feat: 完善 Antigravity 多平台网关支持，修复 Gemini handler 分流逻辑

backend/cmd/server/wire_gen.go

@@ -122,8 +122,10 @@ func initializeApplication(buildInfo handler.BuildInfo) (*Application, error) {
 	timingWheelService := service.ProvideTimingWheelService()
 	deferredService := service.ProvideDeferredService(accountRepository, timingWheelService)
 	gatewayService := service.NewGatewayService(accountRepository, usageLogRepository, userRepository, userSubscriptionRepository, gatewayCache, configConfig, billingService, rateLimitService, billingCacheService, identityService, httpUpstream, deferredService)
-	geminiMessagesCompatService := service.NewGeminiMessagesCompatService(accountRepository, gatewayCache, geminiTokenProvider, rateLimitService, httpUpstream)
-	gatewayHandler := handler.NewGatewayHandler(gatewayService, geminiMessagesCompatService, userService, concurrencyService, billingCacheService)
+	antigravityTokenProvider := service.NewAntigravityTokenProvider(accountRepository, geminiTokenCache, antigravityOAuthService)
+	antigravityGatewayService := service.NewAntigravityGatewayService(accountRepository, gatewayCache, antigravityTokenProvider, rateLimitService, httpUpstream)
+	geminiMessagesCompatService := service.NewGeminiMessagesCompatService(accountRepository, gatewayCache, geminiTokenProvider, rateLimitService, httpUpstream, antigravityGatewayService)
+	gatewayHandler := handler.NewGatewayHandler(gatewayService, geminiMessagesCompatService, antigravityGatewayService, userService, concurrencyService, billingCacheService)
 	openAIGatewayService := service.NewOpenAIGatewayService(accountRepository, usageLogRepository, userRepository, userSubscriptionRepository, gatewayCache, configConfig, billingService, rateLimitService, billingCacheService, httpUpstream, deferredService)
 	openAIGatewayHandler := handler.NewOpenAIGatewayHandler(openAIGatewayService, concurrencyService, billingCacheService)
 	handlerSettingHandler := handler.ProvideSettingHandler(settingService, buildInfo)
@@ -133,7 +135,7 @@ func initializeApplication(buildInfo handler.BuildInfo) (*Application, error) {
 	apiKeyAuthMiddleware := middleware.NewApiKeyAuthMiddleware(apiKeyService, subscriptionService)
 	engine := server.ProvideRouter(configConfig, handlers, jwtAuthMiddleware, adminAuthMiddleware, apiKeyAuthMiddleware, apiKeyService, subscriptionService)
 	httpServer := server.ProvideHTTPServer(configConfig, engine)
-	tokenRefreshService := service.ProvideTokenRefreshService(accountRepository, oAuthService, openAIOAuthService, geminiOAuthService, configConfig)
+	tokenRefreshService := service.ProvideTokenRefreshService(accountRepository, oAuthService, openAIOAuthService, geminiOAuthService, antigravityOAuthService, configConfig)
 	v := provideCleanup(db, client, tokenRefreshService, pricingService, emailQueueService, oAuthService, openAIOAuthService, geminiOAuthService, antigravityOAuthService)
 	application := &Application{
 		Server:  httpServer,

backend/internal/handler/gateway_handler.go

@@ -21,27 +21,30 @@ import (
 
 // GatewayHandler handles API gateway requests
 type GatewayHandler struct {
-	gatewayService      *service.GatewayService
-	geminiCompatService *service.GeminiMessagesCompatService
-	userService         *service.UserService
-	billingCacheService *service.BillingCacheService
-	concurrencyHelper   *ConcurrencyHelper
+	gatewayService            *service.GatewayService
+	geminiCompatService       *service.GeminiMessagesCompatService
+	antigravityGatewayService *service.AntigravityGatewayService
+	userService               *service.UserService
+	billingCacheService       *service.BillingCacheService
+	concurrencyHelper         *ConcurrencyHelper
 }
 
 // NewGatewayHandler creates a new GatewayHandler
 func NewGatewayHandler(
 	gatewayService *service.GatewayService,
 	geminiCompatService *service.GeminiMessagesCompatService,
+	antigravityGatewayService *service.AntigravityGatewayService,
 	userService *service.UserService,
 	concurrencyService *service.ConcurrencyService,
 	billingCacheService *service.BillingCacheService,
 ) *GatewayHandler {
 	return &GatewayHandler{
-		gatewayService:      gatewayService,
-		geminiCompatService: geminiCompatService,
-		userService:         userService,
-		billingCacheService: billingCacheService,
-		concurrencyHelper:   NewConcurrencyHelper(concurrencyService, SSEPingFormatClaude),
+		gatewayService:            gatewayService,
+		geminiCompatService:       geminiCompatService,
+		antigravityGatewayService: antigravityGatewayService,
+		userService:               userService,
+		billingCacheService:       billingCacheService,
+		concurrencyHelper:         NewConcurrencyHelper(concurrencyService, SSEPingFormatClaude),
 	}
 }
 
@@ -163,8 +166,13 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 				return
 			}
 
-			// 转发请求
-			result, err := h.geminiCompatService.Forward(c.Request.Context(), c, account, body)
+			// 转发请求 - 根据账号平台分流
+			var result *service.ForwardResult
+			if account.Platform == service.PlatformAntigravity {
+				result, err = h.antigravityGatewayService.ForwardGemini(c.Request.Context(), c, account, req.Model, "generateContent", req.Stream, body)
+			} else {
+				result, err = h.geminiCompatService.Forward(c.Request.Context(), c, account, body)
+			}
 			if accountReleaseFunc != nil {
 				accountReleaseFunc()
 			}
@@ -240,8 +248,13 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 			return
 		}
 
-		// 转发请求
-		result, err := h.gatewayService.Forward(c.Request.Context(), c, account, body)
+		// 转发请求 - 根据账号平台分流
+		var result *service.ForwardResult
+		if account.Platform == service.PlatformAntigravity {
+			result, err = h.antigravityGatewayService.Forward(c.Request.Context(), c, account, body)
+		} else {
+			result, err = h.gatewayService.Forward(c.Request.Context(), c, account, body)
+		}
 		if accountReleaseFunc != nil {
 			accountReleaseFunc()
 		}

backend/internal/handler/gemini_v1beta_handler.go

@@ -32,6 +32,13 @@ func (h *GatewayHandler) GeminiV1BetaListModels(c *gin.Context) {
 
 	account, err := h.geminiCompatService.SelectAccountForAIStudioEndpoints(c.Request.Context(), apiKey.GroupID)
 	if err != nil {
+		// 没有 gemini 账户，检查是否有 antigravity 账户可用
+		hasAntigravity, _ := h.geminiCompatService.HasAntigravityAccounts(c.Request.Context(), apiKey.GroupID)
+		if hasAntigravity {
+			// antigravity 账户使用静态模型列表
+			c.JSON(http.StatusOK, gemini.FallbackModelsList())
+			return
+		}
 		googleError(c, http.StatusServiceUnavailable, "No available Gemini accounts: "+err.Error())
 		return
 	}
@@ -69,6 +76,13 @@ func (h *GatewayHandler) GeminiV1BetaGetModel(c *gin.Context) {
 
 	account, err := h.geminiCompatService.SelectAccountForAIStudioEndpoints(c.Request.Context(), apiKey.GroupID)
 	if err != nil {
+		// 没有 gemini 账户，检查是否有 antigravity 账户可用
+		hasAntigravity, _ := h.geminiCompatService.HasAntigravityAccounts(c.Request.Context(), apiKey.GroupID)
+		if hasAntigravity {
+			// antigravity 账户使用静态模型信息
+			c.JSON(http.StatusOK, gemini.FallbackModel(modelName))
+			return
+		}
 		googleError(c, http.StatusServiceUnavailable, "No available Gemini accounts: "+err.Error())
 		return
 	}
@@ -182,8 +196,13 @@ func (h *GatewayHandler) GeminiV1BetaModels(c *gin.Context) {
 			return
 		}
 
-		// 5) forward (writes response to client)
-		result, err := h.geminiCompatService.ForwardNative(c.Request.Context(), c, account, modelName, action, stream, body)
+		// 5) forward (根据平台分流)
+		var result *service.ForwardResult
+		if account.Platform == service.PlatformAntigravity {
+			result, err = h.antigravityGatewayService.ForwardGemini(c.Request.Context(), c, account, modelName, action, stream, body)
+		} else {
+			result, err = h.geminiCompatService.ForwardNative(c.Request.Context(), c, account, modelName, action, stream, body)
+		}
 		if accountReleaseFunc != nil {
 			accountReleaseFunc()
 		}

backend/internal/handler/gemini_v1beta_handler_test.go

+//go:build unit
+
+package handler
+
+import (
+	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/stretchr/testify/require"
+)
+
+// TestGeminiV1BetaHandler_PlatformRoutingInvariant 文档化并验证 Handler 层的平台路由逻辑不变量
+// 该测试确保 gemini 和 antigravity 平台的路由逻辑符合预期
+func TestGeminiV1BetaHandler_PlatformRoutingInvariant(t *testing.T) {
+	tests := []struct {
+		name            string
+		platform        string
+		expectedService string
+		description     string
+	}{
+		{
+			name:            "Gemini平台使用ForwardNative",
+			platform:        service.PlatformGemini,
+			expectedService: "GeminiMessagesCompatService.ForwardNative",
+			description:     "Gemini OAuth 账户直接调用 Google API",
+		},
+		{
+			name:            "Antigravity平台使用ForwardGemini",
+			platform:        service.PlatformAntigravity,
+			expectedService: "AntigravityGatewayService.ForwardGemini",
+			description:     "Antigravity 账户通过 CRS 中转，支持 Gemini 协议",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// 模拟 GeminiV1BetaModels 中的路由决策 (lines 199-205 in gemini_v1beta_handler.go)
+			var routedService string
+			if tt.platform == service.PlatformAntigravity {
+				routedService = "AntigravityGatewayService.ForwardGemini"
+			} else {
+				routedService = "GeminiMessagesCompatService.ForwardNative"
+			}
+
+			require.Equal(t, tt.expectedService, routedService,
+				"平台 %s 应该路由到 %s: %s",
+				tt.platform, tt.expectedService, tt.description)
+		})
+	}
+}
+
+// TestGeminiV1BetaHandler_ListModelsAntigravityFallback 验证 ListModels 的 antigravity 降级逻辑
+// 当没有 gemini 账户但有 antigravity 账户时，应返回静态模型列表
+func TestGeminiV1BetaHandler_ListModelsAntigravityFallback(t *testing.T) {
+	tests := []struct {
+		name             string
+		hasGeminiAccount bool
+		hasAntigravity   bool
+		expectedBehavior string
+	}{
+		{
+			name:             "有Gemini账户-调用ForwardAIStudioGET",
+			hasGeminiAccount: true,
+			hasAntigravity:   false,
+			expectedBehavior: "forward_to_upstream",
+		},
+		{
+			name:             "无Gemini有Antigravity-返回静态列表",
+			hasGeminiAccount: false,
+			hasAntigravity:   true,
+			expectedBehavior: "static_fallback",
+		},
+		{
+			name:             "无任何账户-返回503",
+			hasGeminiAccount: false,
+			hasAntigravity:   false,
+			expectedBehavior: "service_unavailable",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// 模拟 GeminiV1BetaListModels 的逻辑 (lines 33-44 in gemini_v1beta_handler.go)
+			var behavior string
+
+			if tt.hasGeminiAccount {
+				behavior = "forward_to_upstream"
+			} else if tt.hasAntigravity {
+				behavior = "static_fallback"
+			} else {
+				behavior = "service_unavailable"
+			}
+
+			require.Equal(t, tt.expectedBehavior, behavior)
+		})
+	}
+}
+
+// TestGeminiV1BetaHandler_GetModelAntigravityFallback 验证 GetModel 的 antigravity 降级逻辑
+func TestGeminiV1BetaHandler_GetModelAntigravityFallback(t *testing.T) {
+	tests := []struct {
+		name             string
+		hasGeminiAccount bool
+		hasAntigravity   bool
+		expectedBehavior string
+	}{
+		{
+			name:             "有Gemini账户-调用ForwardAIStudioGET",
+			hasGeminiAccount: true,
+			hasAntigravity:   false,
+			expectedBehavior: "forward_to_upstream",
+		},
+		{
+			name:             "无Gemini有Antigravity-返回静态模型信息",
+			hasGeminiAccount: false,
+			hasAntigravity:   true,
+			expectedBehavior: "static_model_info",
+		},
+		{
+			name:             "无任何账户-返回503",
+			hasGeminiAccount: false,
+			hasAntigravity:   false,
+			expectedBehavior: "service_unavailable",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// 模拟 GeminiV1BetaGetModel 的逻辑 (lines 77-87 in gemini_v1beta_handler.go)
+			var behavior string
+
+			if tt.hasGeminiAccount {
+				behavior = "forward_to_upstream"
+			} else if tt.hasAntigravity {
+				behavior = "static_model_info"
+			} else {
+				behavior = "service_unavailable"
+			}
+
+			require.Equal(t, tt.expectedBehavior, behavior)
+		})
+	}
+}

backend/internal/repository/account_repo.go

@@ -337,6 +337,56 @@ func (r *accountRepository) ListSchedulableByGroupIDAndPlatform(ctx context.Cont
 	return outAccounts, nil
 }
 
+func (r *accountRepository) ListSchedulableByPlatforms(ctx context.Context, platforms []string) ([]service.Account, error) {
+	if len(platforms) == 0 {
+		return nil, nil
+	}
+	var accounts []accountModel
+	now := time.Now()
+	err := r.db.WithContext(ctx).
+		Where("platform IN ?", platforms).
+		Where("status = ? AND schedulable = ?", service.StatusActive, true).
+		Where("(overload_until IS NULL OR overload_until <= ?)", now).
+		Where("(rate_limit_reset_at IS NULL OR rate_limit_reset_at <= ?)", now).
+		Preload("Proxy").
+		Order("priority ASC").
+		Find(&accounts).Error
+	if err != nil {
+		return nil, err
+	}
+	outAccounts := make([]service.Account, 0, len(accounts))
+	for i := range accounts {
+		outAccounts = append(outAccounts, *accountModelToService(&accounts[i]))
+	}
+	return outAccounts, nil
+}
+
+func (r *accountRepository) ListSchedulableByGroupIDAndPlatforms(ctx context.Context, groupID int64, platforms []string) ([]service.Account, error) {
+	if len(platforms) == 0 {
+		return nil, nil
+	}
+	var accounts []accountModel
+	now := time.Now()
+	err := r.db.WithContext(ctx).
+		Joins("JOIN account_groups ON account_groups.account_id = accounts.id").
+		Where("account_groups.group_id = ?", groupID).
+		Where("accounts.platform IN ?", platforms).
+		Where("accounts.status = ? AND accounts.schedulable = ?", service.StatusActive, true).
+		Where("(accounts.overload_until IS NULL OR accounts.overload_until <= ?)", now).
+		Where("(accounts.rate_limit_reset_at IS NULL OR accounts.rate_limit_reset_at <= ?)", now).
+		Preload("Proxy").
+		Order("account_groups.priority ASC, accounts.priority ASC").
+		Find(&accounts).Error
+	if err != nil {
+		return nil, err
+	}
+	outAccounts := make([]service.Account, 0, len(accounts))
+	for i := range accounts {
+		outAccounts = append(outAccounts, *accountModelToService(&accounts[i]))
+	}
+	return outAccounts, nil
+}
+
 func (r *accountRepository) SetRateLimited(ctx context.Context, id int64, resetAt time.Time) error {
 	now := time.Now()
 	return r.db.WithContext(ctx).Model(&accountModel{}).Where("id = ?", id).

backend/internal/repository/gateway_routing_integration_test.go

+//go:build integration
+
+package repository
+
+import (
+	"context"
+	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/stretchr/testify/suite"
+	"gorm.io/datatypes"
+	"gorm.io/gorm"
+)
+
+// GatewayRoutingSuite 测试网关路由相关的数据库查询
+// 验证账户选择和分流逻辑在真实数据库环境下的行为
+type GatewayRoutingSuite struct {
+	suite.Suite
+	ctx         context.Context
+	db          *gorm.DB
+	accountRepo *accountRepository
+}
+
+func (s *GatewayRoutingSuite) SetupTest() {
+	s.ctx = context.Background()
+	s.db = testTx(s.T())
+	s.accountRepo = NewAccountRepository(s.db).(*accountRepository)
+}
+
+func TestGatewayRoutingSuite(t *testing.T) {
+	suite.Run(t, new(GatewayRoutingSuite))
+}
+
+// TestListSchedulableByPlatforms_GeminiAndAntigravity 验证多平台账户查询
+func (s *GatewayRoutingSuite) TestListSchedulableByPlatforms_GeminiAndAntigravity() {
+	// 创建各平台账户
+	geminiAcc := mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "gemini-oauth",
+		Platform:    service.PlatformGemini,
+		Type:        service.AccountTypeOAuth,
+		Status:      service.StatusActive,
+		Schedulable: true,
+		Priority:    1,
+	})
+
+	antigravityAcc := mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "antigravity-oauth",
+		Platform:    service.PlatformAntigravity,
+		Type:        service.AccountTypeOAuth,
+		Status:      service.StatusActive,
+		Schedulable: true,
+		Priority:    2,
+		Credentials: datatypes.JSONMap{
+			"access_token":  "test-token",
+			"refresh_token": "test-refresh",
+			"project_id":    "test-project",
+		},
+	})
+
+	// 创建不应被选中的 anthropic 账户
+	mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "anthropic-oauth",
+		Platform:    service.PlatformAnthropic,
+		Type:        service.AccountTypeOAuth,
+		Status:      service.StatusActive,
+		Schedulable: true,
+		Priority:    0,
+	})
+
+	// 查询 gemini + antigravity 平台
+	accounts, err := s.accountRepo.ListSchedulableByPlatforms(s.ctx, []string{
+		service.PlatformGemini,
+		service.PlatformAntigravity,
+	})
+
+	s.Require().NoError(err)
+	s.Require().Len(accounts, 2, "应返回 gemini 和 antigravity 两个账户")
+
+	// 验证返回的账户平台
+	platforms := make(map[string]bool)
+	for _, acc := range accounts {
+		platforms[acc.Platform] = true
+	}
+	s.Require().True(platforms[service.PlatformGemini], "应包含 gemini 账户")
+	s.Require().True(platforms[service.PlatformAntigravity], "应包含 antigravity 账户")
+	s.Require().False(platforms[service.PlatformAnthropic], "不应包含 anthropic 账户")
+
+	// 验证账户 ID 匹配
+	ids := make(map[int64]bool)
+	for _, acc := range accounts {
+		ids[acc.ID] = true
+	}
+	s.Require().True(ids[geminiAcc.ID])
+	s.Require().True(ids[antigravityAcc.ID])
+}
+
+// TestListSchedulableByGroupIDAndPlatforms_WithGroupBinding 验证按分组过滤
+func (s *GatewayRoutingSuite) TestListSchedulableByGroupIDAndPlatforms_WithGroupBinding() {
+	// 创建 gemini 分组
+	group := mustCreateGroup(s.T(), s.db, &groupModel{
+		Name:     "gemini-group",
+		Platform: service.PlatformGemini,
+		Status:   service.StatusActive,
+	})
+
+	// 创建账户
+	boundAcc := mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "bound-antigravity",
+		Platform:    service.PlatformAntigravity,
+		Status:      service.StatusActive,
+		Schedulable: true,
+	})
+	unboundAcc := mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "unbound-antigravity",
+		Platform:    service.PlatformAntigravity,
+		Status:      service.StatusActive,
+		Schedulable: true,
+	})
+
+	// 只绑定一个账户到分组
+	mustBindAccountToGroup(s.T(), s.db, boundAcc.ID, group.ID, 1)
+
+	// 查询分组内的账户
+	accounts, err := s.accountRepo.ListSchedulableByGroupIDAndPlatforms(s.ctx, group.ID, []string{
+		service.PlatformGemini,
+		service.PlatformAntigravity,
+	})
+
+	s.Require().NoError(err)
+	s.Require().Len(accounts, 1, "应只返回绑定到分组的账户")
+	s.Require().Equal(boundAcc.ID, accounts[0].ID)
+
+	// 确认未绑定的账户不在结果中
+	for _, acc := range accounts {
+		s.Require().NotEqual(unboundAcc.ID, acc.ID, "不应包含未绑定的账户")
+	}
+}
+
+// TestListSchedulableByPlatform_Antigravity 验证单平台查询
+func (s *GatewayRoutingSuite) TestListSchedulableByPlatform_Antigravity() {
+	// 创建多种平台账户
+	mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "gemini-1",
+		Platform:    service.PlatformGemini,
+		Status:      service.StatusActive,
+		Schedulable: true,
+	})
+
+	antigravity := mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "antigravity-1",
+		Platform:    service.PlatformAntigravity,
+		Status:      service.StatusActive,
+		Schedulable: true,
+	})
+
+	// 只查询 antigravity 平台
+	accounts, err := s.accountRepo.ListSchedulableByPlatform(s.ctx, service.PlatformAntigravity)
+
+	s.Require().NoError(err)
+	s.Require().Len(accounts, 1)
+	s.Require().Equal(antigravity.ID, accounts[0].ID)
+	s.Require().Equal(service.PlatformAntigravity, accounts[0].Platform)
+}
+
+// TestSchedulableFilter_ExcludesInactive 验证不可调度账户被过滤
+func (s *GatewayRoutingSuite) TestSchedulableFilter_ExcludesInactive() {
+	// 创建可调度账户
+	activeAcc := mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "active-antigravity",
+		Platform:    service.PlatformAntigravity,
+		Status:      service.StatusActive,
+		Schedulable: true,
+	})
+
+	// 创建不可调度账户（需要先创建再更新，因为 fixture 默认设置 Schedulable=true）
+	inactiveAcc := mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:     "inactive-antigravity",
+		Platform: service.PlatformAntigravity,
+		Status:   service.StatusActive,
+	})
+	s.Require().NoError(s.db.Model(&accountModel{}).Where("id = ?", inactiveAcc.ID).Update("schedulable", false).Error)
+
+	// 创建错误状态账户
+	mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "error-antigravity",
+		Platform:    service.PlatformAntigravity,
+		Status:      service.StatusError,
+		Schedulable: true,
+	})
+
+	accounts, err := s.accountRepo.ListSchedulableByPlatform(s.ctx, service.PlatformAntigravity)
+
+	s.Require().NoError(err)
+	s.Require().Len(accounts, 1, "应只返回可调度的 active 账户")
+	s.Require().Equal(activeAcc.ID, accounts[0].ID)
+}
+
+// TestPlatformRoutingDecision 验证平台路由决策
+// 这个测试模拟 Handler 层在选择账户后的路由决策逻辑
+func (s *GatewayRoutingSuite) TestPlatformRoutingDecision() {
+	// 创建两种平台的账户
+	geminiAcc := mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "gemini-route-test",
+		Platform:    service.PlatformGemini,
+		Status:      service.StatusActive,
+		Schedulable: true,
+	})
+
+	antigravityAcc := mustCreateAccount(s.T(), s.db, &accountModel{
+		Name:        "antigravity-route-test",
+		Platform:    service.PlatformAntigravity,
+		Status:      service.StatusActive,
+		Schedulable: true,
+	})
+
+	tests := []struct {
+		name            string
+		accountID       int64
+		expectedService string
+	}{
+		{
+			name:            "Gemini账户路由到ForwardNative",
+			accountID:       geminiAcc.ID,
+			expectedService: "GeminiMessagesCompatService.ForwardNative",
+		},
+		{
+			name:            "Antigravity账户路由到ForwardGemini",
+			accountID:       antigravityAcc.ID,
+			expectedService: "AntigravityGatewayService.ForwardGemini",
+		},
+	}
+
+	for _, tt := range tests {
+		s.Run(tt.name, func() {
+			// 从数据库获取账户
+			account, err := s.accountRepo.GetByID(s.ctx, tt.accountID)
+			s.Require().NoError(err)
+
+			// 模拟 Handler 层的路由决策
+			var routedService string
+			if account.Platform == service.PlatformAntigravity {
+				routedService = "AntigravityGatewayService.ForwardGemini"
+			} else {
+				routedService = "GeminiMessagesCompatService.ForwardNative"
+			}
+
+			s.Require().Equal(tt.expectedService, routedService)
+		})
+	}
+}

backend/internal/service/account_service.go

@@ -38,6 +38,8 @@ type AccountRepository interface {
 	ListSchedulableByGroupID(ctx context.Context, groupID int64) ([]Account, error)
 	ListSchedulableByPlatform(ctx context.Context, platform string) ([]Account, error)
 	ListSchedulableByGroupIDAndPlatform(ctx context.Context, groupID int64, platform string) ([]Account, error)
+	ListSchedulableByPlatforms(ctx context.Context, platforms []string) ([]Account, error)
+	ListSchedulableByGroupIDAndPlatforms(ctx context.Context, groupID int64, platforms []string) ([]Account, error)
 
 	SetRateLimited(ctx context.Context, id int64, resetAt time.Time) error
 	SetOverloaded(ctx context.Context, id int64, until time.Time) error

backend/internal/service/antigravity_model_mapping_test.go

+//go:build unit
+
+package service
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestIsAntigravityModelSupported(t *testing.T) {
+	tests := []struct {
+		name     string
+		model    string
+		expected bool
+	}{
+		// 直接支持的模型
+		{"直接支持 - claude-sonnet-4-5", "claude-sonnet-4-5", true},
+		{"直接支持 - claude-opus-4-5-thinking", "claude-opus-4-5-thinking", true},
+		{"直接支持 - claude-sonnet-4-5-thinking", "claude-sonnet-4-5-thinking", true},
+		{"直接支持 - gemini-2.5-flash", "gemini-2.5-flash", true},
+		{"直接支持 - gemini-2.5-flash-lite", "gemini-2.5-flash-lite", true},
+		{"直接支持 - gemini-3-pro-high", "gemini-3-pro-high", true},
+
+		// 可映射的模型
+		{"可映射 - claude-3-5-sonnet-20241022", "claude-3-5-sonnet-20241022", true},
+		{"可映射 - claude-3-5-sonnet-20240620", "claude-3-5-sonnet-20240620", true},
+		{"可映射 - claude-opus-4", "claude-opus-4", true},
+		{"可映射 - claude-haiku-4", "claude-haiku-4", true},
+		{"可映射 - claude-3-haiku-20240307", "claude-3-haiku-20240307", true},
+
+		// Gemini 前缀透传
+		{"Gemini前缀 - gemini-1.5-pro", "gemini-1.5-pro", true},
+		{"Gemini前缀 - gemini-unknown-model", "gemini-unknown-model", true},
+		{"Gemini前缀 - gemini-future-version", "gemini-future-version", true},
+
+		// Claude 前缀兜底
+		{"Claude前缀 - claude-unknown-model", "claude-unknown-model", true},
+		{"Claude前缀 - claude-3-opus-20240229", "claude-3-opus-20240229", true},
+		{"Claude前缀 - claude-future-version", "claude-future-version", true},
+
+		// 不支持的模型
+		{"不支持 - gpt-4", "gpt-4", false},
+		{"不支持 - gpt-4o", "gpt-4o", false},
+		{"不支持 - llama-3", "llama-3", false},
+		{"不支持 - mistral-7b", "mistral-7b", false},
+		{"不支持 - 空字符串", "", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := IsAntigravityModelSupported(tt.model)
+			require.Equal(t, tt.expected, got, "model: %s", tt.model)
+		})
+	}
+}
+
+func TestAntigravityGatewayService_GetMappedModel(t *testing.T) {
+	svc := &AntigravityGatewayService{}
+
+	tests := []struct {
+		name           string
+		requestedModel string
+		accountMapping map[string]string
+		expected       string
+	}{
+		// 1. 账户级映射优先（注意：model_mapping 在 credentials 中存储为 map[string]any）
+		{
+			name:           "账户映射优先",
+			requestedModel: "claude-3-5-sonnet-20241022",
+			accountMapping: map[string]string{"claude-3-5-sonnet-20241022": "custom-model"},
+			expected:       "custom-model",
+		},
+		{
+			name:           "账户映射覆盖系统映射",
+			requestedModel: "claude-opus-4",
+			accountMapping: map[string]string{"claude-opus-4": "my-opus"},
+			expected:       "my-opus",
+		},
+
+		// 2. 系统默认映射
+		{
+			name:           "系统映射 - claude-3-5-sonnet-20241022",
+			requestedModel: "claude-3-5-sonnet-20241022",
+			accountMapping: nil,
+			expected:       "claude-sonnet-4-5",
+		},
+		{
+			name:           "系统映射 - claude-3-5-sonnet-20240620",
+			requestedModel: "claude-3-5-sonnet-20240620",
+			accountMapping: nil,
+			expected:       "claude-sonnet-4-5",
+		},
+		{
+			name:           "系统映射 - claude-opus-4",
+			requestedModel: "claude-opus-4",
+			accountMapping: nil,
+			expected:       "claude-opus-4-5-thinking",
+		},
+		{
+			name:           "系统映射 - claude-opus-4-5-20251101",
+			requestedModel: "claude-opus-4-5-20251101",
+			accountMapping: nil,
+			expected:       "claude-opus-4-5-thinking",
+		},
+		{
+			name:           "系统映射 - claude-haiku-4",
+			requestedModel: "claude-haiku-4",
+			accountMapping: nil,
+			expected:       "claude-sonnet-4-5",
+		},
+		{
+			name:           "系统映射 - claude-3-haiku-20240307",
+			requestedModel: "claude-3-haiku-20240307",
+			accountMapping: nil,
+			expected:       "claude-sonnet-4-5",
+		},
+		{
+			name:           "系统映射 - claude-sonnet-4-5-20250929",
+			requestedModel: "claude-sonnet-4-5-20250929",
+			accountMapping: nil,
+			expected:       "claude-sonnet-4-5-thinking",
+		},
+
+		// 3. Gemini 透传
+		{
+			name:           "Gemini透传 - gemini-2.5-flash",
+			requestedModel: "gemini-2.5-flash",
+			accountMapping: nil,
+			expected:       "gemini-2.5-flash",
+		},
+		{
+			name:           "Gemini透传 - gemini-1.5-pro",
+			requestedModel: "gemini-1.5-pro",
+			accountMapping: nil,
+			expected:       "gemini-1.5-pro",
+		},
+		{
+			name:           "Gemini透传 - gemini-future-model",
+			requestedModel: "gemini-future-model",
+			accountMapping: nil,
+			expected:       "gemini-future-model",
+		},
+
+		// 4. 直接支持的模型
+		{
+			name:           "直接支持 - claude-sonnet-4-5",
+			requestedModel: "claude-sonnet-4-5",
+			accountMapping: nil,
+			expected:       "claude-sonnet-4-5",
+		},
+		{
+			name:           "直接支持 - claude-opus-4-5-thinking",
+			requestedModel: "claude-opus-4-5-thinking",
+			accountMapping: nil,
+			expected:       "claude-opus-4-5-thinking",
+		},
+		{
+			name:           "直接支持 - claude-sonnet-4-5-thinking",
+			requestedModel: "claude-sonnet-4-5-thinking",
+			accountMapping: nil,
+			expected:       "claude-sonnet-4-5-thinking",
+		},
+
+		// 5. 默认值 fallback（未知 claude 模型）
+		{
+			name:           "默认值 - claude-unknown",
+			requestedModel: "claude-unknown",
+			accountMapping: nil,
+			expected:       "claude-sonnet-4-5",
+		},
+		{
+			name:           "默认值 - claude-3-opus-20240229",
+			requestedModel: "claude-3-opus-20240229",
+			accountMapping: nil,
+			expected:       "claude-sonnet-4-5",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			account := &Account{
+				Platform: PlatformAntigravity,
+			}
+			if tt.accountMapping != nil {
+				// GetModelMapping 期望 model_mapping 是 map[string]any 格式
+				mappingAny := make(map[string]any)
+				for k, v := range tt.accountMapping {
+					mappingAny[k] = v
+				}
+				account.Credentials = map[string]any{
+					"model_mapping": mappingAny,
+				}
+			}
+
+			got := svc.getMappedModel(account, tt.requestedModel)
+			require.Equal(t, tt.expected, got, "model: %s", tt.requestedModel)
+		})
+	}
+}
+
+func TestAntigravityGatewayService_GetMappedModel_EdgeCases(t *testing.T) {
+	svc := &AntigravityGatewayService{}
+
+	tests := []struct {
+		name           string
+		requestedModel string
+		expected       string
+	}{
+		// 空字符串回退到默认值
+		{"空字符串", "", "claude-sonnet-4-5"},
+
+		// 非 claude/gemini 前缀回退到默认值
+		{"非claude/gemini前缀 - gpt", "gpt-4", "claude-sonnet-4-5"},
+		{"非claude/gemini前缀 - llama", "llama-3", "claude-sonnet-4-5"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			account := &Account{Platform: PlatformAntigravity}
+			got := svc.getMappedModel(account, tt.requestedModel)
+			require.Equal(t, tt.expected, got)
+		})
+	}
+}
+
+func TestAntigravityGatewayService_IsModelSupported(t *testing.T) {
+	svc := &AntigravityGatewayService{}
+
+	tests := []struct {
+		name     string
+		model    string
+		expected bool
+	}{
+		// 直接支持
+		{"直接支持 - claude-sonnet-4-5", "claude-sonnet-4-5", true},
+		{"直接支持 - gemini-3-flash", "gemini-3-flash", true},
+
+		// 可映射
+		{"可映射 - claude-opus-4", "claude-opus-4", true},
+
+		// 前缀透传
+		{"Gemini前缀", "gemini-unknown", true},
+		{"Claude前缀", "claude-unknown", true},
+
+		// 不支持
+		{"不支持 - gpt-4", "gpt-4", false},
+		{"不支持 - 空字符串", "", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := svc.IsModelSupported(tt.model)
+			require.Equal(t, tt.expected, got)
+		})
+	}
+}

backend/internal/service/antigravity_token_provider.go

+package service
+
+import (
+	"context"
+	"errors"
+	"log"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const (
+	antigravityTokenRefreshSkew = 3 * time.Minute
+	antigravityTokenCacheSkew   = 5 * time.Minute
+)
+
+// AntigravityTokenCache Token 缓存接口（复用 GeminiTokenCache 接口定义）
+type AntigravityTokenCache = GeminiTokenCache
+
+// AntigravityTokenProvider 管理 Antigravity 账户的 access_token
+type AntigravityTokenProvider struct {
+	accountRepo            AccountRepository
+	tokenCache             AntigravityTokenCache
+	antigravityOAuthService *AntigravityOAuthService
+}
+
+func NewAntigravityTokenProvider(
+	accountRepo AccountRepository,
+	tokenCache AntigravityTokenCache,
+	antigravityOAuthService *AntigravityOAuthService,
+) *AntigravityTokenProvider {
+	return &AntigravityTokenProvider{
+		accountRepo:            accountRepo,
+		tokenCache:             tokenCache,
+		antigravityOAuthService: antigravityOAuthService,
+	}
+}
+
+// GetAccessToken 获取有效的 access_token
+func (p *AntigravityTokenProvider) GetAccessToken(ctx context.Context, account *Account) (string, error) {
+	if account == nil {
+		return "", errors.New("account is nil")
+	}
+	if account.Platform != PlatformAntigravity || account.Type != AccountTypeOAuth {
+		return "", errors.New("not an antigravity oauth account")
+	}
+
+	cacheKey := antigravityTokenCacheKey(account)
+
+	// 1. 先尝试缓存
+	if p.tokenCache != nil {
+		if token, err := p.tokenCache.GetAccessToken(ctx, cacheKey); err == nil && strings.TrimSpace(token) != "" {
+			return token, nil
+		}
+	}
+
+	// 2. 如果即将过期则刷新
+	expiresAt := parseAntigravityExpiresAt(account)
+	needsRefresh := expiresAt == nil || time.Until(*expiresAt) <= antigravityTokenRefreshSkew
+	if needsRefresh && p.tokenCache != nil {
+		locked, err := p.tokenCache.AcquireRefreshLock(ctx, cacheKey, 30*time.Second)
+		if err == nil && locked {
+			defer func() { _ = p.tokenCache.ReleaseRefreshLock(ctx, cacheKey) }()
+
+			// 拿到锁后再次检查缓存（另一个 worker 可能已刷新）
+			if token, err := p.tokenCache.GetAccessToken(ctx, cacheKey); err == nil && strings.TrimSpace(token) != "" {
+				return token, nil
+			}
+
+			// 从数据库获取最新账户信息
+			fresh, err := p.accountRepo.GetByID(ctx, account.ID)
+			if err == nil && fresh != nil {
+				account = fresh
+			}
+			expiresAt = parseAntigravityExpiresAt(account)
+			if expiresAt == nil || time.Until(*expiresAt) <= antigravityTokenRefreshSkew {
+				if p.antigravityOAuthService == nil {
+					return "", errors.New("antigravity oauth service not configured")
+				}
+				tokenInfo, err := p.antigravityOAuthService.RefreshAccountToken(ctx, account)
+				if err != nil {
+					return "", err
+				}
+				newCredentials := p.antigravityOAuthService.BuildAccountCredentials(tokenInfo)
+				for k, v := range account.Credentials {
+					if _, exists := newCredentials[k]; !exists {
+						newCredentials[k] = v
+					}
+				}
+				account.Credentials = newCredentials
+				if updateErr := p.accountRepo.Update(ctx, account); updateErr != nil {
+					log.Printf("[AntigravityTokenProvider] Failed to update account credentials: %v", updateErr)
+				}
+				expiresAt = parseAntigravityExpiresAt(account)
+			}
+		}
+	}
+
+	accessToken := account.GetCredential("access_token")
+	if strings.TrimSpace(accessToken) == "" {
+		return "", errors.New("access_token not found in credentials")
+	}
+
+	// 3. 存入缓存
+	if p.tokenCache != nil {
+		ttl := 30 * time.Minute
+		if expiresAt != nil {
+			until := time.Until(*expiresAt)
+			switch {
+			case until > antigravityTokenCacheSkew:
+				ttl = until - antigravityTokenCacheSkew
+			case until > 0:
+				ttl = until
+			default:
+				ttl = time.Minute
+			}
+		}
+		_ = p.tokenCache.SetAccessToken(ctx, cacheKey, accessToken, ttl)
+	}
+
+	return accessToken, nil
+}
+
+func antigravityTokenCacheKey(account *Account) string {
+	projectID := strings.TrimSpace(account.GetCredential("project_id"))
+	if projectID != "" {
+		return "ag:" + projectID
+	}
+	return "ag:account:" + strconv.FormatInt(account.ID, 10)
+}
+
+func parseAntigravityExpiresAt(account *Account) *time.Time {
+	raw := strings.TrimSpace(account.GetCredential("expires_at"))
+	if raw == "" {
+		return nil
+	}
+	if unixSec, err := strconv.ParseInt(raw, 10, 64); err == nil && unixSec > 0 {
+		t := time.Unix(unixSec, 0)
+		return &t
+	}
+	if t, err := time.Parse(time.RFC3339, raw); err == nil {
+		return &t
+	}
+	return nil
+}

backend/internal/service/antigravity_token_refresher.go

+package service
+
+import (
+	"context"
+	"strconv"
+	"time"
+)
+
+// AntigravityTokenRefresher 实现 TokenRefresher 接口
+type AntigravityTokenRefresher struct {
+	antigravityOAuthService *AntigravityOAuthService
+}
+
+func NewAntigravityTokenRefresher(antigravityOAuthService *AntigravityOAuthService) *AntigravityTokenRefresher {
+	return &AntigravityTokenRefresher{
+		antigravityOAuthService: antigravityOAuthService,
+	}
+}
+
+// CanRefresh 检查是否可以刷新此账户
+func (r *AntigravityTokenRefresher) CanRefresh(account *Account) bool {
+	return account.Platform == PlatformAntigravity && account.Type == AccountTypeOAuth
+}
+
+// NeedsRefresh 检查账户是否需要刷新
+func (r *AntigravityTokenRefresher) NeedsRefresh(account *Account, refreshWindow time.Duration) bool {
+	if !r.CanRefresh(account) {
+		return false
+	}
+	expiresAtStr := account.GetCredential("expires_at")
+	if expiresAtStr == "" {
+		return false
+	}
+	expiresAt, err := strconv.ParseInt(expiresAtStr, 10, 64)
+	if err != nil {
+		return false
+	}
+	expiryTime := time.Unix(expiresAt, 0)
+	return time.Until(expiryTime) < refreshWindow
+}
+
+// Refresh 执行 token 刷新
+func (r *AntigravityTokenRefresher) Refresh(ctx context.Context, account *Account) (map[string]any, error) {
+	tokenInfo, err := r.antigravityOAuthService.RefreshAccountToken(ctx, account)
+	if err != nil {
+		return nil, err
+	}
+
+	newCredentials := r.antigravityOAuthService.BuildAccountCredentials(tokenInfo)
+	for k, v := range account.Credentials {
+		if _, exists := newCredentials[k]; !exists {
+			newCredentials[k] = v
+		}
+	}
+
+	return newCredentials, nil
+}

backend/internal/service/gateway_multiplatform_test.go

+//go:build unit
+
+package service
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
+	"github.com/stretchr/testify/require"
+)
+
+// mockAccountRepoForMultiplatform 多平台测试用的 mock
+type mockAccountRepoForMultiplatform struct {
+	accounts          []Account
+	accountsByID      map[int64]*Account
+	listPlatformsFunc func(ctx context.Context, platforms []string) ([]Account, error)
+}
+
+func (m *mockAccountRepoForMultiplatform) GetByID(ctx context.Context, id int64) (*Account, error) {
+	if acc, ok := m.accountsByID[id]; ok {
+		return acc, nil
+	}
+	return nil, errors.New("account not found")
+}
+
+func (m *mockAccountRepoForMultiplatform) ListSchedulableByPlatforms(ctx context.Context, platforms []string) ([]Account, error) {
+	if m.listPlatformsFunc != nil {
+		return m.listPlatformsFunc(ctx, platforms)
+	}
+	// 过滤符合平台的账户
+	var result []Account
+	platformSet := make(map[string]bool)
+	for _, p := range platforms {
+		platformSet[p] = true
+	}
+	for _, acc := range m.accounts {
+		if platformSet[acc.Platform] && acc.IsSchedulable() {
+			result = append(result, acc)
+		}
+	}
+	return result, nil
+}
+
+func (m *mockAccountRepoForMultiplatform) ListSchedulableByGroupIDAndPlatforms(ctx context.Context, groupID int64, platforms []string) ([]Account, error) {
+	return m.ListSchedulableByPlatforms(ctx, platforms)
+}
+
+// Stub methods to implement AccountRepository interface
+func (m *mockAccountRepoForMultiplatform) Create(ctx context.Context, account *Account) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) GetByCRSAccountID(ctx context.Context, crsAccountID string) (*Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForMultiplatform) Update(ctx context.Context, account *Account) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) Delete(ctx context.Context, id int64) error { return nil }
+func (m *mockAccountRepoForMultiplatform) List(ctx context.Context, params pagination.PaginationParams) ([]Account, *pagination.PaginationResult, error) {
+	return nil, nil, nil
+}
+func (m *mockAccountRepoForMultiplatform) ListWithFilters(ctx context.Context, params pagination.PaginationParams, platform, accountType, status, search string) ([]Account, *pagination.PaginationResult, error) {
+	return nil, nil, nil
+}
+func (m *mockAccountRepoForMultiplatform) ListByGroup(ctx context.Context, groupID int64) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForMultiplatform) ListActive(ctx context.Context) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForMultiplatform) ListByPlatform(ctx context.Context, platform string) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForMultiplatform) UpdateLastUsed(ctx context.Context, id int64) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) BatchUpdateLastUsed(ctx context.Context, updates map[int64]time.Time) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) SetError(ctx context.Context, id int64, errorMsg string) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) SetSchedulable(ctx context.Context, id int64, schedulable bool) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) BindGroups(ctx context.Context, accountID int64, groupIDs []int64) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) ListSchedulable(ctx context.Context) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForMultiplatform) ListSchedulableByGroupID(ctx context.Context, groupID int64) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForMultiplatform) ListSchedulableByPlatform(ctx context.Context, platform string) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForMultiplatform) ListSchedulableByGroupIDAndPlatform(ctx context.Context, groupID int64, platform string) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForMultiplatform) SetRateLimited(ctx context.Context, id int64, resetAt time.Time) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) SetOverloaded(ctx context.Context, id int64, until time.Time) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) ClearRateLimit(ctx context.Context, id int64) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) UpdateSessionWindow(ctx context.Context, id int64, start, end *time.Time, status string) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) UpdateExtra(ctx context.Context, id int64, updates map[string]any) error {
+	return nil
+}
+func (m *mockAccountRepoForMultiplatform) BulkUpdate(ctx context.Context, ids []int64, updates AccountBulkUpdate) (int64, error) {
+	return 0, nil
+}
+
+// Verify interface implementation
+var _ AccountRepository = (*mockAccountRepoForMultiplatform)(nil)
+
+// mockGatewayCacheForMultiplatform 多平台测试用的 cache mock
+type mockGatewayCacheForMultiplatform struct {
+	sessionBindings map[string]int64
+}
+
+func (m *mockGatewayCacheForMultiplatform) GetSessionAccountID(ctx context.Context, sessionHash string) (int64, error) {
+	if id, ok := m.sessionBindings[sessionHash]; ok {
+		return id, nil
+	}
+	return 0, errors.New("not found")
+}
+
+func (m *mockGatewayCacheForMultiplatform) SetSessionAccountID(ctx context.Context, sessionHash string, accountID int64, ttl time.Duration) error {
+	if m.sessionBindings == nil {
+		m.sessionBindings = make(map[string]int64)
+	}
+	m.sessionBindings[sessionHash] = accountID
+	return nil
+}
+
+func (m *mockGatewayCacheForMultiplatform) RefreshSessionTTL(ctx context.Context, sessionHash string, ttl time.Duration) error {
+	return nil
+}
+
+func ptr[T any](v T) *T {
+	return &v
+}
+
+func TestGatewayService_SelectAccountForModelWithExclusions_OnlyAnthropic(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForMultiplatform{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformAnthropic, Priority: 1, Status: StatusActive, Schedulable: true},
+			{ID: 2, Platform: PlatformAnthropic, Priority: 2, Status: StatusActive, Schedulable: true},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForMultiplatform{}
+
+	svc := &GatewayService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "", "claude-3-5-sonnet-20241022", nil, []string{PlatformAnthropic, PlatformAntigravity})
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	require.Equal(t, int64(1), acc.ID, "应选择优先级最高的账户")
+}
+
+func TestGatewayService_SelectAccountForModelWithExclusions_OnlyAntigravity(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForMultiplatform{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForMultiplatform{}
+
+	svc := &GatewayService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "", "claude-3-5-sonnet-20241022", nil, []string{PlatformAnthropic, PlatformAntigravity})
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	require.Equal(t, int64(1), acc.ID)
+	require.Equal(t, PlatformAntigravity, acc.Platform)
+}
+
+func TestGatewayService_SelectAccountForModelWithExclusions_MixedPlatforms_SamePriority(t *testing.T) {
+	ctx := context.Background()
+	now := time.Now()
+
+	repo := &mockAccountRepoForMultiplatform{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformAnthropic, Priority: 1, Status: StatusActive, Schedulable: true, LastUsedAt: ptr(now.Add(-1 * time.Hour))},
+			{ID: 2, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true, LastUsedAt: ptr(now.Add(-2 * time.Hour))},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForMultiplatform{}
+
+	svc := &GatewayService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "", "claude-3-5-sonnet-20241022", nil, []string{PlatformAnthropic, PlatformAntigravity})
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	require.Equal(t, int64(2), acc.ID, "应选择最久未用的账户（Antigravity）")
+}
+
+func TestGatewayService_SelectAccountForModelWithExclusions_MixedPlatforms_DiffPriority(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForMultiplatform{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformAnthropic, Priority: 2, Status: StatusActive, Schedulable: true},
+			{ID: 2, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForMultiplatform{}
+
+	svc := &GatewayService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "", "claude-3-5-sonnet-20241022", nil, []string{PlatformAnthropic, PlatformAntigravity})
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	require.Equal(t, int64(2), acc.ID, "应选择优先级更高的账户（Antigravity, priority=1）")
+}
+
+func TestGatewayService_SelectAccountForModelWithExclusions_ModelNotSupported(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForMultiplatform{
+		accounts: []Account{
+			// Anthropic 账户配置了模型映射，只支持 other-model
+			// 注意：model_mapping 需要是 map[string]any 格式
+			{
+				ID: 1, Platform: PlatformAnthropic, Priority: 1, Status: StatusActive, Schedulable: true,
+				Credentials: map[string]any{"model_mapping": map[string]any{"other-model": "x"}},
+			},
+			// Antigravity 账户支持所有 claude 模型
+			{ID: 2, Platform: PlatformAntigravity, Priority: 2, Status: StatusActive, Schedulable: true},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForMultiplatform{}
+
+	svc := &GatewayService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "", "claude-3-5-sonnet-20241022", nil, []string{PlatformAnthropic, PlatformAntigravity})
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	require.Equal(t, int64(2), acc.ID, "Anthropic 不支持该模型，应选择 Antigravity")
+}
+
+func TestGatewayService_SelectAccountForModelWithExclusions_NoAvailableAccounts(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForMultiplatform{
+		accounts:     []Account{},
+		accountsByID: map[int64]*Account{},
+	}
+
+	cache := &mockGatewayCacheForMultiplatform{}
+
+	svc := &GatewayService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "", "claude-3-5-sonnet-20241022", nil, []string{PlatformAnthropic, PlatformAntigravity})
+	require.Error(t, err)
+	require.Nil(t, acc)
+	require.Contains(t, err.Error(), "no available accounts")
+}
+
+func TestGatewayService_SelectAccountForModelWithExclusions_AllExcluded(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForMultiplatform{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformAnthropic, Priority: 1, Status: StatusActive, Schedulable: true},
+			{ID: 2, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForMultiplatform{}
+
+	svc := &GatewayService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	excludedIDs := map[int64]struct{}{1: {}, 2: {}}
+	acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "", "claude-3-5-sonnet-20241022", excludedIDs, []string{PlatformAnthropic, PlatformAntigravity})
+	require.Error(t, err)
+	require.Nil(t, acc)
+}
+
+func TestGatewayService_SelectAccountForModelWithExclusions_Schedulability(t *testing.T) {
+	ctx := context.Background()
+	now := time.Now()
+
+	tests := []struct {
+		name       string
+		accounts   []Account
+		expectedID int64
+	}{
+		{
+			name: "过载账户被跳过",
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAnthropic, Priority: 1, Status: StatusActive, Schedulable: true, OverloadUntil: ptr(now.Add(1 * time.Hour))},
+				{ID: 2, Platform: PlatformAntigravity, Priority: 2, Status: StatusActive, Schedulable: true},
+			},
+			expectedID: 2,
+		},
+		{
+			name: "限流账户被跳过",
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAnthropic, Priority: 1, Status: StatusActive, Schedulable: true, RateLimitResetAt: ptr(now.Add(1 * time.Hour))},
+				{ID: 2, Platform: PlatformAntigravity, Priority: 2, Status: StatusActive, Schedulable: true},
+			},
+			expectedID: 2,
+		},
+		{
+			name: "非active账户被跳过",
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAnthropic, Priority: 1, Status: "error", Schedulable: true},
+				{ID: 2, Platform: PlatformAntigravity, Priority: 2, Status: StatusActive, Schedulable: true},
+			},
+			expectedID: 2,
+		},
+		{
+			name: "schedulable=false被跳过",
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAnthropic, Priority: 1, Status: StatusActive, Schedulable: false},
+				{ID: 2, Platform: PlatformAntigravity, Priority: 2, Status: StatusActive, Schedulable: true},
+			},
+			expectedID: 2,
+		},
+		{
+			name: "过期的过载账户可调度",
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAnthropic, Priority: 1, Status: StatusActive, Schedulable: true, OverloadUntil: ptr(now.Add(-1 * time.Hour))},
+				{ID: 2, Platform: PlatformAntigravity, Priority: 2, Status: StatusActive, Schedulable: true},
+			},
+			expectedID: 1,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			repo := &mockAccountRepoForMultiplatform{
+				accounts:     tt.accounts,
+				accountsByID: map[int64]*Account{},
+			}
+			for i := range repo.accounts {
+				repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+			}
+
+			cache := &mockGatewayCacheForMultiplatform{}
+
+			svc := &GatewayService{
+				accountRepo: repo,
+				cache:       cache,
+			}
+
+			acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "", "claude-3-5-sonnet-20241022", nil, []string{PlatformAnthropic, PlatformAntigravity})
+			require.NoError(t, err)
+			require.NotNil(t, acc)
+			require.Equal(t, tt.expectedID, acc.ID)
+		})
+	}
+}
+
+func TestGatewayService_SelectAccountForModelWithExclusions_StickySession(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("粘性会话命中", func(t *testing.T) {
+		repo := &mockAccountRepoForMultiplatform{
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAnthropic, Priority: 2, Status: StatusActive, Schedulable: true},
+				{ID: 2, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true},
+			},
+			accountsByID: map[int64]*Account{},
+		}
+		for i := range repo.accounts {
+			repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+		}
+
+		cache := &mockGatewayCacheForMultiplatform{
+			sessionBindings: map[string]int64{"session-123": 1},
+		}
+
+		svc := &GatewayService{
+			accountRepo: repo,
+			cache:       cache,
+		}
+
+		acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "session-123", "claude-3-5-sonnet-20241022", nil, []string{PlatformAnthropic, PlatformAntigravity})
+		require.NoError(t, err)
+		require.NotNil(t, acc)
+		require.Equal(t, int64(1), acc.ID, "应返回粘性会话绑定的账户")
+	})
+
+	t.Run("粘性会话账户被排除-降级选择", func(t *testing.T) {
+		repo := &mockAccountRepoForMultiplatform{
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAnthropic, Priority: 2, Status: StatusActive, Schedulable: true},
+				{ID: 2, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true},
+			},
+			accountsByID: map[int64]*Account{},
+		}
+		for i := range repo.accounts {
+			repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+		}
+
+		cache := &mockGatewayCacheForMultiplatform{
+			sessionBindings: map[string]int64{"session-123": 1},
+		}
+
+		svc := &GatewayService{
+			accountRepo: repo,
+			cache:       cache,
+		}
+
+		excludedIDs := map[int64]struct{}{1: {}}
+		acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "session-123", "claude-3-5-sonnet-20241022", excludedIDs, []string{PlatformAnthropic, PlatformAntigravity})
+		require.NoError(t, err)
+		require.NotNil(t, acc)
+		require.Equal(t, int64(2), acc.ID, "粘性会话账户被排除，应选择其他账户")
+	})
+
+	t.Run("粘性会话账户不可调度-降级选择", func(t *testing.T) {
+		repo := &mockAccountRepoForMultiplatform{
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAnthropic, Priority: 2, Status: "error", Schedulable: true},
+				{ID: 2, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true},
+			},
+			accountsByID: map[int64]*Account{},
+		}
+		for i := range repo.accounts {
+			repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+		}
+
+		cache := &mockGatewayCacheForMultiplatform{
+			sessionBindings: map[string]int64{"session-123": 1},
+		}
+
+		svc := &GatewayService{
+			accountRepo: repo,
+			cache:       cache,
+		}
+
+		acc, err := svc.selectAccountForModelWithPlatforms(ctx, nil, "session-123", "claude-3-5-sonnet-20241022", nil, []string{PlatformAnthropic, PlatformAntigravity})
+		require.NoError(t, err)
+		require.NotNil(t, acc)
+		require.Equal(t, int64(2), acc.ID, "粘性会话账户不可调度，应选择其他账户")
+	})
+}
+
+func TestGatewayService_isModelSupportedByAccount(t *testing.T) {
+	svc := &GatewayService{}
+
+	tests := []struct {
+		name     string
+		account  *Account
+		model    string
+		expected bool
+	}{
+		{
+			name:     "Antigravity平台-支持claude模型",
+			account:  &Account{Platform: PlatformAntigravity},
+			model:    "claude-3-5-sonnet-20241022",
+			expected: true,
+		},
+		{
+			name:     "Antigravity平台-支持gemini模型",
+			account:  &Account{Platform: PlatformAntigravity},
+			model:    "gemini-2.5-flash",
+			expected: true,
+		},
+		{
+			name:     "Antigravity平台-不支持gpt模型",
+			account:  &Account{Platform: PlatformAntigravity},
+			model:    "gpt-4",
+			expected: false,
+		},
+		{
+			name:     "Anthropic平台-无映射配置-支持所有模型",
+			account:  &Account{Platform: PlatformAnthropic},
+			model:    "claude-3-5-sonnet-20241022",
+			expected: true,
+		},
+		{
+			name: "Anthropic平台-有映射配置-只支持配置的模型",
+			account: &Account{
+				Platform:    PlatformAnthropic,
+				Credentials: map[string]any{"model_mapping": map[string]any{"claude-opus-4": "x"}},
+			},
+			model:    "claude-3-5-sonnet-20241022",
+			expected: false,
+		},
+		{
+			name: "Anthropic平台-有映射配置-支持配置的模型",
+			account: &Account{
+				Platform:    PlatformAnthropic,
+				Credentials: map[string]any{"model_mapping": map[string]any{"claude-3-5-sonnet-20241022": "x"}},
+			},
+			model:    "claude-3-5-sonnet-20241022",
+			expected: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := svc.isModelSupportedByAccount(tt.account, tt.model)
+			require.Equal(t, tt.expected, got)
+		})
+	}
+}

backend/internal/service/gateway_service.go

@@ -291,6 +291,13 @@ func (s *GatewayService) SelectAccountForModel(ctx context.Context, groupID *int
 
 // SelectAccountForModelWithExclusions selects an account supporting the requested model while excluding specified accounts.
 func (s *GatewayService) SelectAccountForModelWithExclusions(ctx context.Context, groupID *int64, sessionHash string, requestedModel string, excludedIDs map[int64]struct{}) (*Account, error) {
+	// 使用多平台账户选择，包含 anthropic 和 antigravity 平台
+	platforms := []string{PlatformAnthropic, PlatformAntigravity}
+	return s.selectAccountForModelWithPlatforms(ctx, groupID, sessionHash, requestedModel, excludedIDs, platforms)
+}
+
+// selectAccountForModelWithPlatforms 选择多平台账户
+func (s *GatewayService) selectAccountForModelWithPlatforms(ctx context.Context, groupID *int64, sessionHash string, requestedModel string, excludedIDs map[int64]struct{}, platforms []string) (*Account, error) {
 	// 1. 查询粘性会话
 	if sessionHash != "" {
 		accountID, err := s.cache.GetSessionAccountID(ctx, sessionHash)
@@ -298,8 +305,8 @@ func (s *GatewayService) SelectAccountForModelWithExclusions(ctx context.Context
 			if _, excluded := excludedIDs[accountID]; !excluded {
 				account, err := s.accountRepo.GetByID(ctx, accountID)
 				// 使用IsSchedulable代替IsActive，确保限流/过载账号不会被选中
-				// 同时检查模型支持
-				if err == nil && account.IsSchedulable() && (requestedModel == "" || account.IsModelSupported(requestedModel)) {
+				// 同时检查模型支持（根据平台类型分别处理）
+				if err == nil && account.IsSchedulable() && (requestedModel == "" || s.isModelSupportedByAccount(account, requestedModel)) {
 					// 续期粘性会话
 					if err := s.cache.RefreshSessionTTL(ctx, sessionHash, stickySessionTTL); err != nil {
 						log.Printf("refresh session ttl failed: session=%s err=%v", sessionHash, err)
@@ -310,13 +317,13 @@ func (s *GatewayService) SelectAccountForModelWithExclusions(ctx context.Context
 		}
 	}
 
-	// 2. 获取可调度账号列表（排除限流和过载的账号，仅限 Anthropic 平台）
+	// 2. 获取可调度账号列表（排除限流和过载的账号，支持多平台）
 	var accounts []Account
 	var err error
 	if groupID != nil {
-		accounts, err = s.accountRepo.ListSchedulableByGroupIDAndPlatform(ctx, *groupID, PlatformAnthropic)
+		accounts, err = s.accountRepo.ListSchedulableByGroupIDAndPlatforms(ctx, *groupID, platforms)
 	} else {
-		accounts, err = s.accountRepo.ListSchedulableByPlatform(ctx, PlatformAnthropic)
+		accounts, err = s.accountRepo.ListSchedulableByPlatforms(ctx, platforms)
 	}
 	if err != nil {
 		return nil, fmt.Errorf("query accounts failed: %w", err)
@@ -329,8 +336,8 @@ func (s *GatewayService) SelectAccountForModelWithExclusions(ctx context.Context
 		if _, excluded := excludedIDs[acc.ID]; excluded {
 			continue
 		}
-		// 检查模型支持
-		if requestedModel != "" && !acc.IsModelSupported(requestedModel) {
+		// 检查模型支持（根据平台类型分别处理）
+		if requestedModel != "" && !s.isModelSupportedByAccount(acc, requestedModel) {
 			continue
 		}
 		if selected == nil {
@@ -374,6 +381,37 @@ func (s *GatewayService) SelectAccountForModelWithExclusions(ctx context.Context
 	return selected, nil
 }
 
+// isModelSupportedByAccount 根据账户平台检查模型支持
+func (s *GatewayService) isModelSupportedByAccount(account *Account, requestedModel string) bool {
+	if account.Platform == PlatformAntigravity {
+		// Antigravity 平台使用专门的模型支持检查
+		return IsAntigravityModelSupported(requestedModel)
+	}
+	// 其他平台使用账户的模型支持检查
+	return account.IsModelSupported(requestedModel)
+}
+
+// IsAntigravityModelSupported 检查 Antigravity 平台是否支持指定模型
+func IsAntigravityModelSupported(requestedModel string) bool {
+	// 直接支持的模型
+	if antigravitySupportedModels[requestedModel] {
+		return true
+	}
+	// 可映射的模型
+	if _, ok := antigravityModelMapping[requestedModel]; ok {
+		return true
+	}
+	// Gemini 前缀透传
+	if strings.HasPrefix(requestedModel, "gemini-") {
+		return true
+	}
+	// Claude 模型支持（通过默认映射到 claude-sonnet-4-5）
+	if strings.HasPrefix(requestedModel, "claude-") {
+		return true
+	}
+	return false
+}
+
 // GetAccessToken 获取账号凭证
 func (s *GatewayService) GetAccessToken(ctx context.Context, account *Account) (string, string, error) {
 	switch account.Type {

backend/internal/service/gemini_messages_compat_service.go

@@ -33,11 +33,12 @@ const (
 )
 
 type GeminiMessagesCompatService struct {
-	accountRepo      AccountRepository
-	cache            GatewayCache
-	tokenProvider    *GeminiTokenProvider
-	rateLimitService *RateLimitService
-	httpUpstream     HTTPUpstream
+	accountRepo              AccountRepository
+	cache                    GatewayCache
+	tokenProvider            *GeminiTokenProvider
+	rateLimitService         *RateLimitService
+	httpUpstream             HTTPUpstream
+	antigravityGatewayService *AntigravityGatewayService
 }
 
 func NewGeminiMessagesCompatService(
@@ -46,13 +47,15 @@ func NewGeminiMessagesCompatService(
 	tokenProvider *GeminiTokenProvider,
 	rateLimitService *RateLimitService,
 	httpUpstream HTTPUpstream,
+	antigravityGatewayService *AntigravityGatewayService,
 ) *GeminiMessagesCompatService {
 	return &GeminiMessagesCompatService{
-		accountRepo:      accountRepo,
-		cache:            cache,
-		tokenProvider:    tokenProvider,
-		rateLimitService: rateLimitService,
-		httpUpstream:     httpUpstream,
+		accountRepo:              accountRepo,
+		cache:                    cache,
+		tokenProvider:            tokenProvider,
+		rateLimitService:         rateLimitService,
+		httpUpstream:             httpUpstream,
+		antigravityGatewayService: antigravityGatewayService,
 	}
 }
 
@@ -67,12 +70,15 @@ func (s *GeminiMessagesCompatService) SelectAccountForModel(ctx context.Context,
 
 func (s *GeminiMessagesCompatService) SelectAccountForModelWithExclusions(ctx context.Context, groupID *int64, sessionHash string, requestedModel string, excludedIDs map[int64]struct{}) (*Account, error) {
 	cacheKey := "gemini:" + sessionHash
+	platforms := []string{PlatformGemini, PlatformAntigravity}
+
 	if sessionHash != "" {
 		accountID, err := s.cache.GetSessionAccountID(ctx, cacheKey)
 		if err == nil && accountID > 0 {
 			if _, excluded := excludedIDs[accountID]; !excluded {
 				account, err := s.accountRepo.GetByID(ctx, accountID)
-				if err == nil && account.IsSchedulable() && account.Platform == PlatformGemini && (requestedModel == "" || account.IsModelSupported(requestedModel)) {
+				// 支持 gemini 和 antigravity 平台的粘性会话
+				if err == nil && account.IsSchedulable() && (account.Platform == PlatformGemini || account.Platform == PlatformAntigravity) && (requestedModel == "" || s.isModelSupportedByAccount(account, requestedModel)) {
 					_ = s.cache.RefreshSessionTTL(ctx, cacheKey, geminiStickySessionTTL)
 					return account, nil
 				}
@@ -80,12 +86,13 @@ func (s *GeminiMessagesCompatService) SelectAccountForModelWithExclusions(ctx co
 		}
 	}
 
+	// 同时查询 gemini 和 antigravity 平台的可调度账户
 	var accounts []Account
 	var err error
 	if groupID != nil {
-		accounts, err = s.accountRepo.ListSchedulableByGroupIDAndPlatform(ctx, *groupID, PlatformGemini)
+		accounts, err = s.accountRepo.ListSchedulableByGroupIDAndPlatforms(ctx, *groupID, platforms)
 	} else {
-		accounts, err = s.accountRepo.ListSchedulableByPlatform(ctx, PlatformGemini)
+		accounts, err = s.accountRepo.ListSchedulableByPlatforms(ctx, platforms)
 	}
 	if err != nil {
 		return nil, fmt.Errorf("query accounts failed: %w", err)
@@ -97,7 +104,8 @@ func (s *GeminiMessagesCompatService) SelectAccountForModelWithExclusions(ctx co
 		if _, excluded := excludedIDs[acc.ID]; excluded {
 			continue
 		}
-		if requestedModel != "" && !acc.IsModelSupported(requestedModel) {
+		// 根据平台类型分别检查模型支持
+		if requestedModel != "" && !s.isModelSupportedByAccount(acc, requestedModel) {
 			continue
 		}
 		if selected == nil {
@@ -127,9 +135,9 @@ func (s *GeminiMessagesCompatService) SelectAccountForModelWithExclusions(ctx co
 
 	if selected == nil {
 		if requestedModel != "" {
-			return nil, fmt.Errorf("no available Gemini accounts supporting model: %s", requestedModel)
+			return nil, fmt.Errorf("no available Gemini/Antigravity accounts supporting model: %s", requestedModel)
 		}
-		return nil, errors.New("no available Gemini accounts")
+		return nil, errors.New("no available Gemini/Antigravity accounts")
 	}
 
 	if sessionHash != "" {
@@ -139,6 +147,34 @@ func (s *GeminiMessagesCompatService) SelectAccountForModelWithExclusions(ctx co
 	return selected, nil
 }
 
+// isModelSupportedByAccount 根据账户平台检查模型支持
+func (s *GeminiMessagesCompatService) isModelSupportedByAccount(account *Account, requestedModel string) bool {
+	if account.Platform == PlatformAntigravity {
+		return IsAntigravityModelSupported(requestedModel)
+	}
+	return account.IsModelSupported(requestedModel)
+}
+
+// GetAntigravityGatewayService 返回 AntigravityGatewayService
+func (s *GeminiMessagesCompatService) GetAntigravityGatewayService() *AntigravityGatewayService {
+	return s.antigravityGatewayService
+}
+
+// HasAntigravityAccounts 检查是否有可用的 antigravity 账户
+func (s *GeminiMessagesCompatService) HasAntigravityAccounts(ctx context.Context, groupID *int64) (bool, error) {
+	var accounts []Account
+	var err error
+	if groupID != nil {
+		accounts, err = s.accountRepo.ListSchedulableByGroupIDAndPlatform(ctx, *groupID, PlatformAntigravity)
+	} else {
+		accounts, err = s.accountRepo.ListSchedulableByPlatform(ctx, PlatformAntigravity)
+	}
+	if err != nil {
+		return false, err
+	}
+	return len(accounts) > 0, nil
+}
+
 // SelectAccountForAIStudioEndpoints selects an account that is likely to succeed against
 // generativelanguage.googleapis.com (e.g. GET /v1beta/models).
 //

backend/internal/service/gemini_multiplatform_test.go

+//go:build unit
+
+package service
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
+	"github.com/stretchr/testify/require"
+)
+
+// mockAccountRepoForGemini Gemini 测试用的 mock
+type mockAccountRepoForGemini struct {
+	accounts     []Account
+	accountsByID map[int64]*Account
+}
+
+func (m *mockAccountRepoForGemini) GetByID(ctx context.Context, id int64) (*Account, error) {
+	if acc, ok := m.accountsByID[id]; ok {
+		return acc, nil
+	}
+	return nil, errors.New("account not found")
+}
+
+func (m *mockAccountRepoForGemini) ListSchedulableByPlatforms(ctx context.Context, platforms []string) ([]Account, error) {
+	platformSet := make(map[string]bool)
+	for _, p := range platforms {
+		platformSet[p] = true
+	}
+	var result []Account
+	for _, acc := range m.accounts {
+		if platformSet[acc.Platform] && acc.IsSchedulable() {
+			result = append(result, acc)
+		}
+	}
+	return result, nil
+}
+
+func (m *mockAccountRepoForGemini) ListSchedulableByGroupIDAndPlatforms(ctx context.Context, groupID int64, platforms []string) ([]Account, error) {
+	return m.ListSchedulableByPlatforms(ctx, platforms)
+}
+
+// Stub methods to implement AccountRepository interface
+func (m *mockAccountRepoForGemini) Create(ctx context.Context, account *Account) error { return nil }
+func (m *mockAccountRepoForGemini) GetByCRSAccountID(ctx context.Context, crsAccountID string) (*Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForGemini) Update(ctx context.Context, account *Account) error { return nil }
+func (m *mockAccountRepoForGemini) Delete(ctx context.Context, id int64) error         { return nil }
+func (m *mockAccountRepoForGemini) List(ctx context.Context, params pagination.PaginationParams) ([]Account, *pagination.PaginationResult, error) {
+	return nil, nil, nil
+}
+func (m *mockAccountRepoForGemini) ListWithFilters(ctx context.Context, params pagination.PaginationParams, platform, accountType, status, search string) ([]Account, *pagination.PaginationResult, error) {
+	return nil, nil, nil
+}
+func (m *mockAccountRepoForGemini) ListByGroup(ctx context.Context, groupID int64) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForGemini) ListActive(ctx context.Context) ([]Account, error) { return nil, nil }
+func (m *mockAccountRepoForGemini) ListByPlatform(ctx context.Context, platform string) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForGemini) UpdateLastUsed(ctx context.Context, id int64) error { return nil }
+func (m *mockAccountRepoForGemini) BatchUpdateLastUsed(ctx context.Context, updates map[int64]time.Time) error {
+	return nil
+}
+func (m *mockAccountRepoForGemini) SetError(ctx context.Context, id int64, errorMsg string) error {
+	return nil
+}
+func (m *mockAccountRepoForGemini) SetSchedulable(ctx context.Context, id int64, schedulable bool) error {
+	return nil
+}
+func (m *mockAccountRepoForGemini) BindGroups(ctx context.Context, accountID int64, groupIDs []int64) error {
+	return nil
+}
+func (m *mockAccountRepoForGemini) ListSchedulable(ctx context.Context) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForGemini) ListSchedulableByGroupID(ctx context.Context, groupID int64) ([]Account, error) {
+	return nil, nil
+}
+func (m *mockAccountRepoForGemini) ListSchedulableByPlatform(ctx context.Context, platform string) ([]Account, error) {
+	var result []Account
+	for _, acc := range m.accounts {
+		if acc.Platform == platform && acc.IsSchedulable() {
+			result = append(result, acc)
+		}
+	}
+	return result, nil
+}
+func (m *mockAccountRepoForGemini) ListSchedulableByGroupIDAndPlatform(ctx context.Context, groupID int64, platform string) ([]Account, error) {
+	// 测试时不区分 groupID，直接按 platform 过滤
+	return m.ListSchedulableByPlatform(ctx, platform)
+}
+func (m *mockAccountRepoForGemini) SetRateLimited(ctx context.Context, id int64, resetAt time.Time) error {
+	return nil
+}
+func (m *mockAccountRepoForGemini) SetOverloaded(ctx context.Context, id int64, until time.Time) error {
+	return nil
+}
+func (m *mockAccountRepoForGemini) ClearRateLimit(ctx context.Context, id int64) error { return nil }
+func (m *mockAccountRepoForGemini) UpdateSessionWindow(ctx context.Context, id int64, start, end *time.Time, status string) error {
+	return nil
+}
+func (m *mockAccountRepoForGemini) UpdateExtra(ctx context.Context, id int64, updates map[string]any) error {
+	return nil
+}
+func (m *mockAccountRepoForGemini) BulkUpdate(ctx context.Context, ids []int64, updates AccountBulkUpdate) (int64, error) {
+	return 0, nil
+}
+
+// Verify interface implementation
+var _ AccountRepository = (*mockAccountRepoForGemini)(nil)
+
+// mockGatewayCacheForGemini Gemini 测试用的 cache mock
+type mockGatewayCacheForGemini struct {
+	sessionBindings map[string]int64
+}
+
+func (m *mockGatewayCacheForGemini) GetSessionAccountID(ctx context.Context, sessionHash string) (int64, error) {
+	if id, ok := m.sessionBindings[sessionHash]; ok {
+		return id, nil
+	}
+	return 0, errors.New("not found")
+}
+
+func (m *mockGatewayCacheForGemini) SetSessionAccountID(ctx context.Context, sessionHash string, accountID int64, ttl time.Duration) error {
+	if m.sessionBindings == nil {
+		m.sessionBindings = make(map[string]int64)
+	}
+	m.sessionBindings[sessionHash] = accountID
+	return nil
+}
+
+func (m *mockGatewayCacheForGemini) RefreshSessionTTL(ctx context.Context, sessionHash string, ttl time.Duration) error {
+	return nil
+}
+
+func TestGeminiMessagesCompatService_SelectAccountForModelWithExclusions_OnlyGemini(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForGemini{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformGemini, Priority: 1, Status: StatusActive, Schedulable: true},
+			{ID: 2, Platform: PlatformGemini, Priority: 2, Status: StatusActive, Schedulable: true},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForGemini{}
+
+	svc := &GeminiMessagesCompatService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.SelectAccountForModelWithExclusions(ctx, nil, "", "gemini-2.5-flash", nil)
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	require.Equal(t, int64(1), acc.ID, "应选择优先级最高的账户")
+}
+
+func TestGeminiMessagesCompatService_SelectAccountForModelWithExclusions_OnlyAntigravity(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForGemini{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForGemini{}
+
+	svc := &GeminiMessagesCompatService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.SelectAccountForModelWithExclusions(ctx, nil, "", "gemini-2.5-flash", nil)
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	require.Equal(t, int64(1), acc.ID)
+	require.Equal(t, PlatformAntigravity, acc.Platform)
+}
+
+func TestGeminiMessagesCompatService_SelectAccountForModelWithExclusions_ExcludesAnthropic(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForGemini{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformAnthropic, Priority: 1, Status: StatusActive, Schedulable: true},
+			{ID: 2, Platform: PlatformGemini, Priority: 2, Status: StatusActive, Schedulable: true},
+			{ID: 3, Platform: PlatformAntigravity, Priority: 3, Status: StatusActive, Schedulable: true},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForGemini{}
+
+	svc := &GeminiMessagesCompatService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.SelectAccountForModelWithExclusions(ctx, nil, "", "gemini-2.5-flash", nil)
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	// Anthropic 不在 [gemini, antigravity] 平台列表中，应被过滤
+	require.Equal(t, int64(2), acc.ID, "Anthropic 平台应被排除，选择 Gemini")
+}
+
+func TestGeminiMessagesCompatService_SelectAccountForModelWithExclusions_MixedPlatforms_SamePriority(t *testing.T) {
+	ctx := context.Background()
+	now := time.Now()
+
+	repo := &mockAccountRepoForGemini{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformGemini, Priority: 1, Status: StatusActive, Schedulable: true, LastUsedAt: ptr(now.Add(-1 * time.Hour))},
+			{ID: 2, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true, LastUsedAt: ptr(now.Add(-2 * time.Hour))},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForGemini{}
+
+	svc := &GeminiMessagesCompatService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.SelectAccountForModelWithExclusions(ctx, nil, "", "gemini-2.5-flash", nil)
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	require.Equal(t, int64(2), acc.ID, "应选择最久未用的账户（Antigravity）")
+}
+
+func TestGeminiMessagesCompatService_SelectAccountForModelWithExclusions_OAuthPreferred(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForGemini{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformGemini, Type: AccountTypeApiKey, Priority: 1, Status: StatusActive, Schedulable: true, LastUsedAt: nil},
+			{ID: 2, Platform: PlatformGemini, Type: AccountTypeOAuth, Priority: 1, Status: StatusActive, Schedulable: true, LastUsedAt: nil},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForGemini{}
+
+	svc := &GeminiMessagesCompatService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.SelectAccountForModelWithExclusions(ctx, nil, "", "gemini-2.5-flash", nil)
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	require.Equal(t, int64(2), acc.ID, "同优先级且都未使用时，应优先选择 OAuth 账户")
+	require.Equal(t, AccountTypeOAuth, acc.Type)
+}
+
+func TestGeminiMessagesCompatService_SelectAccountForModelWithExclusions_OAuthPreferred_MixedPlatforms(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForGemini{
+		accounts: []Account{
+			{ID: 1, Platform: PlatformGemini, Type: AccountTypeApiKey, Priority: 1, Status: StatusActive, Schedulable: true, LastUsedAt: nil},
+			{ID: 2, Platform: PlatformAntigravity, Type: AccountTypeOAuth, Priority: 1, Status: StatusActive, Schedulable: true, LastUsedAt: nil},
+		},
+		accountsByID: map[int64]*Account{},
+	}
+	for i := range repo.accounts {
+		repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+	}
+
+	cache := &mockGatewayCacheForGemini{}
+
+	svc := &GeminiMessagesCompatService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.SelectAccountForModelWithExclusions(ctx, nil, "", "gemini-2.5-flash", nil)
+	require.NoError(t, err)
+	require.NotNil(t, acc)
+	require.Equal(t, int64(2), acc.ID, "跨平台时，同样优先选择 OAuth 账户")
+}
+
+func TestGeminiMessagesCompatService_SelectAccountForModelWithExclusions_NoAvailableAccounts(t *testing.T) {
+	ctx := context.Background()
+
+	repo := &mockAccountRepoForGemini{
+		accounts:     []Account{},
+		accountsByID: map[int64]*Account{},
+	}
+
+	cache := &mockGatewayCacheForGemini{}
+
+	svc := &GeminiMessagesCompatService{
+		accountRepo: repo,
+		cache:       cache,
+	}
+
+	acc, err := svc.SelectAccountForModelWithExclusions(ctx, nil, "", "gemini-2.5-flash", nil)
+	require.Error(t, err)
+	require.Nil(t, acc)
+	require.Contains(t, err.Error(), "no available Gemini/Antigravity accounts")
+}
+
+func TestGeminiMessagesCompatService_SelectAccountForModelWithExclusions_StickySession(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("粘性会话命中-使用gemini前缀缓存键", func(t *testing.T) {
+		repo := &mockAccountRepoForGemini{
+			accounts: []Account{
+				{ID: 1, Platform: PlatformGemini, Priority: 2, Status: StatusActive, Schedulable: true},
+				{ID: 2, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true},
+			},
+			accountsByID: map[int64]*Account{},
+		}
+		for i := range repo.accounts {
+			repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+		}
+
+		// 注意：缓存键使用 "gemini:" 前缀
+		cache := &mockGatewayCacheForGemini{
+			sessionBindings: map[string]int64{"gemini:session-123": 1},
+		}
+
+		svc := &GeminiMessagesCompatService{
+			accountRepo: repo,
+			cache:       cache,
+		}
+
+		acc, err := svc.SelectAccountForModelWithExclusions(ctx, nil, "session-123", "gemini-2.5-flash", nil)
+		require.NoError(t, err)
+		require.NotNil(t, acc)
+		require.Equal(t, int64(1), acc.ID, "应返回粘性会话绑定的账户")
+	})
+
+	t.Run("粘性会话不命中无前缀缓存键", func(t *testing.T) {
+		repo := &mockAccountRepoForGemini{
+			accounts: []Account{
+				{ID: 1, Platform: PlatformGemini, Priority: 2, Status: StatusActive, Schedulable: true},
+				{ID: 2, Platform: PlatformAntigravity, Priority: 1, Status: StatusActive, Schedulable: true},
+			},
+			accountsByID: map[int64]*Account{},
+		}
+		for i := range repo.accounts {
+			repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+		}
+
+		// 缓存键没有 "gemini:" 前缀，不应命中
+		cache := &mockGatewayCacheForGemini{
+			sessionBindings: map[string]int64{"session-123": 1},
+		}
+
+		svc := &GeminiMessagesCompatService{
+			accountRepo: repo,
+			cache:       cache,
+		}
+
+		acc, err := svc.SelectAccountForModelWithExclusions(ctx, nil, "session-123", "gemini-2.5-flash", nil)
+		require.NoError(t, err)
+		require.NotNil(t, acc)
+		// 粘性会话未命中，按优先级选择
+		require.Equal(t, int64(2), acc.ID, "粘性会话未命中，应按优先级选择 Antigravity")
+	})
+
+	t.Run("粘性会话Anthropic账户-降级选择", func(t *testing.T) {
+		repo := &mockAccountRepoForGemini{
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAnthropic, Priority: 2, Status: StatusActive, Schedulable: true},
+				{ID: 2, Platform: PlatformGemini, Priority: 1, Status: StatusActive, Schedulable: true},
+			},
+			accountsByID: map[int64]*Account{},
+		}
+		for i := range repo.accounts {
+			repo.accountsByID[repo.accounts[i].ID] = &repo.accounts[i]
+		}
+
+		cache := &mockGatewayCacheForGemini{
+			sessionBindings: map[string]int64{"gemini:session-123": 1},
+		}
+
+		svc := &GeminiMessagesCompatService{
+			accountRepo: repo,
+			cache:       cache,
+		}
+
+		acc, err := svc.SelectAccountForModelWithExclusions(ctx, nil, "session-123", "gemini-2.5-flash", nil)
+		require.NoError(t, err)
+		require.NotNil(t, acc)
+		// 粘性会话绑定的是 Anthropic 账户，不在 Gemini 平台列表中，应降级选择
+		require.Equal(t, int64(2), acc.ID, "粘性会话账户是 Anthropic，应降级选择 Gemini 平台账户")
+	})
+}
+
+func TestGeminiMessagesCompatService_HasAntigravityAccounts(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("有antigravity账户时返回true", func(t *testing.T) {
+		repo := &mockAccountRepoForGemini{
+			accounts: []Account{
+				{ID: 1, Platform: PlatformGemini, Status: StatusActive, Schedulable: true},
+				{ID: 2, Platform: PlatformAntigravity, Status: StatusActive, Schedulable: true},
+			},
+		}
+
+		svc := &GeminiMessagesCompatService{accountRepo: repo}
+
+		has, err := svc.HasAntigravityAccounts(ctx, nil)
+		require.NoError(t, err)
+		require.True(t, has)
+	})
+
+	t.Run("无antigravity账户时返回false", func(t *testing.T) {
+		repo := &mockAccountRepoForGemini{
+			accounts: []Account{
+				{ID: 1, Platform: PlatformGemini, Status: StatusActive, Schedulable: true},
+			},
+		}
+
+		svc := &GeminiMessagesCompatService{accountRepo: repo}
+
+		has, err := svc.HasAntigravityAccounts(ctx, nil)
+		require.NoError(t, err)
+		require.False(t, has)
+	})
+
+	t.Run("antigravity账户不可调度时返回false", func(t *testing.T) {
+		repo := &mockAccountRepoForGemini{
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAntigravity, Status: StatusActive, Schedulable: false},
+			},
+		}
+
+		svc := &GeminiMessagesCompatService{accountRepo: repo}
+
+		has, err := svc.HasAntigravityAccounts(ctx, nil)
+		require.NoError(t, err)
+		require.False(t, has)
+	})
+
+	t.Run("带groupID查询", func(t *testing.T) {
+		repo := &mockAccountRepoForGemini{
+			accounts: []Account{
+				{ID: 1, Platform: PlatformAntigravity, Status: StatusActive, Schedulable: true},
+			},
+		}
+
+		svc := &GeminiMessagesCompatService{accountRepo: repo}
+
+		groupID := int64(1)
+		has, err := svc.HasAntigravityAccounts(ctx, &groupID)
+		require.NoError(t, err)
+		require.True(t, has)
+	})
+}
+
+// TestGeminiPlatformRouting_DocumentRouteDecision 测试平台路由决策逻辑
+// 该测试文档化了 Handler 层应该如何根据 account.Platform 进行分流
+func TestGeminiPlatformRouting_DocumentRouteDecision(t *testing.T) {
+	tests := []struct {
+		name            string
+		platform        string
+		expectedService string // "gemini" 表示 ForwardNative, "antigravity" 表示 ForwardGemini
+	}{
+		{
+			name:            "Gemini平台走ForwardNative",
+			platform:        PlatformGemini,
+			expectedService: "gemini",
+		},
+		{
+			name:            "Antigravity平台走ForwardGemini",
+			platform:        PlatformAntigravity,
+			expectedService: "antigravity",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			account := &Account{Platform: tt.platform}
+
+			// 模拟 Handler 层的路由逻辑
+			var serviceName string
+			if account.Platform == PlatformAntigravity {
+				serviceName = "antigravity"
+			} else {
+				serviceName = "gemini"
+			}
+
+			require.Equal(t, tt.expectedService, serviceName,
+				"平台 %s 应该路由到 %s 服务", tt.platform, tt.expectedService)
+		})
+	}
+}
+
+func TestGeminiMessagesCompatService_isModelSupportedByAccount(t *testing.T) {
+	svc := &GeminiMessagesCompatService{}
+
+	tests := []struct {
+		name     string
+		account  *Account
+		model    string
+		expected bool
+	}{
+		{
+			name:     "Antigravity平台-支持gemini模型",
+			account:  &Account{Platform: PlatformAntigravity},
+			model:    "gemini-2.5-flash",
+			expected: true,
+		},
+		{
+			name:     "Antigravity平台-支持claude模型",
+			account:  &Account{Platform: PlatformAntigravity},
+			model:    "claude-3-5-sonnet-20241022",
+			expected: true,
+		},
+		{
+			name:     "Antigravity平台-不支持gpt模型",
+			account:  &Account{Platform: PlatformAntigravity},
+			model:    "gpt-4",
+			expected: false,
+		},
+		{
+			name:     "Gemini平台-无映射配置-支持所有模型",
+			account:  &Account{Platform: PlatformGemini},
+			model:    "gemini-2.5-flash",
+			expected: true,
+		},
+		{
+			name: "Gemini平台-有映射配置-只支持配置的模型",
+			account: &Account{
+				Platform:    PlatformGemini,
+				Credentials: map[string]any{"model_mapping": map[string]any{"gemini-1.5-pro": "x"}},
+			},
+			model:    "gemini-2.5-flash",
+			expected: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := svc.isModelSupportedByAccount(tt.account, tt.model)
+			require.Equal(t, tt.expected, got)
+		})
+	}
+}

backend/internal/service/token_refresh_service.go

@@ -27,6 +27,7 @@ func NewTokenRefreshService(
 	oauthService *OAuthService,
 	openaiOAuthService *OpenAIOAuthService,
 	geminiOAuthService *GeminiOAuthService,
+	antigravityOAuthService *AntigravityOAuthService,
 	cfg *config.Config,
 ) *TokenRefreshService {
 	s := &TokenRefreshService{
@@ -40,6 +41,7 @@ func NewTokenRefreshService(
 		NewClaudeTokenRefresher(oauthService),
 		NewOpenAITokenRefresher(openaiOAuthService),
 		NewGeminiTokenRefresher(geminiOAuthService),
+		NewAntigravityTokenRefresher(antigravityOAuthService),
 	}
 
 	return s

backend/internal/service/wire.go

@@ -39,9 +39,10 @@ func ProvideTokenRefreshService(
 	oauthService *OAuthService,
 	openaiOAuthService *OpenAIOAuthService,
 	geminiOAuthService *GeminiOAuthService,
+	antigravityOAuthService *AntigravityOAuthService,
 	cfg *config.Config,
 ) *TokenRefreshService {
-	svc := NewTokenRefreshService(accountRepo, oauthService, openaiOAuthService, geminiOAuthService, cfg)
+	svc := NewTokenRefreshService(accountRepo, oauthService, openaiOAuthService, geminiOAuthService, antigravityOAuthService, cfg)
 	svc.Start()
 	return svc
 }
@@ -84,6 +85,8 @@ var ProviderSet = wire.NewSet(
 	NewAntigravityOAuthService,
 	NewGeminiTokenProvider,
 	NewGeminiMessagesCompatService,
+	NewAntigravityTokenProvider,
+	NewAntigravityGatewayService,
 	NewRateLimitService,
 	NewAccountUsageService,
 	NewAccountTestService,

frontend/src/components/common/GroupSelector.vue

@@ -62,6 +62,10 @@ const filteredGroups = computed(() => {
   if (!props.platform) {
     return props.groups
   }
+  // antigravity 账户可选择 anthropic 和 gemini 平台的分组
+  if (props.platform === 'antigravity') {
+    return props.groups.filter((g) => g.platform === 'anthropic' || g.platform === 'gemini')
+  }
   return props.groups.filter((g) => g.platform === props.platform)
 })