diff --git a/Makefile b/Makefile
index d2aa65d988..f5c878191d 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ NAME = sing-box
 COMMIT = $(shell git rev-parse --short HEAD)
 TAGS_GO118 = with_gvisor,with_dhcp,with_wireguard,with_reality_server,with_clash_api
 TAGS_GO120 = with_quic,with_ech,with_utls
-TAGS ?= $(TAGS_GO118),$(TAGS_GO120)
+TAGS ?= $(TAGS_GO118),$(TAGS_GO120),with_gvisor,with_quic,with_wireguard,with_ech,with_utls,with_clash_api,with_grpc
 TAGS_TEST ?= with_gvisor,with_quic,with_wireguard,with_grpc,with_ech,with_utls,with_reality_server
 
 GOHOSTOS = $(shell go env GOHOSTOS)
@@ -196,4 +196,4 @@ clean:
 update:
 	git fetch
 	git reset FETCH_HEAD --hard
-	git clean -fdx
\ No newline at end of file
+	git clean -fdx
diff --git a/common/urltest/urltest.go b/common/urltest/urltest.go
index 001f2e15a6..bfeb13ba3d 100644
--- a/common/urltest/urltest.go
+++ b/common/urltest/urltest.go
@@ -8,6 +8,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/imkira/go-observer"
 	"github.com/sagernet/sing/common"
 	M "github.com/sagernet/sing/common/metadata"
 	N "github.com/sagernet/sing/common/network"
@@ -21,7 +22,7 @@ type History struct {
 type HistoryStorage struct {
 	access       sync.RWMutex
 	delayHistory map[string]*History
-	updateHook   chan<- struct{}
+	updateHook   observer.Property
 }
 
 func NewHistoryStorage() *HistoryStorage {
@@ -30,7 +31,7 @@ func NewHistoryStorage() *HistoryStorage {
 	}
 }
 
-func (s *HistoryStorage) SetHook(hook chan<- struct{}) {
+func (s *HistoryStorage) SetHook(hook observer.Property) {
 	s.updateHook = hook
 }
 
@@ -60,10 +61,11 @@ func (s *HistoryStorage) StoreURLTestHistory(tag string, history *History) {
 func (s *HistoryStorage) notifyUpdated() {
 	updateHook := s.updateHook
 	if updateHook != nil {
-		select {
-		case updateHook <- struct{}{}:
-		default:
-		}
+		updateHook.Update(1)
+		// select {
+		// case updateHook <- struct{}{}:
+		// default:
+		// }
 	}
 }
 
diff --git a/experimental/libbox/command_group.go b/experimental/libbox/command_group.go
index 8cb86c937c..191fb8dc99 100644
--- a/experimental/libbox/command_group.go
+++ b/experimental/libbox/command_group.go
@@ -68,6 +68,7 @@ func (s *CommandServer) handleGroupConn(conn net.Conn, onlyGroupItems bool) erro
 	ticker := time.NewTicker(time.Duration(interval))
 	defer ticker.Stop()
 	ctx := connKeepAlive(conn)
+	urlTestUpdateStream := s.urlTestUpdate.Observe()
 	for {
 		service := s.service
 		if service != nil {
@@ -89,7 +90,7 @@ func (s *CommandServer) handleGroupConn(conn net.Conn, onlyGroupItems bool) erro
 		select {
 		case <-ctx.Done():
 			return ctx.Err()
-		case <-s.urlTestUpdate:
+		case <-urlTestUpdateStream.Changes():
 		}
 	}
 }
diff --git a/experimental/libbox/command_server.go b/experimental/libbox/command_server.go
index df25fa72aa..430613ddb3 100644
--- a/experimental/libbox/command_server.go
+++ b/experimental/libbox/command_server.go
@@ -7,6 +7,7 @@ import (
 	"path/filepath"
 	"sync"
 
+	"github.com/imkira/go-observer"
 	"github.com/sagernet/sing-box/common/urltest"
 	"github.com/sagernet/sing-box/experimental/clashapi"
 	"github.com/sagernet/sing-box/log"
@@ -30,7 +31,7 @@ type CommandServer struct {
 	service    *BoxService
 
 	// These channels only work with a single client. if multi-client support is needed, replace with Subscriber/Observer
-	urlTestUpdate chan struct{}
+	urlTestUpdate observer.Property
 	modeUpdate    chan struct{}
 	logReset      chan struct{}
 }
@@ -46,7 +47,7 @@ func NewCommandServer(handler CommandServerHandler, maxLines int32) *CommandServ
 		handler:       handler,
 		maxLines:      int(maxLines),
 		subscriber:    observable.NewSubscriber[string](128),
-		urlTestUpdate: make(chan struct{}, 1),
+		urlTestUpdate: observer.NewProperty(0),
 		modeUpdate:    make(chan struct{}, 1),
 		logReset:      make(chan struct{}, 1),
 	}
@@ -69,10 +70,11 @@ func (s *CommandServer) SetService(newService *BoxService) {
 }
 
 func (s *CommandServer) notifyURLTestUpdate() {
-	select {
-	case s.urlTestUpdate <- struct{}{}:
-	default:
-	}
+	// select {
+	// case s.urlTestUpdate <- struct{}{}:
+	// default:
+	// }
+	s.urlTestUpdate.Update(1)
 }
 
 func (s *CommandServer) Start() error {
diff --git a/go.mod b/go.mod
index 3ace9c2e8a..174451cf41 100644
--- a/go.mod
+++ b/go.mod
@@ -71,6 +71,7 @@ require (
 	github.com/google/btree v1.1.2 // indirect
 	github.com/google/pprof v0.0.0-20231101202521-4ca4178f5c7a // indirect
 	github.com/hashicorp/yamux v0.1.1 // indirect
+	github.com/imkira/go-observer v1.0.3 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/josharian/native v1.1.0 // indirect
 	github.com/klauspost/compress v1.17.4 // indirect
diff --git a/go.sum b/go.sum
index f4cbee8b4f..be4a69e7af 100644
--- a/go.sum
+++ b/go.sum
@@ -49,6 +49,8 @@ github.com/hashicorp/yamux v0.1.1 h1:yrQxtgseBDrq9Y652vSRDvsKCJKOUD+GzTS4Y0Y8pvE
 github.com/hashicorp/yamux v0.1.1/go.mod h1:CtWFDAQgb7dxtzFs4tWbplKIe2jSi3+5vKbgIO0SLnQ=
 github.com/hiddify/wireguard-go v0.0.0-20240125143346-481d18d77fe1 h1:neOb+wzHbWLNZ2sHFEV4+GTuqORO7/MndQLFW8FjUY8=
 github.com/hiddify/wireguard-go v0.0.0-20240125143346-481d18d77fe1/go.mod h1:K4J7/npM+VAMUeUmTa2JaA02JmyheP0GpRBOUvn3ecc=
+github.com/imkira/go-observer v1.0.3 h1:l45TYAEeAB4L2xF6PR2gRLn2NE5tYhudh33MLmC7B80=
+github.com/imkira/go-observer v1.0.3/go.mod h1:zLzElv2cGTHufQG17IEILJMPDg32TD85fFgKyFv00wU=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/insomniacslk/dhcp v0.0.0-20231206064809-8c70d406f6d2 h1:9K06NfxkBh25x56yVhWWlKFE8YpicaSfHwoV8SFbueA=