diff --git a/go.mod b/go.mod
index 18d45fa..2270439 100644
--- a/go.mod
+++ b/go.mod
@@ -4,7 +4,7 @@ go 1.24.0
 
 require (
 	bou.ke/monkey v1.0.2
-	git.hlsq.asia/mmorpg/service-common v0.0.0-20260116143417-d944729ad0e5
+	git.hlsq.asia/mmorpg/service-common v0.0.0-20260116155014-3de703eb83c5
 	github.com/alicebob/miniredis/v2 v2.35.0
 	github.com/gin-contrib/cors v1.7.6
 	github.com/gin-gonic/gin v1.11.0
diff --git a/go.sum b/go.sum
index f7498e0..db46963 100644
--- a/go.sum
+++ b/go.sum
@@ -2,8 +2,8 @@ bou.ke/monkey v1.0.2 h1:kWcnsrCNUatbxncxR/ThdYqbytgOIArtYWqcQLQzKLI=
 bou.ke/monkey v1.0.2/go.mod h1:OqickVX3tNx6t33n1xvtTtu85YN5s6cKwVug+oHMaIA=
 filippo.io/edwards25519 v1.1.0 h1:FNf4tywRC1HmFuKW5xopWpigGjJKiJSV0Cqo0cJWDaA=
 filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
-git.hlsq.asia/mmorpg/service-common v0.0.0-20260116143417-d944729ad0e5 h1:gkPNZ/OiXQhtiqRMdLrL5Zw580zgb9082jkZQqP71Fk=
-git.hlsq.asia/mmorpg/service-common v0.0.0-20260116143417-d944729ad0e5/go.mod h1:Dazg+4woCv9Jk7jgT2qUSGWhZOXx/0WYfJO+FCUDyhw=
+git.hlsq.asia/mmorpg/service-common v0.0.0-20260116155014-3de703eb83c5 h1:b7pTgEyYUKpHtAAt4ea/3EYfX0Y0lYwhjrgf3kTyn0w=
+git.hlsq.asia/mmorpg/service-common v0.0.0-20260116155014-3de703eb83c5/go.mod h1:Dazg+4woCv9Jk7jgT2qUSGWhZOXx/0WYfJO+FCUDyhw=
 github.com/BurntSushi/toml v1.2.0 h1:Rt8g24XnyGTyglgET/PRUNlrUeu9F5L+7FilkXfZgs0=
 github.com/BurntSushi/toml v1.2.0/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/alicebob/miniredis/v2 v2.35.0 h1:QwLphYqCEAo1eu1TqPRN2jgVMPBweeQcR21jeqDCONI=
diff --git a/internal/global/metric.go b/internal/global/metric.go
index b2c16ec..6b4f36f 100644
--- a/internal/global/metric.go
+++ b/internal/global/metric.go
@@ -7,13 +7,20 @@ import (
 
 var (
 	OnlineUsersGauge prometheus.Gauge
+	FlowCounter      prometheus.Counter
 )
 
 func init() {
 	log.Infof("Init prometheus metric...")
 	OnlineUsersGauge = prometheus.NewGauge(prometheus.GaugeOpts{
-		Name: "online_users",
+		Name: "gateway_online_users",
 		Help: "Total number of online users",
 	})
 	prometheus.MustRegister(OnlineUsersGauge)
+
+	FlowCounter = prometheus.NewCounter(prometheus.CounterOpts{
+		Name: "gateway_flow_counter",
+		Help: "Total number of flow",
+	})
+	prometheus.MustRegister(FlowCounter)
 }
diff --git a/internal/grpc_server/server.go b/internal/grpc_server/server.go
index 0a114d9..1a44313 100644
--- a/internal/grpc_server/server.go
+++ b/internal/grpc_server/server.go
@@ -5,6 +5,7 @@ import (
 	"git.hlsq.asia/mmorpg/service-common/log"
 	"git.hlsq.asia/mmorpg/service-common/proto/rs/grpc_pb"
 	"git.hlsq.asia/mmorpg/service-common/proto/ss/ss_pb"
+	"git.hlsq.asia/mmorpg/service-gateway/internal/global"
 	"git.hlsq.asia/mmorpg/service-gateway/internal/handler/ws_handler/client"
 	"google.golang.org/protobuf/proto"
 	"sync"
@@ -39,8 +40,10 @@ func (s *Server) ToClient(server grpc_pb.Gateway_ToClientServer) error {
 						log.Errorf("ToClient proto.Marshal error: %v", err)
 						continue
 					}
+					dataLen := float64(len(data))
 					for _, cli := range client.UserMgr.GetAll() {
 						cli.WriteBytesPreMarshal(data)
+						global.FlowCounter.Add(dataLen)
 					}
 
 					//for _, client := range ws_handler.UserMgr.GetAll() {
@@ -49,6 +52,7 @@ func (s *Server) ToClient(server grpc_pb.Gateway_ToClientServer) error {
 				} else {
 					if cli := client.UserMgr.GetByUSN(args.USN); cli != nil {
 						cli.WriteBytes(ss_pb.MessageID(args.MessageID), args.Payload)
+						global.FlowCounter.Add(float64(len(args.Payload)))
 					}
 				}
 			}
diff --git a/internal/grpc_server/server_init.go b/internal/grpc_server/server_init.go
index 1dfcb6c..eaac01b 100644
--- a/internal/grpc_server/server_init.go
+++ b/internal/grpc_server/server_init.go
@@ -21,11 +21,16 @@ func NewServer(ttl int64) *Server {
 			EtcdTTL:     ttl,
 		},
 	}
+	s.Base.OnCustomGrpcServerOption = s.OnCustomGrpcServerOption
 	s.Base.OnInit = s.OnInit
 	s.Base.OnClose = s.OnClose
 	return s
 }
 
+func (s *Server) OnCustomGrpcServerOption() []grpc.ServerOption {
+	return nil
+}
+
 func (s *Server) OnInit(serve *grpc.Server) {
 	client.GatewaySID = s.SID
 	grpc_pb.RegisterGatewayServer(serve, s)