diff --git a/package.json b/package.json
index 0e3308960d..1e6bc6abf7 100644
--- a/package.json
+++ b/package.json
@@ -73,7 +73,7 @@
     "es6-object-assign": "^1.1.0",
     "eslint-import-resolver-webpack": "^0.10.1",
     "fecha": "^2.3.3",
-    "home-assistant-js-websocket": "^3.1.5",
+    "home-assistant-js-websocket": "^3.2.4",
     "intl-messageformat": "^2.2.0",
     "jquery": "^3.3.1",
     "js-yaml": "^3.12.0",
diff --git a/src/common/auth/external_auth.js b/src/common/auth/external_auth.ts
similarity index 60%
rename from src/common/auth/external_auth.js
rename to src/common/auth/external_auth.ts
index 2a9d3f1483..4f5613af15 100644
--- a/src/common/auth/external_auth.js
+++ b/src/common/auth/external_auth.ts
@@ -6,6 +6,34 @@ import { Auth } from "home-assistant-js-websocket";
 const CALLBACK_SET_TOKEN = "externalAuthSetToken";
 const CALLBACK_REVOKE_TOKEN = "externalAuthRevokeToken";
 
+interface BasePayload {
+  callback: string;
+}
+
+interface RefreshTokenResponse {
+  access_token: string;
+  expires_in: number;
+}
+
+declare global {
+  interface Window {
+    externalApp?: {
+      getExternalAuth(payload: BasePayload);
+      revokeExternalAuth(payload: BasePayload);
+    };
+    webkit?: {
+      messageHandlers: {
+        getExternalAuth: {
+          postMessage(payload: BasePayload);
+        };
+        revokeExternalAuth: {
+          postMessage(payload: BasePayload);
+        };
+      };
+    };
+  }
+}
+
 if (!window.externalApp && !window.webkit) {
   throw new Error(
     "External auth requires either externalApp or webkit defined on Window object."
@@ -14,21 +42,24 @@ if (!window.externalApp && !window.webkit) {
 
 export default class ExternalAuth extends Auth {
   constructor(hassUrl) {
-    super();
-
-    this.data = {
+    super({
       hassUrl,
+      clientId: "",
+      refresh_token: "",
       access_token: "",
+      expires_in: 0,
       // This will trigger connection to do a refresh right away
       expires: 0,
-    };
+    });
   }
 
-  async refreshAccessToken() {
-    const responseProm = new Promise((resolve, reject) => {
-      window[CALLBACK_SET_TOKEN] = (success, data) =>
-        success ? resolve(data) : reject(data);
-    });
+  public async refreshAccessToken() {
+    const responseProm = new Promise<RefreshTokenResponse>(
+      (resolve, reject) => {
+        window[CALLBACK_SET_TOKEN] = (success, data) =>
+          success ? resolve(data) : reject(data);
+      }
+    );
 
     // Allow promise to set resolve on window object.
     await 0;
@@ -38,23 +69,18 @@ export default class ExternalAuth extends Auth {
     if (window.externalApp) {
       window.externalApp.getExternalAuth(callbackPayload);
     } else {
-      window.webkit.messageHandlers.getExternalAuth.postMessage(
+      window.webkit!.messageHandlers.getExternalAuth.postMessage(
         callbackPayload
       );
     }
 
-    // Response we expect back:
-    // {
-    //   "access_token": "qwere",
-    //   "expires_in": 1800
-    // }
     const tokens = await responseProm;
 
     this.data.access_token = tokens.access_token;
     this.data.expires = tokens.expires_in * 1000 + Date.now();
   }
 
-  async revoke() {
+  public async revoke() {
     const responseProm = new Promise((resolve, reject) => {
       window[CALLBACK_REVOKE_TOKEN] = (success, data) =>
         success ? resolve(data) : reject(data);
@@ -68,7 +94,7 @@ export default class ExternalAuth extends Auth {
     if (window.externalApp) {
       window.externalApp.revokeExternalAuth(callbackPayload);
     } else {
-      window.webkit.messageHandlers.revokeExternalAuth.postMessage(
+      window.webkit!.messageHandlers.revokeExternalAuth.postMessage(
         callbackPayload
       );
     }
diff --git a/src/common/auth/token_storage.js b/src/common/auth/token_storage.ts
similarity index 67%
rename from src/common/auth/token_storage.js
rename to src/common/auth/token_storage.ts
index 6483665720..335cb65075 100644
--- a/src/common/auth/token_storage.js
+++ b/src/common/auth/token_storage.ts
@@ -1,5 +1,18 @@
+import { AuthData } from "home-assistant-js-websocket";
+
 const storage = window.localStorage || {};
 
+declare global {
+  interface Window {
+    __tokenCache: {
+      // undefined: we haven't loaded yet
+      // null: none stored
+      tokens?: AuthData | null;
+      writeEnabled?: boolean;
+    };
+  }
+}
+
 // So that core.js and main app hit same shared object.
 let tokenCache = window.__tokenCache;
 if (!tokenCache) {
@@ -15,18 +28,22 @@ export function askWrite() {
   );
 }
 
-export function saveTokens(tokens) {
+export function saveTokens(tokens: AuthData | null) {
   tokenCache.tokens = tokens;
   if (tokenCache.writeEnabled) {
     try {
       storage.hassTokens = JSON.stringify(tokens);
-    } catch (err) {} // eslint-disable-line
+    } catch (err) {
+      // write failed, ignore it. Happens if storage is full or private mode.
+    }
   }
 }
 
 export function enableWrite() {
   tokenCache.writeEnabled = true;
-  saveTokens(tokenCache.tokens);
+  if (tokenCache.tokens) {
+    saveTokens(tokenCache.tokens);
+  }
 }
 
 export function loadTokens() {
diff --git a/src/data/ws-notifications.js b/src/data/ws-notifications.ts
similarity index 62%
rename from src/data/ws-notifications.js
rename to src/data/ws-notifications.ts
index 1fb3b5e07d..261a32aac6 100644
--- a/src/data/ws-notifications.js
+++ b/src/data/ws-notifications.ts
@@ -1,4 +1,4 @@
-import { createCollection } from "home-assistant-js-websocket";
+import { createCollection, Connection } from "home-assistant-js-websocket";
 
 const fetchNotifications = (conn) =>
   conn.sendMessagePromise({
@@ -11,8 +11,11 @@ const subscribeUpdates = (conn, store) =>
     "persistent_notifications_updated"
   );
 
-export const subscribeNotifications = (conn, onChange) =>
-  createCollection(
+export const subscribeNotifications = (
+  conn: Connection,
+  onChange: (notifications: Notification[]) => void
+) =>
+  createCollection<Notification[]>(
     "_ntf",
     fetchNotifications,
     subscribeUpdates,
diff --git a/src/data/ws-panels.js b/src/data/ws-panels.js
deleted file mode 100644
index 515be6628d..0000000000
--- a/src/data/ws-panels.js
+++ /dev/null
@@ -1,10 +0,0 @@
-import { createCollection } from "home-assistant-js-websocket";
-
-export const subscribePanels = (conn, onChange) =>
-  createCollection(
-    "_pnl",
-    (conn_) => conn_.sendMessagePromise({ type: "get_panels" }),
-    null,
-    conn,
-    onChange
-  );
diff --git a/src/data/ws-panels.ts b/src/data/ws-panels.ts
new file mode 100644
index 0000000000..88ec490d06
--- /dev/null
+++ b/src/data/ws-panels.ts
@@ -0,0 +1,14 @@
+import { createCollection, Connection } from "home-assistant-js-websocket";
+import { Panels } from "../types";
+
+export const subscribePanels = (
+  conn: Connection,
+  onChange: (panels: Panels) => void
+) =>
+  createCollection<Panels>(
+    "_pnl",
+    () => conn.sendMessagePromise({ type: "get_panels" }),
+    undefined,
+    conn,
+    onChange
+  );
diff --git a/src/data/ws-themes.js b/src/data/ws-themes.js
deleted file mode 100644
index d5e8cfba74..0000000000
--- a/src/data/ws-themes.js
+++ /dev/null
@@ -1,15 +0,0 @@
-import { createCollection } from "home-assistant-js-websocket";
-
-const fetchThemes = (conn) =>
-  conn.sendMessagePromise({
-    type: "frontend/get_themes",
-  });
-
-const subscribeUpdates = (conn, store) =>
-  conn.subscribeEvents(
-    (event) => store.setState(event.data, true),
-    "themes_updated"
-  );
-
-export const subscribeThemes = (conn, onChange) =>
-  createCollection("_thm", fetchThemes, subscribeUpdates, conn, onChange);
diff --git a/src/data/ws-themes.ts b/src/data/ws-themes.ts
new file mode 100644
index 0000000000..13f37844d4
--- /dev/null
+++ b/src/data/ws-themes.ts
@@ -0,0 +1,25 @@
+import { createCollection, Connection } from "home-assistant-js-websocket";
+import { Themes } from "../types";
+
+const fetchThemes = (conn) =>
+  conn.sendMessagePromise({
+    type: "frontend/get_themes",
+  });
+
+const subscribeUpdates = (conn, store) =>
+  conn.subscribeEvents(
+    (event) => store.setState(event.data, true),
+    "themes_updated"
+  );
+
+export const subscribeThemes = (
+  conn: Connection,
+  onChange: (themes: Themes) => void
+) =>
+  createCollection<Themes>(
+    "_thm",
+    fetchThemes,
+    subscribeUpdates,
+    conn,
+    onChange
+  );
diff --git a/src/data/ws-user.js b/src/data/ws-user.js
deleted file mode 100644
index 9e33811a62..0000000000
--- a/src/data/ws-user.js
+++ /dev/null
@@ -1,4 +0,0 @@
-import { createCollection, getUser } from "home-assistant-js-websocket";
-
-export const subscribeUser = (conn, onChange) =>
-  createCollection("_usr", (conn_) => getUser(conn_), null, conn, onChange);
diff --git a/src/data/ws-user.ts b/src/data/ws-user.ts
new file mode 100644
index 0000000000..e627c20673
--- /dev/null
+++ b/src/data/ws-user.ts
@@ -0,0 +1,20 @@
+import {
+  createCollection,
+  getUser,
+  Connection,
+} from "home-assistant-js-websocket";
+import { User } from "../types";
+
+export const subscribeUser = (
+  conn: Connection,
+  onChange: (user: User) => void
+) =>
+  createCollection<User>(
+    "_usr",
+    // the getUser command is mistyped in current verrsion of HAWS.
+    // Fixed in 3.2.5
+    () => (getUser(conn) as unknown) as Promise<User>,
+    undefined,
+    conn,
+    onChange
+  );
diff --git a/src/entrypoints/core.js b/src/entrypoints/core.ts
similarity index 81%
rename from src/entrypoints/core.js
rename to src/entrypoints/core.ts
index 560fb8c96c..c75e9680a6 100644
--- a/src/entrypoints/core.js
+++ b/src/entrypoints/core.ts
@@ -5,12 +5,21 @@ import {
   subscribeEntities,
   subscribeServices,
   ERR_INVALID_AUTH,
+  Auth,
+  Connection,
 } from "home-assistant-js-websocket";
 
 import { loadTokens, saveTokens } from "../common/auth/token_storage";
 import { subscribePanels } from "../data/ws-panels";
 import { subscribeThemes } from "../data/ws-themes";
 import { subscribeUser } from "../data/ws-user";
+import { HomeAssistant } from "../types";
+
+declare global {
+  interface Window {
+    hassConnection: Promise<{ auth: Auth; conn: Connection }>;
+  }
+}
 
 const hassUrl = `${location.protocol}//${location.host}`;
 const isExternal = location.search.includes("external_auth=1");
@@ -33,7 +42,7 @@ const connProm = async (auth) => {
 
     // Clear url if we have been able to establish a connection
     if (location.search.includes("auth_callback=1")) {
-      history.replaceState(null, null, location.pathname);
+      history.replaceState(null, "", location.pathname);
     }
 
     return { auth, conn };
@@ -43,7 +52,9 @@ const connProm = async (auth) => {
     }
     // We can get invalid auth if auth tokens were stored that are no longer valid
     // Clear stored tokens.
-    if (!isExternal) saveTokens(null);
+    if (!isExternal) {
+      saveTokens(null);
+    }
     auth = await authProm();
     const conn = await createConnection({ auth });
     return { auth, conn };
@@ -54,7 +65,9 @@ window.hassConnection = authProm().then(connProm);
 
 // Start fetching some of the data that we will need.
 window.hassConnection.then(({ conn }) => {
-  const noop = () => {};
+  const noop = () => {
+    // do nothing
+  };
   subscribeEntities(conn, noop);
   subscribeConfig(conn, noop);
   subscribeServices(conn, noop);
@@ -64,8 +77,12 @@ window.hassConnection.then(({ conn }) => {
 });
 
 window.addEventListener("error", (e) => {
-  const homeAssistant = document.querySelector("home-assistant");
-  if (homeAssistant && homeAssistant.hass && homeAssistant.hass.callService) {
+  const homeAssistant = document.querySelector("home-assistant") as any;
+  if (
+    homeAssistant &&
+    homeAssistant.hass &&
+    (homeAssistant.hass as HomeAssistant).callService
+  ) {
     homeAssistant.hass.callService("system_log", "write", {
       logger: `frontend.${
         __DEV__ ? "js_dev" : "js"
diff --git a/src/types.ts b/src/types.ts
index 6cc016d2ee..281eb63a6d 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -8,6 +8,12 @@ import {
   HassEntityAttributeBase,
 } from "home-assistant-js-websocket";
 
+declare global {
+  var __DEV__: boolean;
+  var __BUILD__: "latest" | "es5";
+  var __VERSION__: string;
+}
+
 export interface Credential {
   auth_provider_type: string;
   auth_provider_id: string;
@@ -34,6 +40,11 @@ export interface Theme {
   "accent-color": string;
 }
 
+export interface Themes {
+  default_theme: string;
+  themes: { [key: string]: Theme };
+}
+
 export interface Panel {
   component_name: string;
   config?: { [key: string]: any };
@@ -42,22 +53,31 @@ export interface Panel {
   url_path: string;
 }
 
+export interface Panels {
+  [name: string]: Panel;
+}
+
 export interface Translation {
   nativeName: string;
   fingerprints: { [fragment: string]: string };
 }
 
+export interface Notification {
+  notification_id: string;
+  message: string;
+  title: string;
+  status: "read" | "unread";
+  created_at: string;
+}
+
 export interface HomeAssistant {
   auth: Auth;
   connection: Connection;
   connected: boolean;
   states: HassEntities;
   config: HassConfig;
-  themes: {
-    default_theme: string;
-    themes: { [key: string]: Theme };
-  };
-  panels: { [key: string]: Panel };
+  themes: Themes;
+  panels: Panels;
   panelUrl: string;
   language: string;
   resources: { [key: string]: any };
diff --git a/webpack.config.js b/webpack.config.js
index 87b7105aed..4bc3fb1cc4 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -41,7 +41,7 @@ function createConfig(isProdBuild, latestBuild) {
     app: "./src/entrypoints/app.js",
     authorize: "./src/entrypoints/authorize.js",
     onboarding: "./src/entrypoints/onboarding.js",
-    core: "./src/entrypoints/core.js",
+    core: "./src/entrypoints/core.ts",
     compatibility: "./src/entrypoints/compatibility.js",
     "custom-panel": "./src/entrypoints/custom-panel.js",
     "hass-icons": "./src/entrypoints/hass-icons.js",
@@ -173,7 +173,7 @@ function createConfig(isProdBuild, latestBuild) {
         swDest: "service_worker.js",
         importWorkboxFrom: "local",
         include: [
-          /core.js$/,
+          /core.ts$/,
           /app.js$/,
           /custom-panel.js$/,
           /hass-icons.js$/,
diff --git a/yarn.lock b/yarn.lock
index 38b4426f63..6bb4ab49fa 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -7426,10 +7426,10 @@ hoek@4.x.x:
   resolved "https://registry.yarnpkg.com/hoek/-/hoek-4.2.1.tgz#9634502aa12c445dd5a7c5734b572bb8738aacbb"
   integrity sha512-QLg82fGkfnJ/4iy1xZ81/9SIJiq1NGFUMGs6ParyjBZr6jW2Ufj/snDqTHixNlHdPNwN2RLVD0Pi3igeK9+JfA==
 
-home-assistant-js-websocket@^3.1.5:
-  version "3.1.5"
-  resolved "https://registry.yarnpkg.com/home-assistant-js-websocket/-/home-assistant-js-websocket-3.1.5.tgz#56358660bbccb5f24e16f9197bbad12739f9b756"
-  integrity sha512-BlANSkA9ob6wlUJCYS26n1tfMla+aJzB2rhhXSFi0iiTtWWfuOlcSOw8pxjeWhh1I9oAcbQ4qxhB7Np1EXG+Og==
+home-assistant-js-websocket@^3.2.4:
+  version "3.2.4"
+  resolved "https://registry.yarnpkg.com/home-assistant-js-websocket/-/home-assistant-js-websocket-3.2.4.tgz#0c4212e6ac57b60ed939aa420253994e4f9f0bef"
+  integrity sha512-DaHpWIjJFLwTWNbHeGSCEUsbeyLUWAyWUgsYkiVWxzbfm+vqC5YaLNRu+Ma64SQYh5yGSYr7h25p2hip1GvyhQ==
 
 home-or-tmp@^2.0.0:
   version "2.0.0"