
 	// 其他平台使用账户的模型支持检查
 	return account.IsModelSupported(requestedModel)
@@ -3617,6 +3621,18 @@ func (s *GatewayService) GetAccessToken(ctx context.Context, account *Account) (
 		return apiKey, "apikey", nil
 	case AccountTypeBedrock:
 		return "", "bedrock", nil // Bedrock 使用 SigV4 签名或 API Key，由 forwardBedrock 处理
+	case AccountTypeServiceAccount:
+		if account.Platform != PlatformAnthropic {
+			return "", "", fmt.Errorf("unsupported service account platform: %s", account.Platform)
+		}
+		if s.claudeTokenProvider == nil {
+			return "", "", errors.New("claude token provider not configured")
+		}
+		accessToken, err := s.claudeTokenProvider.GetAccessToken(ctx, account)
+		if err != nil {
+			return "", "", err
+		}
+		return accessToken, "service_account", nil
 	default:
 		return "", "", fmt.Errorf("unsupported account type: %s", account.Type)
 	}
@@ -4219,6 +4235,18 @@ func (s *GatewayService) Forward(ctx context.Context, c *gin.Context, account *A
 			mappingSource = "account"
 		}
 	}
+	if mappingSource == "" && account.Platform == PlatformAnthropic && account.Type == AccountTypeServiceAccount {
+		if candidate, matched := account.ResolveMappedModel(reqModel); matched {
+			mappedModel = candidate
+			mappingSource = "account"
+		} else {
+			normalized := normalizeVertexAnthropicModelID(claude.NormalizeModelID(reqModel))
+			if normalized != reqModel {
+				mappedModel = normalized
+				mappingSource = "vertex"
+			}
+		}
+	}
 	if mappingSource == "" && account.Platform == PlatformAnthropic && account.Type != AccountTypeAPIKey {
 		normalized := claude.NormalizeModelID(reqModel)
 		if normalized != reqModel {
@@ -5688,6 +5716,10 @@ func (s *GatewayService) handleBedrockNonStreamingResponse(
 }
 
 func (s *GatewayService) buildUpstreamRequest(ctx context.Context, c *gin.Context, account *Account, body []byte, token, tokenType, modelID string, reqStream bool, mimicClaudeCode bool) (*http.Request, error) {
+	if account.Platform == PlatformAnthropic && account.Type == AccountTypeServiceAccount {
+		return s.buildUpstreamRequestAnthropicVertex(ctx, c, account, body, token, modelID, reqStream)
+	}
+
 	// 确定目标URL
 	targetURL := claudeAPIURL
 	if account.Type == AccountTypeAPIKey {
@@ -5874,6 +5906,60 @@ func (s *GatewayService) buildUpstreamRequest(ctx context.Context, c *gin.Contex
 	return req, nil
 }
 
+func (s *GatewayService) buildUpstreamRequestAnthropicVertex(
+	ctx context.Context,
+	c *gin.Context,
+	account *Account,
+	body []byte,
+	token string,
+	modelID string,
+	reqStream bool,
+) (*http.Request, error) {
+	vertexBody, err := buildVertexAnthropicRequestBody(body)
+	if err != nil {
+		return nil, err
+	}
+	setOpsUpstreamRequestBody(c, vertexBody)
+	fullURL, err := buildVertexAnthropicURL(account.VertexProjectID(), account.VertexLocation(modelID), modelID, reqStream)
+	if err != nil {
+		return nil, err
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, fullURL, bytes.NewReader(vertexBody))
+	if err != nil {
+		return nil, err
+	}
+
+	if c != nil && c.Request != nil {
+		for key, values := range c.Request.Header {
+			lowerKey := strings.ToLower(strings.TrimSpace(key))
+			if !allowedHeaders[lowerKey] || lowerKey == "anthropic-version" {
+				continue
+			}
+			wireKey := resolveWireCasing(key)
+			for _, v := range values {
+				addHeaderRaw(req.Header, wireKey, v)
+			}
+		}
+	}
+
+	req.Header.Del("authorization")
+	req.Header.Del("x-api-key")
+	req.Header.Del("x-goog-api-key")
+	req.Header.Del("cookie")
+	req.Header.Del("anthropic-version")
+	setHeaderRaw(req.Header, "authorization", "Bearer "+token)
+	setHeaderRaw(req.Header, "content-type", "application/json")
+
+	s.debugLogGatewaySnapshot("UPSTREAM_FORWARD_VERTEX_ANTHROPIC", req.Header, vertexBody, map[string]string{
+		"url":        req.URL.String(),
+		"token_type": "service_account",
+		"model":      modelID,
+		"stream":     strconv.FormatBool(reqStream),
+	})
+
+	return req, nil
+}
+
 // getBetaHeader 处理anthropic-beta header
 // 对于OAuth账号，需要确保包含oauth-2025-04-20
 func (s *GatewayService) getBetaHeader(modelID string, clientBetaHeader string) string {
diff --git a/backend/internal/service/gemini_messages_compat_service.go b/backend/internal/service/gemini_messages_compat_service.go
index 7a24071b..20293ac8 100644
--- a/backend/internal/service/gemini_messages_compat_service.go
+++ b/backend/internal/service/gemini_messages_compat_service.go
@@ -579,7 +579,7 @@ func (s *GeminiMessagesCompatService) Forward(ctx context.Context, c *gin.Contex
 
 	originalModel := req.Model
 	mappedModel := req.Model
-	if account.Type == AccountTypeAPIKey {
+	if account.Type == AccountTypeAPIKey || account.Type == AccountTypeServiceAccount {
 		mappedModel = account.GetMappedModel(req.Model)
 	}
 
@@ -712,6 +712,36 @@ func (s *GeminiMessagesCompatService) Forward(ctx context.Context, c *gin.Contex
 		}
 		requestIDHeader = "x-request-id"
 
+	case AccountTypeServiceAccount:
+		buildReq = func(ctx context.Context) (*http.Request, string, error) {
+			if s.tokenProvider == nil {
+				return nil, "", errors.New("gemini token provider not configured")
+			}
+			accessToken, err := s.tokenProvider.GetAccessToken(ctx, account)
+			if err != nil {
+				return nil, "", err
+			}
+
+			action := "generateContent"
+			if req.Stream {
+				action = "streamGenerateContent"
+			}
+			fullURL, err := buildVertexGeminiURL(account.VertexProjectID(), account.VertexLocation(mappedModel), mappedModel, action, req.Stream)
+			if err != nil {
+				return nil, "", err
+			}
+
+			restGeminiReq := normalizeGeminiRequestForAIStudio(geminiReq)
+			upstreamReq, err := http.NewRequestWithContext(ctx, http.MethodPost, fullURL, bytes.NewReader(restGeminiReq))
+			if err != nil {
+				return nil, "", err
+			}
+			upstreamReq.Header.Set("Content-Type", "application/json")
+			upstreamReq.Header.Set("Authorization", "Bearer "+accessToken)
+			return upstreamReq, "x-request-id", nil
+		}
+		requestIDHeader = "x-request-id"
+
 	default:
 		return nil, fmt.Errorf("unsupported account type: %s", account.Type)
 	}
@@ -1094,7 +1124,7 @@ func (s *GeminiMessagesCompatService) ForwardNative(ctx context.Context, c *gin.
 	body = ensureGeminiFunctionCallThoughtSignatures(body)
 
 	mappedModel := originalModel
-	if account.Type == AccountTypeAPIKey {
+	if account.Type == AccountTypeAPIKey || account.Type == AccountTypeServiceAccount {
 		mappedModel = account.GetMappedModel(originalModel)
 	}
 
@@ -1213,6 +1243,31 @@ func (s *GeminiMessagesCompatService) ForwardNative(ctx context.Context, c *gin.
 		}
 		requestIDHeader = "x-request-id"
 
+	case AccountTypeServiceAccount:
+		buildReq = func(ctx context.Context) (*http.Request, string, error) {
+			if s.tokenProvider == nil {
+				return nil, "", errors.New("gemini token provider not configured")
+			}
+			accessToken, err := s.tokenProvider.GetAccessToken(ctx, account)
+			if err != nil {
+				return nil, "", err
+			}
+
+			fullURL, err := buildVertexGeminiURL(account.VertexProjectID(), account.VertexLocation(mappedModel), mappedModel, upstreamAction, useUpstreamStream)
+			if err != nil {
+				return nil, "", err
+			}
+
+			upstreamReq, err := http.NewRequestWithContext(ctx, http.MethodPost, fullURL, bytes.NewReader(body))
+			if err != nil {
+				return nil, "", err
+			}
+			upstreamReq.Header.Set("Content-Type", "application/json")
+			upstreamReq.Header.Set("Authorization", "Bearer "+accessToken)
+			return upstreamReq, "x-request-id", nil
+		}
+		requestIDHeader = "x-request-id"
+
 	default:
 		return nil, s.writeGoogleError(c, http.StatusBadGateway, "Unsupported account type: "+account.Type)
 	}
diff --git a/backend/internal/service/gemini_token_provider.go b/backend/internal/service/gemini_token_provider.go
index 7add3460..c22f2131 100644
--- a/backend/internal/service/gemini_token_provider.go
+++ b/backend/internal/service/gemini_token_provider.go
@@ -15,7 +15,7 @@ const (
 	geminiTokenCacheSkew   = 5 * time.Minute
 )
 
-// GeminiTokenProvider manages access_token for Gemini OAuth accounts.
+// GeminiTokenProvider manages access_token for Gemini OAuth and Vertex service account accounts.
 type GeminiTokenProvider struct {
 	accountRepo        AccountRepository
 	tokenCache         GeminiTokenCache
@@ -53,8 +53,11 @@ func (p *GeminiTokenProvider) GetAccessToken(ctx context.Context, account *Accou
 	if account == nil {
 		return "", errors.New("account is nil")
 	}
-	if account.Platform != PlatformGemini || account.Type != AccountTypeOAuth {
-		return "", errors.New("not a gemini oauth account")
+	if account.Platform != PlatformGemini || (account.Type != AccountTypeOAuth && account.Type != AccountTypeServiceAccount) {
+		return "", errors.New("not a gemini oauth or service account")
+	}
+	if account.Type == AccountTypeServiceAccount {
+		return p.getServiceAccountAccessToken(ctx, account)
 	}
 
 	cacheKey := GeminiTokenCacheKey(account)
@@ -168,7 +171,51 @@ func (p *GeminiTokenProvider) GetAccessToken(ctx context.Context, account *Accou
 	return accessToken, nil
 }
 
+func (p *GeminiTokenProvider) getServiceAccountAccessToken(ctx context.Context, account *Account) (string, error) {
+	key, err := parseVertexServiceAccountKey(account)
+	if err != nil {
+		return "", err
+	}
+	cacheKey := vertexServiceAccountCacheKey(account, key)
+
+	if p.tokenCache != nil {
+		if token, err := p.tokenCache.GetAccessToken(ctx, cacheKey); err == nil && strings.TrimSpace(token) != "" {
+			return token, nil
+		}
+	}
+
+	locked := false
+	if p.tokenCache != nil {
+		var lockErr error
+		locked, lockErr = p.tokenCache.AcquireRefreshLock(ctx, cacheKey, 30*time.Second)
+		if lockErr == nil && locked {
+			defer func() { _ = p.tokenCache.ReleaseRefreshLock(ctx, cacheKey) }()
+		} else if lockErr != nil {
+			slog.Warn("vertex_service_account_token_lock_failed", "account_id", account.ID, "error", lockErr)
+		} else {
+			time.Sleep(200 * time.Millisecond)
+			if token, err := p.tokenCache.GetAccessToken(ctx, cacheKey); err == nil && strings.TrimSpace(token) != "" {
+				return token, nil
+			}
+		}
+	}
+
+	accessToken, ttl, err := exchangeVertexServiceAccountToken(ctx, key)
+	if err != nil {
+		return "", err
+	}
+	if p.tokenCache != nil {
+		_ = p.tokenCache.SetAccessToken(ctx, cacheKey, accessToken, ttl)
+	}
+	return accessToken, nil
+}
+
 func GeminiTokenCacheKey(account *Account) string {
+	if account != nil && account.Type == AccountTypeServiceAccount {
+		if key, err := parseVertexServiceAccountKey(account); err == nil {
+			return vertexServiceAccountCacheKey(account, key)
+		}
+	}
 	projectID := strings.TrimSpace(account.GetCredential("project_id"))
 	if projectID != "" {
 		return "gemini:" + projectID
diff --git a/backend/internal/service/vertex_service_account.go b/backend/internal/service/vertex_service_account.go
new file mode 100644
index 00000000..d4130b93
--- /dev/null
+++ b/backend/internal/service/vertex_service_account.go
@@ -0,0 +1,303 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+const (
+	vertexDefaultLocation         = "us-central1"
+	vertexDefaultTokenURL         = "https://oauth2.googleapis.com/token"
+	vertexCloudPlatformScope      = "https://www.googleapis.com/auth/cloud-platform"
+	vertexServiceAccountCacheSkew = 5 * time.Minute
+	vertexAnthropicVersion        = "vertex-2023-10-16"
+)
+
+var (
+	vertexLocationPattern                = regexp.MustCompile(`^[a-z0-9-]+$`)
+	vertexAnthropicDatedModelIDPattern   = regexp.MustCompile(`^(.+)-([0-9]{8})$`)
+	vertexAnthropicAlreadyDatedIDPattern = regexp.MustCompile(`^.+@[0-9]{8}$`)
+)
+
+type vertexServiceAccountKey struct {
+	Type         string `json:"type"`
+	ProjectID    string `json:"project_id"`
+	PrivateKeyID string `json:"private_key_id"`
+	PrivateKey   string `json:"private_key"`
+	ClientEmail  string `json:"client_email"`
+	TokenURI     string `json:"token_uri"`
+}
+
+type vertexTokenResponse struct {
+	AccessToken string `json:"access_token"`
+	TokenType   string `json:"token_type"`
+	ExpiresIn   int64  `json:"expires_in"`
+	Error       string `json:"error"`
+	ErrorDesc   string `json:"error_description"`
+}
+
+func (a *Account) IsVertexServiceAccount() bool {
+	return a != nil && a.Type == AccountTypeServiceAccount
+}
+
+func (a *Account) VertexProjectID() string {
+	if a == nil {
+		return ""
+	}
+	if v := strings.TrimSpace(a.GetCredential("project_id")); v != "" {
+		return v
+	}
+	key, err := parseVertexServiceAccountKey(a)
+	if err == nil {
+		return strings.TrimSpace(key.ProjectID)
+	}
+	return ""
+}
+
+func (a *Account) VertexLocation(model string) string {
+	if a == nil {
+		return vertexDefaultLocation
+	}
+	if model != "" && a.Credentials != nil {
+		if raw, ok := a.Credentials["vertex_model_locations"].(map[string]any); ok {
+			if loc, ok := raw[model].(string); ok && strings.TrimSpace(loc) != "" {
+				return strings.TrimSpace(loc)
+			}
+		}
+	}
+	if v := strings.TrimSpace(a.GetCredential("location")); v != "" {
+		return v
+	}
+	if v := strings.TrimSpace(a.GetCredential("vertex_location")); v != "" {
+		return v
+	}
+	return vertexDefaultLocation
+}
+
+func parseVertexServiceAccountKey(account *Account) (*vertexServiceAccountKey, error) {
+	if account == nil || account.Credentials == nil {
+		return nil, errors.New("service account credentials not configured")
+	}
+
+	if raw := strings.TrimSpace(account.GetCredential("service_account_json")); raw != "" {
+		return parseVertexServiceAccountJSON([]byte(raw))
+	}
+	if raw := strings.TrimSpace(account.GetCredential("service_account")); raw != "" {
+		return parseVertexServiceAccountJSON([]byte(raw))
+	}
+	if nested, ok := account.Credentials["service_account_json"].(map[string]any); ok {
+		b, _ := json.Marshal(nested)
+		return parseVertexServiceAccountJSON(b)
+	}
+	if nested, ok := account.Credentials["service_account"].(map[string]any); ok {
+		b, _ := json.Marshal(nested)
+		return parseVertexServiceAccountJSON(b)
+	}
+	return nil, errors.New("service_account_json not found in credentials")
+}
+
+func parseVertexServiceAccountJSON(raw []byte) (*vertexServiceAccountKey, error) {
+	var key vertexServiceAccountKey
+	if err := json.Unmarshal(raw, &key); err != nil {
+		return nil, fmt.Errorf("invalid service account json: %w", err)
+	}
+	if strings.TrimSpace(key.ClientEmail) == "" {
+		return nil, errors.New("service account json missing client_email")
+	}
+	if strings.TrimSpace(key.PrivateKey) == "" {
+		return nil, errors.New("service account json missing private_key")
+	}
+	if strings.TrimSpace(key.ProjectID) == "" {
+		return nil, errors.New("service account json missing project_id")
+	}
+	if strings.TrimSpace(key.TokenURI) == "" {
+		key.TokenURI = vertexDefaultTokenURL
+	}
+	return &key, nil
+}
+
+func vertexServiceAccountCacheKey(account *Account, key *vertexServiceAccountKey) string {
+	fingerprint := ""
+	if key != nil {
+		sum := sha256.Sum256([]byte(key.ClientEmail + "\x00" + key.PrivateKeyID))
+		fingerprint = hex.EncodeToString(sum[:8])
+	}
+	if fingerprint == "" && account != nil {
+		fingerprint = fmt.Sprintf("account:%d", account.ID)
+	}
+	return "vertex:service_account:" + fingerprint
+}
+
+func exchangeVertexServiceAccountToken(ctx context.Context, key *vertexServiceAccountKey) (string, time.Duration, error) {
+	now := time.Now()
+	claims := jwt.MapClaims{
+		"iss":   key.ClientEmail,
+		"scope": vertexCloudPlatformScope,
+		"aud":   key.TokenURI,
+		"iat":   now.Unix(),
+		"exp":   now.Add(time.Hour).Unix(),
+	}
+	token := jwt.NewWithClaims(jwt.SigningMethodRS256, claims)
+	if strings.TrimSpace(key.PrivateKeyID) != "" {
+		token.Header["kid"] = key.PrivateKeyID
+	}
+	privateKey, err := jwt.ParseRSAPrivateKeyFromPEM([]byte(key.PrivateKey))
+	if err != nil {
+		return "", 0, fmt.Errorf("parse service account private key: %w", err)
+	}
+	assertion, err := token.SignedString(privateKey)
+	if err != nil {
+		return "", 0, fmt.Errorf("sign service account assertion: %w", err)
+	}
+
+	values := url.Values{}
+	values.Set("grant_type", "urn:ietf:params:oauth:grant-type:jwt-bearer")
+	values.Set("assertion", assertion)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, key.TokenURI, strings.NewReader(values.Encode()))
+	if err != nil {
+		return "", 0, err
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	client := &http.Client{Timeout: 15 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", 0, fmt.Errorf("service account token request failed: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	body, _ := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	var parsed vertexTokenResponse
+	_ = json.Unmarshal(body, &parsed)
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		msg := strings.TrimSpace(parsed.ErrorDesc)
+		if msg == "" {
+			msg = strings.TrimSpace(parsed.Error)
+		}
+		if msg == "" {
+			msg = string(bytes.TrimSpace(body))
+		}
+		return "", 0, fmt.Errorf("service account token request returned %d: %s", resp.StatusCode, msg)
+	}
+	if strings.TrimSpace(parsed.AccessToken) == "" {
+		return "", 0, errors.New("service account token response missing access_token")
+	}
+	ttl := time.Duration(parsed.ExpiresIn) * time.Second
+	if ttl <= 0 {
+		ttl = time.Hour
+	}
+	if ttl > vertexServiceAccountCacheSkew {
+		ttl -= vertexServiceAccountCacheSkew
+	}
+	return parsed.AccessToken, ttl, nil
+}
+
+func buildVertexGeminiURL(projectID, location, model, action string, stream bool) (string, error) {
+	projectID = strings.TrimSpace(projectID)
+	location = strings.TrimSpace(location)
+	model = strings.TrimSpace(model)
+	action = strings.TrimSpace(action)
+	if projectID == "" {
+		return "", errors.New("vertex project_id is required")
+	}
+	if location == "" {
+		location = vertexDefaultLocation
+	}
+	if !vertexLocationPattern.MatchString(location) {
+		return "", fmt.Errorf("invalid vertex location: %s", location)
+	}
+	if model == "" {
+		return "", errors.New("vertex model is required")
+	}
+	switch action {
+	case "generateContent", "streamGenerateContent", "countTokens":
+	default:
+		return "", fmt.Errorf("unsupported vertex gemini action: %s", action)
+	}
+	host := fmt.Sprintf("%s-aiplatform.googleapis.com", location)
+	if location == "global" {
+		host = "aiplatform.googleapis.com"
+	}
+	u := fmt.Sprintf(
+		"https://%s/v1/projects/%s/locations/%s/publishers/google/models/%s:%s",
+		host,
+		url.PathEscape(projectID),
+		url.PathEscape(location),
+		url.PathEscape(model),
+		action,
+	)
+	if stream {
+		u += "?alt=sse"
+	}
+	return u, nil
+}
+
+func buildVertexAnthropicURL(projectID, location, model string, stream bool) (string, error) {
+	projectID = strings.TrimSpace(projectID)
+	location = strings.TrimSpace(location)
+	model = strings.TrimSpace(model)
+	if projectID == "" {
+		return "", errors.New("vertex project_id is required")
+	}
+	if location == "" {
+		location = vertexDefaultLocation
+	}
+	if !vertexLocationPattern.MatchString(location) {
+		return "", fmt.Errorf("invalid vertex location: %s", location)
+	}
+	if model == "" {
+		return "", errors.New("vertex model is required")
+	}
+	action := "rawPredict"
+	if stream {
+		action = "streamRawPredict"
+	}
+	host := fmt.Sprintf("%s-aiplatform.googleapis.com", location)
+	if location == "global" {
+		host = "aiplatform.googleapis.com"
+	}
+	escapedModel := strings.ReplaceAll(url.PathEscape(model), "%40", "@")
+	return fmt.Sprintf(
+		"https://%s/v1/projects/%s/locations/%s/publishers/anthropic/models/%s:%s",
+		host,
+		url.PathEscape(projectID),
+		url.PathEscape(location),
+		escapedModel,
+		action,
+	), nil
+}
+
+func normalizeVertexAnthropicModelID(model string) string {
+	model = strings.TrimSpace(model)
+	if model == "" || vertexAnthropicAlreadyDatedIDPattern.MatchString(model) {
+		return model
+	}
+	if m := vertexAnthropicDatedModelIDPattern.FindStringSubmatch(model); len(m) == 3 {
+		return m[1] + "@" + m[2]
+	}
+	return model
+}
+
+func buildVertexAnthropicRequestBody(body []byte) ([]byte, error) {
+	var payload map[string]any
+	if err := json.Unmarshal(body, &payload); err != nil {
+		return nil, fmt.Errorf("parse anthropic vertex request body: %w", err)
+	}
+	delete(payload, "model")
+	payload["anthropic_version"] = vertexAnthropicVersion
+	return json.Marshal(payload)
+}
diff --git a/backend/internal/service/vertex_service_account_test.go b/backend/internal/service/vertex_service_account_test.go
new file mode 100644
index 00000000..519f5b2f
--- /dev/null
+++ b/backend/internal/service/vertex_service_account_test.go
@@ -0,0 +1,77 @@
+package service
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/tidwall/gjson"
+)
+
+func TestBuildVertexGeminiURL(t *testing.T) {
+	got, err := buildVertexGeminiURL("my-project", "us-central1", "gemini-3-pro", "streamGenerateContent", true)
+	require.NoError(t, err)
+	require.Equal(t, "https://us-central1-aiplatform.googleapis.com/v1/projects/my-project/locations/us-central1/publishers/google/models/gemini-3-pro:streamGenerateContent?alt=sse", got)
+}
+
+func TestBuildVertexGeminiURLUsesGlobalEndpointHost(t *testing.T) {
+	got, err := buildVertexGeminiURL("my-project", "global", "gemini-3-flash-preview", "streamGenerateContent", true)
+	require.NoError(t, err)
+	require.Equal(t, "https://aiplatform.googleapis.com/v1/projects/my-project/locations/global/publishers/google/models/gemini-3-flash-preview:streamGenerateContent?alt=sse", got)
+}
+
+func TestBuildVertexAnthropicURL(t *testing.T) {
+	got, err := buildVertexAnthropicURL("my-project", "us-east5", "claude-sonnet-4-5@20250929", false)
+	require.NoError(t, err)
+	require.Equal(t, "https://us-east5-aiplatform.googleapis.com/v1/projects/my-project/locations/us-east5/publishers/anthropic/models/claude-sonnet-4-5@20250929:rawPredict", got)
+}
+
+func TestBuildVertexAnthropicURLUsesGlobalEndpointHost(t *testing.T) {
+	got, err := buildVertexAnthropicURL("my-project", "global", "claude-haiku-4-5@20251001", true)
+	require.NoError(t, err)
+	require.Equal(t, "https://aiplatform.googleapis.com/v1/projects/my-project/locations/global/publishers/anthropic/models/claude-haiku-4-5@20251001:streamRawPredict", got)
+}
+
+func TestNormalizeVertexAnthropicModelID(t *testing.T) {
+	require.Equal(t, "claude-sonnet-4-5@20250929", normalizeVertexAnthropicModelID("claude-sonnet-4-5-20250929"))
+	require.Equal(t, "claude-sonnet-4-5@20250929", normalizeVertexAnthropicModelID("claude-sonnet-4-5@20250929"))
+	require.Equal(t, "claude-sonnet-4-6", normalizeVertexAnthropicModelID("claude-sonnet-4-6"))
+}
+
+func TestBuildVertexAnthropicRequestBody(t *testing.T) {
+	got, err := buildVertexAnthropicRequestBody([]byte(`{"model":"claude-sonnet-4-5","anthropic_version":"2023-06-01","max_tokens":64,"messages":[{"role":"user","content":"hi"}]}`))
+	require.NoError(t, err)
+	require.Equal(t, "", gjson.GetBytes(got, "model").String())
+	require.Equal(t, vertexAnthropicVersion, gjson.GetBytes(got, "anthropic_version").String())
+	require.Equal(t, int64(64), gjson.GetBytes(got, "max_tokens").Int())
+	require.Equal(t, "hi", gjson.GetBytes(got, "messages.0.content").String())
+}
+
+func TestBuildVertexGeminiURLRejectsInvalidLocation(t *testing.T) {
+	_, err := buildVertexGeminiURL("my-project", "us-central1/path", "gemini-3-pro", "generateContent", false)
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "invalid vertex location")
+}
+
+func TestParseVertexServiceAccountKey(t *testing.T) {
+	raw := `{
+		"type": "service_account",
+		"project_id": "vertex-proj",
+		"private_key_id": "kid",
+		"private_key": "-----BEGIN PRIVATE KEY-----\nabc\n-----END PRIVATE KEY-----\n",
+		"client_email": "svc@vertex-proj.iam.gserviceaccount.com"
+	}`
+	account := &Account{
+		Type:     AccountTypeServiceAccount,
+		Platform: PlatformGemini,
+		Credentials: map[string]any{
+			"service_account_json": raw,
+		},
+	}
+	key, err := parseVertexServiceAccountKey(account)
+	require.NoError(t, err)
+	require.Equal(t, "vertex-proj", key.ProjectID)
+	require.Equal(t, "svc@vertex-proj.iam.gserviceaccount.com", key.ClientEmail)
+	require.Equal(t, vertexDefaultTokenURL, key.TokenURI)
+	require.True(t, strings.Contains(key.PrivateKey, "BEGIN PRIVATE KEY"))
+}
diff --git a/frontend/src/components/account/CreateAccountModal.vue b/frontend/src/components/account/CreateAccountModal.vue
index 96673f8f..e7a790ec 100644
--- a/frontend/src/components/account/CreateAccountModal.vue
+++ b/frontend/src/components/account/CreateAccountModal.vue
@@ -153,7 +153,7 @@
       <!-- Account Type Selection (Anthropic) -->
       <div v-if="form.platform === 'anthropic'">
         <label class="input-label">{{ t('admin.accounts.accountType') }}</label>
-        <div class="mt-2 grid grid-cols-3 gap-3" data-tour="account-form-type">
+        <div class="mt-2 grid grid-cols-2 gap-3 sm:grid-cols-4" data-tour="account-form-type">
           <button
             type="button"
             @click="accountCategory = 'oauth-based'"
@@ -244,6 +244,39 @@
             </div>
           </button>
 
+          <button
+            type="button"
+            @click="accountCategory = 'service_account'"
+            :class="[
+              'flex items-center gap-3 rounded-lg border-2 p-3 text-left transition-all',
+              accountCategory === 'service_account'
+                ? 'border-sky-500 bg-sky-50 dark:bg-sky-900/20'
+                : 'border-gray-200 hover:border-sky-300 dark:border-dark-600 dark:hover:border-sky-700'
+            ]"
+          >
+            <div
+              :class="[
+                'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
+                accountCategory === 'service_account'
+                  ? 'bg-sky-500 text-white'
+                  : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
+              ]"
+            >
+              <Icon name="cloud" size="sm" />
+            </div>
+            <div>
+              <span class="block text-sm font-medium text-gray-900 dark:text-white">Vertex</span>
+              <span class="text-xs text-gray-500 dark:text-gray-400">Service Account</span>
+            </div>
+          </button>
+
+        </div>
+
+        <div
+          v-if="accountCategory === 'service_account'"
+          class="mt-3 rounded-lg border border-sky-200 bg-sky-50 px-3 py-2 text-xs text-sky-800 dark:border-sky-800/40 dark:bg-sky-900/20 dark:text-sky-200"
+        >
+          <p>使用 Google Cloud Service Account JSON 通过 Vertex AI 调用 Anthropic Claude。建议配置模型映射，将客户端 Claude 模型名映射到 Vertex 模型 ID。</p>
         </div>
       </div>
 
@@ -302,6 +335,7 @@
               <span class="text-xs text-gray-500 dark:text-gray-400">{{ t('admin.accounts.types.responsesApi') }}</span>
             </div>
           </button>
+
         </div>
       </div>
 
@@ -320,7 +354,7 @@
             {{ t('admin.accounts.gemini.helpButton') }}
           </button>
         </div>
-        <div class="mt-2 grid grid-cols-2 gap-3" data-tour="account-form-type">
+        <div class="mt-2 grid grid-cols-3 gap-3" data-tour="account-form-type">
           <button
             type="button"
             @click="accountCategory = 'oauth-based'"
@@ -392,6 +426,36 @@
               </span>
             </div>
           </button>
+
+          <button
+            type="button"
+            @click="accountCategory = 'service_account'"
+            :class="[
+              'flex items-center gap-3 rounded-lg border-2 p-3 text-left transition-all',
+              accountCategory === 'service_account'
+                ? 'border-sky-500 bg-sky-50 dark:bg-sky-900/20'
+                : 'border-gray-200 hover:border-sky-300 dark:border-dark-600 dark:hover:border-sky-700'
+            ]"
+          >
+            <div
+              :class="[
+                'flex h-8 w-8 shrink-0 items-center justify-center rounded-lg',
+                accountCategory === 'service_account'
+                  ? 'bg-sky-500 text-white'
+                  : 'bg-gray-100 text-gray-500 dark:bg-dark-600 dark:text-gray-400'
+              ]"
+            >
+              <Icon name="cloud" size="sm" />
+            </div>
+            <div>
+              <span class="block text-sm font-medium text-gray-900 dark:text-white">
+                Vertex
+              </span>
+              <span class="text-xs text-gray-500 dark:text-gray-400">
+                Service Account
+              </span>
+            </div>
+          </button>
         </div>
 
         <div
@@ -411,6 +475,13 @@
           </div>
         </div>
 
+        <div
+          v-if="accountCategory === 'service_account'"
+          class="mt-3 rounded-lg border border-sky-200 bg-sky-50 px-3 py-2 text-xs text-sky-800 dark:border-sky-800/40 dark:bg-sky-900/20 dark:text-sky-200"
+        >
+          <p>使用 Google Cloud Service Account JSON 访问 Vertex AI Gemini。建议将 Vertex 账号放入独立分组，避免和 AI Studio/Gemini OAuth 同模型混调。</p>
+        </div>
+
         <!-- OAuth Type Selection (only show when oauth-based is selected) -->
         <div v-if="accountCategory === 'oauth-based'" class="mt-4">
           <label class="input-label">{{ t('admin.accounts.oauth.gemini.oauthTypeLabel') }}</label>
@@ -610,7 +681,7 @@
         </div>
 
         <!-- Tier selection (used as fallback when auto-detection is unavailable/fails) -->
-        <div class="mt-4">
+        <div v-if="accountCategory !== 'service_account'" class="mt-4">
           <label class="input-label">{{ t('admin.accounts.gemini.tier.label') }}</label>
           <div class="mt-2">
             <select
@@ -729,6 +800,96 @@
         </div>
       </div>
 
+      <!-- Vertex Service Account -->
+      <div v-if="(form.platform === 'gemini' || form.platform === 'anthropic') && accountCategory === 'service_account'" class="space-y-4">
+        <div>
+          <label class="input-label">Service Account JSON</label>
+          <input
+            ref="vertexServiceAccountFileInput"
+            type="file"
+            accept="application/json,.json"
+            class="hidden"
+            @change="handleVertexServiceAccountFile"
+          />
+          <div
+            :class="[
+              'rounded-lg border-2 border-dashed px-4 py-5 transition-colors',
+              vertexServiceAccountDragActive
+                ? 'border-sky-500 bg-sky-50 dark:border-sky-500 dark:bg-sky-900/20'
+                : 'border-gray-300 bg-gray-50 hover:border-sky-400 hover:bg-sky-50/60 dark:border-dark-500 dark:bg-dark-700/40 dark:hover:border-sky-600 dark:hover:bg-sky-900/10'
+            ]"
+            @dragenter.prevent="vertexServiceAccountDragActive = true"
+            @dragover.prevent="vertexServiceAccountDragActive = true"
+            @dragleave.prevent="vertexServiceAccountDragActive = false"
+            @drop.prevent="handleVertexServiceAccountDrop"
+          >
+            <div class="flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
+              <div class="min-w-0">
+                <div class="flex items-center gap-2 text-sm font-medium text-gray-900 dark:text-white">
+                  <Icon name="upload" size="sm" />
+                  <span>{{ vertexClientEmail ? '已读取 Service Account JSON' : '拖入 Service Account JSON' }}</span>
+                </div>
+                <p class="mt-1 text-xs text-gray-500 dark:text-gray-400">
+                  {{ vertexClientEmail ? '密钥内容不会在表单中显示。' : '把 .json 文件拖到这里，或点击按钮选择文件。' }}
+                </p>
+              </div>
+              <button
+                type="button"
+                class="btn btn-secondary shrink-0"
+                @click="vertexServiceAccountFileInput?.click()"
+              >
+                <Icon name="upload" size="sm" />
+                选择 JSON
+              </button>
+            </div>
+            <div
+              v-if="vertexClientEmail"
+              class="mt-3 rounded-md border border-sky-200 bg-white px-3 py-2 text-xs text-sky-900 dark:border-sky-800/50 dark:bg-dark-800 dark:text-sky-200"
+            >
+              <div class="truncate">Project ID: <span class="font-mono">{{ vertexProjectId }}</span></div>
+              <div class="truncate">Client Email: <span class="font-mono">{{ vertexClientEmail }}</span></div>
+            </div>
+          </div>
+          <p class="input-hint">上传或拖入 JSON 后会自动读取 project_id，密钥内容仅用于创建账号提交。</p>
+        </div>
+
+        <div class="grid grid-cols-1 gap-4 sm:grid-cols-2">
+          <div>
+            <label class="input-label">Project ID</label>
+            <input
+              v-model="vertexProjectId"
+              type="text"
+              class="input font-mono"
+              readonly
+              placeholder="从 JSON 自动读取"
+            />
+          </div>
+          <div>
+            <label class="input-label">Location</label>
+            <select
+              v-model="vertexLocation"
+              required
+              class="input font-mono"
+            >
+              <optgroup
+                v-for="group in vertexLocationOptions"
+                :key="group.label"
+                :label="group.label"
+              >
+                <option
+                  v-for="option in group.options"
+                  :key="option.value"
+                  :value="option.value"
+                >
+                  {{ option.label }}
+                </option>
+              </optgroup>
+            </select>
+            <p class="input-hint">不同 Vertex 模型可用 location 可能不同，这里选择账号默认 endpoint location。</p>
+          </div>
+        </div>
+      </div>
+
       <!-- Antigravity model restriction (applies to OAuth + Upstream) -->
       <!-- Antigravity 只支持模型映射模式，不支持白名单模式 -->
       <div v-if="form.platform === 'antigravity'" class="border-t border-gray-200 pt-4 dark:border-dark-600">
@@ -3085,7 +3246,7 @@ interface TempUnschedRuleForm {
 // State
 const step = ref(1)
 const submitting = ref(false)
-const accountCategory = ref<'oauth-based' | 'apikey' | 'bedrock'>('oauth-based') // UI selection for account category
+const accountCategory = ref<'oauth-based' | 'apikey' | 'bedrock' | 'service_account'>('oauth-based') // UI selection for account category
 const addMethod = ref<AddMethod>('oauth') // For oauth-based: 'oauth' or 'setup-token'
 const apiKeyBaseUrl = ref('https://api.anthropic.com')
 const apiKeyValue = ref('')
@@ -3151,6 +3312,58 @@ const bedrockSessionToken = ref('')
 const bedrockRegion = ref('us-east-1')
 const bedrockForceGlobal = ref(false)
 const bedrockApiKeyValue = ref('')
+const vertexServiceAccountFileInput = ref<HTMLInputElement | null>(null)
+const vertexServiceAccountJson = ref('')
+const vertexProjectId = ref('')
+const vertexClientEmail = ref('')
+const vertexLocation = ref('global')
+const vertexServiceAccountDragActive = ref(false)
+const vertexLocationOptions = [
+  {
+    label: 'Common',
+    options: [
+      { value: 'us-central1', label: 'us-central1 (Iowa)' },
+      { value: 'global', label: 'global' },
+      { value: 'us', label: 'us' },
+      { value: 'eu', label: 'eu' }
+    ]
+  },
+  {
+    label: 'United States',
+    options: [
+      { value: 'us-east1', label: 'us-east1 (South Carolina)' },
+      { value: 'us-east4', label: 'us-east4 (Northern Virginia)' },
+      { value: 'us-east5', label: 'us-east5 (Columbus)' },
+      { value: 'us-south1', label: 'us-south1 (Dallas)' },
+      { value: 'us-west1', label: 'us-west1 (Oregon)' },
+      { value: 'us-west4', label: 'us-west4 (Las Vegas)' }
+    ]
+  },
+  {
+    label: 'Europe',
+    options: [
+      { value: 'europe-west1', label: 'europe-west1 (Belgium)' },
+      { value: 'europe-west2', label: 'europe-west2 (London)' },
+      { value: 'europe-west3', label: 'europe-west3 (Frankfurt)' },
+      { value: 'europe-west4', label: 'europe-west4 (Netherlands)' },
+      { value: 'europe-west6', label: 'europe-west6 (Zurich)' },
+      { value: 'europe-west8', label: 'europe-west8 (Milan)' },
+      { value: 'europe-west9', label: 'europe-west9 (Paris)' }
+    ]
+  },
+  {
+    label: 'Asia Pacific',
+    options: [
+      { value: 'asia-east1', label: 'asia-east1 (Taiwan)' },
+      { value: 'asia-east2', label: 'asia-east2 (Hong Kong)' },
+      { value: 'asia-northeast1', label: 'asia-northeast1 (Tokyo)' },
+      { value: 'asia-northeast3', label: 'asia-northeast3 (Seoul)' },
+      { value: 'asia-south1', label: 'asia-south1 (Mumbai)' },
+      { value: 'asia-southeast1', label: 'asia-southeast1 (Singapore)' },
+      { value: 'australia-southeast1', label: 'australia-southeast1 (Sydney)' }
+    ]
+  }
+] as const
 const tempUnschedEnabled = ref(false)
 const tempUnschedRules = ref<TempUnschedRuleForm[]>([])
 const getModelMappingKey = createStableObjectKeyResolver<ModelMapping>('create-model-mapping')
@@ -3397,7 +3610,7 @@ watch(
 
 // Sync form.type based on accountCategory, addMethod, and platform-specific type
 watch(
-  [accountCategory, addMethod, antigravityAccountType],
+  [accountCategory, addMethod, antigravityAccountType, () => form.platform],
   ([category, method, agType]) => {
     // Antigravity upstream 类型（实际创建为 apikey）
     if (form.platform === 'antigravity' && agType === 'upstream') {
@@ -3409,7 +3622,9 @@ watch(
       form.type = 'bedrock' as AccountType
       return
     }
-    if (category === 'oauth-based') {
+    if ((form.platform === 'gemini' || form.platform === 'anthropic') && category === 'service_account') {
+      form.type = 'service_account' as AccountType
+    } else if (category === 'oauth-based') {
       form.type = method as AccountType // 'oauth' or 'setup-token'
     } else {
       form.type = 'apikey'
@@ -3447,6 +3662,12 @@ watch(
       antigravityModelMappings.value = []
       antigravityModelRestrictionMode.value = 'mapping'
     }
+    if (newPlatform !== 'gemini' && newPlatform !== 'anthropic' && accountCategory.value === 'service_account') {
+      accountCategory.value = 'oauth-based'
+    }
+    if (newPlatform !== 'anthropic' && accountCategory.value === 'bedrock') {
+      accountCategory.value = 'oauth-based'
+    }
     // Reset Bedrock fields when switching platforms
     bedrockAccessKeyId.value = ''
     bedrockSecretAccessKey.value = ''
@@ -3455,6 +3676,10 @@ watch(
     bedrockForceGlobal.value = false
     bedrockAuthMode.value = 'sigv4'
     bedrockApiKeyValue.value = ''
+    vertexServiceAccountJson.value = ''
+    vertexProjectId.value = ''
+    vertexClientEmail.value = ''
+    vertexLocation.value = 'global'
     // Reset Anthropic/Antigravity-specific settings when switching to other platforms
     if (newPlatform !== 'anthropic' && newPlatform !== 'antigravity') {
       interceptWarmupRequests.value = false
@@ -3886,6 +4111,10 @@ const resetForm = () => {
   antigravityAccountType.value = 'oauth'
   upstreamBaseUrl.value = ''
   upstreamApiKey.value = ''
+  vertexServiceAccountJson.value = ''
+  vertexProjectId.value = ''
+  vertexClientEmail.value = ''
+  vertexLocation.value = 'global'
   tempUnschedEnabled.value = false
   tempUnschedRules.value = []
   geminiOAuthType.value = 'code_assist'
@@ -4009,6 +4238,52 @@ const normalizePoolModeRetryCount = (value: number) => {
   return normalized
 }
 
+const applyVertexServiceAccountJson = (value: string) => {
+  const raw = value.trim()
+  if (!raw) {
+    vertexProjectId.value = ''
+    vertexClientEmail.value = ''
+    return false
+  }
+  try {
+    const parsed = JSON.parse(raw) as Record<string, unknown>
+    const projectId = typeof parsed.project_id === 'string' ? parsed.project_id.trim() : ''
+    const clientEmail = typeof parsed.client_email === 'string' ? parsed.client_email.trim() : ''
+    const privateKey = typeof parsed.private_key === 'string' ? parsed.private_key.trim() : ''
+    if (!projectId || !clientEmail || !privateKey) {
+      appStore.showError('Service Account JSON 缺少 project_id、client_email 或 private_key')
+      return false
+    }
+    vertexProjectId.value = projectId
+    vertexClientEmail.value = clientEmail
+    vertexServiceAccountJson.value = JSON.stringify(parsed)
+    return true
+  } catch {
+    appStore.showError('Service Account JSON 格式无效')
+    return false
+  }
+}
+
+const parseVertexServiceAccountJson = () => applyVertexServiceAccountJson(vertexServiceAccountJson.value)
+
+const handleVertexServiceAccountFile = async (event: Event) => {
+  const input = event.target as HTMLInputElement
+  const file = input.files?.[0]
+  if (!file) return
+  try {
+    applyVertexServiceAccountJson(await file.text())
+  } finally {
+    input.value = ''
+  }
+}
+
+const handleVertexServiceAccountDrop = async (event: DragEvent) => {
+  vertexServiceAccountDragActive.value = false
+  const file = event.dataTransfer?.files?.[0]
+  if (!file) return
+  applyVertexServiceAccountJson(await file.text())
+}
+
 const handleSubmit = async () => {
   // For OAuth-based type, handle OAuth flow (goes to step 2)
   if (isOAuthFlow.value) {
@@ -4122,6 +4397,29 @@ const handleSubmit = async () => {
     return
   }
 
+  if ((form.platform === 'gemini' || form.platform === 'anthropic') && accountCategory.value === 'service_account') {
+    if (!form.name.trim()) {
+      appStore.showError(t('admin.accounts.pleaseEnterAccountName'))
+      return
+    }
+    if (!parseVertexServiceAccountJson()) {
+      return
+    }
+    if (!vertexLocation.value.trim()) {
+      appStore.showError('请填写 Vertex location')
+      return
+    }
+    const credentials: Record<string, unknown> = {
+      service_account_json: vertexServiceAccountJson.value.trim(),
+      project_id: vertexProjectId.value.trim(),
+      client_email: vertexClientEmail.value.trim(),
+      location: vertexLocation.value.trim(),
+      tier_id: 'vertex'
+    }
+    await createAccountAndFinish(form.platform, 'service_account' as AccountType, credentials)
+    return
+  }
+
   // For apikey type, create directly
   if (!apiKeyValue.value.trim()) {
     appStore.showError(t('admin.accounts.pleaseEnterApiKey'))
diff --git a/frontend/src/components/account/EditAccountModal.vue b/frontend/src/components/account/EditAccountModal.vue
index 42211ba7..69e2186b 100644
--- a/frontend/src/components/account/EditAccountModal.vue
+++ b/frontend/src/components/account/EditAccountModal.vue
@@ -567,6 +567,46 @@
         </div>
       </div>
 
+      <!-- Vertex Service Account -->
+      <div v-if="(account.platform === 'gemini' || account.platform === 'anthropic') && account.type === 'service_account'" class="space-y-4">
+        <div class="grid grid-cols-1 gap-4 sm:grid-cols-2">
+          <div>
+            <label class="input-label">Project ID</label>
+            <input
+              v-model="editVertexProjectId"
+              type="text"
+              class="input font-mono"
+              readonly
+              placeholder="从 JSON 自动读取"
+            />
+            <p class="input-hint">Service Account JSON 不在编辑页显示；需要更换 JSON 时请删除账号后重新创建。</p>
+          </div>
+          <div>
+            <label class="input-label">Location</label>
+            <select
+              v-model="editVertexLocation"
+              required
+              class="input font-mono"
+            >
+              <optgroup
+                v-for="group in vertexLocationOptions"
+                :key="group.label"
+                :label="group.label"
+              >
+                <option
+                  v-for="option in group.options"
+                  :key="option.value"
+                  :value="option.value"
+                >
+                  {{ option.label }}
+                </option>
+              </optgroup>
+            </select>
+            <p class="input-hint">不同 Vertex 模型可用 location 可能不同，这里选择账号默认 endpoint location。</p>
+          </div>
+        </div>
+      </div>
+
       <!-- Bedrock fields (for bedrock type, both SigV4 and API Key modes) -->
       <div v-if="account.type === 'bedrock'" class="space-y-4">
         <!-- SigV4 fields -->
@@ -1987,6 +2027,55 @@ const editBedrockSessionToken = ref('')
 const editBedrockRegion = ref('')
 const editBedrockForceGlobal = ref(false)
 const editBedrockApiKeyValue = ref('')
+const editVertexProjectId = ref('')
+const editVertexClientEmail = ref('')
+const editVertexLocation = ref('us-central1')
+const vertexLocationOptions = [
+  {
+    label: 'Common',
+    options: [
+      { value: 'us-central1', label: 'us-central1 (Iowa)' },
+      { value: 'global', label: 'global' },
+      { value: 'us', label: 'us' },
+      { value: 'eu', label: 'eu' }
+    ]
+  },
+  {
+    label: 'United States',
+    options: [
+      { value: 'us-east1', label: 'us-east1 (South Carolina)' },
+      { value: 'us-east4', label: 'us-east4 (Northern Virginia)' },
+      { value: 'us-east5', label: 'us-east5 (Columbus)' },
+      { value: 'us-south1', label: 'us-south1 (Dallas)' },
+      { value: 'us-west1', label: 'us-west1 (Oregon)' },
+      { value: 'us-west4', label: 'us-west4 (Las Vegas)' }
+    ]
+  },
+  {
+    label: 'Europe',
+    options: [
+      { value: 'europe-west1', label: 'europe-west1 (Belgium)' },
+      { value: 'europe-west2', label: 'europe-west2 (London)' },
+      { value: 'europe-west3', label: 'europe-west3 (Frankfurt)' },
+      { value: 'europe-west4', label: 'europe-west4 (Netherlands)' },
+      { value: 'europe-west6', label: 'europe-west6 (Zurich)' },
+      { value: 'europe-west8', label: 'europe-west8 (Milan)' },
+      { value: 'europe-west9', label: 'europe-west9 (Paris)' }
+    ]
+  },
+  {
+    label: 'Asia Pacific',
+    options: [
+      { value: 'asia-east1', label: 'asia-east1 (Taiwan)' },
+      { value: 'asia-east2', label: 'asia-east2 (Hong Kong)' },
+      { value: 'asia-northeast1', label: 'asia-northeast1 (Tokyo)' },
+      { value: 'asia-northeast3', label: 'asia-northeast3 (Seoul)' },
+      { value: 'asia-south1', label: 'asia-south1 (Mumbai)' },
+      { value: 'asia-southeast1', label: 'asia-southeast1 (Singapore)' },
+      { value: 'australia-southeast1', label: 'australia-southeast1 (Sydney)' }
+    ]
+  }
+] as const
 const isBedrockAPIKeyMode = computed(() =>
   props.account?.type === 'bedrock' &&
   (props.account?.credentials as Record<string, unknown>)?.auth_mode === 'apikey'
@@ -2246,6 +2335,9 @@ const syncFormFromAccount = (newAccount: Account | null) => {
   const credentials = newAccount.credentials as Record<string, unknown> | undefined
   interceptWarmupRequests.value = credentials?.intercept_warmup_requests === true
   autoPauseOnExpired.value = newAccount.auto_pause_on_expired === true
+  editVertexProjectId.value = ''
+  editVertexClientEmail.value = ''
+  editVertexLocation.value = 'us-central1'
 
   // Load mixed scheduling setting (only for antigravity accounts)
   mixedScheduling.value = false
@@ -2467,6 +2559,11 @@ const syncFormFromAccount = (newAccount: Account | null) => {
   } else if (newAccount.type === 'upstream' && newAccount.credentials) {
     const credentials = newAccount.credentials as Record<string, unknown>
     editBaseUrl.value = (credentials.base_url as string) || ''
+  } else if ((newAccount.platform === 'gemini' || newAccount.platform === 'anthropic') && newAccount.type === 'service_account' && newAccount.credentials) {
+    const credentials = newAccount.credentials as Record<string, unknown>
+    editVertexProjectId.value = (credentials.project_id as string) || ''
+    editVertexClientEmail.value = (credentials.client_email as string) || ''
+    editVertexLocation.value = (credentials.location as string) || (credentials.vertex_location as string) || 'us-central1'
   } else {
     const platformDefaultUrl =
       newAccount.platform === 'openai'
@@ -3057,6 +3154,38 @@ const handleSubmit = async () => {
         return
       }
 
+      updatePayload.credentials = newCredentials
+    } else if ((props.account.platform === 'gemini' || props.account.platform === 'anthropic') && props.account.type === 'service_account') {
+      const currentCredentials = (props.account.credentials as Record<string, unknown>) || {}
+      const newCredentials: Record<string, unknown> = { ...currentCredentials }
+
+      if (!editVertexProjectId.value.trim()) {
+        appStore.showError('Service Account JSON 缺少 project_id')
+        return
+      }
+      if (!editVertexClientEmail.value.trim()) {
+        appStore.showError('Service Account JSON 缺少 client_email')
+        return
+      }
+      if (!editVertexLocation.value.trim()) {
+        appStore.showError('请填写 Vertex location')
+        return
+      }
+
+      if (!currentCredentials.service_account_json && !currentCredentials.service_account) {
+        appStore.showError('请上传 Service Account JSON')
+        return
+      }
+      newCredentials.project_id = editVertexProjectId.value.trim()
+      newCredentials.client_email = editVertexClientEmail.value.trim()
+      newCredentials.location = editVertexLocation.value.trim()
+      newCredentials.tier_id = 'vertex'
+
+      applyInterceptWarmup(newCredentials, interceptWarmupRequests.value, 'edit')
+      if (!applyTempUnschedConfig(newCredentials)) {
+        return
+      }
+
       updatePayload.credentials = newCredentials
     } else if (props.account.type === 'bedrock') {
       const currentCredentials = (props.account.credentials as Record<string, unknown>) || {}
diff --git a/frontend/src/components/common/PlatformTypeBadge.vue b/frontend/src/components/common/PlatformTypeBadge.vue
index 1ebc8892..1c7b08c0 100644
--- a/frontend/src/components/common/PlatformTypeBadge.vue
+++ b/frontend/src/components/common/PlatformTypeBadge.vue
@@ -25,6 +25,7 @@
         <!-- Setup Token icon -->
         <Icon v-else-if="type === 'setup-token'" name="shield" size="xs" />
         <!-- API Key icon -->
+        <Icon v-else-if="type === 'service_account'" name="cloud" size="xs" />
         <Icon v-else name="key" size="xs" />
         <span>{{ typeLabel }}</span>
       </span>
@@ -88,6 +89,8 @@ const typeLabel = computed(() => {
       return 'Key'
     case 'bedrock':
       return 'AWS'
+    case 'service_account':
+      return 'Vertex'
     default:
       return props.type
   }
diff --git a/frontend/src/types/index.ts b/frontend/src/types/index.ts
index 2a15ad00..80789011 100644
--- a/frontend/src/types/index.ts
+++ b/frontend/src/types/index.ts
@@ -641,7 +641,7 @@ export interface UpdateGroupRequest {
 // ==================== Account & Proxy Types ====================
 
 export type AccountPlatform = 'anthropic' | 'openai' | 'gemini' | 'antigravity'
-export type AccountType = 'oauth' | 'setup-token' | 'apikey' | 'upstream' | 'bedrock'
+export type AccountType = 'oauth' | 'setup-token' | 'apikey' | 'upstream' | 'bedrock' | 'service_account'
 export type OAuthAddMethod = 'oauth' | 'setup-token'
 export type ProxyProtocol = 'http' | 'https' | 'socks5' | 'socks5h'