diff --git a/components/app.js b/components/app.js
index 4788788..ec5d74a 100644
--- a/components/app.js
+++ b/components/app.js
@@ -28,6 +28,21 @@ const baseConfig = {
 	server: {},
 };
 
+function urlBase64ToUint8Array(base64String) {
+	var padding = '='.repeat((4 - base64String.length % 4) % 4);
+	var base64 = (base64String + padding)
+		.replace(/\-/g, '+')
+		.replace(/_/g, '/');
+
+	var rawData = window.atob(base64);
+	var outputArray = new Uint8Array(rawData.length);
+
+	for (var i = 0; i < rawData.length; ++i) {
+		outputArray[i] = rawData.charCodeAt(i);
+	}
+	return outputArray;
+}
+
 const configPromise = fetch("./config.json")
 	.then((resp) => {
 		if (resp.ok) {
@@ -981,9 +996,37 @@ export default class App extends Component {
 				affectedBuffers.push(prefix.name);
 			}
 			return affectedBuffers;
+		case irc.RPL_ISUPPORT: {
+			const params = msg.params;
+			for (const p of params) {
+				if (p.indexOf("VAPID") === 0) {
+					const value = p.replace("VAPID=", "");
+					const vapidPubKey = urlBase64ToUint8Array(value);
+					navigator.serviceWorker.ready.then((registration) => {
+					return registration.pushManager.getSubscription()
+					.then((subscription) => {
+						if (subscription) {
+							return subscription;
+						}
+						return registration.pushManager.subscribe({
+							userVisibleOnly: true,
+							applicationServerKey: vapidPubKey,
+						});
+					}).then((subscription) => {
+						var data = subscription.toJSON();
+						var keysStr = irc.formatTags(data.keys);
+						client.send({
+							command: "WEBPUSH",
+							params: ["REGISTER", data.endpoint, keysStr],
+						});
+					});
+				});
+				}
+			}
+			return [];
+		}
 		case irc.RPL_YOURHOST:
 		case irc.RPL_MYINFO:
-		case irc.RPL_ISUPPORT:
 		case irc.RPL_ENDOFMOTD:
 		case irc.ERR_NOMOTD:
 		case irc.RPL_AWAY:
diff --git a/lib/client.js b/lib/client.js
index a1a969a..90e736e 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -25,6 +25,7 @@ const permanentCaps = [
 	"draft/read-marker",
 
 	"soju.im/bouncer-networks",
+	"soju.im/webpush",
 ];
 
 const RECONNECT_MIN_DELAY_MSEC = 10 * 1000; // 10s
diff --git a/main.js b/main.js
index 2b73e7d..93a7737 100644
--- a/main.js
+++ b/main.js
@@ -1,4 +1,6 @@
 import { html, render } from "./lib/index.js";
 import App from "./components/app.js";
 
+navigator.serviceWorker.register("./service-worker.js").catch(console.error);
+
 render(html`<${App}/>`, document.body);
diff --git a/service-worker.js b/service-worker.js
new file mode 100644
index 0000000..6398c4e
--- /dev/null
+++ b/service-worker.js
@@ -0,0 +1,6 @@
+self.addEventListener("push", (event) => {
+	var payload = event.data ? event.data.text() : "no payload";
+	event.waitUntil(self.registration.showNotification("gamja service worker", {
+		body: payload,
+	}));
+});