diff --git a/package.json b/package.json
index 9d14e8b41519565b77d25994562b97392adce589..c41c561ef1b2228e47cecf0fb1230366bdca218b 100644
--- a/package.json
+++ b/package.json
@@ -159,6 +159,7 @@
 		"typescript": "2.6.1",
 		"uuid": "3.1.0",
 		"vhost": "3.0.2",
+		"web-push": "^3.2.4",
 		"websocket": "1.0.25",
 		"xev": "2.0.0"
 	}
diff --git a/src/api/common/push-sw.ts b/src/api/common/push-sw.ts
new file mode 100644
index 0000000000000000000000000000000000000000..927dc506350a04871f681e2c9bc0f2cc1787b83c
--- /dev/null
+++ b/src/api/common/push-sw.ts
@@ -0,0 +1,44 @@
+const push = require('web-push');
+import * as mongo from 'mongodb';
+import Subscription from '../models/sw-subscription';
+import config from '../../conf';
+
+push.setGCMAPIKey(config.sw.gcm_api_key);
+
+export default async function(userId: mongo.ObjectID | string, type, body?) {
+	if (typeof userId === 'string') {
+		userId = new mongo.ObjectID(userId);
+	}
+
+	// Fetch
+	const subscriptions = await Subscription.find({
+		user_id: userId
+	});
+
+	subscriptions.forEach(subscription => {
+		const pushSubscription = {
+			endpoint: subscription.endpoint,
+			keys: {
+				auth: subscription.auth,
+				p256dh: subscription.publickey
+			}
+		};
+
+		push.sendNotification(pushSubscription, JSON.stringify({
+			type, body
+		})).catch(err => {
+			//console.log(err.statusCode);
+			//console.log(err.headers);
+			//console.log(err.body);
+
+			if (err.statusCode == 410) {
+				Subscription.remove({
+					user_id: userId,
+					endpoint: subscription.endpoint,
+					auth: subscription.auth,
+					publickey: subscription.publickey
+				});
+			}
+		});
+	});
+}
diff --git a/src/api/endpoints.ts b/src/api/endpoints.ts
index 2783c920277ec79ef1a0e2f7851cde4236323c3c..06fb9a64ae2fb4e068f9de943e637e2626dd944e 100644
--- a/src/api/endpoints.ts
+++ b/src/api/endpoints.ts
@@ -146,6 +146,11 @@ const endpoints: Endpoint[] = [
 		name: 'aggregation/posts/reactions'
 	},
 
+	{
+		name: 'sw/register',
+		withCredential: true
+	},
+
 	{
 		name: 'i',
 		withCredential: true
diff --git a/src/api/endpoints/posts/create.ts b/src/api/endpoints/posts/create.ts
index 4f4b7e2e832775626a69527fc838474de65f206e..ae4959dae4be93ca9812180781a6784314e42196 100644
--- a/src/api/endpoints/posts/create.ts
+++ b/src/api/endpoints/posts/create.ts
@@ -14,7 +14,7 @@ import ChannelWatching from '../../models/channel-watching';
 import serialize from '../../serializers/post';
 import notify from '../../common/notify';
 import watch from '../../common/watch-post';
-import { default as event, publishChannelStream } from '../../event';
+import event, { pushSw, publishChannelStream } from '../../event';
 import config from '../../../conf';
 
 /**
@@ -234,7 +234,7 @@ module.exports = (params, user: IUser, app) => new Promise(async (res, rej) => {
 
 	const mentions = [];
 
-	function addMention(mentionee, type) {
+	function addMention(mentionee, reason) {
 		// Reject if already added
 		if (mentions.some(x => x.equals(mentionee))) return;
 
@@ -243,7 +243,8 @@ module.exports = (params, user: IUser, app) => new Promise(async (res, rej) => {
 
 		// Publish event
 		if (!user._id.equals(mentionee)) {
-			event(mentionee, type, postObj);
+			event(mentionee, reason, postObj);
+			pushSw(mentionee, reason, postObj);
 		}
 	}
 
diff --git a/src/api/endpoints/sw/register.ts b/src/api/endpoints/sw/register.ts
new file mode 100644
index 0000000000000000000000000000000000000000..99406138dba57801e85118a10c7201ebca308c49
--- /dev/null
+++ b/src/api/endpoints/sw/register.ts
@@ -0,0 +1,50 @@
+/**
+ * Module dependencies
+ */
+import $ from 'cafy';
+import Subscription from '../../models/sw-subscription';
+
+/**
+ * subscribe service worker
+ *
+ * @param {any} params
+ * @param {any} user
+ * @param {any} _
+ * @param {boolean} isSecure
+ * @return {Promise<any>}
+ */
+module.exports = async (params, user, _, isSecure) => new Promise(async (res, rej) => {
+	// Get 'endpoint' parameter
+	const [endpoint, endpointErr] = $(params.endpoint).string().$;
+	if (endpointErr) return rej('invalid endpoint param');
+
+	// Get 'auth' parameter
+	const [auth, authErr] = $(params.auth).string().$;
+	if (authErr) return rej('invalid auth param');
+
+	// Get 'publickey' parameter
+	const [publickey, publickeyErr] = $(params.publickey).string().$;
+	if (publickeyErr) return rej('invalid publickey param');
+
+	// if already subscribed
+	const exist = await Subscription.findOne({
+		user_id: user._id,
+		endpoint: endpoint,
+		auth: auth,
+		publickey: publickey,
+		deleted_at: { $exists: false }
+	});
+
+	if (exist !== null) {
+		return res();
+	}
+
+	await Subscription.insert({
+		user_id: user._id,
+		endpoint: endpoint,
+		auth: auth,
+		publickey: publickey
+	});
+
+	res();
+});
diff --git a/src/api/event.ts b/src/api/event.ts
index 8605a0f1e45b641f1e255ca49597ae973799968b..4a2e4e453dd02aaf814ea5c454b0bb88ddba546e 100644
--- a/src/api/event.ts
+++ b/src/api/event.ts
@@ -1,5 +1,6 @@
 import * as mongo from 'mongodb';
 import * as redis from 'redis';
+import swPush from './common/push-sw';
 import config from '../conf';
 
 type ID = string | mongo.ObjectID;
@@ -17,6 +18,10 @@ class MisskeyEvent {
 		this.publish(`user-stream:${userId}`, type, typeof value === 'undefined' ? null : value);
 	}
 
+	public publishSw(userId: ID, type: string, value?: any): void {
+		swPush(userId, type, value);
+	}
+
 	public publishDriveStream(userId: ID, type: string, value?: any): void {
 		this.publish(`drive-stream:${userId}`, type, typeof value === 'undefined' ? null : value);
 	}
@@ -50,6 +55,8 @@ const ev = new MisskeyEvent();
 
 export default ev.publishUserStream.bind(ev);
 
+export const pushSw = ev.publishSw.bind(ev);
+
 export const publishDriveStream = ev.publishDriveStream.bind(ev);
 
 export const publishPostStream = ev.publishPostStream.bind(ev);
diff --git a/src/api/models/sw-subscription.ts b/src/api/models/sw-subscription.ts
new file mode 100644
index 0000000000000000000000000000000000000000..ecca04cb91f244f64471e020c68aa63e292d2f7a
--- /dev/null
+++ b/src/api/models/sw-subscription.ts
@@ -0,0 +1,3 @@
+import db from '../../db/mongodb';
+
+export default db.get('sw_subscriptions') as any; // fuck type definition
diff --git a/src/config.ts b/src/config.ts
index d37d227a412e0732c44cc54d44c8a6da22121386..e8322d8333af718eaa9facc4b6bc3fe3b5b9f0aa 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -75,6 +75,14 @@ type Source = {
 	analysis?: {
 		mecab_command?: string;
 	};
+
+	/**
+	 * Service Worker
+	 */
+	sw?: {
+		gcm_sender_id: string;
+		gcm_api_key: string;
+	};
 };
 
 /**
@@ -109,7 +117,7 @@ export default function load() {
 	const url = URL.parse(config.url);
 	const head = url.host.split('.')[0];
 
-	if (head != 'misskey') {
+	if (head != 'misskey' && head != 'localhost') {
 		console.error(`プライマリドメインは、必ず「misskey」ドメインで始まっていなければなりません(現在の設定では「${head}」で始まっています)。例えば「https://misskey.xyz」「http://misskey.my.app.example.com」などが正しいプライマリURLです。`);
 		process.exit();
 	}
diff --git a/src/web/app/boot.js b/src/web/app/boot.js
index ac6c18d64957b03dc2ebddbc0dc78dbe03c026e9..4a8ea030a1c3d8a73d36bf7a2482bd908a1de353 100644
--- a/src/web/app/boot.js
+++ b/src/web/app/boot.js
@@ -27,7 +27,9 @@
 	//   misskey.alice               => misskey
 	//   misskey.strawberry.pasta    => misskey
 	//   dev.misskey.arisu.tachibana => dev
-	let app = url.host.split('.')[0];
+	let app = url.host == 'localhost'
+		? 'misskey'
+		: url.host.split('.')[0];
 
 	// Detect the user language
 	// Note: The default language is English
diff --git a/src/web/app/common/mios.ts b/src/web/app/common/mios.ts
index 9704e92af8e5585d8245011aed8239aeecaff71e..4a36d6375f412d053fc8f6c613c22b3371c049f8 100644
--- a/src/web/app/common/mios.ts
+++ b/src/web/app/common/mios.ts
@@ -37,6 +37,11 @@ export default class MiOS extends EventEmitter {
 	 */
 	public stream: HomeStreamManager;
 
+	/**
+	 * A registration of service worker
+	 */
+	private swRegistration: ServiceWorkerRegistration = null;
+
 	constructor() {
 		super();
 
@@ -44,6 +49,7 @@ export default class MiOS extends EventEmitter {
 		this.init = this.init.bind(this);
 		this.api = this.api.bind(this);
 		this.getMeta = this.getMeta.bind(this);
+		this.swSubscribe = this.swSubscribe.bind(this);
 		//#endregion
 	}
 
@@ -126,6 +132,25 @@ export default class MiOS extends EventEmitter {
 
 			// Finish init
 			callback();
+
+			//#region Service worker
+			const isSwSupported =
+				('serviceWorker' in navigator) && ('PushManager' in window);
+
+			if (isSwSupported && this.isSignedin) {
+				// When service worker activated
+				navigator.serviceWorker.ready.then(this.swSubscribe);
+
+				// Register service worker
+				navigator.serviceWorker.register('/sw.js').then(registration => {
+					// 登録成功
+					console.info('ServiceWorker registration successful with scope: ', registration.scope);
+				}).catch(err => {
+					// 登録失敗 :(
+					console.error('ServiceWorker registration failed: ', err);
+				});
+			}
+			//#endregion
 		};
 
 		// Get cached account data
@@ -147,6 +172,30 @@ export default class MiOS extends EventEmitter {
 		}
 	}
 
+	private async swSubscribe(swRegistration: ServiceWorkerRegistration) {
+		this.swRegistration = swRegistration;
+
+		// Subscribe
+		this.swRegistration.pushManager.subscribe({
+			// A boolean indicating that the returned push subscription
+			// will only be used for messages whose effect is made visible to the user.
+			userVisibleOnly: true
+		}).then(subscription => {
+			console.log('Subscribe OK:', subscription);
+
+			// Register
+			this.api('sw/register', {
+				endpoint: subscription.endpoint,
+				auth: subscription.getKey('auth') ? btoa(String.fromCharCode.apply(null, new Uint8Array(subscription.getKey('auth')))) : '',
+				publickey: subscription.getKey('p256dh') ? btoa(String.fromCharCode.apply(null, new Uint8Array(subscription.getKey('p256dh')))) : ''
+			});
+		}).then(() => {
+			console.log('Server Stored Subscription.');
+		}).catch(err => {
+			console.error('Subscribe Error:', err);
+		});
+	}
+
 	/**
 	 * Misskey APIにリクエストします
 	 * @param endpoint エンドポイント名
diff --git a/src/web/app/common/scripts/config.ts b/src/web/app/common/scripts/config.ts
index c5015622f0de29d6794c2a95adbb28eaab9b5568..b4801a44de22c56a080a1cbeeaa9bbd705dd5556 100644
--- a/src/web/app/common/scripts/config.ts
+++ b/src/web/app/common/scripts/config.ts
@@ -1,9 +1,11 @@
-const Url = new URL(location.href);
+const _url = new URL(location.href);
 
-const isRoot = Url.host.split('.')[0] == 'misskey';
+const isRoot = _url.host == 'localhost'
+	? true
+	: _url.host.split('.')[0] == 'misskey';
 
-const host = isRoot ? Url.host : Url.host.substring(Url.host.indexOf('.') + 1, Url.host.length);
-const scheme = Url.protocol;
+const host = isRoot ? _url.host : _url.host.substring(_url.host.indexOf('.') + 1, _url.host.length);
+const scheme = _url.protocol;
 const url = `${scheme}//${host}`;
 const apiUrl = `${scheme}//api.${host}`;
 const chUrl = `${scheme}//ch.${host}`;
diff --git a/src/web/assets/sw.js b/src/web/assets/sw.js
new file mode 100644
index 0000000000000000000000000000000000000000..6a1251614acfacda2da0b0f3f472cfa6ca066722
--- /dev/null
+++ b/src/web/assets/sw.js
@@ -0,0 +1,31 @@
+/**
+ * Service Worker
+ */
+
+// インストールされたとき
+self.addEventListener('install', () => {
+	console.log('[sw]', 'Your ServiceWorker is installed');
+});
+
+// プッシュ通知を受け取ったとき
+self.addEventListener('push', ev => {
+	// クライアント取得
+	self.clients.matchAll({
+		includeUncontrolled: true
+	}).then(clients => {
+		// クライアントがあったらストリームに接続しているということなので通知しない
+		if (clients.length != 0) return;
+
+		const { type, body } = ev.data.json();
+		handlers[type](body);
+	});
+});
+
+const handlers = {
+	mention: body => {
+		self.registration.showNotification('mentioned', {
+			body: body.text,
+			icon: body.user.avatar_url + '?thumbnail&size=64',
+		});
+	}
+};
diff --git a/src/web/server.ts b/src/web/server.ts
index dde4eca5ec126862faa684131ecb2d80fd5e46aa..300f3ed477101a48860f711bf3b76e8613bf39c7 100644
--- a/src/web/server.ts
+++ b/src/web/server.ts
@@ -37,28 +37,45 @@ app.use((req, res, next) => {
  * Static assets
  */
 app.use(favicon(`${__dirname}/assets/favicon.ico`));
-app.get('/manifest.json', (req, res) => res.sendFile(`${__dirname}/assets/manifest.json`));
 app.get('/apple-touch-icon.png', (req, res) => res.sendFile(`${__dirname}/assets/apple-touch-icon.png`));
 app.use('/assets', express.static(`${__dirname}/assets`, {
 	maxAge: ms('7 days')
 }));
 
+app.get('/sw.js', (req, res) => res.sendFile(`${__dirname}/assets/sw.js`));
+
 /**
- * Common API
+ * Manifest
  */
-app.get(/\/api:url/, require('./service/url-preview'));
+app.get('/manifest.json', (req, res) => {
+	const manifest = require((`${__dirname}/assets/manifest.json`));
+
+	// Service Worker
+	if (config.sw) {
+		manifest['gcm_sender_id'] = config.sw.gcm_sender_id;
+	}
+
+	res.send(manifest);
+});
 
 /**
  * Serve config
  */
 app.get('/config.json', (req, res) => {
-	res.send({
+	const conf = {
 		recaptcha: {
 			siteKey: config.recaptcha.siteKey
 		}
-	});
+	};
+
+	res.send(conf);
 });
 
+/**
+ * Common API
+ */
+app.get(/\/api:url/, require('./service/url-preview'));
+
 /**
  * Routing
  */