diff --git a/_example/app.psgi b/_example/app.psgi
index 13de0e3..a9fa635 100644
--- a/_example/app.psgi
+++ b/_example/app.psgi
@@ -33,6 +33,17 @@ $router->add("/connect", sub {
     return ["200", ["X-Kuiperbelt-Session" => $session], ["joined success"]];
 });
 
+$router->add("/close", sub {
+    my $env = shift;
+    my $req = Plack::Request->new($env);
+
+    my @session = $req->header("X-Kuiperbelt-Session");
+
+    $redis->srem("sessions", @session);
+
+    return ["200", [], ["success closed"]];
+});
+
 $router->add("/recent", sub {
     my $env = shift;
     my $req = Plack::Request->new($env);
diff --git a/_example/config.yml b/_example/config.yml
index 8943170..8347f0b 100644
--- a/_example/config.yml
+++ b/_example/config.yml
@@ -1,4 +1,4 @@
 port: 12345
 callback:
   connect: "http://localhost:12346/connect"
-  receive: "http://localhost:12346/receive"
+  close: "http://localhost:12346/close"
diff --git a/cmd/ekbo/config.yml b/cmd/ekbo/config.yml
index 8943170..bb962b8 100644
--- a/cmd/ekbo/config.yml
+++ b/cmd/ekbo/config.yml
@@ -1,4 +1,3 @@
 port: 12345
 callback:
   connect: "http://localhost:12346/connect"
-  receive: "http://localhost:12346/receive"
diff --git a/config.go b/config.go
index 216a631..f700a0e 100644
--- a/config.go
+++ b/config.go
@@ -19,7 +19,7 @@ type Config struct {
 
 type Callback struct {
 	Connect string `yaml:"connect"`
-	Receive string `yaml:"receive"`
+	Close   string `yaml:"close"`
 }
 
 func NewConfig(filename string) (*Config, error) {
diff --git a/config_test.go b/config_test.go
index 16cb72a..e63c0f3 100644
--- a/config_test.go
+++ b/config_test.go
@@ -10,14 +10,13 @@ session_header: "X-Kuiperbelt-Session-Key"
 port: 12345
 callback:
   connect: "http://localhost:12346/connect"
-  receive: "http://localhost:12346/receive"
 `)
 var TestConfig = Config{
 	Port:          ":12345",
 	SessionHeader: "X-Kuiperbelt-Session-Key",
 	Callback: Callback{
 		Connect: "http://localhost:12346/connect",
-		Receive: "http://localhost:12346/receive",
+		Close:   "",
 	},
 }
 
diff --git a/server.go b/server.go
index 7efd713..b8e87db 100644
--- a/server.go
+++ b/server.go
@@ -15,7 +15,8 @@ import (
 )
 
 const (
-	ENDPOINT_HEADER_NAME = "X-Kuiperbelt-Endpoint"
+	ENDPOINT_HEADER_NAME               = "X-Kuiperbelt-Endpoint"
+	CALLBACK_CLIENT_MAX_CONNS_PER_HOST = 32
 )
 
 var (
@@ -60,6 +61,10 @@ func (s *WebSocketServer) Handler(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *WebSocketServer) Register() {
+	callbackClient.Transport = &http.Transport{
+		MaxIdleConnsPerHost: CALLBACK_CLIENT_MAX_CONNS_PER_HOST,
+	}
+
 	http.HandleFunc("/connect", s.Handler)
 }
 
@@ -121,7 +126,7 @@ func (s *WebSocketServer) NewWebSocketHandler(resp *http.Response) func(ws *webs
 
 		defer DelSession(session.Key())
 		log.WithFields(log.Fields{
-			"session_key": session.Key(),
+			"session": session.Key(),
 		}).Info("connected session")
 		go session.WatchClose()
 		session.WaitClose()
@@ -163,19 +168,59 @@ func (s *WebSocketSession) WaitClose() {
 func (s *WebSocketSession) WatchClose() {
 	defer s.Close()
 	_, err := io.Copy(new(blackholeWriter), s)
-	if err == io.EOF {
+	if err == nil {
+		go s.SendCloseCallback()
 		return
 	}
 	// ignore closed session error
+	if strings.HasSuffix(err.Error(), "use of closed network connection") {
+		return
+	}
+
+	log.WithFields(log.Fields{
+		"error": err.Error(),
+	}).Error("watch close frame error")
+}
+
+func (s *WebSocketSession) SendCloseCallback() {
+	// cancel sending when not set callback url
+	if s.Config.Callback.Close == "" {
+		return
+	}
+
+	callbackRequest, err := http.NewRequest("POST", s.Config.Callback.Close, nil)
 	if err != nil {
-		if strings.HasSuffix(err.Error(), "use of closed network connection") {
-			return
-		}
+		log.WithFields(log.Fields{
+			"session": s.Key(),
+			"error":   err.Error(),
+		}).Error("cannot create close callback request.")
+		return
+	}
 
+	callbackRequest.Header.Add(s.Config.SessionHeader, s.Key())
+	resp, err := callbackClient.Do(callbackRequest)
+	if err != nil {
 		log.WithFields(log.Fields{
-			"error": err.Error(),
-		}).Error("watch close frame error")
+			"session": s.Key(),
+			"error":   err.Error(),
+		}).Error("failed send close callback request.")
+		return
 	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		b := new(bytes.Buffer)
+		b.ReadFrom(resp.Body)
+		log.WithFields(log.Fields{
+			"session": s.Key(),
+			"status":  resp.Status,
+			"error":   b.String(),
+		}).Error("invalid close callback status.")
+		return
+	}
+
+	log.WithFields(log.Fields{
+		"session": s.Key(),
+	}).Info("success close callback.")
 }
 
 type blackholeWriter struct {
diff --git a/server_test.go b/server_test.go
index 273115d..7a9e6ea 100644
--- a/server_test.go
+++ b/server_test.go
@@ -20,6 +20,7 @@ const (
 
 type testSuccessConnectCallbackServer struct {
 	IsCallbacked bool
+	IsClosed     bool
 	Header       http.Header
 }
 
@@ -38,6 +39,13 @@ func (s *testSuccessConnectCallbackServer) FailHandler(w http.ResponseWriter, r
 	io.WriteString(w, "fail authorization!")
 }
 
+func (s *testSuccessConnectCallbackServer) CloseHandler(w http.ResponseWriter, r *http.Request) {
+	s.IsClosed = true
+	s.Header = r.Header
+	w.WriteHeader(http.StatusOK)
+	io.WriteString(w, "")
+}
+
 func newTestWebSocketRequest(url string) (*http.Request, error) {
 	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {
@@ -133,10 +141,12 @@ func TestWebSocketServer__Handler__FailAuthorized(t *testing.T) {
 
 func TestWebSocketServer__Handler__CloseByClient(t *testing.T) {
 	callbackServer := new(testSuccessConnectCallbackServer)
-	tcc := httptest.NewServer(http.HandlerFunc(callbackServer.SuccessHandler))
+	tcc1 := httptest.NewServer(http.HandlerFunc(callbackServer.SuccessHandler))
+	tcc2 := httptest.NewServer(http.HandlerFunc(callbackServer.CloseHandler))
 
 	c := TestConfig
-	c.Callback.Connect = tcc.URL
+	c.Callback.Connect = tcc1.URL
+	c.Callback.Close = tcc2.URL
 
 	server := WebSocketServer{c}
 
@@ -183,4 +193,8 @@ func TestWebSocketServer__Handler__CloseByClient(t *testing.T) {
 		t.Error("not removed session:", err)
 	}
 
+	if !callbackServer.IsClosed {
+		t.Error("not receive close callback")
+	}
+
 }