diff --git a/examples/client/main.cpp b/examples/client/main.cpp
index 6e5abaa..f3f0491 100644
--- a/examples/client/main.cpp
+++ b/examples/client/main.cpp
@@ -354,12 +354,35 @@ void test_callback() {
 	std::cin >> str;
 }
 
+void wait_for_notification(rpc_client& client) {
+	client.async_call<0>("sub", [&client](const boost::system::error_code & ec, string_view data) {
+		auto str = as<std::string>(data);
+		std::cout << str << '\n';
+
+		wait_for_notification(client);
+	});
+}
+
+void test_sub() {
+	rpc_client client;
+	bool r = client.connect("127.0.0.1", 9000);
+	if (!r) {
+		return;
+	}
+
+	wait_for_notification(client);
+
+	std::string str;
+	std::cin >> str;
+}
+
 int main() {
 	test_callback();
 	test_echo();
 	test_sync_client();
 	test_async_client();
 	
+	//test_sub();
 	//test_call_with_timeout();
 	//test_connect();
 	//test_upload();
diff --git a/examples/server/main.cpp b/examples/server/main.cpp
index 4394a9b..8a45ab6 100644
--- a/examples/server/main.cpp
+++ b/examples/server/main.cpp
@@ -85,6 +85,57 @@ std::string echo(rpc_conn conn, const std::string& src) {
 	return src;
 }
 
+struct notifier {
+public:
+	notifier() {
+		std::thread thd([this] {
+			while (!stop_) {
+				if (has_subs_) {
+					notify("this a notification from the server");
+				}
+
+				std::this_thread::sleep_for(std::chrono::seconds(1));
+			}
+		});
+		thd.detach();
+	}
+
+	~notifier() {
+		stop_ = true;
+	}
+
+	void sub(rpc_conn conn) {
+		if (!has_subs_) {
+			has_subs_ = true;
+		}
+		auto req_id = conn.lock()->request_id();
+		std::unique_lock<std::mutex> lock(mtx_);
+		subs_.emplace_back(conn, req_id);
+	}
+
+private:
+	void notify(const std::string& result) {
+		{
+			std::unique_lock<std::mutex> lock(mtx_);
+			for (auto& pair : subs_) {
+				auto sp_conn = pair.first.lock();
+				if (sp_conn) {
+					sp_conn->pack_and_response(pair.second, result);
+				}
+			}
+
+			subs_.clear();
+		}
+
+		has_subs_ = false;
+	}
+
+	std::vector<std::pair<rpc_conn, uint64_t>> subs_;
+	std::mutex mtx_;
+	std::atomic_bool has_subs_ = { false };
+	bool stop_ = false;
+};
+
 int main() {
 	rpc_server server(9000, std::thread::hardware_concurrency());
 
@@ -100,6 +151,9 @@ int main() {
 	server.register_handler<ExecMode::async>("async_echo", async_echo);
 	server.register_handler("echo", echo);
 
+	notifier n;
+	server.register_handler<ExecMode::async>("sub", &notifier::sub, &n);
+
 	server.run();
 
 	std::string str;