diff --git a/backend/internal/handler/openai_gateway_handler.go b/backend/internal/handler/openai_gateway_handler.go
index 8602be7abd..2f3a95985d 100644
--- a/backend/internal/handler/openai_gateway_handler.go
+++ b/backend/internal/handler/openai_gateway_handler.go
@@ -104,6 +104,16 @@ func openAICompatibleRequestPlatform(apiKey *service.APIKey) string {
 	return service.PlatformOpenAI
 }
 
+func allowOpenAICompatibleMessagesDispatch(apiKey *service.APIKey) bool {
+	if apiKey == nil || apiKey.Group == nil {
+		return true
+	}
+	if apiKey.Group.Platform == service.PlatformGrok {
+		return true
+	}
+	return apiKey.Group.AllowMessagesDispatch
+}
+
 // NewOpenAIGatewayHandler creates a new OpenAIGatewayHandler
 func NewOpenAIGatewayHandler(
 	gatewayService *service.OpenAIGatewayService,
@@ -660,7 +670,7 @@ func (h *OpenAIGatewayHandler) Messages(c *gin.Context) {
 	)
 
 	// 检查分组是否允许 /v1/messages 调度
-	if apiKey.Group != nil && !apiKey.Group.AllowMessagesDispatch {
+	if !allowOpenAICompatibleMessagesDispatch(apiKey) {
 		h.anthropicErrorResponse(c, http.StatusForbidden, "permission_error",
 			"This group does not allow /v1/messages dispatch")
 		return
diff --git a/backend/internal/handler/openai_gateway_handler_test.go b/backend/internal/handler/openai_gateway_handler_test.go
index 5886388a9e..c4ccb5a024 100644
--- a/backend/internal/handler/openai_gateway_handler_test.go
+++ b/backend/internal/handler/openai_gateway_handler_test.go
@@ -434,6 +434,16 @@ func TestResolveOpenAIMessagesDispatchMappedModel(t *testing.T) {
 		require.Empty(t, resolveOpenAIMessagesDispatchMappedModel(&service.APIKey{Group: &service.Group{}}, "gpt-5.4"))
 	})
 
+	t.Run("grok_group_maps_claude_cli_model_to_grok_default", func(t *testing.T) {
+		apiKey := &service.APIKey{
+			Group: &service.Group{
+				Platform: service.PlatformGrok,
+			},
+		}
+		require.Equal(t, "grok-4.3", resolveOpenAIMessagesDispatchMappedModel(apiKey, "claude-sonnet-4-5"))
+		require.Empty(t, resolveOpenAIMessagesDispatchMappedModel(apiKey, "grok"))
+	})
+
 	t.Run("does_not_fall_back_to_group_default_mapped_model", func(t *testing.T) {
 		apiKey := &service.APIKey{
 			Group: &service.Group{
@@ -445,6 +455,60 @@ func TestResolveOpenAIMessagesDispatchMappedModel(t *testing.T) {
 	})
 }
 
+func TestOpenAIGatewayMessagesDispatchGateAllowsGrokGroups(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	t.Run("openai_group_without_dispatch_flag_is_rejected", func(t *testing.T) {
+		rec := httptest.NewRecorder()
+		c, _ := gin.CreateTestContext(rec)
+		c.Request = httptest.NewRequest(http.MethodPost, "/v1/messages", strings.NewReader(`{"model":"claude-sonnet-4-5","messages":[{"role":"user","content":"hi"}]}`))
+		groupID := int64(4101)
+		c.Set(string(middleware.ContextKeyAPIKey), &service.APIKey{
+			ID:      5101,
+			GroupID: &groupID,
+			User:    &service.User{ID: 6101},
+			Group: &service.Group{
+				ID:                    groupID,
+				Platform:              service.PlatformOpenAI,
+				AllowMessagesDispatch: false,
+			},
+		})
+		c.Set(string(middleware.ContextKeyUser), middleware.AuthSubject{UserID: 6101, Concurrency: 1})
+
+		h := &OpenAIGatewayHandler{}
+		h.Messages(c)
+
+		require.Equal(t, http.StatusForbidden, rec.Code)
+		require.Equal(t, "permission_error", gjson.GetBytes(rec.Body.Bytes(), "error.type").String())
+		require.Contains(t, rec.Body.String(), "This group does not allow /v1/messages dispatch")
+	})
+
+	t.Run("grok_group_without_dispatch_flag_reaches_gateway_dependencies", func(t *testing.T) {
+		rec := httptest.NewRecorder()
+		c, _ := gin.CreateTestContext(rec)
+		c.Request = httptest.NewRequest(http.MethodPost, "/v1/messages", strings.NewReader(`{"model":"grok-4.3","messages":[{"role":"user","content":"hi"}]}`))
+		groupID := int64(4102)
+		c.Set(string(middleware.ContextKeyAPIKey), &service.APIKey{
+			ID:      5102,
+			GroupID: &groupID,
+			User:    &service.User{ID: 6102},
+			Group: &service.Group{
+				ID:                    groupID,
+				Platform:              service.PlatformGrok,
+				AllowMessagesDispatch: false,
+			},
+		})
+		c.Set(string(middleware.ContextKeyUser), middleware.AuthSubject{UserID: 6102, Concurrency: 1})
+
+		h := &OpenAIGatewayHandler{}
+		h.Messages(c)
+
+		require.Equal(t, http.StatusServiceUnavailable, rec.Code)
+		require.Equal(t, "api_error", gjson.GetBytes(rec.Body.Bytes(), "error.type").String())
+		require.NotContains(t, rec.Body.String(), "This group does not allow /v1/messages dispatch")
+	})
+}
+
 func TestOpenAIModelMappedBody(t *testing.T) {
 	body := []byte(`{"model":"alias","input":"hello"}`)
 	calls := 0
diff --git a/backend/internal/service/openai_messages_dispatch.go b/backend/internal/service/openai_messages_dispatch.go
index f2c1ad3c1b..f72b84a7f3 100644
--- a/backend/internal/service/openai_messages_dispatch.go
+++ b/backend/internal/service/openai_messages_dispatch.go
@@ -1,6 +1,10 @@
 package service
 
-import "strings"
+import (
+	"strings"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/xai"
+)
 
 const (
 	defaultOpenAIMessagesDispatchOpusMappedModel   = "gpt-5.4"
@@ -64,6 +68,13 @@ func (g *Group) ResolveMessagesDispatchModel(requestedModel string) string {
 		return ""
 	}
 
+	if g.Platform == PlatformGrok {
+		if claudeMessagesDispatchFamily(requestedModel) != "" {
+			return xai.DefaultModelMapping()["grok"]
+		}
+		return ""
+	}
+
 	cfg := normalizeOpenAIMessagesDispatchModelConfig(g.MessagesDispatchModelConfig)
 	if mappedModel := strings.TrimSpace(cfg.ExactModelMappings[requestedModel]); mappedModel != "" {
 		return mappedModel
diff --git a/backend/internal/service/openai_messages_dispatch_test.go b/backend/internal/service/openai_messages_dispatch_test.go
index a625aaddd4..e0b8ab0aa0 100644
--- a/backend/internal/service/openai_messages_dispatch_test.go
+++ b/backend/internal/service/openai_messages_dispatch_test.go
@@ -25,3 +25,15 @@ func TestNormalizeOpenAIMessagesDispatchModelConfig(t *testing.T) {
 		"claude-sonnet-4-5-20250929": "gpt-5.2",
 	}, cfg.ExactModelMappings)
 }
+
+func TestGroupResolveMessagesDispatchModel_GrokMapsClaudeFamilyToGrok(t *testing.T) {
+	t.Parallel()
+
+	group := &Group{Platform: PlatformGrok}
+
+	require.Equal(t, "grok-4.3", group.ResolveMessagesDispatchModel("claude-sonnet-4-5"))
+	require.Equal(t, "grok-4.3", group.ResolveMessagesDispatchModel("claude-opus-4-6"))
+	require.Equal(t, "grok-4.3", group.ResolveMessagesDispatchModel("claude-haiku-4-5"))
+	require.Empty(t, group.ResolveMessagesDispatchModel("grok"))
+	require.Empty(t, group.ResolveMessagesDispatchModel("gpt-5.3-codex"))
+}