diff --git a/package.json b/package.json
index 9d14e8b41..c41c561ef 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 000000000..782a4a6a6
--- /dev/null
+++ b/src/api/common/push-sw.ts
@@ -0,0 +1,48 @@
+const push = require('web-push');
+import * as mongo from 'mongodb';
+import Subscription from '../models/sw-subscription';
+import config from '../../conf';
+
+if (config.sw) {
+	push.setGCMAPIKey(config.sw.gcm_api_key);
+}
+
+export default async function(userId: mongo.ObjectID | string, type, body?) {
+	if (!config.sw) return;
+
+	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 2783c9202..06fb9a64a 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/messaging/messages/create.ts b/src/api/endpoints/messaging/messages/create.ts
index 29a4671f8..3c7689f96 100644
--- a/src/api/endpoints/messaging/messages/create.ts
+++ b/src/api/endpoints/messaging/messages/create.ts
@@ -9,8 +9,7 @@ import User from '../../../models/user';
 import DriveFile from '../../../models/drive-file';
 import serialize from '../../../serializers/messaging-message';
 import publishUserStream from '../../../event';
-import { publishMessagingStream } from '../../../event';
-import { publishMessagingIndexStream } from '../../../event';
+import { publishMessagingStream, publishMessagingIndexStream, pushSw } from '../../../event';
 import config from '../../../../conf';
 
 /**
@@ -99,6 +98,7 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 		const freshMessage = await Message.findOne({ _id: message._id }, { is_read: true });
 		if (!freshMessage.is_read) {
 			publishUserStream(message.recipient_id, 'unread_messaging_message', messageObj);
+			pushSw(message.recipient_id, 'unread_messaging_message', messageObj);
 		}
 	}, 3000);
 
diff --git a/src/api/endpoints/posts/create.ts b/src/api/endpoints/posts/create.ts
index 4f4b7e2e8..ae4959dae 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 000000000..99406138d
--- /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 8605a0f1e..4a2e4e453 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 000000000..ecca04cb9
--- /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 d37d227a4..e8322d833 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 ac6c18d64..4a8ea030a 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 9704e92af..cf7841d84 100644
--- a/src/web/app/common/mios.ts
+++ b/src/web/app/common/mios.ts
@@ -6,6 +6,9 @@ import HomeStreamManager from './scripts/streaming/home-stream-manager';
 import CONFIG from './scripts/config';
 import api from './scripts/api';
 
+declare var VERSION: string;
+declare var LANG: string;
+
 /**
  * Misskey Operating System
  */
@@ -32,21 +35,58 @@ export default class MiOS extends EventEmitter {
 		return this.i != null;
 	}
 
+	/**
+	 * Whether is debug mode
+	 */
+	public get debug() {
+		return localStorage.getItem('debug') == 'true';
+	}
+
 	/**
 	 * A connection manager of home stream
 	 */
 	public stream: HomeStreamManager;
 
+	/**
+	 * A registration of service worker
+	 */
+	private swRegistration: ServiceWorkerRegistration = null;
+
 	constructor() {
 		super();
 
 		//#region BIND
+		this.log = this.log.bind(this);
+		this.logInfo = this.logInfo.bind(this);
+		this.logWarn = this.logWarn.bind(this);
+		this.logError = this.logError.bind(this);
 		this.init = this.init.bind(this);
 		this.api = this.api.bind(this);
 		this.getMeta = this.getMeta.bind(this);
+		this.registerSw = this.registerSw.bind(this);
 		//#endregion
 	}
 
+	public log(...args) {
+		if (!this.debug) return;
+		console.log.apply(null, args);
+	}
+
+	public logInfo(...args) {
+		if (!this.debug) return;
+		console.info.apply(null, args);
+	}
+
+	public logWarn(...args) {
+		if (!this.debug) return;
+		console.warn.apply(null, args);
+	}
+
+	public logError(...args) {
+		if (!this.debug) return;
+		console.error.apply(null, args);
+	}
+
 	/**
 	 * Initialize MiOS (boot)
 	 * @param callback A function that call when initialized
@@ -126,12 +166,21 @@ export default class MiOS extends EventEmitter {
 
 			// Finish init
 			callback();
+
+			//#region Post
+
+			// Init service worker
+			this.registerSw();
+
+			//#endregion
 		};
 
 		// Get cached account data
 		const cachedMe = JSON.parse(localStorage.getItem('me'));
 
+		// キャッシュがあったとき
 		if (cachedMe) {
+			// とりあえずキャッシュされたデータでお茶を濁して(?)おいて、
 			fetched(cachedMe);
 
 			// 後から新鮮なデータをフェッチ
@@ -147,6 +196,67 @@ export default class MiOS extends EventEmitter {
 		}
 	}
 
+	/**
+	 * Register service worker
+	 */
+	private registerSw() {
+		// Check whether service worker and push manager supported
+		const isSwSupported =
+			('serviceWorker' in navigator) && ('PushManager' in window);
+
+		// Reject when browser not service worker supported
+		if (!isSwSupported) return;
+
+		// Reject when not signed in to Misskey
+		if (!this.isSignedin) return;
+
+		// When service worker activated
+		navigator.serviceWorker.ready.then(registration => {
+			this.log('[sw] ready: ', registration);
+
+			this.swRegistration = registration;
+
+			// Options of pushManager.subscribe
+			const opts = {
+				// A boolean indicating that the returned push subscription
+				// will only be used for messages whose effect is made visible to the user.
+				userVisibleOnly: true
+			};
+
+			// Subscribe push notification
+			this.swRegistration.pushManager.subscribe(opts).then(subscription => {
+				this.log('[sw] Subscribe OK:', subscription);
+
+				function encode(buffer: ArrayBuffer) {
+					return btoa(String.fromCharCode.apply(null, new Uint8Array(buffer)));
+				}
+
+				// Register
+				this.api('sw/register', {
+					endpoint: subscription.endpoint,
+					auth: encode(subscription.getKey('auth')),
+					publickey: encode(subscription.getKey('p256dh'))
+				});
+			}).then(() => {
+				this.logInfo('[sw] Server Stored Subscription.');
+			}).catch(err => {
+				this.logError('[sw] Subscribe Error:', err);
+			});
+		});
+
+		// The path of service worker script
+		const sw = `/sw.${VERSION}.${LANG}.js`;
+
+		// Register service worker
+		navigator.serviceWorker.register(sw).then(registration => {
+			// 登録成功
+			this.logInfo('[sw] Registration successful with scope: ', registration.scope);
+		}).catch(err => {
+			// 登録失敗 :(
+			this.logError('[sw] Registration failed: ', 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/compose-notification.ts b/src/web/app/common/scripts/compose-notification.ts
new file mode 100644
index 000000000..181dca734
--- /dev/null
+++ b/src/web/app/common/scripts/compose-notification.ts
@@ -0,0 +1,52 @@
+import getPostSummary from '../../../../common/get-post-summary';
+
+type Notification = {
+	title: string;
+	body: string;
+	icon: string;
+	onclick?: any;
+};
+
+// TODO: i18n
+
+export default function(type, data): Notification {
+	switch (type) {
+		case 'drive_file_created':
+			return {
+				title: 'ファイルがアップロードされました',
+				body: data.name,
+				icon: data.url + '?thumbnail&size=64'
+			};
+
+		case 'mention':
+			return {
+				title: `${data.user.name}さんから:`,
+				body: getPostSummary(data),
+				icon: data.user.avatar_url + '?thumbnail&size=64'
+			};
+
+		case 'reply':
+			return {
+				title: `${data.user.name}さんから返信:`,
+				body: getPostSummary(data),
+				icon: data.user.avatar_url + '?thumbnail&size=64'
+			};
+
+		case 'quote':
+			return {
+				title: `${data.user.name}さんが引用:`,
+				body: getPostSummary(data),
+				icon: data.user.avatar_url + '?thumbnail&size=64'
+			};
+
+		case 'unread_messaging_message':
+			return {
+				title: `${data.user.name}さんからメッセージ:`,
+				body: data.text, // TODO: getMessagingMessageSummary(data),
+				icon: data.user.avatar_url + '?thumbnail&size=64'
+			};
+
+		default:
+			return null;
+	}
+}
diff --git a/src/web/app/common/scripts/config.ts b/src/web/app/common/scripts/config.ts
index c5015622f..b4801a44d 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/app/desktop/script.ts b/src/web/app/desktop/script.ts
index bc0fc8dfe..694cb7879 100644
--- a/src/web/app/desktop/script.ts
+++ b/src/web/app/desktop/script.ts
@@ -11,9 +11,9 @@ import * as riot from 'riot';
 import init from '../init';
 import route from './router';
 import fuckAdBlock from './scripts/fuck-ad-block';
-import getPostSummary from '../../../common/get-post-summary';
 import MiOS from '../common/mios';
 import HomeStreamManager from '../common/scripts/streaming/home-stream-manager';
+import composeNotification from '../common/scripts/compose-notification';
 
 /**
  * init
@@ -55,41 +55,46 @@ function registerNotifications(stream: HomeStreamManager) {
 
 	function attach(connection) {
 		connection.on('drive_file_created', file => {
-			const n = new Notification('ファイルがアップロードされました', {
-				body: file.name,
-				icon: file.url + '?thumbnail&size=64'
+			const _n = composeNotification('drive_file_created', file);
+			const n = new Notification(_n.title, {
+				body: _n.body,
+				icon: _n.icon
 			});
 			setTimeout(n.close.bind(n), 5000);
 		});
 
 		connection.on('mention', post => {
-			const n = new Notification(`${post.user.name}さんから:`, {
-				body: getPostSummary(post),
-				icon: post.user.avatar_url + '?thumbnail&size=64'
+			const _n = composeNotification('mention', post);
+			const n = new Notification(_n.title, {
+				body: _n.body,
+				icon: _n.icon
 			});
 			setTimeout(n.close.bind(n), 6000);
 		});
 
 		connection.on('reply', post => {
-			const n = new Notification(`${post.user.name}さんから返信:`, {
-				body: getPostSummary(post),
-				icon: post.user.avatar_url + '?thumbnail&size=64'
+			const _n = composeNotification('reply', post);
+			const n = new Notification(_n.title, {
+				body: _n.body,
+				icon: _n.icon
 			});
 			setTimeout(n.close.bind(n), 6000);
 		});
 
 		connection.on('quote', post => {
-			const n = new Notification(`${post.user.name}さんが引用:`, {
-				body: getPostSummary(post),
-				icon: post.user.avatar_url + '?thumbnail&size=64'
+			const _n = composeNotification('quote', post);
+			const n = new Notification(_n.title, {
+				body: _n.body,
+				icon: _n.icon
 			});
 			setTimeout(n.close.bind(n), 6000);
 		});
 
 		connection.on('unread_messaging_message', message => {
-			const n = new Notification(`${message.user.name}さんからメッセージ:`, {
-				body: message.text, // TODO: getMessagingMessageSummary(message),
-				icon: message.user.avatar_url + '?thumbnail&size=64'
+			const _n = composeNotification('unread_messaging_message', message);
+			const n = new Notification(_n.title, {
+				body: _n.body,
+				icon: _n.icon
 			});
 			n.onclick = () => {
 				n.close();
diff --git a/src/web/app/init.ts b/src/web/app/init.ts
index 0bb687ec6..652cbfde4 100644
--- a/src/web/app/init.ts
+++ b/src/web/app/init.ts
@@ -18,7 +18,9 @@ require('./common/tags');
 
 console.info(`Misskey v${VERSION} (葵 aoi)`);
 
-document.domain = CONFIG.host;
+if (CONFIG.host != 'localhost') {
+	document.domain = CONFIG.host;
+}
 
 { // Set lang attr
 	const html = document.documentElement;
diff --git a/src/web/app/sw.js b/src/web/app/sw.js
new file mode 100644
index 000000000..a7c84d022
--- /dev/null
+++ b/src/web/app/sw.js
@@ -0,0 +1,33 @@
+/**
+ * Service Worker
+ */
+
+import composeNotification from './common/scripts/compose-notification';
+
+// インストールされたとき
+self.addEventListener('install', () => {
+	console.info('installed');
+});
+
+// プッシュ通知を受け取ったとき
+self.addEventListener('push', ev => {
+	console.log('pushed');
+
+	// クライアント取得
+	ev.waitUntil(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();
+
+		console.log(type, body);
+
+		const n = composeNotification(type, body);
+		return self.registration.showNotification(n.title, {
+			body: n.body,
+			icon: n.icon,
+		});
+	}));
+});
diff --git a/src/web/server.ts b/src/web/server.ts
index dde4eca5e..0be07b2d8 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.${req.params[0]}.js`));
+
 /**
- * Common API
+ * Manifest
  */
-app.get(/\/api:url/, require('./service/url-preview'));
+app.get('/manifest.json', (req, res) => {
+	const manifest = require((`${__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
  */
diff --git a/webpack/webpack.config.ts b/webpack/webpack.config.ts
index f2bcf48f3..753d89fed 100644
--- a/webpack/webpack.config.ts
+++ b/webpack/webpack.config.ts
@@ -20,7 +20,8 @@ module.exports = langs.map(([lang, locale]) => {
 		stats: './src/web/app/stats/script.ts',
 		status: './src/web/app/status/script.ts',
 		dev: './src/web/app/dev/script.ts',
-		auth: './src/web/app/auth/script.ts'
+		auth: './src/web/app/auth/script.ts',
+		sw: './src/web/app/sw.js'
 	};
 
 	const output = {