diff --git a/docs/openapi/relay.json b/docs/openapi/relay.json
index 2e04217e..30e9cbde 100644
--- a/docs/openapi/relay.json
+++ b/docs/openapi/relay.json
@@ -3981,7 +3981,8 @@
           },
           "model": {
             "type": "string",
-            "example": "text-moderation-latest"
+            "description": "Optional. Defaults to omni-moderation-latest when omitted. Tokens with model limits must explicitly allow this model. Channels serving model-less moderation requests must include omni-moderation-latest in their model list.",
+            "example": "omni-moderation-latest"
           }
         }
       },
diff --git a/middleware/distributor.go b/middleware/distributor.go
index d99f15bb..53c45eea 100644
--- a/middleware/distributor.go
+++ b/middleware/distributor.go
@@ -388,7 +388,7 @@ func getModelRequest(c *gin.Context) (*ModelRequest, bool, error) {
 	}
 	if strings.HasPrefix(c.Request.URL.Path, "/v1/moderations") {
 		if modelRequest.Model == "" {
-			modelRequest.Model = "text-moderation-stable"
+			modelRequest.Model = "omni-moderation-latest"
 		}
 	}
 	if strings.HasSuffix(c.Request.URL.Path, "embeddings") {
diff --git a/middleware/distributor_routing_test.go b/middleware/distributor_routing_test.go
index 18c73687..5b4fd01b 100644
--- a/middleware/distributor_routing_test.go
+++ b/middleware/distributor_routing_test.go
@@ -44,6 +44,19 @@ func TestGetModelFromJSONBodyPreservesProviderRoutingFields(t *testing.T) {
 	require.Equal(t, "openai", gjson.GetBytes(body, "provider.order.0").String())
 }
 
+func TestGetModelRequestDefaultsOmittedModerationModel(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	ctx, _ := gin.CreateTestContext(httptest.NewRecorder())
+	ctx.Request = httptest.NewRequest(http.MethodPost, "/v1/moderations", bytes.NewBufferString(`{"input":"check this"}`))
+	ctx.Request.Header.Set("Content-Type", "application/json")
+	t.Cleanup(func() { common.CleanupBodyStorage(ctx) })
+
+	request, shouldSelectChannel, err := getModelRequest(ctx)
+	require.NoError(t, err)
+	require.True(t, shouldSelectChannel)
+	require.Equal(t, "omni-moderation-latest", request.Model)
+}
+
 func TestPlaygroundExplicitGroupBypassesStoredTokenRoutePlan(t *testing.T) {
 	previousDB := model.DB
 	previousMemoryCache := common.MemoryCacheEnabled
diff --git a/relay/helper/moderation_request_test.go b/relay/helper/moderation_request_test.go
new file mode 100644
index 00000000..0b704987
--- /dev/null
+++ b/relay/helper/moderation_request_test.go
@@ -0,0 +1,25 @@
+package helper
+
+import (
+	"bytes"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/MAX-API-Next/MAX-API/common"
+	relayconstant "github.com/MAX-API-Next/MAX-API/relay/constant"
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetAndValidateTextRequestDefaultsOmittedModerationModel(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	ctx, _ := gin.CreateTestContext(httptest.NewRecorder())
+	ctx.Request = httptest.NewRequest(http.MethodPost, "/v1/moderations", bytes.NewBufferString(`{"input":"check this"}`))
+	ctx.Request.Header.Set("Content-Type", "application/json")
+	t.Cleanup(func() { common.CleanupBodyStorage(ctx) })
+
+	request, err := GetAndValidateTextRequest(ctx, relayconstant.RelayModeModerations)
+	require.NoError(t, err)
+	require.Equal(t, "omni-moderation-latest", request.Model)
+}
diff --git a/relay/helper/price_test.go b/relay/helper/price_test.go
index f9c2bcdc..3b150914 100644
--- a/relay/helper/price_test.go
+++ b/relay/helper/price_test.go
@@ -135,6 +135,42 @@ func TestModelPriceHelperDefersAlphaSearchFloorUntilSurcharge(t *testing.T) {
 	require.Equal(t, 200, priceData.QuotaToPreConsume)
 }
 
+func TestModelPriceHelperDoesNotReserveQuotaForOmniModeration(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	originalModelRatio := ratio_setting.ModelRatio2JSONString()
+	originalGroupRatio := ratio_setting.GroupRatio2JSONString()
+	originalPreConsumedQuota := common.PreConsumedQuota
+	originalFreeModelPreConsume := operation_setting.GetQuotaSetting().EnableFreeModelPreConsume
+	t.Cleanup(func() {
+		require.NoError(t, ratio_setting.UpdateModelRatioByJSONString(originalModelRatio))
+		require.NoError(t, ratio_setting.UpdateGroupRatioByJSONString(originalGroupRatio))
+		common.PreConsumedQuota = originalPreConsumedQuota
+		operation_setting.GetQuotaSetting().EnableFreeModelPreConsume = originalFreeModelPreConsume
+	})
+	require.NoError(t, ratio_setting.UpdateModelRatioByJSONString(`{"omni-moderation-latest":0}`))
+	require.NoError(t, ratio_setting.UpdateGroupRatioByJSONString(`{"default":1}`))
+	operation_setting.GetQuotaSetting().EnableFreeModelPreConsume = false
+
+	ctx, _ := gin.CreateTestContext(httptest.NewRecorder())
+	info := &relaycommon.RelayInfo{
+		RelayMode:       relayconstant.RelayModeModerations,
+		OriginModelName: "omni-moderation-latest",
+		UserGroup:       "default",
+		UsingGroup:      "default",
+	}
+
+	priceData, err := ModelPriceHelper(ctx, info, 100, &types.TokenCountMeta{})
+	require.NoError(t, err)
+	require.Zero(t, priceData.ModelRatio)
+	require.Zero(t, priceData.QuotaToPreConsume)
+
+	common.PreConsumedQuota = 500
+	operation_setting.GetQuotaSetting().EnableFreeModelPreConsume = true
+	priceData, err = ModelPriceHelper(ctx, info, 100, &types.TokenCountMeta{})
+	require.NoError(t, err)
+	require.Equal(t, 500, priceData.QuotaToPreConsume)
+}
+
 func TestModelPriceHelperPerCallRejectsUnpricedMJSunoTaskModels(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 	originalSelfUseMode := operation_setting.SelfUseModeEnabled
diff --git a/relay/helper/valid_request.go b/relay/helper/valid_request.go
index 567f8bec..7cf99f43 100644
--- a/relay/helper/valid_request.go
+++ b/relay/helper/valid_request.go
@@ -309,7 +309,7 @@ func GetAndValidateTextRequest(c *gin.Context, relayMode int) (*dto.GeneralOpenA
 	}
 
 	if relayMode == relayconstant.RelayModeModerations && textRequest.Model == "" {
-		textRequest.Model = "text-moderation-latest"
+		textRequest.Model = "omni-moderation-latest"
 	}
 	if relayMode == relayconstant.RelayModeEmbeddings && textRequest.Model == "" {
 		textRequest.Model = c.Param("model")
diff --git a/setting/ratio_setting/model_ratio.go b/setting/ratio_setting/model_ratio.go
index dd88da35..ec2c1914 100644
--- a/setting/ratio_setting/model_ratio.go
+++ b/setting/ratio_setting/model_ratio.go
@@ -130,6 +130,8 @@ var defaultModelRatio = map[string]float64{
 	"text-search-ada-doc-001":                   10,
 	"text-moderation-stable":                    0.1,
 	"text-moderation-latest":                    0.1,
+	"omni-moderation-latest":                    0, // OpenAI moderation models are free
+	"omni-moderation-2024-09-26":                0,
 	"claude-3-haiku-20240307":                   0.125, // $0.25 / 1M tokens
 	"claude-3-5-haiku-20241022":                 0.5,   // $1 / 1M tokens
 	"claude-haiku-4-5-20251001":                 0.5,   // $1 / 1M tokens
diff --git a/setting/ratio_setting/pricing_validation_test.go b/setting/ratio_setting/pricing_validation_test.go
index ba1925dc..5730eaac 100644
--- a/setting/ratio_setting/pricing_validation_test.go
+++ b/setting/ratio_setting/pricing_validation_test.go
@@ -48,6 +48,14 @@ func TestLoadPricingMapWithoutNormalizerPreservesRawKeys(t *testing.T) {
 	require.Equal(t, 2.5, value)
 }
 
+func TestDefaultModerationRatiosAreFree(t *testing.T) {
+	for _, model := range []string{"omni-moderation-latest", "omni-moderation-2024-09-26"} {
+		ratio, ok := GetDefaultModelRatioMap()[model]
+		require.True(t, ok, model)
+		require.Zero(t, ratio, model)
+	}
+}
+
 func TestValidatePricingMapRejectsOversizedJSONBeforeLoad(t *testing.T) {
 	raw := `{"` + strings.Repeat("a", maxPricingMapJSONBytes) + `":1}`