diff --git a/backend/internal/domain/constants.go b/backend/internal/domain/constants.go
index f889281e87..463a1839a9 100644
--- a/backend/internal/domain/constants.go
+++ b/backend/internal/domain/constants.go
@@ -113,6 +113,14 @@ var DefaultAntigravityModelMapping = map[string]string{
 	// Claude 白名单
 	"claude-fable-5-1":           "claude-fable-5-1",         // 官方模型
 	"claude-fable-5":             "claude-fable-5",           // 官方模型
+	"claude-opus-5-5":            "claude-opus-5-5-high",     // 简称映射
+	"claude-opus-5-5-high":       "claude-opus-5-5-high",     // 官方模型
+	"claude-opus-5-5-medium":     "claude-opus-5-5-medium",   // 官方模型
+	"claude-opus-5-5-low":        "claude-opus-5-5-low",      // 官方模型
+	"claude-sonnet-5-5":          "claude-sonnet-5-5-high",   // 简称映射
+	"claude-sonnet-5-5-high":     "claude-sonnet-5-5-high",   // 官方模型
+	"claude-sonnet-5-5-medium":   "claude-sonnet-5-5-medium", // 官方模型
+	"claude-sonnet-5-5-low":      "claude-sonnet-5-5-low",    // 官方模型
 	"claude-opus-4-8":            "claude-opus-4-8",          // 官方模型
 	"claude-opus-4-7":            "claude-opus-4-7",          // 官方模型
 	"claude-opus-4-6-thinking":   "claude-opus-4-6-thinking", // 官方模型
@@ -170,6 +178,11 @@ var DefaultAntigravityModelMapping = map[string]string{
 	"gemini-3.8-flash-low":    "gemini-3.8-flash-low",
 	"gemini-3.8-flash-medium": "gemini-3.8-flash-medium",
 	"gemini-3.8-flash-tiered": "gemini-3.8-flash-tiered",
+	// Gemini 4 Argon tiered models
+	"gemini-4-argon":        "gemini-4-argon-high",
+	"gemini-4-argon-high":   "gemini-4-argon-high",
+	"gemini-4-argon-low":    "gemini-4-argon-low",
+	"gemini-4-argon-medium": "gemini-4-argon-medium",
 	// Gemini 3 image 兼容映射（向 3.1 image 迁移）
 	"gemini-3-pro-image":         "gemini-3.1-flash-image",
 	"gemini-3-pro-image-preview": "gemini-3.1-flash-image",
diff --git a/backend/internal/domain/constants_test.go b/backend/internal/domain/constants_test.go
index 076688d6c0..430d4802ee 100644
--- a/backend/internal/domain/constants_test.go
+++ b/backend/internal/domain/constants_test.go
@@ -105,6 +105,28 @@ func TestDefaultAntigravityModelMapping_Gemini38FlashModels(t *testing.T) {
 	}
 }
 
+func TestDefaultAntigravityModelMapping_Gemini4ArgonAndClaude55Models(t *testing.T) {
+	cases := map[string]string{
+		"gemini-4-argon":           "gemini-4-argon-high",
+		"gemini-4-argon-high":      "gemini-4-argon-high",
+		"gemini-4-argon-low":       "gemini-4-argon-low",
+		"gemini-4-argon-medium":    "gemini-4-argon-medium",
+		"claude-opus-5-5":          "claude-opus-5-5-high",
+		"claude-opus-5-5-high":     "claude-opus-5-5-high",
+		"claude-opus-5-5-low":      "claude-opus-5-5-low",
+		"claude-opus-5-5-medium":   "claude-opus-5-5-medium",
+		"claude-sonnet-5-5":        "claude-sonnet-5-5-high",
+		"claude-sonnet-5-5-high":   "claude-sonnet-5-5-high",
+		"claude-sonnet-5-5-low":    "claude-sonnet-5-5-low",
+		"claude-sonnet-5-5-medium": "claude-sonnet-5-5-medium",
+	}
+	for from, want := range cases {
+		if got := DefaultAntigravityModelMapping[from]; got != want {
+			t.Fatalf("expected %s to map to %q, got %q", from, want, got)
+		}
+	}
+}
+
 func TestDefaultBedrockModelMapping_ContainsNewClaudeModels(t *testing.T) {
 	t.Parallel()
 
diff --git a/backend/internal/handler/admin/account_handler.go b/backend/internal/handler/admin/account_handler.go
index f954cce572..4c2fbd37ca 100644
--- a/backend/internal/handler/admin/account_handler.go
+++ b/backend/internal/handler/admin/account_handler.go
@@ -3004,13 +3004,13 @@ func antigravityAccountTestModels(rawMapping any) []antigravity.ClaudeModel {
 	switch mapping := rawMapping.(type) {
 	case map[string]any:
 		for id := range mapping {
-			if strings.TrimSpace(id) != "" {
+			if strings.TrimSpace(id) != "" && !strings.Contains(id, "*") {
 				mappedIDs = append(mappedIDs, id)
 			}
 		}
 	case map[string]string:
 		for id := range mapping {
-			if strings.TrimSpace(id) != "" {
+			if strings.TrimSpace(id) != "" && !strings.Contains(id, "*") {
 				mappedIDs = append(mappedIDs, id)
 			}
 		}
diff --git a/backend/internal/handler/admin/account_handler_available_models_test.go b/backend/internal/handler/admin/account_handler_available_models_test.go
index b8f091bccc..79fbbc79e0 100644
--- a/backend/internal/handler/admin/account_handler_available_models_test.go
+++ b/backend/internal/handler/admin/account_handler_available_models_test.go
@@ -345,11 +345,12 @@ func TestAccountHandlerGetAvailableModels_Antigravity(t *testing.T) {
 		{name: "empty JSON mapping", credentials: map[string]any{"model_mapping": map[string]any{}}, want: defaults},
 		{name: "empty string mapping", credentials: map[string]any{"model_mapping": map[string]string{}}, want: defaults},
 		{name: "blank key", credentials: map[string]any{"model_mapping": map[string]any{" ": "upstream-model"}}, want: defaults},
-		{name: "JSON mapping keys and metadata", credentials: map[string]any{"model_mapping": map[string]any{
-			known.ID: known.ID, custom.ID: "upstream-model",
+		{name: "wildcard only falls back to defaults", credentials: map[string]any{"model_mapping": map[string]any{"claude-*": "claude-sonnet-4-6", "gemini-3*": "gemini-3-flash"}}, want: defaults},
+		{name: "JSON mapping keys and metadata skips wildcards", credentials: map[string]any{"model_mapping": map[string]any{
+			known.ID: known.ID, custom.ID: "upstream-model", "claude-*": "claude-sonnet-4-6",
 		}}, want: []antigravity.ClaudeModel{custom, known}},
-		{name: "string mapping keys and metadata", credentials: map[string]any{"model_mapping": map[string]string{
-			known.ID: known.ID, custom.ID: "upstream-model",
+		{name: "string mapping keys and metadata skips wildcards", credentials: map[string]any{"model_mapping": map[string]string{
+			known.ID: known.ID, custom.ID: "upstream-model", "gemini-*": "gemini-3-flash",
 		}}, want: []antigravity.ClaudeModel{custom, known}},
 	}
 	for _, tc := range cases {
diff --git a/backend/internal/handler/gateway_models_test.go b/backend/internal/handler/gateway_models_test.go
index e3bb7be616..25b05a8c7a 100644
--- a/backend/internal/handler/gateway_models_test.go
+++ b/backend/internal/handler/gateway_models_test.go
@@ -1408,6 +1408,60 @@ func modelIDsForTest(models []gatewayModelItemForTest) []string {
 	return ids
 }
 
+func TestGatewayModels_AntigravityExplicitMappingAppearsInBothCatalogs(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	const groupID int64 = 93
+	mapping := map[string]any{
+		"gemini-3.8-flash":         "gemini-3.8-flash-high",
+		"gemini-3.8-flash-high":    "gemini-3.8-flash-high",
+		"claude-opus-4-6-thinking": "claude-opus-4-6-thinking",
+		"gemini-pro-agent":         "gemini-pro-agent",
+	}
+	for _, platform := range []string{service.PlatformAntigravity, service.PlatformComposite, service.PlatformGemini} {
+		t.Run(platform, func(t *testing.T) {
+			h := newGatewayModelsHandlerForTest(&gatewayModelsAccountRepoStub{
+				byGroup: map[int64][]service.Account{groupID: {{
+					ID: 25, Platform: service.PlatformAntigravity,
+					Extra:       map[string]any{"mixed_scheduling": true},
+					Credentials: map[string]any{"model_mapping": mapping},
+				}}},
+			})
+			want := []string{"gemini-3.8-flash", "gemini-3.8-flash-high", "gemini-pro-agent", "claude-opus-4-6-thinking"}
+			if platform == service.PlatformGemini {
+				want = want[:3]
+			}
+			for _, codex := range []bool{false, true} {
+				rec := httptest.NewRecorder()
+				c, _ := gin.CreateTestContext(rec)
+				c.Request = httptest.NewRequest(http.MethodGet, "/v1/models", nil)
+				c.Set(string(middleware2.ContextKeyAPIKey), &service.APIKey{
+					Group: &service.Group{ID: groupID, Platform: platform},
+				})
+				var ids []string
+				if codex {
+					h.CodexModels(c)
+					var got codexModelsResponseForTest
+					require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &got))
+					for _, model := range got.Models {
+						ids = append(ids, model.Slug)
+					}
+				} else {
+					h.Models(c)
+					var got gatewayModelsResponseForTest
+					require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &got))
+					ids = modelIDsForTest(got.Data)
+				}
+				require.Equal(t, http.StatusOK, rec.Code)
+				// 显式条目必须同时出现在两种目录；默认透传补齐的条目不锁定。
+				require.Subset(t, ids, want, "codex=%t", codex)
+				if platform == service.PlatformGemini {
+					require.NotContains(t, ids, "claude-opus-4-6-thinking", "codex=%t", codex)
+				}
+			}
+		})
+	}
+}
+
 // gemini 分组混合调度：组内 antigravity 账号的 gemini-* 映射也应出现在 /v1/models，
 // 与路由层（listSchedulableAccountsOnce 的 useMixedScheduling）同源；claude-* 不带入，
 // 非混合调度的异平台账号（anthropic）仍被过滤。
diff --git a/backend/internal/handler/gemini_v1beta_handler.go b/backend/internal/handler/gemini_v1beta_handler.go
index 8627e0d139..95c550302e 100644
--- a/backend/internal/handler/gemini_v1beta_handler.go
+++ b/backend/internal/handler/gemini_v1beta_handler.go
@@ -39,9 +39,11 @@ func (h *GatewayHandler) GeminiV1BetaListModels(c *gin.Context) {
 		googleError(c, http.StatusUnauthorized, "Invalid API key")
 		return
 	}
-	// 检查平台：优先使用强制平台（/antigravity 路由），否则要求 gemini 分组
+	// 检查平台：优先使用强制平台（/antigravity 路由），否则要求 gemini 分组（composite 分组允许路由到 antigravity）
 	forcePlatform, hasForcePlatform := middleware.GetForcePlatformFromContext(c)
-	if !hasForcePlatform && effectiveAPIKeyPlatform(c, apiKey) != service.PlatformGemini {
+	effectivePlatform := effectiveAPIKeyPlatform(c, apiKey)
+	if !hasForcePlatform && effectivePlatform != service.PlatformGemini &&
+		!servesCompositeAntigravityGemini(apiKey, effectivePlatform) {
 		googleError(c, http.StatusBadRequest, "API key group platform is not gemini")
 		return
 	}
@@ -223,9 +225,11 @@ func (h *GatewayHandler) GeminiV1BetaGetModel(c *gin.Context) {
 		googleError(c, http.StatusUnauthorized, "Invalid API key")
 		return
 	}
-	// 检查平台：优先使用强制平台（/antigravity 路由），否则要求 gemini 分组
+	// 检查平台：优先使用强制平台（/antigravity 路由），否则要求 gemini 分组（composite 分组允许路由到 antigravity）
 	forcePlatform, hasForcePlatform := middleware.GetForcePlatformFromContext(c)
-	if !hasForcePlatform && effectiveAPIKeyPlatform(c, apiKey) != service.PlatformGemini {
+	effectivePlatform := effectiveAPIKeyPlatform(c, apiKey)
+	if !hasForcePlatform && effectivePlatform != service.PlatformGemini &&
+		!servesCompositeAntigravityGemini(apiKey, effectivePlatform) {
 		googleError(c, http.StatusBadRequest, "API key group platform is not gemini")
 		return
 	}
@@ -244,9 +248,13 @@ func (h *GatewayHandler) GeminiV1BetaGetModel(c *gin.Context) {
 	if resolvedModel, ok := service.ResolvedUpstreamModelFromContext(c.Request.Context()); ok && strings.TrimSpace(resolvedModel) != "" {
 		modelName = strings.TrimSpace(resolvedModel)
 	}
+	if !hasForcePlatform && servesCompositeAntigravityGemini(apiKey, effectivePlatform) && !isAntigravityGeminiModel(modelName) {
+		googleError(c, http.StatusBadRequest, "API key group platform is not gemini")
+		return
+	}
 
-	// 强制 antigravity 模式：返回 antigravity 模型信息
-	if forcePlatform == service.PlatformAntigravity {
+	// 强制 antigravity 模式或 composite 路由到 antigravity：返回 antigravity 模型信息
+	if forcePlatform == service.PlatformAntigravity || effectivePlatform == service.PlatformAntigravity {
 		c.JSON(http.StatusOK, antigravity.FallbackGeminiModel(modelName))
 		return
 	}
@@ -299,9 +307,11 @@ func (h *GatewayHandler) GeminiV1BetaModels(c *gin.Context) {
 		zap.Any("group_id", apiKey.GroupID),
 	)
 
-	// 检查平台：优先使用强制平台（/antigravity 路由，中间件已设置 request.Context），否则要求 gemini 分组
+	// 检查平台：优先使用强制平台（/antigravity 路由，中间件已设置 request.Context），否则要求 gemini 分组（composite 分组允许路由到 antigravity）
+	effectivePlatform := effectiveAPIKeyPlatform(c, apiKey)
 	if !middleware.HasForcePlatform(c) {
-		if effectiveAPIKeyPlatform(c, apiKey) != service.PlatformGemini {
+		if effectivePlatform != service.PlatformGemini &&
+			!servesCompositeAntigravityGemini(apiKey, effectivePlatform) {
 			googleError(c, http.StatusBadRequest, "API key group platform is not gemini")
 			return
 		}
@@ -321,6 +331,10 @@ func (h *GatewayHandler) GeminiV1BetaModels(c *gin.Context) {
 	if resolvedModel, ok := service.ResolvedUpstreamModelFromContext(c.Request.Context()); ok && strings.TrimSpace(resolvedModel) != "" {
 		modelName = strings.TrimSpace(resolvedModel)
 	}
+	if !middleware.HasForcePlatform(c) && servesCompositeAntigravityGemini(apiKey, effectivePlatform) && !isAntigravityGeminiModel(modelName) {
+		googleError(c, http.StatusBadRequest, "API key group platform is not gemini")
+		return
+	}
 
 	stream := action == "streamGenerateContent"
 	reqLog = reqLog.With(zap.String("model", modelName), zap.String("action", action), zap.Bool("stream", stream))
@@ -567,7 +581,11 @@ func (h *GatewayHandler) GeminiV1BetaModels(c *gin.Context) {
 				return
 			}
 			if len(fs.FailedAccountIDs) == 0 {
-				cls := classifyNoAccountErrorFromGin(c, h.gatewayService, apiKey, modelName, modelName, service.PlatformGemini)
+				diagPlatform := service.PlatformGemini
+				if p := effectiveAPIKeyPlatform(c, apiKey); p == service.PlatformAntigravity {
+					diagPlatform = service.PlatformAntigravity
+				}
+				cls := classifyNoAccountErrorFromGin(c, h.gatewayService, apiKey, modelName, modelName, diagPlatform)
 				if !cls.ModelNotFound {
 					markOpsRoutingCapacityLimitedIfNoAvailable(c, err)
 				}
@@ -1053,3 +1071,16 @@ func derefGroupID(groupID *int64) int64 {
 	}
 	return *groupID
 }
+
+func servesCompositeAntigravityGemini(apiKey *service.APIKey, effectivePlatform string) bool {
+	return apiKey.Group != nil && apiKey.Group.Platform == service.PlatformComposite && effectivePlatform == service.PlatformAntigravity
+}
+
+func isAntigravityGeminiModel(model string) bool {
+	trimmed := strings.ToLower(strings.TrimSpace(strings.TrimPrefix(model, "models/")))
+	if trimmed == "" || strings.HasPrefix(trimmed, "claude-") {
+		return false
+	}
+	detected, ok := service.DetectModelPlatform(trimmed)
+	return ok && detected == service.PlatformGemini
+}
diff --git a/backend/internal/handler/gemini_v1beta_handler_test.go b/backend/internal/handler/gemini_v1beta_handler_test.go
index 44d66d5c97..4f84879599 100644
--- a/backend/internal/handler/gemini_v1beta_handler_test.go
+++ b/backend/internal/handler/gemini_v1beta_handler_test.go
@@ -216,3 +216,75 @@ func TestShouldFallbackGeminiModel_DelegatesScopeFallback(t *testing.T) {
 	}
 	require.True(t, shouldFallbackGeminiModel("gemini-future-model", res))
 }
+
+func TestGeminiV1BetaGetModel_CompositeAntigravityRoute(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	t.Run("composite route to antigravity gemini model succeeds", func(t *testing.T) {
+		rec := httptest.NewRecorder()
+		c, _ := gin.CreateTestContext(rec)
+		req := httptest.NewRequest(http.MethodGet, "/v1beta/models/gemini-4-argon", nil)
+		req = req.WithContext(service.WithCompositeRouteDecision(req.Context(), service.CompositeRouteDecision{
+			Matched:        true,
+			TargetPlatform: service.PlatformAntigravity,
+			UpstreamModel:  "gemini-4-argon-high",
+		}))
+		c.Request = req
+		c.Params = gin.Params{{Key: "model", Value: "gemini-4-argon"}}
+		groupID := int64(4)
+		c.Set(string(middleware.ContextKeyAPIKey), &service.APIKey{
+			ID:      1,
+			GroupID: &groupID,
+			Group:   &service.Group{ID: groupID, Platform: service.PlatformComposite},
+		})
+
+		(&GatewayHandler{}).GeminiV1BetaGetModel(c)
+		require.Equal(t, http.StatusOK, rec.Code, rec.Body.String())
+		require.Contains(t, rec.Body.String(), "models/gemini-4-argon-high")
+	})
+
+	t.Run("composite route to antigravity claude model is rejected on v1beta", func(t *testing.T) {
+		rec := httptest.NewRecorder()
+		c, _ := gin.CreateTestContext(rec)
+		req := httptest.NewRequest(http.MethodGet, "/v1beta/models/claude-sonnet-5-5-high", nil)
+		req = req.WithContext(service.WithCompositeRouteDecision(req.Context(), service.CompositeRouteDecision{
+			Matched:        true,
+			TargetPlatform: service.PlatformAntigravity,
+			UpstreamModel:  "claude-sonnet-5-5-high",
+		}))
+		c.Request = req
+		c.Params = gin.Params{{Key: "model", Value: "claude-sonnet-5-5-high"}}
+		groupID := int64(4)
+		c.Set(string(middleware.ContextKeyAPIKey), &service.APIKey{
+			ID:      1,
+			GroupID: &groupID,
+			Group:   &service.Group{ID: groupID, Platform: service.PlatformComposite},
+		})
+
+		(&GatewayHandler{}).GeminiV1BetaGetModel(c)
+		require.Equal(t, http.StatusBadRequest, rec.Code, rec.Body.String())
+	})
+
+	t.Run("composite route to antigravity claude model is rejected on generateContent", func(t *testing.T) {
+		rec := httptest.NewRecorder()
+		c, _ := gin.CreateTestContext(rec)
+		req := httptest.NewRequest(http.MethodPost, "/v1beta/models/claude-sonnet-5-5-high:generateContent", nil)
+		req = req.WithContext(service.WithCompositeRouteDecision(req.Context(), service.CompositeRouteDecision{
+			Matched:        true,
+			TargetPlatform: service.PlatformAntigravity,
+			UpstreamModel:  "claude-sonnet-5-5-high",
+		}))
+		c.Request = req
+		c.Params = gin.Params{{Key: "modelAction", Value: "/claude-sonnet-5-5-high:generateContent"}}
+		groupID := int64(4)
+		c.Set(string(middleware.ContextKeyAPIKey), &service.APIKey{
+			ID:      1,
+			GroupID: &groupID,
+			Group:   &service.Group{ID: groupID, Platform: service.PlatformComposite},
+		})
+		c.Set(string(middleware.ContextKeyUser), middleware.AuthSubject{UserID: 1, Concurrency: 1})
+
+		(&GatewayHandler{}).GeminiV1BetaModels(c)
+		require.Equal(t, http.StatusBadRequest, rec.Code, rec.Body.String())
+	})
+}
diff --git a/backend/internal/pkg/antigravity/claude_types.go b/backend/internal/pkg/antigravity/claude_types.go
index 61e32b615d..3af852c8f1 100644
--- a/backend/internal/pkg/antigravity/claude_types.go
+++ b/backend/internal/pkg/antigravity/claude_types.go
@@ -169,6 +169,12 @@ type modelDef struct {
 var claudeModels = []modelDef{
 	{ID: "claude-fable-5-1", DisplayName: "Claude Fable 5.1", CreatedAt: "2026-09-01T00:00:00Z"},
 	{ID: "claude-fable-5", DisplayName: "Claude Fable 5", CreatedAt: "2026-06-09T00:00:00Z"},
+	{ID: "claude-opus-5-5-high", DisplayName: "Claude Opus 5.5 (High)", CreatedAt: "2026-09-22T00:00:00Z"},
+	{ID: "claude-opus-5-5-medium", DisplayName: "Claude Opus 5.5 (Medium)", CreatedAt: "2026-09-22T00:00:00Z"},
+	{ID: "claude-opus-5-5-low", DisplayName: "Claude Opus 5.5 (Low)", CreatedAt: "2026-09-22T00:00:00Z"},
+	{ID: "claude-sonnet-5-5-high", DisplayName: "Claude Sonnet 5.5 (High)", CreatedAt: "2026-09-28T00:00:00Z"},
+	{ID: "claude-sonnet-5-5-medium", DisplayName: "Claude Sonnet 5.5 (Medium)", CreatedAt: "2026-09-28T00:00:00Z"},
+	{ID: "claude-sonnet-5-5-low", DisplayName: "Claude Sonnet 5.5 (Low)", CreatedAt: "2026-09-28T00:00:00Z"},
 	{ID: "claude-opus-4-5-thinking", DisplayName: "Claude Opus 4.5 Thinking", CreatedAt: "2025-11-01T00:00:00Z"},
 	{ID: "claude-sonnet-4-5", DisplayName: "Claude Sonnet 4.5", CreatedAt: "2025-09-29T00:00:00Z"},
 	{ID: "claude-sonnet-4-5-thinking", DisplayName: "Claude Sonnet 4.5 Thinking", CreatedAt: "2025-09-29T00:00:00Z"},
@@ -208,6 +214,9 @@ var geminiModels = []modelDef{
 	{ID: "gemini-3.8-flash-low", DisplayName: "Gemini 3.8 Flash Low", CreatedAt: "2026-09-02T00:00:00Z", IsReasoning: true},
 	{ID: "gemini-3.8-flash-medium", DisplayName: "Gemini 3.8 Flash Medium", CreatedAt: "2026-09-02T00:00:00Z", IsReasoning: true},
 	{ID: "gemini-3.8-flash-tiered", DisplayName: "Gemini 3.8 Flash", CreatedAt: "2026-09-02T00:00:00Z", IsReasoning: true},
+	{ID: "gemini-4-argon-high", DisplayName: "Gemini 4 Argon (High)", CreatedAt: "2026-10-13T00:00:00Z", IsReasoning: true},
+	{ID: "gemini-4-argon-low", DisplayName: "Gemini 4 Argon (Low)", CreatedAt: "2026-10-13T00:00:00Z", IsReasoning: true},
+	{ID: "gemini-4-argon-medium", DisplayName: "Gemini 4 Argon (Medium)", CreatedAt: "2026-10-13T00:00:00Z", IsReasoning: true},
 	{ID: "gemini-3-pro-preview", DisplayName: "Gemini 3 Pro Preview", CreatedAt: "2025-06-01T00:00:00Z", IsReasoning: true},
 	{ID: "gemini-3-pro-image", DisplayName: "Gemini 3 Pro Image", CreatedAt: "2025-06-01T00:00:00Z"},
 }
@@ -277,6 +286,9 @@ func FallbackGeminiModel(model string) GeminiModel {
 // IsGeminiReasoningModel 判断是否为不支持参数和强制 ToolConfig 的 Gemini 推理模型
 func IsGeminiReasoningModel(modelID string) bool {
 	lowerID := strings.ToLower(modelID)
+	if strings.Contains(lowerID, "gemini-pro-agent") || strings.Contains(lowerID, "gemini-4-argon") {
+		return true
+	}
 	for _, m := range geminiModels {
 		if strings.Contains(lowerID, m.ID) && m.IsReasoning {
 			return true
diff --git a/backend/internal/pkg/antigravity/claude_types_test.go b/backend/internal/pkg/antigravity/claude_types_test.go
index 1aa5bca312..e65dcc2862 100644
--- a/backend/internal/pkg/antigravity/claude_types_test.go
+++ b/backend/internal/pkg/antigravity/claude_types_test.go
@@ -39,6 +39,15 @@ func TestDefaultModels_ContainsNewAndLegacyImageModels(t *testing.T) {
 		"gemini-3.8-flash-low",
 		"gemini-3.8-flash-medium",
 		"gemini-3.8-flash-tiered",
+		"gemini-4-argon-high",
+		"gemini-4-argon-low",
+		"gemini-4-argon-medium",
+		"claude-opus-5-5-high",
+		"claude-opus-5-5-low",
+		"claude-opus-5-5-medium",
+		"claude-sonnet-5-5-high",
+		"claude-sonnet-5-5-low",
+		"claude-sonnet-5-5-medium",
 	}
 
 	for _, id := range requiredIDs {
@@ -67,3 +76,23 @@ func TestClaudeContentItem_ThinkingAlwaysHasSignature(t *testing.T) {
 		t.Fatalf("text block = %s, want %s", got, want)
 	}
 }
+
+func TestIsGeminiReasoningModel_IncludesProAgent(t *testing.T) {
+	t.Parallel()
+
+	if !IsGeminiReasoningModel("gemini-pro-agent") {
+		t.Fatal("expected gemini-pro-agent to be recognized as a Gemini reasoning model")
+	}
+	if !IsGeminiReasoningModel("gemini-3.8-flash-high") {
+		t.Fatal("expected gemini-3.8-flash-high to be recognized as a Gemini reasoning model")
+	}
+	if !IsGeminiReasoningModel("gemini-4-argon") {
+		t.Fatal("expected gemini-4-argon to be recognized as a Gemini reasoning model")
+	}
+	if !IsGeminiReasoningModel("gemini-4-argon-high") {
+		t.Fatal("expected gemini-4-argon-high to be recognized as a Gemini reasoning model")
+	}
+	if IsGeminiReasoningModel("gemini-2.5-flash") {
+		t.Fatal("did not expect gemini-2.5-flash to be recognized as a Gemini reasoning model")
+	}
+}
diff --git a/backend/internal/pkg/antigravity/client.go b/backend/internal/pkg/antigravity/client.go
index a3ea6709f7..b147e5b24b 100644
--- a/backend/internal/pkg/antigravity/client.go
+++ b/backend/internal/pkg/antigravity/client.go
@@ -239,10 +239,39 @@ func TierIDToPlanType(tierID string) string {
 		if tierID == "" {
 			return "Free"
 		}
+		// Google 新增的细分档位（如 g1-ultra-lite-tier、g1-pro-plus-tier）仍归入 Ultra / Pro。
+		if plan := paidPlanFromTierID(tierID); plan != "" {
+			return plan
+		}
 		return tierID
 	}
 }
 
+// paidPlanFromTierID 识别 g1-ultra-*-tier / g1-pro-*-tier 形式的付费档位 ID，未知时返回空串。
+func paidPlanFromTierID(tierID string) string {
+	id := strings.ToLower(strings.TrimSpace(tierID))
+	if !strings.HasSuffix(id, "-tier") {
+		return ""
+	}
+	switch {
+	case strings.HasPrefix(id, "g1-ultra-"):
+		return "Ultra"
+	case strings.HasPrefix(id, "g1-pro-"):
+		return "Pro"
+	default:
+		return ""
+	}
+}
+
+// IsPaidPlanType 判断账号记录的 plan_type 是否为付费套餐，兼容旧记录里直接保存的档位 ID。
+func IsPaidPlanType(planType string) bool {
+	switch strings.ToLower(strings.TrimSpace(planType)) {
+	case "pro", "ultra":
+		return true
+	}
+	return paidPlanFromTierID(planType) != ""
+}
+
 // Client Antigravity API 客户端
 type Client struct {
 	httpClient *http.Client
@@ -653,8 +682,22 @@ type FetchAvailableModelsResponse struct {
 }
 
 // FetchAvailableModels 获取可用模型和配额信息，返回解析后的结构体和原始 JSON
-// 支持 URL fallback：sandbox → daily → prod
+// 保留旧调用的 URL fallback：prod → daily。
 func (c *Client) FetchAvailableModels(ctx context.Context, accessToken, projectID string, bodyLimit int64) (*FetchAvailableModelsResponse, map[string]any, error) {
+	return c.fetchAvailableModels(ctx, BaseURLs, accessToken, projectID, bodyLimit, false)
+}
+
+// FetchAvailableModelsFromURL 获取指定端点的模型目录，不回退到其他端点。
+// 模型发现应使用与生成请求相同的端点，避免返回该端点无法访问的模型。
+func (c *Client) FetchAvailableModelsFromURL(ctx context.Context, baseURL, accessToken, projectID string, bodyLimit int64) (*FetchAvailableModelsResponse, map[string]any, error) {
+	baseURL = strings.TrimRight(strings.TrimSpace(baseURL), "/")
+	if baseURL == "" {
+		return nil, nil, errors.New("fetchAvailableModels base URL is required")
+	}
+	return c.fetchAvailableModels(ctx, []string{baseURL}, accessToken, projectID, bodyLimit, true)
+}
+
+func (c *Client) fetchAvailableModels(ctx context.Context, availableURLs []string, accessToken, projectID string, bodyLimit int64, fixedEndpoint bool) (*FetchAvailableModelsResponse, map[string]any, error) {
 	if c == nil || c.httpClient == nil {
 		return nil, nil, errors.New("antigravity client is not configured")
 	}
@@ -668,10 +711,10 @@ func (c *Client) FetchAvailableModels(ctx context.Context, accessToken, projectI
 		return nil, nil, fmt.Errorf("序列化请求失败: %w", err)
 	}
 
-	// 固定顺序：prod -> daily
-	availableURLs := BaseURLs
-
 	fetchClient := c.fetchAvailableModelsHTTPClient()
+	if fixedEndpoint {
+		fetchClient.CheckRedirect = func(*http.Request, []*http.Request) error { return http.ErrUseLastResponse }
+	}
 	var lastErr error
 	for urlIdx, baseURL := range availableURLs {
 		apiURL := baseURL + "/v1internal:fetchAvailableModels"
diff --git a/backend/internal/pkg/antigravity/client_test.go b/backend/internal/pkg/antigravity/client_test.go
index 7a525879fa..b6a3427885 100644
--- a/backend/internal/pkg/antigravity/client_test.go
+++ b/backend/internal/pkg/antigravity/client_test.go
@@ -6,6 +6,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -260,6 +261,8 @@ func TestTierIDToPlanType(t *testing.T) {
 		{"free-tier", "Free"},
 		{"g1-pro-tier", "Pro"},
 		{"g1-ultra-tier", "Ultra"},
+		{"g1-ultra-lite-tier", "Ultra"},
+		{"G1-Pro-Plus-Tier", "Pro"},
 		{"FREE-TIER", "Free"},
 		{"", "Free"},
 		{"unknown-tier", "unknown-tier"},
@@ -1468,6 +1471,113 @@ func TestClient_LoadCodeAssist_ContextCanceled_RealCall(t *testing.T) {
 // Client.FetchAvailableModels - 真正调用方法的测试
 // ---------------------------------------------------------------------------
 
+func TestClient_FetchAvailableModelsFromURL_UsesSelectedEndpoint(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/v1internal:fetchAvailableModels" || r.Method != http.MethodPost {
+			t.Errorf("unexpected model list request: %s %s", r.Method, r.URL.Path)
+		}
+		if r.Header.Get("Authorization") != "Bearer selected-token" {
+			t.Errorf("unexpected authorization header")
+		}
+		var body FetchAvailableModelsRequest
+		if err := json.NewDecoder(r.Body).Decode(&body); err != nil || body.Project != "selected-project" {
+			t.Errorf("unexpected project request: %+v, %v", body, err)
+		}
+		_, _ = w.Write([]byte(`{"models":{"gemini-3.8-flash-high":{"displayName":"Gemini 3.8 Flash High","supportsImages":true,"supportsThinking":true,"thinkingBudget":24576,"maxTokens":1048576,"maxOutputTokens":65536}}}`))
+	}))
+	defer server.Close()
+
+	client := mustNewClient(t, "")
+	response, raw, err := client.FetchAvailableModelsFromURL(context.Background(), server.URL, "selected-token", "selected-project", defaultFetchAvailableModelsBodyLimit)
+	if err != nil {
+		t.Fatalf("selected endpoint should return its catalog: %v", err)
+	}
+	model, ok := response.Models["gemini-3.8-flash-high"]
+	if !ok || model.SupportsThinking == nil || !*model.SupportsThinking || model.MaxTokens == nil || *model.MaxTokens != 1048576 {
+		t.Fatalf("selected endpoint metadata must remain available: %+v", model)
+	}
+	if raw["models"] == nil {
+		t.Fatal("selected endpoint raw catalog must remain available")
+	}
+}
+
+func TestClient_FetchAvailableModelsFromURL_DoesNotFollowAnotherEndpoint(t *testing.T) {
+	otherEndpointCalls := 0
+	other := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		otherEndpointCalls++
+		_, _ = w.Write([]byte(`{"models":{"other-endpoint-model":{}}}`))
+	}))
+	defer other.Close()
+	selected := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.Redirect(w, r, other.URL+"/v1internal:fetchAvailableModels", http.StatusTemporaryRedirect)
+	}))
+	defer selected.Close()
+	withMockBaseURLs(t, []string{selected.URL, other.URL})
+
+	response, _, err := mustNewClient(t, "").FetchAvailableModelsFromURL(context.Background(), selected.URL, "token", "project", defaultFetchAvailableModelsBodyLimit)
+	if err == nil || response != nil {
+		t.Fatalf("selected endpoint redirect must not produce another endpoint's catalog: %v, %v", response, err)
+	}
+	if otherEndpointCalls != 0 {
+		t.Fatalf("model discovery must stay on selected endpoint; other endpoint received %d requests", otherEndpointCalls)
+	}
+}
+
+func TestClient_FetchAvailableModelsFromURL_DoesNotFallbackOnFailure(t *testing.T) {
+	for _, status := range []int{http.StatusNotFound, http.StatusTooManyRequests, http.StatusInternalServerError, http.StatusForbidden} {
+		t.Run(fmt.Sprint(status), func(t *testing.T) {
+			otherEndpointCalls := 0
+			other := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				otherEndpointCalls++
+				_, _ = w.Write([]byte(`{"models":{"other-endpoint-model":{}}}`))
+			}))
+			defer other.Close()
+			selected := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.WriteHeader(status)
+				_, _ = w.Write([]byte(`{"error":"selected endpoint unavailable"}`))
+			}))
+			defer selected.Close()
+			withMockBaseURLs(t, []string{selected.URL, other.URL})
+
+			response, raw, err := mustNewClient(t, "").FetchAvailableModelsFromURL(context.Background(), selected.URL, "token", "project", defaultFetchAvailableModelsBodyLimit)
+			if err == nil || response != nil || raw != nil {
+				t.Fatalf("selected endpoint HTTP %d must fail without another catalog: %v, %v", status, response, err)
+			}
+			if otherEndpointCalls != 0 {
+				t.Fatalf("another endpoint must not receive fallback requests: %d", otherEndpointCalls)
+			}
+			if status == http.StatusForbidden {
+				if _, ok := err.(*ForbiddenError); !ok {
+					t.Fatalf("403 must preserve typed forbidden error: %T", err)
+				}
+			}
+		})
+	}
+}
+
+func TestClient_FetchAvailableModelsFromURL_ValidatesResponseAndLimit(t *testing.T) {
+	for _, tc := range []struct {
+		name  string
+		body  string
+		limit int64
+	}{
+		{name: "invalid JSON", body: `not JSON`, limit: defaultFetchAvailableModelsBodyLimit},
+		{name: "oversized response", body: `{"models":{"model":{}}}`, limit: 8},
+		{name: "nonpositive limit", body: `{"models":{"model":{}}}`, limit: 0},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				_, _ = io.WriteString(w, tc.body)
+			}))
+			defer server.Close()
+			_, _, err := mustNewClient(t, "").FetchAvailableModelsFromURL(context.Background(), server.URL, "token", "project", tc.limit)
+			if err == nil {
+				t.Fatal("invalid model catalog response or limit must fail")
+			}
+		})
+	}
+}
+
 func TestClient_FetchAvailableModels_Success_RealCall(t *testing.T) {
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodPost {
@@ -1787,6 +1897,51 @@ func TestClient_FetchAvailableModels_404Fallback_RealCall(t *testing.T) {
 	}
 }
 
+func TestClient_HubUserAgentAndIDEVersionUseContextOverride(t *testing.T) {
+	withTestUserAgentVersionResolver(t)
+	ctx := context.WithValue(context.Background(), userAgentVersionTestContextKey{}, "3.4.5")
+	const expectedUserAgent = "antigravity/hub/3.4.5 windows/amd64"
+	for _, action := range []string{"generateContent", "streamGenerateContent"} {
+		req, err := NewAPIRequestWithURL(ctx, "https://upstream.example", action, "test-token", []byte(`{}`))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if got := req.Header.Get("User-Agent"); got != expectedUserAgent {
+			t.Fatalf("generation request must use the context Hub user agent: %q", got)
+		}
+	}
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if got := r.Header.Get("User-Agent"); got != expectedUserAgent {
+			t.Errorf("client API must use the context Hub user agent: %q", got)
+		}
+		switch r.URL.Path {
+		case "/v1internal:loadCodeAssist":
+			var body LoadCodeAssistRequest
+			if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+				t.Error(err)
+			}
+			if body.Metadata.IDEVersion != "3.4.5" {
+				t.Errorf("ideVersion must match the user agent version: %q", body.Metadata.IDEVersion)
+			}
+			_, _ = io.WriteString(w, `{"cloudaicompanionProject":"test-project"}`)
+		case "/v1internal:fetchAvailableModels":
+			_, _ = io.WriteString(w, `{"models":{"gemini-4-argon-high":{}}}`)
+		default:
+			t.Errorf("unexpected client endpoint: %s", r.URL.Path)
+			w.WriteHeader(http.StatusNotFound)
+		}
+	}))
+	defer server.Close()
+	withMockBaseURLs(t, []string{server.URL})
+	client := mustNewClient(t, "")
+	if _, _, err := client.LoadCodeAssist(ctx, "test-token"); err != nil {
+		t.Fatal(err)
+	}
+	if _, _, err := client.FetchAvailableModelsFromURL(ctx, server.URL, "test-token", "test-project", defaultFetchAvailableModelsBodyLimit); err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestExtractProjectIDFromOnboardResponse(t *testing.T) {
 	t.Parallel()
 
diff --git a/backend/internal/pkg/antigravity/oauth.go b/backend/internal/pkg/antigravity/oauth.go
index 625dcaea69..2ad14afd91 100644
--- a/backend/internal/pkg/antigravity/oauth.go
+++ b/backend/internal/pkg/antigravity/oauth.go
@@ -34,7 +34,7 @@ const (
 	AntigravityUserAgentVersionEnv = "ANTIGRAVITY_USER_AGENT_VERSION"
 
 	// DefaultUserAgentVersion 是未通过环境变量或后台设置覆盖时使用的默认版本号。
-	DefaultUserAgentVersion = "2.9.1"
+	DefaultUserAgentVersion = "2.23.0"
 
 	// 固定的 redirect_uri（用户需手动复制 code）
 	RedirectURI = "http://localhost:8085/callback"
@@ -123,9 +123,9 @@ func GetUserAgentVersionForContext(ctx context.Context) string {
 // BuildUserAgent 使用指定版本号构造 User-Agent；版本为空或非法时回退默认值。
 func BuildUserAgent(version string) string {
 	if normalized := NormalizeUserAgentVersion(version); normalized != "" {
-		return fmt.Sprintf("antigravity/%s windows/amd64", normalized)
+		return fmt.Sprintf("antigravity/hub/%s windows/amd64", normalized)
 	}
-	return fmt.Sprintf("antigravity/%s windows/amd64", defaultUserAgentVersion)
+	return fmt.Sprintf("antigravity/hub/%s windows/amd64", defaultUserAgentVersion)
 }
 
 // GetUserAgentForContext 返回当前请求应使用的 User-Agent。
diff --git a/backend/internal/pkg/antigravity/oauth_test.go b/backend/internal/pkg/antigravity/oauth_test.go
index 4ebc7e5434..f75f2b4ff8 100644
--- a/backend/internal/pkg/antigravity/oauth_test.go
+++ b/backend/internal/pkg/antigravity/oauth_test.go
@@ -3,16 +3,119 @@
 package antigravity
 
 import (
+	"context"
 	"crypto/sha256"
 	"encoding/base64"
 	"encoding/hex"
 	"net/url"
 	"os"
+	"os/exec"
 	"strings"
 	"testing"
 	"time"
 )
 
+func TestBuildUserAgentUsesHubClientFamily(t *testing.T) {
+	if got := BuildUserAgent(" 2.23.0 "); got != "antigravity/hub/2.23.0 windows/amd64" {
+		t.Fatalf("Hub client family must be sent with the configured version: %q", got)
+	}
+}
+
+func TestBuildUserAgentValidatesCustomVersion(t *testing.T) {
+	previous := defaultUserAgentVersion
+	defaultUserAgentVersion = "2.23.0"
+	t.Cleanup(func() { defaultUserAgentVersion = previous })
+	for _, tc := range []struct {
+		version string
+		want    string
+	}{
+		{version: " 3.4.5 ", want: "antigravity/hub/3.4.5 windows/amd64"},
+		{version: "", want: "antigravity/hub/2.23.0 windows/amd64"},
+		{version: "hub/3.4.5", want: "antigravity/hub/2.23.0 windows/amd64"},
+		{version: "3.4", want: "antigravity/hub/2.23.0 windows/amd64"},
+		{version: "3.4.5\r\nInjected: header", want: "antigravity/hub/2.23.0 windows/amd64"},
+	} {
+		t.Run(tc.version, func(t *testing.T) {
+			if got := BuildUserAgent(tc.version); got != tc.want {
+				t.Fatalf("custom version must be validated before building Hub user agent: got %q, want %q", got, tc.want)
+			}
+		})
+	}
+}
+
+type userAgentVersionTestContextKey struct{}
+
+func withTestUserAgentVersionResolver(t *testing.T) {
+	t.Helper()
+	userAgentVersionMu.RLock()
+	previous := userAgentVersionResolver
+	userAgentVersionMu.RUnlock()
+	SetUserAgentVersionResolver(func(ctx context.Context) string {
+		version, _ := ctx.Value(userAgentVersionTestContextKey{}).(string)
+		return version
+	})
+	t.Cleanup(func() { SetUserAgentVersionResolver(previous) })
+}
+
+func TestGetUserAgentForContextPreservesVersionOverride(t *testing.T) {
+	withTestUserAgentVersionResolver(t)
+	previous := defaultUserAgentVersion
+	defaultUserAgentVersion = "2.23.0"
+	t.Cleanup(func() { defaultUserAgentVersion = previous })
+	for _, tc := range []struct {
+		version string
+		want    string
+	}{
+		{version: " 3.4.5 ", want: "antigravity/hub/3.4.5 windows/amd64"},
+		{version: "invalid", want: "antigravity/hub/2.23.0 windows/amd64"},
+	} {
+		ctx := context.WithValue(context.Background(), userAgentVersionTestContextKey{}, tc.version)
+		if got := GetUserAgentForContext(ctx); got != tc.want {
+			t.Fatalf("context version override must use Hub family: got %q, want %q", got, tc.want)
+		}
+	}
+	if got := GetUserAgentForContext(nil); got != "antigravity/hub/2.23.0 windows/amd64" {
+		t.Fatalf("nil context must keep the default Hub user agent: %q", got)
+	}
+}
+
+func TestGetUserAgentEnvironmentOverride(t *testing.T) {
+	const expectedVersionEnv = "SUB2API_TEST_EXPECTED_ANTIGRAVITY_VERSION"
+	if expected := os.Getenv(expectedVersionEnv); expected != "" {
+		if got := GetDefaultUserAgentVersion(); got != expected {
+			t.Fatalf("environment version must be loaded during initialization: got %q, want %q", got, expected)
+		}
+		if got := GetUserAgent(); got != "antigravity/hub/"+expected+" windows/amd64" {
+			t.Fatalf("environment override must keep Hub family: %q", got)
+		}
+		return
+	}
+	for _, tc := range []struct {
+		version string
+		want    string
+	}{
+		{version: " 3.4.5 ", want: "3.4.5"},
+		{version: "invalid", want: "2.23.0"},
+	} {
+		t.Run(tc.version, func(t *testing.T) {
+			binary, err := os.Executable()
+			if err != nil {
+				t.Fatal(err)
+			}
+			command := exec.Command(binary, "-test.run=^TestGetUserAgentEnvironmentOverride$")
+			for _, variable := range os.Environ() {
+				if !strings.HasPrefix(variable, AntigravityUserAgentVersionEnv+"=") && !strings.HasPrefix(variable, expectedVersionEnv+"=") {
+					command.Env = append(command.Env, variable)
+				}
+			}
+			command.Env = append(command.Env, AntigravityUserAgentVersionEnv+"="+tc.version, expectedVersionEnv+"="+tc.want)
+			if output, err := command.CombinedOutput(); err != nil {
+				t.Fatalf("environment override failed: %v\n%s", err, output)
+			}
+		})
+	}
+}
+
 // ---------------------------------------------------------------------------
 // getClientSecret
 // ---------------------------------------------------------------------------
@@ -693,7 +796,10 @@ func TestConstants_值正确(t *testing.T) {
 	if RedirectURI != "http://localhost:8085/callback" {
 		t.Errorf("RedirectURI 不匹配: got %s", RedirectURI)
 	}
-	if GetUserAgent() != "antigravity/2.9.1 windows/amd64" {
+	if DefaultUserAgentVersion != "2.23.0" {
+		t.Errorf("default Hub version must match the verified upstream release: got %s", DefaultUserAgentVersion)
+	}
+	if GetUserAgent() != "antigravity/hub/2.23.0 windows/amd64" {
 		t.Errorf("UserAgent 不匹配: got %s", GetUserAgent())
 	}
 	if SessionTTL != 30*time.Minute {
diff --git a/backend/internal/pkg/antigravity/request_transformer.go b/backend/internal/pkg/antigravity/request_transformer.go
index 9349e54ee8..a13748926e 100644
--- a/backend/internal/pkg/antigravity/request_transformer.go
+++ b/backend/internal/pkg/antigravity/request_transformer.go
@@ -588,6 +588,7 @@ func buildParts(content json.RawMessage, toolIDToName map[string]string, allowDu
 					ID: block.ToolUseID,
 				},
 			})
+			parts = append(parts, extractToolResultInlineParts(block.Content)...)
 		}
 	}
 
@@ -638,6 +639,31 @@ func parseToolResultContent(content json.RawMessage, isError bool) string {
 	return string(content)
 }
 
+func extractToolResultInlineParts(content json.RawMessage) []GeminiPart {
+	if len(content) == 0 {
+		return nil
+	}
+	var innerBlocks []ContentBlock
+	if err := json.Unmarshal(content, &innerBlocks); err != nil {
+		return nil
+	}
+	var inlineParts []GeminiPart
+	for _, item := range innerBlocks {
+		if (item.Type == "image" || item.Type == "document") &&
+			item.Source != nil &&
+			item.Source.Type == "base64" &&
+			strings.TrimSpace(item.Source.Data) != "" {
+			inlineParts = append(inlineParts, GeminiPart{
+				InlineData: &GeminiInlineData{
+					MimeType: item.Source.MediaType,
+					Data:     item.Source.Data,
+				},
+			})
+		}
+	}
+	return inlineParts
+}
+
 // buildGenerationConfig 构建 generationConfig
 const (
 	defaultMaxOutputTokens    = 64000
diff --git a/backend/internal/pkg/antigravity/request_transformer_test.go b/backend/internal/pkg/antigravity/request_transformer_test.go
index 1aff9f5775..7bdb40914b 100644
--- a/backend/internal/pkg/antigravity/request_transformer_test.go
+++ b/backend/internal/pkg/antigravity/request_transformer_test.go
@@ -694,3 +694,64 @@ func TestToolConfigAlwaysPresent(t *testing.T) {
 		})
 	}
 }
+
+func TestTransformClaudeToGemini_ToolResultImagesReachUpstream(t *testing.T) {
+	claudeReq := &ClaudeRequest{
+		Model: "claude-sonnet-4-5",
+		Messages: []ClaudeMessage{
+			{
+				Role: "assistant",
+				Content: json.RawMessage(`[
+					{"type":"tool_use","id":"toolu_img_1","name":"read_image","input":{"path":"colors.png"}}
+				]`),
+			},
+			{
+				Role: "user",
+				Content: json.RawMessage(`[
+					{
+						"type":"tool_result",
+						"tool_use_id":"toolu_img_1",
+						"content":[
+							{"type":"text","text":"loaded colors.png"},
+							{"type":"image","source":{"type":"base64","media_type":"image/png","data":"aGVsbG8="}}
+						]
+					},
+					{
+						"type":"tool_result",
+						"tool_use_id":"toolu_img_1",
+						"content":[
+							{"type":"image","source":{"type":"base64","media_type":"image/jpeg","data":"d29ybGQ="}}
+						]
+					}
+				]`),
+			},
+		},
+	}
+
+	body, err := TransformClaudeToGeminiWithOptions(claudeReq, "project-1", "claude-sonnet-4-5", DefaultTransformOptions())
+	require.NoError(t, err)
+
+	var req V1InternalRequest
+	require.NoError(t, json.Unmarshal(body, &req))
+	require.Len(t, req.Request.Contents, 2)
+
+	userParts := req.Request.Contents[1].Parts
+	require.Len(t, userParts, 4)
+
+	require.NotNil(t, userParts[0].FunctionResponse)
+	require.Equal(t, "read_image", userParts[0].FunctionResponse.Name)
+	require.Equal(t, "toolu_img_1", userParts[0].FunctionResponse.ID)
+	require.Equal(t, "loaded colors.png", userParts[0].FunctionResponse.Response["result"])
+
+	require.NotNil(t, userParts[1].InlineData)
+	require.Equal(t, "image/png", userParts[1].InlineData.MimeType)
+	require.Equal(t, "aGVsbG8=", userParts[1].InlineData.Data)
+
+	require.NotNil(t, userParts[2].FunctionResponse)
+	require.Equal(t, "read_image", userParts[2].FunctionResponse.Name)
+	require.Equal(t, "Command executed successfully.", userParts[2].FunctionResponse.Response["result"])
+
+	require.NotNil(t, userParts[3].InlineData)
+	require.Equal(t, "image/jpeg", userParts[3].InlineData.MimeType)
+	require.Equal(t, "d29ybGQ=", userParts[3].InlineData.Data)
+}
diff --git a/backend/internal/pkg/gemini/models.go b/backend/internal/pkg/gemini/models.go
index d5d4ed64ce..1d38fc9909 100644
--- a/backend/internal/pkg/gemini/models.go
+++ b/backend/internal/pkg/gemini/models.go
@@ -28,6 +28,7 @@ func DefaultModels() []Model {
 		{Name: "models/gemini-3.1-pro-preview", SupportedGenerationMethods: methods},
 		{Name: "models/gemini-3.1-pro-preview-customtools", SupportedGenerationMethods: methods},
 		{Name: "models/gemini-3.1-flash-image", SupportedGenerationMethods: methods},
+		{Name: "models/gemini-4-argon", SupportedGenerationMethods: methods},
 	}
 }
 
diff --git a/backend/internal/pkg/geminicli/models.go b/backend/internal/pkg/geminicli/models.go
index cc9cbc80b2..4e2fa55bb1 100644
--- a/backend/internal/pkg/geminicli/models.go
+++ b/backend/internal/pkg/geminicli/models.go
@@ -20,6 +20,7 @@ var DefaultModels = []Model{
 	{ID: "gemini-3-pro-preview", Type: "model", DisplayName: "Gemini 3 Pro Preview", CreatedAt: ""},
 	{ID: "gemini-3.1-pro-preview", Type: "model", DisplayName: "Gemini 3.1 Pro Preview", CreatedAt: ""},
 	{ID: "gemini-3.1-flash-image", Type: "model", DisplayName: "Gemini 3.1 Flash Image", CreatedAt: ""},
+	{ID: "gemini-4-argon", Type: "model", DisplayName: "Gemini 4 Argon", CreatedAt: ""},
 }
 
 // GoogleOneModels is the conservative model set exposed for legacy Google One
diff --git a/backend/internal/service/account.go b/backend/internal/service/account.go
index 1cb756b79e..7d1428ff8e 100644
--- a/backend/internal/service/account.go
+++ b/backend/internal/service/account.go
@@ -8,6 +8,7 @@ import (
 	"log/slog"
 	"net/url"
 	"reflect"
+	"slices"
 	"sort"
 	"strconv"
 	"strings"
@@ -690,26 +691,7 @@ func (a *Account) resolveModelMapping(rawMapping map[string]any) map[string]stri
 	}
 	if len(result) > 0 {
 		if a.Platform == domain.PlatformAntigravity {
-			ensureAntigravityDefaultPassthroughs(result, []string{
-				"gemini-3-flash",
-				"gemini-3.1-pro-high",
-				"gemini-3.1-pro-low",
-				"gemini-3.6-flash",
-				"gemini-3.6-flash-high",
-				"gemini-3.6-flash-low",
-				"gemini-3.6-flash-medium",
-				"gemini-3.6-flash-tiered",
-				"gemini-3.7-flash",
-				"gemini-3.7-flash-high",
-				"gemini-3.7-flash-low",
-				"gemini-3.7-flash-medium",
-				"gemini-3.7-flash-tiered",
-				"gemini-3.8-flash",
-				"gemini-3.8-flash-high",
-				"gemini-3.8-flash-low",
-				"gemini-3.8-flash-medium",
-				"gemini-3.8-flash-tiered",
-			})
+			ensureAntigravityDefaultPassthroughs(result, antigravityDefaultPassthroughModels)
 			applyAntigravityGemini31ProAliases(result)
 		}
 		return result
@@ -759,6 +741,51 @@ func modelMappingSignature(rawMapping map[string]any) uint64 {
 	return h.Sum64()
 }
 
+// antigravityDefaultPassthroughModels 是 Antigravity 显式 model_mapping 运行时补齐的默认透传条目：
+// 让新模型发布前保存的映射也能调用这些模型。
+var antigravityDefaultPassthroughModels = []string{
+	"gemini-3-flash",
+	"gemini-3.1-pro-high",
+	"gemini-3.1-pro-low",
+	"gemini-3.6-flash",
+	"gemini-3.6-flash-high",
+	"gemini-3.6-flash-low",
+	"gemini-3.6-flash-medium",
+	"gemini-3.6-flash-tiered",
+	"gemini-3.7-flash",
+	"gemini-3.7-flash-high",
+	"gemini-3.7-flash-low",
+	"gemini-3.7-flash-medium",
+	"gemini-3.7-flash-tiered",
+	"gemini-3.8-flash",
+	"gemini-3.8-flash-high",
+	"gemini-3.8-flash-low",
+	"gemini-3.8-flash-medium",
+	"gemini-3.8-flash-tiered",
+}
+
+// isAntigravityInjectedDefaultPassthrough 判断 GetModelMapping 中的 key→target 是否仅由
+// resolveModelMapping 运行时补齐（管理员未写入 credentials.model_mapping）。
+func (a *Account) isAntigravityInjectedDefaultPassthrough(key, target string) bool {
+	if a == nil || a.Platform != domain.PlatformAntigravity || key != target || !slices.Contains(antigravityDefaultPassthroughModels, key) {
+		return false
+	}
+	rawMapping, _ := a.Credentials["model_mapping"].(map[string]any)
+	hasExplicitEntry := false
+	for _, v := range rawMapping {
+		if _, ok := v.(string); ok {
+			hasExplicitEntry = true
+			break
+		}
+	}
+	if !hasExplicitEntry {
+		// 空映射走默认目录，不做运行时补齐。
+		return false
+	}
+	_, configured := rawMapping[key].(string)
+	return !configured
+}
+
 func ensureAntigravityDefaultPassthrough(mapping map[string]string, model string) {
 	if mapping == nil || model == "" {
 		return
diff --git a/backend/internal/service/account_test_service.go b/backend/internal/service/account_test_service.go
index 26060efc78..210033179a 100644
--- a/backend/internal/service/account_test_service.go
+++ b/backend/internal/service/account_test_service.go
@@ -2464,12 +2464,12 @@ func (s *AccountTestService) routeAntigravityTest(c *gin.Context, account *Accou
 		}
 		return s.testClaudeAccountConnection(c, account, modelID)
 	}
-	return s.testAntigravityAccountConnection(c, account, modelID)
+	return s.testAntigravityAccountConnection(c, account, modelID, prompt)
 }
 
 // testAntigravityAccountConnection tests an Antigravity account's connection
 // 支持 Claude 和 Gemini 两种协议，使用非流式请求
-func (s *AccountTestService) testAntigravityAccountConnection(c *gin.Context, account *Account, modelID string) error {
+func (s *AccountTestService) testAntigravityAccountConnection(c *gin.Context, account *Account, modelID string, prompt string) error {
 	ctx := c.Request.Context()
 
 	testModelID := antigravityConnectionTestModel(modelID)
@@ -2488,8 +2488,8 @@ func (s *AccountTestService) testAntigravityAccountConnection(c *gin.Context, ac
 	// Send test_start event
 	s.sendEvent(c, TestEvent{Type: "test_start", Model: testModelID})
 
-	// 调用 AntigravityGatewayService.TestConnection（复用协议转换逻辑）
-	result, err := s.antigravityGatewayService.TestConnection(ctx, account, testModelID)
+	// 调用 AntigravityGatewayService.TestConnectionWithPrompt（复用协议转换逻辑）
+	result, err := s.antigravityGatewayService.TestConnectionWithPrompt(ctx, account, testModelID, prompt)
 	if err != nil {
 		return s.sendErrorAndEnd(c, err.Error())
 	}
@@ -2498,6 +2498,13 @@ func (s *AccountTestService) testAntigravityAccountConnection(c *gin.Context, ac
 	if result.Text != "" {
 		s.sendEvent(c, TestEvent{Type: "content", Text: result.Text})
 	}
+	for _, img := range result.Images {
+		s.sendEvent(c, TestEvent{
+			Type:     "image",
+			ImageURL: img.ImageURL,
+			MimeType: img.MimeType,
+		})
+	}
 
 	s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
 	return nil
diff --git a/backend/internal/service/account_test_service_antigravity_test.go b/backend/internal/service/account_test_service_antigravity_test.go
index b3362f3f69..6a14ea85c1 100644
--- a/backend/internal/service/account_test_service_antigravity_test.go
+++ b/backend/internal/service/account_test_service_antigravity_test.go
@@ -3,6 +3,7 @@
 package service
 
 import (
+	"encoding/json"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -14,3 +15,68 @@ func TestAntigravityConnectionTestModel(t *testing.T) {
 	require.Equal(t, "claude-sonnet-4-6", antigravityConnectionTestModel(""))
 	require.Equal(t, "gemini-3.1-pro-preview", antigravityConnectionTestModel("gemini-3.1-pro-preview"))
 }
+
+func TestAntigravityBuildGeminiTestRequest_IncludesValidatedToolConfig(t *testing.T) {
+	t.Parallel()
+
+	svc := &AntigravityGatewayService{}
+	raw, err := svc.buildGeminiTestRequestWithPrompt("proj-123", "gemini-3.8-flash-high", "")
+	require.NoError(t, err)
+
+	var v1Req map[string]any
+	require.NoError(t, json.Unmarshal(raw, &v1Req))
+	require.Equal(t, "proj-123", v1Req["project"])
+	require.Equal(t, "gemini-3.8-flash-high", v1Req["model"])
+
+	inner, ok := v1Req["request"].(map[string]any)
+	require.True(t, ok)
+	toolCfg, ok := inner["toolConfig"].(map[string]any)
+	require.True(t, ok, "expected toolConfig to be present in Gemini test request")
+	fcCfg, ok := toolCfg["functionCallingConfig"].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, "VALIDATED", fcCfg["mode"])
+}
+
+func TestAntigravityBuildGeminiTestRequestWithPrompt_ImageModel(t *testing.T) {
+	t.Parallel()
+
+	svc := &AntigravityGatewayService{}
+	raw, err := svc.buildGeminiTestRequestWithPrompt("proj-123", "gemini-3.1-flash-image", "a cute cat")
+	require.NoError(t, err)
+
+	var v1Req map[string]any
+	require.NoError(t, json.Unmarshal(raw, &v1Req))
+	inner, ok := v1Req["request"].(map[string]any)
+	require.True(t, ok)
+
+	genCfg, ok := inner["generationConfig"].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, []any{"TEXT", "IMAGE"}, genCfg["responseModalities"])
+
+	contents, ok := inner["contents"].([]any)
+	require.True(t, ok)
+	require.Len(t, contents, 1)
+	firstContent := contents[0].(map[string]any)
+	parts := firstContent["parts"].([]any)
+	require.Equal(t, "a cute cat", parts[0].(map[string]any)["text"])
+}
+
+func TestExtractContentFromSSEResponse_ExtractsTextAndInlineImages(t *testing.T) {
+	t.Parallel()
+
+	sse := "data: {\"response\":{\"candidates\":[{\"content\":{\"parts\":[{\"text\":\"Here is your image\"},{\"inlineData\":{\"mimeType\":\"image/png\",\"data\":\"iVBORw0KGgo=\"}}]}}]}}\n\n"
+	text, images := extractContentFromSSEResponse([]byte(sse))
+	require.Equal(t, "Here is your image", text)
+	require.Len(t, images, 1)
+	require.Equal(t, "image/png", images[0].MimeType)
+	require.Equal(t, "data:image/png;base64,iVBORw0KGgo=", images[0].ImageURL)
+}
+
+func TestAntigravityShouldUseGeminiTestBuilder_UsesMappedModel(t *testing.T) {
+	t.Parallel()
+
+	require.True(t, shouldUseAntigravityGeminiTestRequest("custom-alias", "gemini-2.5-flash"))
+	require.True(t, shouldUseAntigravityGeminiTestRequest("gemini-3.1-pro", "gemini-pro-agent"))
+	require.False(t, shouldUseAntigravityGeminiTestRequest("gemini-alias", "claude-sonnet-4-6"))
+	require.False(t, shouldUseAntigravityGeminiTestRequest("claude-sonnet-4-6", "claude-sonnet-4-6"))
+}
diff --git a/backend/internal/service/antigravity_gateway_gemini.go b/backend/internal/service/antigravity_gateway_gemini.go
index 4a8c70dcfb..b6396cb08a 100644
--- a/backend/internal/service/antigravity_gateway_gemini.go
+++ b/backend/internal/service/antigravity_gateway_gemini.go
@@ -141,6 +141,8 @@ func (s *AntigravityGatewayService) ForwardGemini(ctx context.Context, c *gin.Co
 		injectedBody = reconciled
 	}
 
+	injectedBody = ensureGeminiFunctionCallThoughtSignatures(injectedBody)
+
 	// 包装请求
 	wrappedBody, err := s.wrapV1InternalRequest(projectID, mappedModel, injectedBody)
 	if err != nil {
diff --git a/backend/internal/service/antigravity_gateway_retry.go b/backend/internal/service/antigravity_gateway_retry.go
index 78d46a4b23..ee7a983481 100644
--- a/backend/internal/service/antigravity_gateway_retry.go
+++ b/backend/internal/service/antigravity_gateway_retry.go
@@ -78,12 +78,7 @@ func accountHasAntigravityPaidTier(account *Account) bool {
 	if !ok {
 		return false
 	}
-	switch strings.ToLower(strings.TrimSpace(planType)) {
-	case "pro", "ultra":
-		return true
-	default:
-		return false
-	}
+	return antigravity.IsPaidPlanType(planType)
 }
 
 // smartRetryAction 智能重试的处理结果
diff --git a/backend/internal/service/antigravity_gateway_service.go b/backend/internal/service/antigravity_gateway_service.go
index 086466d319..66a0f02cdb 100644
--- a/backend/internal/service/antigravity_gateway_service.go
+++ b/backend/internal/service/antigravity_gateway_service.go
@@ -344,16 +344,32 @@ func (s *AntigravityGatewayService) IsModelSupported(requestedModel string) bool
 		strings.HasPrefix(requestedModel, "gemini-")
 }
 
+// TestConnectionImage 测试连接返回的图片结果
+type TestConnectionImage struct {
+	ImageURL string
+	MimeType string
+}
+
 // TestConnectionResult 测试连接结果
 type TestConnectionResult struct {
-	Text        string // 响应文本
-	MappedModel string // 实际使用的模型
+	Text        string                // 响应文本
+	Images      []TestConnectionImage // 响应图片（图片生成模型）
+	MappedModel string                // 实际使用的模型
+}
+
+func shouldUseAntigravityGeminiTestRequest(_, mappedModel string) bool {
+	return strings.HasPrefix(strings.ToLower(strings.TrimSpace(mappedModel)), "gemini-")
 }
 
 // TestConnection 测试 Antigravity 账号连接。
 // 复用 antigravityRetryLoop 的完整重试 / credits overages / 智能重试逻辑，
 // 与真实调度行为一致。差异：不做账号切换（测试指定账号）、不记录 ops 错误。
 func (s *AntigravityGatewayService) TestConnection(ctx context.Context, account *Account, modelID string) (*TestConnectionResult, error) {
+	return s.TestConnectionWithPrompt(ctx, account, modelID, "")
+}
+
+// TestConnectionWithPrompt 测试 Antigravity 账号连接，支持为图片生成模型指定测试提示词。
+func (s *AntigravityGatewayService) TestConnectionWithPrompt(ctx context.Context, account *Account, modelID string, prompt string) (*TestConnectionResult, error) {
 
 	// 获取 token
 	if s.tokenProvider == nil {
@@ -377,8 +393,8 @@ func (s *AntigravityGatewayService) TestConnection(ctx context.Context, account
 
 	// 构建请求体
 	var requestBody []byte
-	if strings.HasPrefix(modelID, "gemini-") {
-		requestBody, err = s.buildGeminiTestRequest(projectID, mappedModel)
+	if shouldUseAntigravityGeminiTestRequest(modelID, mappedModel) {
+		requestBody, err = s.buildGeminiTestRequestWithPrompt(projectID, mappedModel, prompt)
 	} else {
 		requestBody, err = s.buildClaudeTestRequest(projectID, mappedModel)
 	}
@@ -434,8 +450,8 @@ func (s *AntigravityGatewayService) TestConnection(ctx context.Context, account
 		return nil, fmt.Errorf("API 返回 %d: %s", result.resp.StatusCode, string(respBody))
 	}
 
-	text := extractTextFromSSEResponse(respBody)
-	return &TestConnectionResult{Text: text, MappedModel: mappedModel}, nil
+	text, images := extractContentFromSSEResponse(respBody)
+	return &TestConnectionResult{Text: text, Images: images, MappedModel: mappedModel}, nil
 }
 
 // testConnectionHandleError 是 TestConnection 使用的轻量 handleError 回调。
@@ -451,9 +467,39 @@ func testConnectionHandleError(
 	return nil
 }
 
-// buildGeminiTestRequest 构建 Gemini 格式测试请求
-// 使用最小 token 消耗：输入 "." + maxOutputTokens: 1
-func (s *AntigravityGatewayService) buildGeminiTestRequest(projectID, model string) ([]byte, error) {
+// buildGeminiTestRequestWithPrompt 构建 Gemini 格式测试请求
+// 文本模型使用最小 token 消耗：输入 "." + maxOutputTokens: 1；图片模型使用图片生成配置
+func (s *AntigravityGatewayService) buildGeminiTestRequestWithPrompt(projectID, model, prompt string) ([]byte, error) {
+	if isImageGenerationModel(model) {
+		imagePrompt := strings.TrimSpace(prompt)
+		if imagePrompt == "" {
+			imagePrompt = defaultGeminiImageTestPrompt
+		}
+		payload := map[string]any{
+			"contents": []map[string]any{
+				{
+					"role": "user",
+					"parts": []map[string]any{
+						{"text": imagePrompt},
+					},
+				},
+			},
+			"systemInstruction": map[string]any{
+				"parts": []map[string]any{
+					{"text": antigravity.GetDefaultIdentityPatch()},
+				},
+			},
+			"generationConfig": map[string]any{
+				"responseModalities": []string{"TEXT", "IMAGE"},
+				"imageConfig": map[string]any{
+					"aspectRatio": "1:1",
+				},
+			},
+		}
+		payloadBytes, _ := json.Marshal(payload)
+		return s.wrapV1InternalRequest(projectID, model, payloadBytes)
+	}
+
 	payload := map[string]any{
 		"contents": []map[string]any{
 			{
@@ -472,6 +518,11 @@ func (s *AntigravityGatewayService) buildGeminiTestRequest(projectID, model stri
 		"generationConfig": map[string]any{
 			"maxOutputTokens": 1,
 		},
+		"toolConfig": map[string]any{
+			"functionCallingConfig": map[string]any{
+				"mode": "VALIDATED",
+			},
+		},
 	}
 	payloadBytes, _ := json.Marshal(payload)
 	return s.wrapV1InternalRequest(projectID, model, payloadBytes)
@@ -504,9 +555,10 @@ func (s *AntigravityGatewayService) getClaudeTransformOptions(ctx context.Contex
 	return opts
 }
 
-// extractTextFromSSEResponse 从 SSE 流式响应中提取文本
-func extractTextFromSSEResponse(respBody []byte) string {
+// extractContentFromSSEResponse 从 SSE 流式响应中提取文本和内联图片
+func extractContentFromSSEResponse(respBody []byte) (string, []TestConnectionImage) {
 	var texts []string
+	var images []TestConnectionImage
 	lines := bytes.Split(respBody, []byte("\n"))
 
 	for _, line := range lines {
@@ -532,7 +584,7 @@ func extractTextFromSSEResponse(respBody []byte) string {
 			continue
 		}
 
-		// 尝试从 response.candidates[0].content.parts[].text 提取
+		// 尝试从 response.candidates[0].content.parts[] 提取
 		response, ok := data["response"].(map[string]any)
 		if !ok {
 			// 尝试直接从 candidates 提取（某些响应格式）
@@ -564,11 +616,21 @@ func extractTextFromSSEResponse(respBody []byte) string {
 				if text, ok := partMap["text"].(string); ok && text != "" {
 					texts = append(texts, text)
 				}
+				if inlineData, ok := partMap["inlineData"].(map[string]any); ok {
+					mimeType, _ := inlineData["mimeType"].(string)
+					b64Data, _ := inlineData["data"].(string)
+					if strings.HasPrefix(strings.ToLower(mimeType), "image/") && b64Data != "" {
+						images = append(images, TestConnectionImage{
+							ImageURL: fmt.Sprintf("data:%s;base64,%s", mimeType, b64Data),
+							MimeType: mimeType,
+						})
+					}
+				}
 			}
 		}
 	}
 
-	return strings.Join(texts, "")
+	return strings.Join(texts, ""), images
 }
 
 // injectIdentityPatchToGeminiRequest 为 Gemini 格式请求注入身份提示词
diff --git a/backend/internal/service/antigravity_gateway_service_test.go b/backend/internal/service/antigravity_gateway_service_test.go
index 79ce35f596..92735948aa 100644
--- a/backend/internal/service/antigravity_gateway_service_test.go
+++ b/backend/internal/service/antigravity_gateway_service_test.go
@@ -2012,3 +2012,175 @@ func generateLargeUnwrapJSON(minSize int) []byte {
 	b, _ := json.Marshal(outer)
 	return b
 }
+
+func TestAntigravityGatewayService_ForwardGemini_NonStreamPreservesFunctionCallAndThoughtSignature(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	body := []byte(`{"contents":[{"role":"user","parts":[{"text":"Call get_weather for Tokyo."}]}],"tools":[{"functionDeclarations":[{"name":"get_weather","description":"Get weather","parameters":{"type":"object","properties":{"city":{"type":"string"}},"required":["city"]}}]}]}`)
+
+	writer := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(writer)
+	c.Request = httptest.NewRequest(http.MethodPost, "/v1beta/models/gemini-4-argon:generateContent", bytes.NewReader(body))
+
+	sseStream := strings.Join([]string{
+		`data: {"response":{"candidates":[{"content":{"role":"model","parts":[{"thoughtSignature":"sig_fc_1","functionCall":{"name":"get_weather","args":{"city":"Tokyo"},"id":"call_1"}}]}}],"usageMetadata":{"promptTokenCount":300,"candidatesTokenCount":16,"totalTokenCount":328,"thoughtsTokenCount":12},"modelVersion":"gemini-4-argon","responseId":"resp_1"}}`,
+		"",
+		`data: {"response":{"candidates":[{"content":{"role":"model","parts":[{"text":""}]},"finishReason":"STOP"}],"usageMetadata":{"promptTokenCount":300,"candidatesTokenCount":22,"totalTokenCount":334,"thoughtsTokenCount":12},"modelVersion":"gemini-4-argon","responseId":"resp_1"}}`,
+		"",
+	}, "\n")
+
+	upstream := &queuedHTTPUpstreamStub{
+		responses: []*http.Response{{
+			StatusCode: http.StatusOK,
+			Header:     http.Header{"Content-Type": []string{"text/event-stream"}},
+			Body:       io.NopCloser(strings.NewReader(sseStream)),
+		}},
+	}
+	svc := &AntigravityGatewayService{
+		settingService: NewSettingService(&antigravitySettingRepoStub{}, &config.Config{Gateway: config.GatewayConfig{MaxLineSize: defaultMaxLineSize}}),
+		tokenProvider:  &AntigravityTokenProvider{},
+		httpUpstream:   upstream,
+	}
+	account := &Account{
+		ID:          109,
+		Name:        "antigravity-fc-nonstream",
+		Platform:    PlatformAntigravity,
+		Type:        AccountTypeOAuth,
+		Status:      StatusActive,
+		Concurrency: 1,
+		Credentials: map[string]any{
+			"access_token": "test-access-token",
+			"project_id":   "test-project",
+			"model_mapping": map[string]any{
+				"gemini-4-argon": "gemini-4-argon",
+			},
+		},
+	}
+
+	result, err := svc.ForwardGemini(context.Background(), c, account, "gemini-4-argon", "generateContent", false, body, false)
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.Equal(t, http.StatusOK, writer.Code)
+
+	var respPayload map[string]any
+	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), &respPayload))
+	candidates, ok := respPayload["candidates"].([]any)
+	require.True(t, ok)
+	require.Len(t, candidates, 1)
+	candidate, ok := candidates[0].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, "STOP", candidate["finishReason"])
+
+	content, ok := candidate["content"].(map[string]any)
+	require.True(t, ok)
+	parts, ok := content["parts"].([]any)
+	require.True(t, ok)
+	require.Len(t, parts, 1, "trailing empty text part should not overwrite or pollute functionCall part")
+
+	part0, ok := parts[0].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, "sig_fc_1", part0["thoughtSignature"])
+	fc, ok := part0["functionCall"].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, "get_weather", fc["name"])
+	require.Equal(t, "call_1", fc["id"])
+	require.Equal(t, map[string]any{"city": "Tokyo"}, fc["args"])
+}
+
+func TestAntigravityGatewayService_ForwardGemini_StreamAndFunctionResponseFollowUp(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	// 1) Stream request with functionDeclarations returns unwrapped functionCall and thoughtSignature
+	streamReqBody := []byte(`{"contents":[{"role":"user","parts":[{"text":"Call get_weather for Tokyo."}]}],"tools":[{"functionDeclarations":[{"name":"get_weather","parameters":{"type":"object","properties":{"city":{"type":"string"}}}}]}]}`)
+	streamWriter := httptest.NewRecorder()
+	streamCtx, _ := gin.CreateTestContext(streamWriter)
+	streamCtx.Request = httptest.NewRequest(http.MethodPost, "/v1beta/models/gemini-4-argon:streamGenerateContent?alt=sse", bytes.NewReader(streamReqBody))
+
+	streamSSE := strings.Join([]string{
+		`data: {"response":{"candidates":[{"content":{"role":"model","parts":[{"thoughtSignature":"sig_stream_1","functionCall":{"name":"get_weather","args":{"city":"Tokyo"},"id":"call_s1"}}]}}],"usageMetadata":{"promptTokenCount":10,"candidatesTokenCount":5}}}`,
+		"",
+		`data: {"response":{"candidates":[{"content":{"role":"model","parts":[{"text":""}]},"finishReason":"STOP"}],"usageMetadata":{"promptTokenCount":10,"candidatesTokenCount":6}}}`,
+		"",
+	}, "\n")
+
+	// 2) Non-stream follow-up with functionCall (missing thoughtSignature) + functionResponse (with inlineData image)
+	followUpReqBody := []byte(`{"contents":[{"role":"user","parts":[{"text":"Call get_weather for Tokyo."}]},{"role":"model","parts":[{"functionCall":{"name":"get_weather","args":{"city":"Tokyo"},"id":"call_s1"}}]},{"role":"user","parts":[{"functionResponse":{"name":"get_weather","id":"call_s1","response":{"weather":"Sunny"},"parts":[{"inlineData":{"mimeType":"image/png","data":"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg=="}}]}}]}],"tools":[{"functionDeclarations":[{"name":"get_weather","parameters":{"type":"object","properties":{"city":{"type":"string"}}}}]}]}`)
+	followUpWriter := httptest.NewRecorder()
+	followUpCtx, _ := gin.CreateTestContext(followUpWriter)
+	followUpCtx.Request = httptest.NewRequest(http.MethodPost, "/v1beta/models/gemini-4-argon:generateContent", bytes.NewReader(followUpReqBody))
+
+	followUpSSE := strings.Join([]string{
+		`data: {"response":{"candidates":[{"content":{"role":"model","parts":[{"text":"It is sunny in "}]}}],"usageMetadata":{"promptTokenCount":20,"candidatesTokenCount":4}}}`,
+		"",
+		`data: {"response":{"candidates":[{"content":{"role":"model","parts":[{"text":"Tokyo."}]}}],"usageMetadata":{"promptTokenCount":20,"candidatesTokenCount":6}}}`,
+		"",
+		`data: {"response":{"candidates":[{"content":{"role":"model","parts":[{"thoughtSignature":"sig_final","text":""}]},"finishReason":"STOP"}],"usageMetadata":{"promptTokenCount":20,"candidatesTokenCount":8}}}`,
+		"",
+	}, "\n")
+
+	upstream := &queuedHTTPUpstreamStub{
+		responses: []*http.Response{
+			{
+				StatusCode: http.StatusOK,
+				Header:     http.Header{"Content-Type": []string{"text/event-stream"}},
+				Body:       io.NopCloser(strings.NewReader(streamSSE)),
+			},
+			{
+				StatusCode: http.StatusOK,
+				Header:     http.Header{"Content-Type": []string{"text/event-stream"}},
+				Body:       io.NopCloser(strings.NewReader(followUpSSE)),
+			},
+		},
+	}
+
+	svc := &AntigravityGatewayService{
+		settingService: NewSettingService(&antigravitySettingRepoStub{}, &config.Config{Gateway: config.GatewayConfig{MaxLineSize: defaultMaxLineSize}}),
+		tokenProvider:  &AntigravityTokenProvider{},
+		httpUpstream:   upstream,
+	}
+	account := &Account{
+		ID:          110,
+		Name:        "antigravity-fc-stream",
+		Platform:    PlatformAntigravity,
+		Type:        AccountTypeOAuth,
+		Status:      StatusActive,
+		Concurrency: 1,
+		Credentials: map[string]any{
+			"access_token": "test-access-token",
+			"project_id":   "test-project",
+			"model_mapping": map[string]any{
+				"gemini-4-argon": "gemini-4-argon",
+			},
+		},
+	}
+
+	res1, err := svc.ForwardGemini(context.Background(), streamCtx, account, "gemini-4-argon", "streamGenerateContent", true, streamReqBody, false)
+	require.NoError(t, err)
+	require.NotNil(t, res1)
+	require.Contains(t, streamWriter.Body.String(), `"functionCall":{"name":"get_weather","args":{"city":"Tokyo"},"id":"call_s1"}`)
+	require.Contains(t, streamWriter.Body.String(), `"thoughtSignature":"sig_stream_1"`)
+
+	res2, err := svc.ForwardGemini(context.Background(), followUpCtx, account, "gemini-4-argon", "generateContent", false, followUpReqBody, false)
+	require.NoError(t, err)
+	require.NotNil(t, res2)
+	require.Len(t, upstream.requestBodies, 2)
+
+	// Verify follow-up request had dummy thoughtSignature injected on functionCall and preserved functionResponse image part
+	secondSent := string(upstream.requestBodies[1])
+	require.Contains(t, secondSent, `"thoughtSignature":"skip_thought_signature_validator"`)
+	require.Contains(t, secondSent, `"mimeType":"image/png"`)
+
+	var followUpResp map[string]any
+	require.NoError(t, json.Unmarshal(followUpWriter.Body.Bytes(), &followUpResp))
+	cands, ok := followUpResp["candidates"].([]any)
+	require.True(t, ok)
+	cand0, ok := cands[0].(map[string]any)
+	require.True(t, ok)
+	content, ok := cand0["content"].(map[string]any)
+	require.True(t, ok)
+	parts, ok := content["parts"].([]any)
+	require.True(t, ok)
+	require.NotEmpty(t, parts)
+	firstPart, ok := parts[0].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, "It is sunny in Tokyo.", firstPart["text"])
+}
diff --git a/backend/internal/service/antigravity_gateway_streaming.go b/backend/internal/service/antigravity_gateway_streaming.go
index 675f0d7f87..58d5b9ce4f 100644
--- a/backend/internal/service/antigravity_gateway_streaming.go
+++ b/backend/internal/service/antigravity_gateway_streaming.go
@@ -350,8 +350,7 @@ func (s *AntigravityGatewayService) handleGeminiStreamToNonStreaming(c *gin.Cont
 	var firstTokenMs *int
 	var last map[string]any
 	var lastWithParts map[string]any
-	var collectedImageParts []map[string]any // 收集所有包含图片的 parts
-	var collectedTextParts []string          // 收集所有文本片段
+	var collectedParts []map[string]any // 收集所有 parts（text、thinking、functionCall、inlineData 等）
 
 	type scanEvent struct {
 		line string
@@ -467,19 +466,10 @@ func (s *AntigravityGatewayService) handleGeminiStreamToNonStreaming(c *gin.Cont
 				}
 			}
 
-			// 保留最后一个有 parts 的响应
+			// 保留最后一个有 parts 的响应，并收集所有 parts
 			if parts := extractGeminiParts(parsed); len(parts) > 0 {
 				lastWithParts = parsed
-				// 收集包含图片和文本的 parts
-				for _, part := range parts {
-					if inlineData, ok := part["inlineData"].(map[string]any); ok {
-						collectedImageParts = append(collectedImageParts, part)
-						_ = inlineData // 避免 unused 警告
-					}
-					if text, ok := part["text"].(string); ok && text != "" {
-						collectedTextParts = append(collectedTextParts, text)
-					}
-				}
+				collectedParts = append(collectedParts, parts...)
 			}
 
 		case <-intervalCh:
@@ -506,14 +496,9 @@ returnResponse:
 		}
 	}
 
-	// 如果收集到了图片 parts，需要合并到最终响应中
-	if len(collectedImageParts) > 0 {
-		finalResponse = mergeImagePartsToResponse(finalResponse, collectedImageParts)
-	}
-
-	// 如果收集到了文本，需要合并到最终响应中
-	if len(collectedTextParts) > 0 {
-		finalResponse = mergeTextPartsToResponse(finalResponse, collectedTextParts)
+	// 将收集的所有 parts 合并到最终响应中
+	if len(collectedParts) > 0 {
+		finalResponse = mergeCollectedPartsToResponse(finalResponse, collectedParts)
 	}
 
 	respBody, err := json.Marshal(finalResponse)
@@ -576,21 +561,27 @@ func mergeCollectedPartsToResponse(response map[string]any, collectedParts []map
 		return response
 	}
 
-	result, _, setParts := getOrCreateGeminiParts(response)
+	result, existingParts, setParts := getOrCreateGeminiParts(response)
 
 	// 合并策略：
 	// 1. 保持原始顺序
-	// 2. 连续的普通 text parts 合并为一个
+	// 2. 连续的普通 text parts 合并为一个，并保留关联的 thoughtSignature
 	// 3. thinking、functionCall、inlineData 等保持原样
 	var mergedParts []any
 	var textBuffer strings.Builder
+	var textSignature string
 
 	flushTextBuffer := func() {
-		if textBuffer.Len() > 0 {
-			mergedParts = append(mergedParts, map[string]any{
+		if textBuffer.Len() > 0 || textSignature != "" {
+			part := map[string]any{
 				"text": textBuffer.String(),
-			})
+			}
+			if textSignature != "" {
+				part["thoughtSignature"] = textSignature
+			}
+			mergedParts = append(mergedParts, part)
 			textBuffer.Reset()
+			textSignature = ""
 		}
 	}
 
@@ -605,6 +596,9 @@ func mergeCollectedPartsToResponse(response map[string]any, collectedParts []map
 			} else {
 				// 普通 text，累积到 buffer
 				_, _ = textBuffer.WriteString(text)
+				if sig, ok := part["thoughtSignature"].(string); ok && sig != "" {
+					textSignature = sig
+				}
 			}
 		} else {
 			// 非 text part（functionCall、inlineData 等），先刷新 text buffer，然后保留原样
@@ -616,76 +610,14 @@ func mergeCollectedPartsToResponse(response map[string]any, collectedParts []map
 	// 刷新剩余的 text
 	flushTextBuffer()
 
+	if len(mergedParts) == 0 {
+		mergedParts = existingParts
+	}
+
 	setParts(mergedParts)
 	return result
 }
 
-// mergeImagePartsToResponse 将收集到的图片 parts 合并到 Gemini 响应中
-func mergeImagePartsToResponse(response map[string]any, imageParts []map[string]any) map[string]any {
-	if len(imageParts) == 0 {
-		return response
-	}
-
-	result, existingParts, setParts := getOrCreateGeminiParts(response)
-
-	// 检查现有 parts 中是否已经有图片
-	for _, p := range existingParts {
-		if pm, ok := p.(map[string]any); ok {
-			if _, hasInline := pm["inlineData"]; hasInline {
-				return result // 已有图片，不重复添加
-			}
-		}
-	}
-
-	// 添加收集到的图片 parts
-	for _, imgPart := range imageParts {
-		existingParts = append(existingParts, imgPart)
-	}
-	setParts(existingParts)
-	return result
-}
-
-// mergeTextPartsToResponse 将收集到的文本合并到 Gemini 响应中
-func mergeTextPartsToResponse(response map[string]any, textParts []string) map[string]any {
-	if len(textParts) == 0 {
-		return response
-	}
-
-	mergedText := strings.Join(textParts, "")
-	result, existingParts, setParts := getOrCreateGeminiParts(response)
-
-	// 查找并更新第一个 text part，或创建新的
-	newParts := make([]any, 0, len(existingParts)+1)
-	textUpdated := false
-
-	for _, p := range existingParts {
-		pm, ok := p.(map[string]any)
-		if !ok {
-			newParts = append(newParts, p)
-			continue
-		}
-		if _, hasText := pm["text"]; hasText && !textUpdated {
-			// 用累积的文本替换
-			newPart := make(map[string]any)
-			for k, v := range pm {
-				newPart[k] = v
-			}
-			newPart["text"] = mergedText
-			newParts = append(newParts, newPart)
-			textUpdated = true
-		} else {
-			newParts = append(newParts, pm)
-		}
-	}
-
-	if !textUpdated {
-		newParts = append([]any{map[string]any{"text": mergedText}}, newParts...)
-	}
-
-	setParts(newParts)
-	return result
-}
-
 // antigravityStatusClientClosed 是客户端在上游响应前断开时回写的状态码（499 client closed request）。
 const antigravityStatusClientClosed = 499
 
diff --git a/backend/internal/service/antigravity_gemini_thinking_variant.go b/backend/internal/service/antigravity_gemini_thinking_variant.go
index 88c4906864..e0ebc5c470 100644
--- a/backend/internal/service/antigravity_gemini_thinking_variant.go
+++ b/backend/internal/service/antigravity_gemini_thinking_variant.go
@@ -108,17 +108,6 @@ func geminiThinkingLevelFromClaudeThinking(thinking *antigravity.ThinkingConfig)
 	}
 }
 
-// accountRawModelMappingHasKey 判断 key 是否由用户写在账号 credentials.model_mapping 里
-// （而不是 resolveModelMapping 运行时补进来的默认透传条目）。
-func accountRawModelMappingHasKey(account *Account, key string) bool {
-	if account == nil || account.Credentials == nil {
-		return false
-	}
-	raw, _ := account.Credentials["model_mapping"].(map[string]any)
-	_, ok := raw[key]
-	return ok
-}
-
 // resolveGeminiThinkingVariant 为裸 Gemini 模型名挑选账号映射表里存在的思考深度变体。
 // 返回 (映射后的上游模型名, 是否命中)。未命中时调用方应回退到常规 getMappedModel 流程。
 func resolveGeminiThinkingVariant(account *Account, requestedModel string, body []byte) (string, bool) {
@@ -140,16 +129,16 @@ func resolveGeminiThinkingVariantForLevel(account *Account, requestedModel strin
 	if len(mapping) == 0 {
 		return "", false
 	}
-	// 裸名本身已有"真正的"映射 → 尊重现有配置，不做推导。判定分两层：
-	//   1. 映射目标不是自己（如 gemini-3.8-flash → gemini-3.8-flash-tiered）：用户明确指定了目标；
-	//   2. 映射目标是自己（原样透传）：仅当这条是用户亲手写进 credentials.model_mapping 的才尊重。
-	//      resolveModelMapping 会给每个 Antigravity 账号自动补 gemini-3.x-flash 裸名自映射
-	//      （ensureAntigravityDefaultPassthroughs），而上游目录里并没有裸名模型，那条自映射
-	//      正是导致 404 的来源，不能算作用户意图。
-	if mapped, matched := resolveRequestedModelInMapping(mapping, model); matched {
-		if strings.TrimSpace(mapped) != model || accountRawModelMappingHasKey(account, model) {
-			return "", false
-		}
+	// 裸名本身若已映射到其他具体模型（如 gemini-3.8-flash → gemini-3.8-flash-tiered、
+	// gemini-3.1-pro → gemini-pro-agent），尊重显式别名配置。
+	// 若裸名映射目标是自己（如前端从 DefaultAntigravityModelMapping 拉取并持久化的
+	// gemini-3.8-flash → gemini-3.8-flash，或 ensureAntigravityDefaultPassthroughs 注入的条目），
+	// 当映射表中存在该模型的精确思考变体（-high/-medium/-low/-tiered）时继续解析变体，
+	// 避免把上游不存在的裸名直接发出导致 404；而对已在映射表中的真实裸模型（如 gemini-2.5-flash），
+	// 仅查找精确变体键以避免被通配符误匹配。
+	mapped, modelMatched := resolveRequestedModelInMapping(mapping, model)
+	if modelMatched && strings.TrimSpace(mapped) != model {
+		return "", false
 	}
 
 	if preferred == "" {
@@ -163,8 +152,17 @@ func resolveGeminiThinkingVariantForLevel(account *Account, requestedModel strin
 	}
 	for _, level := range order {
 		candidate := model + "-" + level
-		if mapped, matched := resolveRequestedModelInMapping(mapping, candidate); matched && strings.TrimSpace(mapped) != "" {
-			return mapped, true
+		var (
+			variantMapped  string
+			variantMatched bool
+		)
+		if modelMatched {
+			variantMapped, variantMatched = mapping[candidate]
+		} else {
+			variantMapped, variantMatched = resolveRequestedModelInMapping(mapping, candidate)
+		}
+		if variantMatched && strings.TrimSpace(variantMapped) != "" {
+			return variantMapped, true
 		}
 	}
 	return "", false
diff --git a/backend/internal/service/antigravity_gemini_thinking_variant_test.go b/backend/internal/service/antigravity_gemini_thinking_variant_test.go
index d0c17765a9..d700182bc1 100644
--- a/backend/internal/service/antigravity_gemini_thinking_variant_test.go
+++ b/backend/internal/service/antigravity_gemini_thinking_variant_test.go
@@ -74,10 +74,10 @@ func TestResolveGeminiThinkingVariant(t *testing.T) {
 		{"agy low (1000) -> -low", catalog, "gemini-3.8-flash", budget("1000"), "gemini-3.8-flash-low", true},
 		{"models/ prefix stripped", catalog, "models/gemini-3.8-flash", budget("1000"), "gemini-3.8-flash-low", true},
 		{"no thinkingConfig -> -high", catalog, "gemini-3.8-flash", []byte(`{"contents":[]}`), "gemini-3.8-flash-high", true},
-		// gemini-3.6/3.7/3.8-flash 的四个变体会被 resolveModelMapping 自动补齐，所以降级用一个不在默认表里的型号
 		{"only -high exists: low request degrades to high", map[string]string{
 			"gemini-3.5-flash-high": "gemini-3.5-flash-high",
 		}, "gemini-3.5-flash", budget("1000"), "gemini-3.5-flash-high", true},
+		// gemini-3.6/3.7/3.8-flash 的四个变体会被 resolveModelMapping 自动补齐（存量显式映射账号的兼容透传）。
 		{"injected default variants are usable", catalog, "gemini-3.6-flash", budget("1000"), "gemini-3.6-flash-low", true},
 		{"already suffixed: untouched", catalog, "gemini-3.8-flash-low", budget("-1"), "", false},
 		{"bare name explicitly mapped: untouched", catalog, "gemini-2.5-flash", budget("-1"), "", false},
@@ -90,16 +90,22 @@ func TestResolveGeminiThinkingVariant(t *testing.T) {
 		{"variant value is itself a mapping target", map[string]string{
 			"gemini-3.8-flash-high": "gemini-3.8-flash-tiered",
 		}, "gemini-3.8-flash", budget("-1"), "gemini-3.8-flash-tiered", true},
-		{"user-written bare identity passthrough: respected", map[string]string{
+		// 前端持久化的默认目录含裸名自映射；-low 由默认透传补齐，按预算命中。
+		{"persisted default bare identity passthrough still resolves when variants exist", map[string]string{
 			"gemini-3.8-flash":      "gemini-3.8-flash",
 			"gemini-3.8-flash-high": "gemini-3.8-flash-high",
-		}, "gemini-3.8-flash", budget("1000"), "", false},
-		{"runtime-injected bare passthrough (not in credentials): still resolved", map[string]string{
-			// resolveModelMapping 会补 gemini-3.7-flash → gemini-3.7-flash 的默认透传，
-			// 但 credentials 里没有这条，应当继续推导变体。
+		}, "gemini-3.8-flash", budget("1000"), "gemini-3.8-flash-low", true},
+		{"bare identity passthrough resolves a configured variant outside the default passthroughs", map[string]string{
+			"gemini-3.5-flash":      "gemini-3.5-flash",
+			"gemini-3.5-flash-high": "gemini-3.5-flash-high",
+		}, "gemini-3.5-flash", budget("1000"), "gemini-3.5-flash-high", true},
+		{"wildcard mapping does not fabricate variants for non-tiered bare model", map[string]string{
+			"gemini-2.5*": "gemini-2.5-flash",
+		}, "gemini-2.5-flash", budget("-1"), "", false},
+		{"bare model absent from whitelist: configured variant still resolved", map[string]string{
 			"gemini-3.7-flash-medium": "gemini-3.7-flash-medium",
 		}, "gemini-3.7-flash", budget("4000"), "gemini-3.7-flash-medium", true},
-		// 空 credentials 映射 → 走 DefaultAntigravityModelMapping，其中同样只有带后缀的 3.8 flash
+		// 空 credentials 映射保留默认目录兼容行为。
 		{"empty mapping falls back to default catalog", map[string]string{}, "gemini-3.8-flash", budget("-1"), "gemini-3.8-flash-high", true},
 	}
 	for _, tt := range tests {
diff --git a/backend/internal/service/antigravity_rate_limit_test.go b/backend/internal/service/antigravity_rate_limit_test.go
index 2721e54a7f..d81219a1d9 100644
--- a/backend/internal/service/antigravity_rate_limit_test.go
+++ b/backend/internal/service/antigravity_rate_limit_test.go
@@ -1093,6 +1093,15 @@ func TestResolveAntigravityForwardBaseURL(t *testing.T) {
 			name: "ultra defaults to daily", account: &Account{Credentials: map[string]any{"plan_type": "ULTRA"}},
 			want: dailyURL,
 		},
+		{
+			name: "stored ultra tier id defaults to daily", account: &Account{Credentials: map[string]any{"plan_type": "g1-ultra-lite-tier"}},
+			want: dailyURL,
+		},
+		{
+			name: "stored pro tier id defaults to daily", account: &Account{Credentials: map[string]any{"plan_type": "g1-pro-tier"}},
+			want: dailyURL,
+		},
+		{name: "free tier id defaults to prod", account: &Account{Credentials: map[string]any{"plan_type": "free-tier"}}, want: prodURL},
 		{name: "free defaults to prod", account: &Account{Credentials: map[string]any{"plan_type": "free"}}, want: prodURL},
 		{name: "abnormal defaults to prod", account: &Account{Credentials: map[string]any{"plan_type": "Abnormal"}}, want: prodURL},
 		{name: "unknown defaults to prod", account: &Account{Credentials: map[string]any{"plan_type": "enterprise"}}, want: prodURL},
diff --git a/backend/internal/service/billing_service.go b/backend/internal/service/billing_service.go
index 45014870ee..7341fb123d 100644
--- a/backend/internal/service/billing_service.go
+++ b/backend/internal/service/billing_service.go
@@ -1035,7 +1035,7 @@ func (s *BillingService) initFallbackPricing() {
 
 // getFallbackPricing 根据模型系列获取回退价格
 func (s *BillingService) getFallbackPricing(model string) *ModelPricing {
-	modelLower := strings.ToLower(model)
+	modelLower := normalizeAntigravityClaudeTierAlias(strings.ToLower(model))
 	if modelLower == "jev-latest" {
 		return s.fallbackPrices["jev-latest"]
 	}
diff --git a/backend/internal/service/openai_codex_model_metadata.go b/backend/internal/service/openai_codex_model_metadata.go
index 69e452b751..7f60212bf4 100644
--- a/backend/internal/service/openai_codex_model_metadata.go
+++ b/backend/internal/service/openai_codex_model_metadata.go
@@ -123,6 +123,12 @@ func codexModelRoutingAccountIDs(group *Group, modelID string) []int64 {
 	return group.GetRoutingAccountIDs(strings.TrimSpace(modelID))
 }
 
+func codexAccountServesPlatformModel(account *Account, platform, modelID string) bool {
+	return account.Platform == platform ||
+		(account.Platform == PlatformAntigravity && mixedListingAccountAllowed(platform, account) &&
+			mixedListingModelAllowed(platform, modelID))
+}
+
 func groupCodexModelMetadata(
 	platform string,
 	modelID string,
@@ -168,7 +174,7 @@ func groupCodexModelMetadata(
 			if routed && !containsInt64(routedAccountIDs, account.ID) {
 				continue
 			}
-			if account.Platform == platform && codexExplicitModelMappingClaims(*account, modelID) {
+			if codexAccountServesPlatformModel(account, platform, modelID) && codexExplicitModelMappingClaims(*account, modelID) {
 				explicitClaims = true
 				break
 			}
@@ -183,7 +189,7 @@ func groupCodexModelMetadata(
 	missingMetadata := false
 	for i := range accounts {
 		account := &accounts[i]
-		if account.Platform != platform {
+		if !codexAccountServesPlatformModel(account, platform, modelID) {
 			continue
 		}
 		if routed && !containsInt64(routedAccountIDs, account.ID) {
@@ -251,7 +257,7 @@ func codexExplicitModelTargetsConflictForPlatform(accounts []Account, platform,
 	targets := make(map[string]struct{})
 	for i := range accounts {
 		account := &accounts[i]
-		if account.Platform != platform {
+		if !codexAccountServesPlatformModel(account, platform, modelID) {
 			continue
 		}
 		mappedModel, matched := account.ResolveMappedModel(modelID)
diff --git a/backend/internal/service/openai_codex_model_metadata_test.go b/backend/internal/service/openai_codex_model_metadata_test.go
index 16ed878e90..aafe8aae1f 100644
--- a/backend/internal/service/openai_codex_model_metadata_test.go
+++ b/backend/internal/service/openai_codex_model_metadata_test.go
@@ -9,6 +9,71 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestCodexCatalogUsesAntigravityCapabilitiesInGeminiMixedGroup(t *testing.T) {
+	const groupID int64 = 93
+	account := Account{
+		ID: 25, Platform: PlatformAntigravity, Type: AccountTypeOAuth,
+		Extra: map[string]any{"mixed_scheduling": true},
+		Credentials: map[string]any{"model_mapping": map[string]any{
+			"gemini-custom": "gemini-3.8-flash-high",
+		}},
+	}
+	reasoning := true
+	account.SetUpstreamModelMetadataSnapshot(UpstreamModelMetadataSnapshot{
+		Models: map[string]UpstreamModelMetadata{"gemini-3.8-flash-high": {
+			ID: "gemini-3.8-flash-high", Reasoning: &reasoning,
+			DefaultReasoningLevel: "high", SupportedReasoningLevels: []string{"high"},
+			InputModalities: []string{"text", "image"}, ContextWindow: 1_048_576,
+			MaxOutputTokens: 65_536,
+		}},
+	})
+	svc := &GatewayService{accountRepo: codexModelsVisibilityAccountRepo{
+		byGroup: map[int64][]Account{groupID: {account}},
+	}}
+	for _, platform := range []string{PlatformAntigravity, PlatformComposite, PlatformGemini} {
+		t.Run(platform, func(t *testing.T) {
+			body, err := svc.BuildCodexModelsManifestForGroup(context.Background(),
+				&Group{ID: groupID, Platform: platform}, "", []string{"gemini-custom"})
+			require.NoError(t, err)
+			model := decodeCodexManifestModels(t, body)[0]
+			require.Equal(t, "gemini-custom", model["slug"])
+			require.Equal(t, float64(1_048_576), model["context_window"])
+			require.Equal(t, []any{"text", "image"}, model["input_modalities"])
+			require.Equal(t, []string{"high"}, effortsFromManifestModel(t, model))
+		})
+	}
+}
+
+func TestCodexCatalogGeminiCapabilitiesExcludeNonMixedAntigravityAccounts(t *testing.T) {
+	const groupID int64 = 94
+	reasoning := true
+	native := Account{ID: 1, Platform: PlatformGemini, Type: AccountTypeAPIKey,
+		Credentials: map[string]any{"model_mapping": map[string]any{"gemini-custom": "gemini-3.8-flash-high"}},
+	}
+	native.SetUpstreamModelMetadataSnapshot(UpstreamModelMetadataSnapshot{
+		Models: map[string]UpstreamModelMetadata{"gemini-3.8-flash-high": {
+			ID: "gemini-3.8-flash-high", Reasoning: &reasoning,
+			SupportedReasoningLevels: []string{"high"}, InputModalities: []string{"text", "image"},
+			ContextWindow: 1_048_576,
+		}},
+	})
+	for _, extra := range []map[string]any{nil, {"mixed_scheduling": false}} {
+		// A peer lacking capabilities would narrow the catalog if included.
+		peer := Account{ID: 2, Platform: PlatformAntigravity, Type: AccountTypeOAuth,
+			Extra: extra, Credentials: native.Credentials}
+		svc := &GatewayService{accountRepo: codexModelsVisibilityAccountRepo{
+			byGroup: map[int64][]Account{groupID: {native, peer}},
+		}}
+		body, err := svc.BuildCodexModelsManifestForGroup(context.Background(),
+			&Group{ID: groupID, Platform: PlatformGemini}, "", []string{"gemini-custom"})
+		require.NoError(t, err)
+		model := decodeCodexManifestModels(t, body)[0]
+		require.Equal(t, float64(1_048_576), model["context_window"])
+		require.Equal(t, []any{"text", "image"}, model["input_modalities"])
+		require.Equal(t, []string{"high"}, effortsFromManifestModel(t, model))
+	}
+}
+
 func TestAstraUltraCatalogPreservesWorkflowMetadata(t *testing.T) {
 	// Ultra is a Codex workflow. Its inference effort must survive catalog sync,
 	// aliases and group generation instead of silently falling back to max.
diff --git a/backend/internal/service/openai_codex_models_service.go b/backend/internal/service/openai_codex_models_service.go
index ae58ddf200..40dbd00297 100644
--- a/backend/internal/service/openai_codex_models_service.go
+++ b/backend/internal/service/openai_codex_models_service.go
@@ -1094,7 +1094,7 @@ func uniqueCodexMappedModel(accounts []Account, platform string, modelID string)
 	targets := make(map[string]struct{})
 	for i := range accounts {
 		account := &accounts[i]
-		if account.Platform != platform {
+		if !codexAccountServesPlatformModel(account, platform, modelID) {
 			continue
 		}
 		mappedModel, matched := account.ResolveMappedModel(modelID)
diff --git a/backend/internal/service/pricing_service.go b/backend/internal/service/pricing_service.go
index 5df65b5be8..6b8c6e0665 100644
--- a/backend/internal/service/pricing_service.go
+++ b/backend/internal/service/pricing_service.go
@@ -1309,7 +1309,7 @@ func (s *PricingService) buildModelLookupCandidates(modelLower string) []string
 	// one later. Antigravity's Gemini thinking tiers share the base rate,
 	// so the normalized base remains the fallback after the exact aliases.
 	candidates := rawCandidates
-	if normalizeGeminiThinkingTierAlias(lastSegment(modelLower)) != lastSegment(modelLower) {
+	if isAntigravityThinkingTierAlias(lastSegment(modelLower)) {
 		candidates = append(candidates, normalized)
 	} else {
 		// Prefer canonical model names for all other aliases (including models/xxx).
@@ -1365,7 +1365,29 @@ func normalizeModelNameForPricing(model string) string {
 		}
 		return canonical
 	}
-	return normalizeGeminiThinkingTierAlias(model)
+	return normalizeAntigravityClaudeTierAlias(normalizeGeminiThinkingTierAlias(model))
+}
+
+// normalizeAntigravityClaudeTierAlias maps Antigravity's Claude 5.5 thinking-tier
+// model IDs (claude-opus-5-5-high, claude-sonnet-5-5-low, ...) to the public base
+// model. Like the Gemini tiers, the suffix selects reasoning depth rather than a
+// separate token rate; without this the IDs fall into substring family matching
+// and are billed as claude-opus-5 / claude-sonnet-4-5.
+func normalizeAntigravityClaudeTierAlias(model string) string {
+	for _, baseModel := range []string{"claude-opus-5-5", "claude-sonnet-5-5"} {
+		for _, tier := range []string{"-high", "-low", "-medium"} {
+			if model == baseModel+tier {
+				return baseModel
+			}
+		}
+	}
+	return model
+}
+
+// isAntigravityThinkingTierAlias reports whether model is an Antigravity
+// Gemini or Claude thinking-tier alias of a priced base model.
+func isAntigravityThinkingTierAlias(model string) bool {
+	return normalizeGeminiThinkingTierAlias(model) != model || normalizeAntigravityClaudeTierAlias(model) != model
 }
 
 // normalizeGeminiThinkingTierAlias maps Antigravity's Gemini thinking-tier
@@ -1411,6 +1433,7 @@ func (s *PricingService) extractBaseName(model string) string {
 
 // matchByModelFamily 基于模型系列匹配
 func (s *PricingService) matchByModelFamily(model string) *LiteLLMModelPricing {
+	model = normalizeAntigravityClaudeTierAlias(model)
 	if claude.IsOpus55(model) {
 		if pricing, ok := s.pricingData["claude-opus-5-5"]; ok {
 			return pricing
diff --git a/backend/internal/service/pricing_service_test.go b/backend/internal/service/pricing_service_test.go
index 4466be1f3f..08f5171a7c 100644
--- a/backend/internal/service/pricing_service_test.go
+++ b/backend/internal/service/pricing_service_test.go
@@ -1278,3 +1278,42 @@ func TestCalculateCost_ClaudeSonnetCatalogLadderIsDataDriven(t *testing.T) {
 	require.NoError(t, err)
 	require.False(t, cost.LongContextBillingApplied, "恰好 200000 不进高档（严格大于）")
 }
+
+// Antigravity 的 Claude 5.5 思考档位 ID 只决定推理深度，必须按基础型号计价，
+// 不能落入子串家族匹配（opus-5-5-high → claude-opus-5、sonnet-5-5-high → sonnet-4-5）。
+func TestPricingService_AntigravityClaude55TiersUseBaseModelPricing(t *testing.T) {
+	opus := &LiteLLMModelPricing{InputCostPerToken: 4e-6, OutputCostPerToken: 20e-6}
+	sonnet := &LiteLLMModelPricing{InputCostPerToken: 2e-6, OutputCostPerToken: 10e-6}
+	svc := &PricingService{pricingData: map[string]*LiteLLMModelPricing{
+		"claude-opus-5-5":   opus,
+		"claude-sonnet-5-5": sonnet,
+		"claude-opus-5":     {InputCostPerToken: 5e-6, OutputCostPerToken: 25e-6},
+		"claude-sonnet-4-5": {InputCostPerToken: 3e-6, OutputCostPerToken: 15e-6},
+	}}
+	for _, tier := range []string{"high", "medium", "low"} {
+		require.Same(t, opus, svc.GetModelPricing("claude-opus-5-5-"+tier))
+		require.Same(t, sonnet, svc.GetModelPricing("claude-sonnet-5-5-"+tier))
+	}
+
+	// 价格目录缺基础型号时走家族兜底，同样不能落到 claude-opus-5 / sonnet-4-5。
+	sparse := &PricingService{pricingData: map[string]*LiteLLMModelPricing{
+		"claude-opus-5":     {InputCostPerToken: 5e-6, OutputCostPerToken: 25e-6},
+		"claude-sonnet-4-5": {InputCostPerToken: 3e-6, OutputCostPerToken: 15e-6},
+	}}
+	require.Same(t, claudeOpus55FallbackPricing, sparse.GetModelPricing("claude-opus-5-5-high"))
+	require.Same(t, claudeSonnet55FallbackPricing, sparse.GetModelPricing("claude-sonnet-5-5-low"))
+}
+
+func TestBillingService_AntigravityClaude55TierFallbacksUseBaseRates(t *testing.T) {
+	svc := NewBillingService(&config.Config{}, nil)
+	tokens := UsageTokens{InputTokens: 1_000_000, OutputTokens: 1_000_000}
+	for _, tier := range []string{"high", "medium", "low"} {
+		for base, want := range map[string]string{"claude-opus-5-5": "claude-opus-5-5", "claude-sonnet-5-5": "claude-sonnet-5-5"} {
+			got, err := svc.CalculateCost(base+"-"+tier, tokens, 1)
+			require.NoError(t, err)
+			ref, err := svc.CalculateCost(want, tokens, 1)
+			require.NoError(t, err)
+			require.InDelta(t, ref.TotalCost, got.TotalCost, 1e-12, base+"-"+tier)
+		}
+	}
+}
diff --git a/backend/internal/service/upstream_models.go b/backend/internal/service/upstream_models.go
index 447f2fdb98..bfd82887f5 100644
--- a/backend/internal/service/upstream_models.go
+++ b/backend/internal/service/upstream_models.go
@@ -340,7 +340,11 @@ func configuredUpstreamModelsForCapabilitySync(account *Account) []string {
 		return nil
 	}
 	models := make([]string, 0)
-	for _, mappedModel := range account.GetModelMapping() {
+	for requestedModel, mappedModel := range account.GetModelMapping() {
+		// Antigravity 运行时补齐的默认透传不是管理员配置的目标，上游目录未列出时不应拉低能力同步完整度。
+		if account.isAntigravityInjectedDefaultPassthrough(requestedModel, mappedModel) {
+			continue
+		}
 		mappedModel = strings.TrimSpace(mappedModel)
 		if mappedModel == "" || strings.Contains(mappedModel, "*") {
 			continue
@@ -738,8 +742,7 @@ func (s *AccountTestService) fetchUpstreamModelList(ctx context.Context, account
 	}
 
 	if account.Platform == PlatformAntigravity && account.Type != AccountTypeAPIKey {
-		models, err := s.fetchAntigravityOAuthUpstreamModels(ctx, account)
-		return models, nil, err
+		return s.fetchAntigravityOAuthUpstreamModels(ctx, account)
 	}
 
 	if s.httpUpstream == nil {
@@ -1263,42 +1266,47 @@ func (s *AccountTestService) buildGeminiUpstreamModelsRequest(ctx context.Contex
 	return req, nil
 }
 
-func (s *AccountTestService) fetchAntigravityOAuthUpstreamModels(ctx context.Context, account *Account) ([]string, error) {
+func (s *AccountTestService) fetchAntigravityOAuthUpstreamModels(ctx context.Context, account *Account) ([]string, []byte, error) {
 	if s.antigravityGatewayService == nil || s.antigravityGatewayService.GetTokenProvider() == nil {
-		return nil, newUpstreamModelSyncConfigError("Antigravity token provider is not configured", nil)
+		return nil, nil, newUpstreamModelSyncConfigError("Antigravity token provider is not configured", nil)
 	}
 
 	accessToken, err := s.antigravityGatewayService.GetTokenProvider().GetAccessToken(ctx, account)
 	if err != nil {
-		return nil, newUpstreamModelSyncUpstreamError("Failed to get Antigravity access token", err)
+		return nil, nil, newUpstreamModelSyncUpstreamError("Failed to get Antigravity access token", err)
 	}
 	accessToken = strings.TrimSpace(accessToken)
 	if accessToken == "" {
-		return nil, newUpstreamModelSyncConfigError("No Antigravity access token is available", nil)
+		return nil, nil, newUpstreamModelSyncConfigError("No Antigravity access token is available", nil)
 	}
 
 	client, err := antigravity.NewClient(upstreamModelsProxyURL(account))
 	if err != nil {
-		return nil, newUpstreamModelSyncConfigError("Failed to configure Antigravity client", err)
+		return nil, nil, newUpstreamModelSyncConfigError("Failed to configure Antigravity client", err)
 	}
-	modelsResp, _, err := client.FetchAvailableModels(
+	modelsResp, raw, err := client.FetchAvailableModelsFromURL(
 		ctx,
+		resolveAntigravityForwardBaseURL(account),
 		accessToken,
 		strings.TrimSpace(account.GetCredential("project_id")),
 		resolveModelsListReadLimit(s.cfg),
 	)
 	if err != nil {
-		return nil, newUpstreamModelSyncUpstreamError("Failed to fetch Antigravity available models", err)
+		return nil, nil, newUpstreamModelSyncUpstreamError("Failed to fetch Antigravity available models", err)
 	}
 	if modelsResp == nil || len(modelsResp.Models) == 0 {
-		return nil, newUpstreamModelSyncUpstreamError("Upstream returned no supported models", nil)
+		return nil, nil, newUpstreamModelSyncUpstreamError("Upstream returned no supported models", nil)
 	}
 
 	models := make([]string, 0, len(modelsResp.Models))
 	for modelID := range modelsResp.Models {
 		models = append(models, strings.TrimSpace(modelID))
 	}
-	return dedupeAndSortModelIDs(models), nil
+	body, err := json.Marshal(raw)
+	if err != nil {
+		return nil, nil, newUpstreamModelSyncUpstreamError("Failed to read Antigravity model metadata", err)
+	}
+	return dedupeAndSortModelIDs(models), body, nil
 }
 
 func (s *AccountTestService) doUpstreamModelsRequest(req *http.Request, proxyURL string, account *Account) (*http.Response, error) {
@@ -1394,6 +1402,12 @@ type upstreamModelCapabilityEntry struct {
 	MaxContextWindow         int64                      `json:"max_context_window"`
 	MaxOutputTokens          int64                      `json:"max_output_tokens"`
 	Limit                    modelsDevLimit             `json:"limit"`
+	DisplayNameCamel         string                     `json:"displayName"`
+	SupportsImages           *bool                      `json:"supportsImages"`
+	SupportsThinking         *bool                      `json:"supportsThinking"`
+	ThinkingBudget           *int64                     `json:"thinkingBudget"`
+	MaxTokens                int64                      `json:"maxTokens"`
+	MaxOutputTokensCamel     int64                      `json:"maxOutputTokens"`
 }
 
 func extractUpstreamModelIDs(body []byte) ([]string, error) {
@@ -1442,12 +1456,33 @@ func extractUpstreamModelCatalog(body []byte, grok bool) ([]string, map[string]U
 func extractUpstreamModelRawEntries(body []byte) ([]json.RawMessage, error) {
 	var response struct {
 		Data   []json.RawMessage `json:"data"`
-		Models []json.RawMessage `json:"models"`
+		Models json.RawMessage   `json:"models"`
 	}
 	if err := json.Unmarshal(body, &response); err == nil && (response.Data != nil || response.Models != nil) {
-		entries := make([]json.RawMessage, 0, len(response.Data)+len(response.Models))
-		entries = append(entries, response.Data...)
-		entries = append(entries, response.Models...)
+		entries := append([]json.RawMessage{}, response.Data...)
+		if len(response.Models) > 0 && string(response.Models) != "null" {
+			var list []json.RawMessage
+			if err := json.Unmarshal(response.Models, &list); err == nil {
+				entries = append(entries, list...)
+			} else {
+				// Antigravity keys its model catalog by the exact generation model ID.
+				var models map[string]map[string]json.RawMessage
+				if err := json.Unmarshal(response.Models, &models); err != nil {
+					return nil, fmt.Errorf("parse upstream model catalog: %w", err)
+				}
+				for modelID, fields := range models {
+					if fields == nil {
+						fields = make(map[string]json.RawMessage)
+					}
+					fields["id"], _ = json.Marshal(modelID)
+					raw, err := json.Marshal(fields)
+					if err != nil {
+						return nil, fmt.Errorf("parse upstream model metadata: %w", err)
+					}
+					entries = append(entries, raw)
+				}
+			}
+		}
 		return entries, nil
 	}
 	var entries []json.RawMessage
@@ -1463,6 +1498,34 @@ func upstreamMetadataFromCapabilityEntry(modelID string, entry upstreamModelCapa
 		levels = reasoningLevelsFromModelsDevOptions(entry.ReasoningOptions)
 	}
 	reasoning := entry.Reasoning
+	if reasoning == nil {
+		reasoning = entry.SupportsThinking
+	}
+	if len(levels) == 0 && entry.SupportsThinking != nil && *entry.SupportsThinking {
+		level := "high"
+		fixedLevel := normalizeReasoningLevel(modelID[strings.LastIndex(modelID, "-")+1:])
+		if fixedLevel != "" && fixedLevel != "none" {
+			level = fixedLevel
+		} else if entry.ThinkingBudget != nil {
+			switch budget := *entry.ThinkingBudget; {
+			case budget < 0:
+			case budget <= geminiThinkingBudgetLowMax:
+				level = "low"
+			case budget <= geminiThinkingBudgetMediumMax:
+				level = "medium"
+			}
+		}
+		if fixedLevel == "" || fixedLevel == "none" {
+			// Bare and tiered AGY models accept configurable budgets. The fetched
+			// thinkingBudget is their default, not the only supported budget.
+			levels = []string{"low", "medium", "high"}
+			if entry.DefaultReasoningLevel == "" {
+				entry.DefaultReasoningLevel = level
+			}
+		} else {
+			levels = []string{level}
+		}
+	}
 	if reasoning == nil && len(levels) > 0 {
 		inferred := len(levels) != 1 || levels[0] != "none"
 		reasoning = &inferred
@@ -1471,6 +1534,13 @@ func upstreamMetadataFromCapabilityEntry(modelID string, entry upstreamModelCapa
 	if len(modalities) == 0 {
 		modalities = entry.Modalities.Input
 	}
+	if len(modalities) == 0 && (entry.SupportsImages != nil || entry.SupportsThinking != nil || entry.MaxTokens > 0) {
+		// AGY models accept text; image input requires an explicit capability.
+		modalities = []string{"text"}
+		if entry.SupportsImages != nil && *entry.SupportsImages {
+			modalities = append(modalities, "image")
+		}
+	}
 	contextWindow := entry.ContextWindow
 	if contextWindow <= 0 {
 		contextWindow = entry.MaxContextWindow
@@ -1478,15 +1548,24 @@ func upstreamMetadataFromCapabilityEntry(modelID string, entry upstreamModelCapa
 	if contextWindow <= 0 {
 		contextWindow = entry.Limit.Context
 	}
+	if contextWindow <= 0 {
+		contextWindow = entry.MaxTokens
+	}
 	maxOutputTokens := entry.MaxOutputTokens
 	if maxOutputTokens <= 0 {
 		maxOutputTokens = entry.Limit.Output
 	}
+	if maxOutputTokens <= 0 {
+		maxOutputTokens = entry.MaxOutputTokensCamel
+	}
 	defaultReasoningLevel := normalizeReasoningLevel(entry.DefaultReasoningLevel)
 	if defaultReasoningLevel == "" && len(levels) > 0 {
 		defaultReasoningLevel = levels[0]
 	}
 	displayName := strings.TrimSpace(entry.DisplayName)
+	if displayName == "" {
+		displayName = strings.TrimSpace(entry.DisplayNameCamel)
+	}
 	if displayName == "" && strings.TrimSpace(entry.Name) != "" && strings.TrimSpace(entry.Name) != modelID {
 		displayName = strings.TrimSpace(entry.Name)
 	}
diff --git a/backend/internal/service/upstream_models_antigravity_test.go b/backend/internal/service/upstream_models_antigravity_test.go
new file mode 100644
index 0000000000..53ff31478d
--- /dev/null
+++ b/backend/internal/service/upstream_models_antigravity_test.go
@@ -0,0 +1,245 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/antigravity"
+	"github.com/stretchr/testify/require"
+)
+
+func antigravityModelSyncAccount(plan string) *Account {
+	return &Account{
+		ID: 121, Platform: PlatformAntigravity, Type: AccountTypeOAuth,
+		Credentials: map[string]any{
+			"access_token": "model-sync-test-token",
+			"expires_at":   time.Now().Add(time.Hour).UTC().Format(time.RFC3339),
+			"project_id":   "model-sync-test-project",
+			"plan_type":    plan,
+		},
+	}
+}
+
+func antigravityModelSyncService() *AccountTestService {
+	return &AccountTestService{
+		antigravityGatewayService: &AntigravityGatewayService{tokenProvider: &AntigravityTokenProvider{}},
+		cfg:                       upstreamModelSyncTestConfig(),
+	}
+}
+
+func withAntigravityModelSyncEndpoints(t *testing.T, production, daily string) {
+	t.Helper()
+	previous := antigravity.BaseURLs
+	antigravity.BaseURLs = []string{production, daily}
+	t.Cleanup(func() { antigravity.BaseURLs = previous })
+}
+
+func TestFetchUpstreamSupportedModelsAntigravityUsesGenerationEndpoint(t *testing.T) {
+	t.Setenv(antigravityForwardBaseURLEnv, "")
+	production := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.WriteString(w, `{"models":{"gemini-3.7-flash-high":{}}}`)
+	}))
+	defer production.Close()
+	daily := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.WriteString(w, `{"models":{"gemini-3.8-flash-high":{}}}`)
+	}))
+	defer daily.Close()
+	withAntigravityModelSyncEndpoints(t, production.URL, daily.URL)
+
+	for _, tc := range []struct {
+		name  string
+		plan  string
+		mode  string
+		model string
+	}{
+		{name: "Ultra daily", plan: "Ultra", model: "gemini-3.8-flash-high"},
+		{name: "Pro daily", plan: "Pro", model: "gemini-3.8-flash-high"},
+		{name: "Free production", plan: "Free", model: "gemini-3.7-flash-high"},
+		{name: "explicit production", plan: "Ultra", mode: "prod", model: "gemini-3.7-flash-high"},
+		{name: "explicit daily", plan: "Free", mode: "daily", model: "gemini-3.8-flash-high"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv(antigravityForwardBaseURLEnv, tc.mode)
+			models, err := antigravityModelSyncService().FetchUpstreamSupportedModels(context.Background(), antigravityModelSyncAccount(tc.plan))
+			require.NoError(t, err)
+			require.Equal(t, []string{tc.model}, models, "catalog must come from the endpoint used for generation")
+		})
+	}
+}
+
+func TestSyncUpstreamModelCatalogAntigravityPreservesDirectCapabilities(t *testing.T) {
+	t.Setenv(antigravityForwardBaseURLEnv, "")
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.WriteString(w, `{"models":{"gemini-3.8-flash-high":{
+			"displayName":"Gemini 3.8 Flash High",
+			"supportsImages":true,"supportsThinking":true,"thinkingBudget":24576,
+			"maxTokens":1048576,"maxOutputTokens":65536
+		}}}`)
+	}))
+	defer server.Close()
+	withAntigravityModelSyncEndpoints(t, server.URL, server.URL)
+	account := antigravityModelSyncAccount("Ultra")
+	account.Credentials["model_mapping"] = map[string]any{"gemini-3.8-flash-high": "gemini-3.8-flash-high"}
+	registry := &httpUpstreamRecorder{resp: &http.Response{StatusCode: http.StatusBadGateway, Body: io.NopCloser(strings.NewReader(`{"error":"registry unavailable"}`))}}
+	svc := antigravityModelSyncService()
+	svc.accountRepo = &upstreamModelMetadataRepoStub{}
+	svc.httpUpstream = registry
+
+	catalog, err := svc.SyncUpstreamModelCatalog(context.Background(), account)
+	require.NoError(t, err)
+	require.Equal(t, []string{"gemini-3.8-flash-high"}, catalog.Models)
+	require.Contains(t, catalog.Metadata, "gemini-3.8-flash-high")
+	metadata := catalog.Metadata["gemini-3.8-flash-high"]
+	require.Equal(t, "Gemini 3.8 Flash High", metadata.DisplayName)
+	require.NotNil(t, metadata.Reasoning)
+	require.True(t, *metadata.Reasoning)
+	require.Equal(t, []string{"high"}, metadata.SupportedReasoningLevels, "fixed variant must advertise only its own reasoning level")
+	require.Equal(t, "high", metadata.DefaultReasoningLevel)
+	require.Equal(t, []string{"text", "image"}, metadata.InputModalities)
+	require.Equal(t, int64(1048576), metadata.ContextWindow)
+	require.Equal(t, int64(65536), metadata.MaxOutputTokens)
+	require.Empty(t, registry.requests, "complete upstream capabilities must not need guessed registry capabilities")
+	require.Empty(t, catalog.Warnings)
+	snapshot := account.GetUpstreamModelMetadataSnapshot()
+	require.NotNil(t, snapshot)
+	require.Equal(t, "upstream", snapshot.Source)
+	serializedMetadata, err := json.Marshal(metadata)
+	require.NoError(t, err)
+	serializedSnapshotEntry, err := json.Marshal(snapshot.Models["gemini-3.8-flash-high"])
+	require.NoError(t, err)
+	require.JSONEq(t, string(serializedMetadata), string(serializedSnapshotEntry))
+}
+
+func TestSyncUpstreamModelCatalogAntigravityTieredReasoning(t *testing.T) {
+	t.Setenv(antigravityForwardBaseURLEnv, "")
+	for _, tc := range []struct {
+		budget       string
+		defaultLevel string
+	}{
+		{budget: "-1", defaultLevel: "high"},
+		{budget: "0", defaultLevel: "low"},
+		{budget: "1024", defaultLevel: "low"},
+		{budget: "1025", defaultLevel: "medium"},
+		{budget: "4000", defaultLevel: "medium"},
+		{budget: "8192", defaultLevel: "medium"},
+		{budget: "8193", defaultLevel: "high"},
+		{defaultLevel: "high"},
+	} {
+		t.Run("budget="+tc.budget, func(t *testing.T) {
+			budgetJSON := ""
+			if tc.budget != "" {
+				budgetJSON = `"thinkingBudget":` + tc.budget + ","
+			}
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				_, _ = io.WriteString(w, fmt.Sprintf(`{"models":{"gemini-3.8-flash-tiered":{
+					"supportsImages":false,"supportsThinking":true,%s
+					"maxTokens":1048576,"maxOutputTokens":65536
+				}}}`, budgetJSON))
+			}))
+			defer server.Close()
+			withAntigravityModelSyncEndpoints(t, server.URL, server.URL)
+			account := antigravityModelSyncAccount("Ultra")
+			account.Credentials["model_mapping"] = map[string]any{"gemini-3.8-flash-tiered": "gemini-3.8-flash-tiered"}
+			svc := antigravityModelSyncService()
+			svc.accountRepo = &upstreamModelMetadataRepoStub{}
+
+			catalog, err := svc.SyncUpstreamModelCatalog(context.Background(), account)
+			require.NoError(t, err)
+			metadata := catalog.Metadata["gemini-3.8-flash-tiered"]
+			require.Equal(t, []string{"low", "medium", "high"}, metadata.SupportedReasoningLevels)
+			require.Equal(t, tc.defaultLevel, metadata.DefaultReasoningLevel, "tiered default must follow its upstream thinking budget")
+			require.Equal(t, []string{"text"}, metadata.InputModalities)
+		})
+	}
+}
+
+func TestSyncUpstreamModelCatalogAntigravityMissingImageSupportIsTextOnly(t *testing.T) {
+	t.Setenv(antigravityForwardBaseURLEnv, "")
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.WriteString(w, `{"models":{"claude-plain":{
+			"supportsThinking":false,"maxTokens":200000,"maxOutputTokens":64000
+		}}}`)
+	}))
+	defer server.Close()
+	withAntigravityModelSyncEndpoints(t, server.URL, server.URL)
+	account := antigravityModelSyncAccount("Ultra")
+	account.Credentials["model_mapping"] = map[string]any{"claude-plain": "claude-plain"}
+	registry := &httpUpstreamRecorder{resp: &http.Response{StatusCode: http.StatusBadGateway, Body: io.NopCloser(strings.NewReader(`{"error":"registry unavailable"}`))}}
+	svc := antigravityModelSyncService()
+	svc.accountRepo = &upstreamModelMetadataRepoStub{}
+	svc.httpUpstream = registry
+
+	catalog, err := svc.SyncUpstreamModelCatalog(context.Background(), account)
+	require.NoError(t, err)
+	metadata := catalog.Metadata["claude-plain"]
+	require.Equal(t, []string{"text"}, metadata.InputModalities, "missing image declaration must not advertise image input")
+	require.NotNil(t, metadata.Reasoning)
+	require.False(t, *metadata.Reasoning)
+	require.Empty(t, metadata.SupportedReasoningLevels)
+	require.Empty(t, registry.requests)
+}
+
+func TestSyncUpstreamModelCatalogAntigravityBudgetReasoningLevels(t *testing.T) {
+	t.Setenv(antigravityForwardBaseURLEnv, "")
+	for _, tc := range []struct {
+		model        string
+		budget       int
+		defaultLevel string
+		levels       []string
+	}{
+		{model: "gemini-2.5-flash", budget: -1, defaultLevel: "high", levels: []string{"low", "medium", "high"}},
+		{model: "gemini-2.5-flash-lite", budget: 4000, defaultLevel: "medium", levels: []string{"low", "medium", "high"}},
+		{model: "gemini-3.8-flash-low", budget: -1, defaultLevel: "low", levels: []string{"low"}},
+		{model: "gemini-3.8-flash-medium", budget: 1000, defaultLevel: "medium", levels: []string{"medium"}},
+		{model: "gemini-3.8-flash-high", budget: 4000, defaultLevel: "high", levels: []string{"high"}},
+	} {
+		t.Run(tc.model, func(t *testing.T) {
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				_, _ = io.WriteString(w, fmt.Sprintf(`{"models":{%q:{
+					"supportsImages":true,"supportsThinking":true,"thinkingBudget":%d,
+					"maxTokens":1048576,"maxOutputTokens":65536
+				}}}`, tc.model, tc.budget))
+			}))
+			defer server.Close()
+			withAntigravityModelSyncEndpoints(t, server.URL, server.URL)
+			account := antigravityModelSyncAccount("Ultra")
+			account.Credentials["model_mapping"] = map[string]any{tc.model: tc.model}
+			svc := antigravityModelSyncService()
+			svc.accountRepo = &upstreamModelMetadataRepoStub{}
+
+			catalog, err := svc.SyncUpstreamModelCatalog(context.Background(), account)
+			require.NoError(t, err)
+			metadata := catalog.Metadata[tc.model]
+			require.Equal(t, tc.levels, metadata.SupportedReasoningLevels, "default budget must not restrict configurable models to one reasoning level")
+			require.Equal(t, tc.defaultLevel, metadata.DefaultReasoningLevel)
+			require.Empty(t, catalog.Warnings)
+		})
+	}
+}
+
+func TestConfiguredUpstreamModelsForCapabilitySyncSkipsInjectedAntigravityPassthroughs(t *testing.T) {
+	account := &Account{
+		Platform: PlatformAntigravity,
+		Credentials: map[string]any{"model_mapping": map[string]any{
+			"gemini-3.8-flash-high": "gemini-3.8-flash-high",
+			"gemini-3.8-flash":      "gemini-3.8-flash-tiered",
+			"custom-alias":          "gemini-3.6-flash-low",
+		}},
+	}
+	// 运行时补齐的默认透传仍可调用（存量账号兼容）。
+	require.True(t, account.IsModelSupported("gemini-3.7-flash-medium"))
+
+	got := configuredUpstreamModelsForCapabilitySync(account)
+	require.ElementsMatch(t, []string{"gemini-3.8-flash-high", "gemini-3.8-flash-tiered", "gemini-3.6-flash-low"}, got)
+
+	// 空映射走默认目录，其中的同名条目不是运行时补齐。
+	empty := &Account{Platform: PlatformAntigravity, Credentials: map[string]any{}}
+	require.Contains(t, configuredUpstreamModelsForCapabilitySync(empty), "gemini-3.8-flash-low")
+}
diff --git a/frontend/src/components/account/AccountTestModal.vue b/frontend/src/components/account/AccountTestModal.vue
index 5192d0b667..4ef3c50a94 100644
--- a/frontend/src/components/account/AccountTestModal.vue
+++ b/frontend/src/components/account/AccountTestModal.vue
@@ -298,7 +298,7 @@ const supportsGeminiImageTest = computed(() => {
   const modelID = selectedModelId.value.toLowerCase()
   if (!modelID.startsWith('gemini-') || !modelID.includes('-image')) return false
 
-  return props.account?.platform === 'gemini' || (props.account?.platform === 'antigravity' && props.account?.type === 'apikey')
+  return props.account?.platform === 'gemini' || props.account?.platform === 'antigravity'
 })
 
 const supportsOpenAIImageTest = computed(() => {
diff --git a/frontend/src/components/admin/account/AccountTestModal.vue b/frontend/src/components/admin/account/AccountTestModal.vue
index 766686e3de..226fed8786 100644
--- a/frontend/src/components/admin/account/AccountTestModal.vue
+++ b/frontend/src/components/admin/account/AccountTestModal.vue
@@ -442,7 +442,7 @@ const supportsGeminiImageTest = computed(() => {
   const modelID = selectedModelId.value.toLowerCase()
   if (!modelID.startsWith('gemini-') || !modelID.includes('-image')) return false
 
-  return props.account?.platform === 'gemini' || (props.account?.platform === 'antigravity' && props.account?.type === 'apikey')
+  return props.account?.platform === 'gemini' || props.account?.platform === 'antigravity'
 })
 
 const supportsOpenAIImageTest = computed(() => {
diff --git a/frontend/src/composables/__tests__/useModelWhitelist.spec.ts b/frontend/src/composables/__tests__/useModelWhitelist.spec.ts
index fab6c2fc38..97d132b1ad 100644
--- a/frontend/src/composables/__tests__/useModelWhitelist.spec.ts
+++ b/frontend/src/composables/__tests__/useModelWhitelist.spec.ts
@@ -171,6 +171,21 @@ describe('useModelWhitelist', () => {
     expect(models).toContain('gemini-3.1-pro')
   })
 
+  it('Gemini 4 Argon 在 gemini 与 antigravity 平台使用对应真实模型 ID 与预设映射', () => {
+    expect(getModelsByPlatform('gemini')).toContain('gemini-4-argon')
+    const agModels = getModelsByPlatform('antigravity')
+    expect(agModels).not.toContain('gemini-4-argon')
+    expect(agModels).toContain('gemini-4-argon-high')
+    expect(agModels).toContain('gemini-4-argon-medium')
+    expect(agModels).toContain('gemini-4-argon-low')
+    expect(getPresetMappingsByPlatform('antigravity')).toEqual(expect.arrayContaining([
+      expect.objectContaining({ from: 'gemini-4-argon', to: 'gemini-4-argon-high' }),
+      expect.objectContaining({ from: 'gemini-4-argon-high', to: 'gemini-4-argon-high' }),
+      expect.objectContaining({ from: 'gemini-4-argon-medium', to: 'gemini-4-argon-medium' }),
+      expect.objectContaining({ from: 'gemini-4-argon-low', to: 'gemini-4-argon-low' })
+    ]))
+  })
+
   it('whitelist 模式会忽略通配符条目', () => {
     const mapping = buildModelMappingObject('whitelist', ['claude-*', 'gemini-3.1-flash-image'], [])
     expect(mapping).toEqual({
diff --git a/frontend/src/composables/useModelWhitelist.ts b/frontend/src/composables/useModelWhitelist.ts
index 12c5ef2d3e..cf1db73156 100644
--- a/frontend/src/composables/useModelWhitelist.ts
+++ b/frontend/src/composables/useModelWhitelist.ts
@@ -57,15 +57,22 @@ const geminiModels = [
   'gemini-2.5-pro',
   'gemini-3.5-flash',
   'gemini-3-flash-preview',
-  'gemini-3-pro-preview'
+  'gemini-3-pro-preview',
+  'gemini-4-argon'
 ]
 
 // Antigravity 官方支持的模型（精确匹配）
 // 基于官方 API 返回的模型列表，只支持 Claude 4.5+ 和 Gemini 2.5+
 const antigravityModels = [
-  // Claude 4.5+ 系列
+  // Claude 4.5+ / 5.5 系列
   'claude-fable-5-1',
   'claude-fable-5',
+  'claude-opus-5-5-high',
+  'claude-opus-5-5-medium',
+  'claude-opus-5-5-low',
+  'claude-sonnet-5-5-high',
+  'claude-sonnet-5-5-medium',
+  'claude-sonnet-5-5-low',
   'claude-opus-4-6',
   'claude-opus-4-6-thinking',
   'claude-opus-4-7',
@@ -89,7 +96,28 @@ const antigravityModels = [
   'gemini-3.1-pro',
   'gemini-3.1-pro-high',
   'gemini-3.1-pro-low',
+  'gemini-pro-agent',
   'gemini-3-pro-image',
+  // Gemini 3.6 / 3.7 / 3.8 Flash 系列
+  'gemini-3.6-flash',
+  'gemini-3.6-flash-low',
+  'gemini-3.6-flash-medium',
+  'gemini-3.6-flash-high',
+  'gemini-3.6-flash-tiered',
+  'gemini-3.7-flash',
+  'gemini-3.7-flash-low',
+  'gemini-3.7-flash-medium',
+  'gemini-3.7-flash-high',
+  'gemini-3.7-flash-tiered',
+  'gemini-3.8-flash',
+  'gemini-3.8-flash-low',
+  'gemini-3.8-flash-medium',
+  'gemini-3.8-flash-high',
+  'gemini-3.8-flash-tiered',
+  // Gemini 4 Argon 系列
+  'gemini-4-argon-low',
+  'gemini-4-argon-medium',
+  'gemini-4-argon-high',
   // 其他
   'gpt-oss-120b-medium',
   'tab_flash_lite_preview'
@@ -357,7 +385,22 @@ const grokPresetMappings = [
 
 // Antigravity 预设映射（支持通配符）
 const antigravityPresetMappings = [
+  // Claude 5.5 / Gemini 4 Argon / 3.8 Flash 推荐映射
+  { label: '4 Argon→High', from: 'gemini-4-argon', to: 'gemini-4-argon-high', color: 'bg-amber-100 text-amber-700 hover:bg-amber-200 dark:bg-amber-900/30 dark:text-amber-400' },
+  { label: '4 Argon High', from: 'gemini-4-argon-high', to: 'gemini-4-argon-high', color: 'bg-orange-100 text-orange-700 hover:bg-orange-200 dark:bg-orange-900/30 dark:text-orange-400' },
+  { label: '4 Argon Medium', from: 'gemini-4-argon-medium', to: 'gemini-4-argon-medium', color: 'bg-yellow-100 text-yellow-700 hover:bg-yellow-200 dark:bg-yellow-900/30 dark:text-yellow-400' },
+  { label: '4 Argon Low', from: 'gemini-4-argon-low', to: 'gemini-4-argon-low', color: 'bg-lime-100 text-lime-700 hover:bg-lime-200 dark:bg-lime-900/30 dark:text-lime-400' },
+  { label: '3.8 Flash', from: 'gemini-3.8-flash', to: 'gemini-3.8-flash', color: 'bg-emerald-100 text-emerald-700 hover:bg-emerald-200 dark:bg-emerald-900/30 dark:text-emerald-400' },
+  { label: '3.8 Flash High', from: 'gemini-3.8-flash-high', to: 'gemini-3.8-flash-high', color: 'bg-teal-100 text-teal-700 hover:bg-teal-200 dark:bg-teal-900/30 dark:text-teal-400' },
+  { label: 'Opus 5.5→High', from: 'claude-opus-5-5', to: 'claude-opus-5-5-high', color: 'bg-pink-100 text-pink-700 hover:bg-pink-200 dark:bg-pink-900/30 dark:text-pink-400' },
+  { label: 'Opus 5.5 High', from: 'claude-opus-5-5-high', to: 'claude-opus-5-5-high', color: 'bg-pink-100 text-pink-700 hover:bg-pink-200 dark:bg-pink-900/30 dark:text-pink-400' },
+  { label: 'Opus 5.5 Medium', from: 'claude-opus-5-5-medium', to: 'claude-opus-5-5-medium', color: 'bg-purple-100 text-purple-700 hover:bg-purple-200 dark:bg-purple-900/30 dark:text-purple-400' },
+  { label: 'Sonnet 5.5→High', from: 'claude-sonnet-5-5', to: 'claude-sonnet-5-5-high', color: 'bg-indigo-100 text-indigo-700 hover:bg-indigo-200 dark:bg-indigo-900/30 dark:text-indigo-400' },
+  { label: 'Sonnet 5.5 High', from: 'claude-sonnet-5-5-high', to: 'claude-sonnet-5-5-high', color: 'bg-indigo-100 text-indigo-700 hover:bg-indigo-200 dark:bg-indigo-900/30 dark:text-indigo-400' },
+  { label: 'Sonnet 5.5 Medium', from: 'claude-sonnet-5-5-medium', to: 'claude-sonnet-5-5-medium', color: 'bg-cyan-100 text-cyan-700 hover:bg-cyan-200 dark:bg-cyan-900/30 dark:text-cyan-400' },
   // Claude 通配符映射
+  { label: 'Claude→Sonnet 5.5', from: 'claude-*', to: 'claude-sonnet-5-5-high', color: 'bg-blue-100 text-blue-700 hover:bg-blue-200 dark:bg-blue-900/30 dark:text-blue-400' },
+  { label: 'Opus→Opus 5.5', from: 'claude-opus-*', to: 'claude-opus-5-5-high', color: 'bg-purple-100 text-purple-700 hover:bg-purple-200 dark:bg-purple-900/30 dark:text-purple-400' },
   { label: 'Claude→Sonnet', from: 'claude-*', to: 'claude-sonnet-4-5', color: 'bg-blue-100 text-blue-700 hover:bg-blue-200 dark:bg-blue-900/30 dark:text-blue-400' },
   { label: 'Fable 5.1', from: 'claude-fable-5-1', to: 'claude-fable-5-1', color: 'bg-rose-100 text-rose-700 hover:bg-rose-200 dark:bg-rose-900/30 dark:text-rose-400' },
   { label: 'Fable 5', from: 'claude-fable-5', to: 'claude-fable-5', color: 'bg-rose-100 text-rose-700 hover:bg-rose-200 dark:bg-rose-900/30 dark:text-rose-400' },
@@ -368,7 +411,8 @@ const antigravityPresetMappings = [
   { label: 'Sonnet4.5→4.6', from: 'claude-sonnet-4-5-20250929', to: 'claude-sonnet-4-6', color: 'bg-cyan-100 text-cyan-700 hover:bg-cyan-200 dark:bg-cyan-900/30 dark:text-cyan-400' },
   { label: 'Sonnet3.5→4.6', from: 'claude-3-5-sonnet-20241022', to: 'claude-sonnet-4-6', color: 'bg-teal-100 text-teal-700 hover:bg-teal-200 dark:bg-teal-900/30 dark:text-teal-400' },
   { label: 'Opus4.5→4.6', from: 'claude-opus-4-5-20251101', to: 'claude-opus-4-6-thinking', color: 'bg-violet-100 text-violet-700 hover:bg-violet-200 dark:bg-violet-900/30 dark:text-violet-400' },
-  // Gemini 3→3.1 映射
+  // Gemini 3→3.1 / 4 Argon 映射
+  { label: '3.1-Pro→4-Argon-High', from: 'gemini-3.1-pro*', to: 'gemini-4-argon-high', color: 'bg-amber-100 text-amber-700 hover:bg-amber-200 dark:bg-amber-900/30 dark:text-amber-400' },
   { label: '3-Pro-Preview→Pro-Agent', from: 'gemini-3-pro-preview', to: 'gemini-pro-agent', color: 'bg-amber-100 text-amber-700 hover:bg-amber-200 dark:bg-amber-900/30 dark:text-amber-400' },
   { label: '3-Pro-High→Pro-Agent', from: 'gemini-3-pro-high', to: 'gemini-pro-agent', color: 'bg-orange-100 text-orange-700 hover:bg-orange-200 dark:bg-orange-900/30 dark:text-orange-400' },
   { label: '3-Pro-Low→3.1-Pro-Low', from: 'gemini-3-pro-low', to: 'gemini-3.1-pro-low', color: 'bg-yellow-100 text-yellow-700 hover:bg-yellow-200 dark:bg-yellow-900/30 dark:text-yellow-400' },
@@ -378,6 +422,7 @@ const antigravityPresetMappings = [
   { label: '3.1-Pro-Low透传', from: 'gemini-3.1-pro-low', to: 'gemini-3.1-pro-low', color: 'bg-yellow-100 text-yellow-700 hover:bg-yellow-200 dark:bg-yellow-900/30 dark:text-yellow-400' },
   { label: '3.1-Pro-Preview→Pro-Agent', from: 'gemini-3.1-pro-preview', to: 'gemini-pro-agent', color: 'bg-amber-100 text-amber-700 hover:bg-amber-200 dark:bg-amber-900/30 dark:text-amber-400' },
   // Gemini 通配符映射
+  { label: 'Gemini 3→3.8 Flash', from: 'gemini-3*', to: 'gemini-3.8-flash-high', color: 'bg-yellow-100 text-yellow-700 hover:bg-yellow-200 dark:bg-yellow-900/30 dark:text-yellow-400' },
   { label: 'Gemini 3→Flash', from: 'gemini-3*', to: 'gemini-3-flash', color: 'bg-yellow-100 text-yellow-700 hover:bg-yellow-200 dark:bg-yellow-900/30 dark:text-yellow-400' },
   { label: 'Gemini 2.5→Flash', from: 'gemini-2.5*', to: 'gemini-2.5-flash', color: 'bg-orange-100 text-orange-700 hover:bg-orange-200 dark:bg-orange-900/30 dark:text-orange-400' },
   { label: '2.5-Flash-Image透传', from: 'gemini-2.5-flash-image', to: 'gemini-2.5-flash-image', color: 'bg-sky-100 text-sky-700 hover:bg-sky-200 dark:bg-sky-900/30 dark:text-sky-400' },