diff --git a/example/websocket/websocket.el b/example/websocket/websocket.el
new file mode 100644
index 0000000..04fc36a
--- /dev/null
+++ b/example/websocket/websocket.el
@@ -0,0 +1,35 @@
+;; -*- coding: utf-8; lexical-binding: t; -*-
+
+(require 'websocket)
+
+(setq-local websocket-eldoc-callback nil)
+(defun test-websocket-eldoc (callback)
+  (setq websocket-eldoc-callback
+        (if (compiled-function-p callback) callback nil)))
+(set (make-local-variable 'eldoc-documentation-strategy)
+     'eldoc-documentation-compose-eagerly)
+
+(run-with-timer 1 nil
+                (lambda ()
+                  (funcall websocket-eldoc-callback "hel")))
+
+(test-websocket-eldoc "hel")
+
+(make-local-variable 'eldoc-documentation-functions)
+(add-to-list 'eldoc-documentation-functions #'test-websocket-eldoc)
+
+(setq ws-server (websocket-server
+                 4000
+                 :host 'local
+                 :on-message (lambda (ws frame)
+                               (when (and (boundp 'websocket-eldoc-callback) (compiled-function-p websocket-eldoc-callback))
+                                 (websocket-send-text ws (format "eldoc showed: %s" (websocket-frame-text frame)))
+                                 (funcall websocket-eldoc-callback (websocket-frame-text frame))))))
+
+(funcall (symbol-value (obarray-get obarray "websocket-eldoc-callback")) "hello")
+
+(symbol-value 'websocket-eldoc-callback)
+
+(websocket-server-close ws-server)
+
+(funcall websocket-eldoc-callback "hello")
diff --git a/example/websocket/websocket.html b/example/websocket/websocket.html
new file mode 100644
index 0000000..0604799
--- /dev/null
+++ b/example/websocket/websocket.html
@@ -0,0 +1,9 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <title>emacs websocket test</title>
+    <script type="text/javascript" src="./websocket.js"></script>
+  </head>
+  <body></body>
+</html>
diff --git a/example/websocket/websocket.js b/example/websocket/websocket.js
new file mode 100644
index 0000000..85653f1
--- /dev/null
+++ b/example/websocket/websocket.js
@@ -0,0 +1,41 @@
+let ws = new WebSocket("ws://127.0.0.1:4000");
+ws.onopen = () => {
+    console.log('websocket opened');
+}
+
+ws.onclose = () => {
+    console.log('websocket closed');
+}
+
+ws.onmessage = (e) => {
+    console.log('recv:', e.data)
+}
+
+let timeout = 0;
+let timer = null;
+
+/**
+ * 发送消息到 Emacs
+ * @param {string} msg 消息内容
+ */
+function sendMsgToEmacs(msg) {
+    if (!(ws instanceof WebSocket) || ws.readyState !== WebSocket.OPEN) return;
+
+    ws.send(msg);
+}
+
+const range = 10;
+
+function calcNextTimeout() {
+    return (Math.round(Math.random() * range) + 2) * 1000;
+}
+
+function schedule() {
+    sendMsgToEmacs(window.crypto.randomUUID());
+    window.clearTimeout(timer);
+    timeout = calcNextTimeout();
+
+    timer = window.setTimeout(schedule, timeout);
+}
+
+schedule();