diff --git a/homeassistant/auth/permissions/__init__.py b/homeassistant/auth/permissions/__init__.py
index 5680b0aecb2..25253a1601c 100644
--- a/homeassistant/auth/permissions/__init__.py
+++ b/homeassistant/auth/permissions/__init__.py
@@ -7,6 +7,7 @@ from typing import (  # noqa: F401
     Dict,
     List,
     Mapping,
+    Optional,
     Set,
     Tuple,
     Union,
@@ -31,7 +32,7 @@ _LOGGER = logging.getLogger(__name__)
 class AbstractPermissions:
     """Default permissions class."""
 
-    _cached_entity_func = None
+    _cached_entity_func: Optional[Callable[[str, str], bool]] = None
 
     def _entity_func(self) -> Callable[[str, str], bool]:
         """Return a function that can test entity access."""
diff --git a/homeassistant/components/__init__.py b/homeassistant/components/__init__.py
index 8c14276ccc9..7bb572dcf6b 100644
--- a/homeassistant/components/__init__.py
+++ b/homeassistant/components/__init__.py
@@ -11,6 +11,9 @@ import logging
 
 from homeassistant.core import split_entity_id
 
+
+# mypy: allow-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 
diff --git a/homeassistant/components/automation/__init__.py b/homeassistant/components/automation/__init__.py
index 935f6ea0d02..5de9336d1d9 100644
--- a/homeassistant/components/automation/__init__.py
+++ b/homeassistant/components/automation/__init__.py
@@ -30,6 +30,10 @@ from homeassistant.helpers.restore_state import RestoreEntity
 from homeassistant.loader import bind_hass
 from homeassistant.util.dt import parse_datetime, utcnow
 
+
+# mypy: allow-incomplete-defs, allow-untyped-calls, allow-untyped-defs
+# mypy: no-check-untyped-defs, no-warn-return-any
+
 DOMAIN = "automation"
 ENTITY_ID_FORMAT = DOMAIN + ".{}"
 
diff --git a/homeassistant/components/automation/device.py b/homeassistant/components/automation/device.py
index 2bb70fa1c96..b090484ab67 100644
--- a/homeassistant/components/automation/device.py
+++ b/homeassistant/components/automation/device.py
@@ -5,6 +5,8 @@ from homeassistant.const import CONF_DOMAIN, CONF_PLATFORM
 from homeassistant.loader import async_get_integration
 
 
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 TRIGGER_SCHEMA = vol.Schema(
     {vol.Required(CONF_PLATFORM): "device", vol.Required(CONF_DOMAIN): str},
     extra=vol.ALLOW_EXTRA,
diff --git a/homeassistant/components/automation/event.py b/homeassistant/components/automation/event.py
index b353eb56196..d372aedd1d7 100644
--- a/homeassistant/components/automation/event.py
+++ b/homeassistant/components/automation/event.py
@@ -7,6 +7,9 @@ from homeassistant.core import callback
 from homeassistant.const import CONF_PLATFORM
 from homeassistant.helpers import config_validation as cv
 
+
+# mypy: allow-untyped-defs
+
 CONF_EVENT_TYPE = "event_type"
 CONF_EVENT_DATA = "event_data"
 
diff --git a/homeassistant/components/automation/geo_location.py b/homeassistant/components/automation/geo_location.py
index 7c0994c4b30..3f2aa1c00d7 100644
--- a/homeassistant/components/automation/geo_location.py
+++ b/homeassistant/components/automation/geo_location.py
@@ -13,6 +13,9 @@ from homeassistant.const import (
 from homeassistant.helpers import condition, config_validation as cv
 from homeassistant.helpers.config_validation import entity_domain
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 EVENT_ENTER = "enter"
 EVENT_LEAVE = "leave"
 DEFAULT_EVENT = EVENT_ENTER
diff --git a/homeassistant/components/automation/homeassistant.py b/homeassistant/components/automation/homeassistant.py
index 96931e62766..bd1da7e7e1f 100644
--- a/homeassistant/components/automation/homeassistant.py
+++ b/homeassistant/components/automation/homeassistant.py
@@ -6,6 +6,9 @@ import voluptuous as vol
 from homeassistant.core import callback, CoreState
 from homeassistant.const import CONF_PLATFORM, CONF_EVENT, EVENT_HOMEASSISTANT_STOP
 
+
+# mypy: allow-untyped-defs
+
 EVENT_START = "start"
 EVENT_SHUTDOWN = "shutdown"
 _LOGGER = logging.getLogger(__name__)
diff --git a/homeassistant/components/automation/litejet.py b/homeassistant/components/automation/litejet.py
index c642781ca66..7bc4c937765 100644
--- a/homeassistant/components/automation/litejet.py
+++ b/homeassistant/components/automation/litejet.py
@@ -9,6 +9,9 @@ import homeassistant.helpers.config_validation as cv
 import homeassistant.util.dt as dt_util
 from homeassistant.helpers.event import track_point_in_utc_time
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 CONF_NUMBER = "number"
diff --git a/homeassistant/components/automation/mqtt.py b/homeassistant/components/automation/mqtt.py
index 26c1ea5683d..fd9a778dbfc 100644
--- a/homeassistant/components/automation/mqtt.py
+++ b/homeassistant/components/automation/mqtt.py
@@ -8,6 +8,9 @@ from homeassistant.components import mqtt
 from homeassistant.const import CONF_PLATFORM, CONF_PAYLOAD
 import homeassistant.helpers.config_validation as cv
 
+
+# mypy: allow-untyped-defs
+
 CONF_ENCODING = "encoding"
 CONF_TOPIC = "topic"
 DEFAULT_ENCODING = "utf-8"
diff --git a/homeassistant/components/automation/numeric_state.py b/homeassistant/components/automation/numeric_state.py
index f990e599552..b33d724d770 100644
--- a/homeassistant/components/automation/numeric_state.py
+++ b/homeassistant/components/automation/numeric_state.py
@@ -16,6 +16,9 @@ from homeassistant.const import (
 from homeassistant.helpers.event import async_track_state_change, async_track_same_state
 from homeassistant.helpers import condition, config_validation as cv, template
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 TRIGGER_SCHEMA = vol.All(
     vol.Schema(
         {
diff --git a/homeassistant/components/automation/state.py b/homeassistant/components/automation/state.py
index ccea3d9ec5a..5fbe97185a7 100644
--- a/homeassistant/components/automation/state.py
+++ b/homeassistant/components/automation/state.py
@@ -9,6 +9,9 @@ from homeassistant.const import MATCH_ALL, CONF_PLATFORM, CONF_FOR
 from homeassistant.helpers import config_validation as cv, template
 from homeassistant.helpers.event import async_track_state_change, async_track_same_state
 
+
+# mypy: allow-untyped-calls, allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 CONF_ENTITY_ID = "entity_id"
diff --git a/homeassistant/components/automation/sun.py b/homeassistant/components/automation/sun.py
index e4d41830e0f..7cbbe56f326 100644
--- a/homeassistant/components/automation/sun.py
+++ b/homeassistant/components/automation/sun.py
@@ -14,6 +14,9 @@ from homeassistant.const import (
 from homeassistant.helpers.event import async_track_sunrise, async_track_sunset
 import homeassistant.helpers.config_validation as cv
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 TRIGGER_SCHEMA = vol.Schema(
diff --git a/homeassistant/components/automation/template.py b/homeassistant/components/automation/template.py
index a48f252312b..c83d660912c 100644
--- a/homeassistant/components/automation/template.py
+++ b/homeassistant/components/automation/template.py
@@ -10,6 +10,9 @@ from homeassistant.helpers import condition
 from homeassistant.helpers.event import async_track_same_state, async_track_template
 from homeassistant.helpers import config_validation as cv, template
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 TRIGGER_SCHEMA = IF_ACTION_SCHEMA = vol.Schema(
diff --git a/homeassistant/components/automation/time.py b/homeassistant/components/automation/time.py
index 958c1f007bc..3942d0efadb 100644
--- a/homeassistant/components/automation/time.py
+++ b/homeassistant/components/automation/time.py
@@ -8,6 +8,9 @@ from homeassistant.const import CONF_AT, CONF_PLATFORM
 from homeassistant.helpers import config_validation as cv
 from homeassistant.helpers.event import async_track_time_change
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 TRIGGER_SCHEMA = vol.Schema(
diff --git a/homeassistant/components/automation/time_pattern.py b/homeassistant/components/automation/time_pattern.py
index 15180e07094..f749a308bf7 100644
--- a/homeassistant/components/automation/time_pattern.py
+++ b/homeassistant/components/automation/time_pattern.py
@@ -8,6 +8,9 @@ from homeassistant.const import CONF_PLATFORM
 from homeassistant.helpers import config_validation as cv
 from homeassistant.helpers.event import async_track_time_change
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 CONF_HOURS = "hours"
 CONF_MINUTES = "minutes"
 CONF_SECONDS = "seconds"
diff --git a/homeassistant/components/automation/webhook.py b/homeassistant/components/automation/webhook.py
index ceb764cea96..706afbe9042 100644
--- a/homeassistant/components/automation/webhook.py
+++ b/homeassistant/components/automation/webhook.py
@@ -11,6 +11,9 @@ import homeassistant.helpers.config_validation as cv
 
 from . import DOMAIN as AUTOMATION_DOMAIN
 
+
+# mypy: allow-untyped-defs
+
 DEPENDENCIES = ("webhook",)
 
 _LOGGER = logging.getLogger(__name__)
diff --git a/homeassistant/components/automation/zone.py b/homeassistant/components/automation/zone.py
index 1f0f558f0de..35b11006024 100644
--- a/homeassistant/components/automation/zone.py
+++ b/homeassistant/components/automation/zone.py
@@ -12,6 +12,9 @@ from homeassistant.const import (
 from homeassistant.helpers.event import async_track_state_change
 from homeassistant.helpers import condition, config_validation as cv, location
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 EVENT_ENTER = "enter"
 EVENT_LEAVE = "leave"
 DEFAULT_EVENT = EVENT_ENTER
diff --git a/homeassistant/components/binary_sensor/__init__.py b/homeassistant/components/binary_sensor/__init__.py
index 951f4a423e5..9af6a10c425 100644
--- a/homeassistant/components/binary_sensor/__init__.py
+++ b/homeassistant/components/binary_sensor/__init__.py
@@ -13,6 +13,9 @@ from homeassistant.helpers.config_validation import (  # noqa
     PLATFORM_SCHEMA_BASE,
 )
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 DOMAIN = "binary_sensor"
 SCAN_INTERVAL = timedelta(seconds=30)
 
diff --git a/homeassistant/components/calendar/__init__.py b/homeassistant/components/calendar/__init__.py
index e538b6b802a..32817242642 100644
--- a/homeassistant/components/calendar/__init__.py
+++ b/homeassistant/components/calendar/__init__.py
@@ -17,6 +17,9 @@ from homeassistant.helpers.entity_component import EntityComponent
 from homeassistant.helpers.template import DATE_STR_FORMAT
 from homeassistant.util import dt
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 DOMAIN = "calendar"
diff --git a/homeassistant/components/camera/__init__.py b/homeassistant/components/camera/__init__.py
index efe7a37b310..1b2bfb5fdb1 100644
--- a/homeassistant/components/camera/__init__.py
+++ b/homeassistant/components/camera/__init__.py
@@ -7,6 +7,7 @@ from datetime import timedelta
 import logging
 import hashlib
 from random import SystemRandom
+from typing import Deque
 
 import attr
 from aiohttp import web
@@ -52,6 +53,9 @@ from homeassistant.setup import async_when_setup
 from .const import DOMAIN, DATA_CAMERA_PREFS
 from .prefs import CameraPreferences
 
+
+# mypy: allow-untyped-calls, allow-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 SERVICE_ENABLE_MOTION = "enable_motion_detection"
@@ -311,7 +315,7 @@ class Camera(Entity):
         """Initialize a camera."""
         self.is_streaming = False
         self.content_type = DEFAULT_CONTENT_TYPE
-        self.access_tokens = collections.deque([], 2)
+        self.access_tokens: Deque[str] = collections.deque([], 2)
         self.async_update_token()
 
     @property
diff --git a/homeassistant/components/camera/prefs.py b/homeassistant/components/camera/prefs.py
index 5e22b882d0a..d83e0b55c96 100644
--- a/homeassistant/components/camera/prefs.py
+++ b/homeassistant/components/camera/prefs.py
@@ -1,6 +1,9 @@
 """Preference management for camera component."""
 from .const import DOMAIN, PREF_PRELOAD_STREAM
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 STORAGE_KEY = DOMAIN
 STORAGE_VERSION = 1
 _UNDEF = object()
diff --git a/homeassistant/components/cover/__init__.py b/homeassistant/components/cover/__init__.py
index 696524f5792..d491765bb00 100644
--- a/homeassistant/components/cover/__init__.py
+++ b/homeassistant/components/cover/__init__.py
@@ -32,6 +32,9 @@ from homeassistant.const import (
     STATE_CLOSING,
 )
 
+
+# mypy: allow-untyped-calls, allow-incomplete-defs, allow-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 DOMAIN = "cover"
diff --git a/homeassistant/components/fan/__init__.py b/homeassistant/components/fan/__init__.py
index 235e8cf5fad..f5edfe5bb59 100644
--- a/homeassistant/components/fan/__init__.py
+++ b/homeassistant/components/fan/__init__.py
@@ -2,6 +2,7 @@
 from datetime import timedelta
 import functools as ft
 import logging
+from typing import Optional
 
 import voluptuous as vol
 
@@ -74,7 +75,7 @@ FAN_SET_DIRECTION_SCHEMA = ENTITY_SERVICE_SCHEMA.extend(
 
 
 @bind_hass
-def is_on(hass, entity_id: str = None) -> bool:
+def is_on(hass, entity_id: Optional[str] = None) -> bool:
     """Return if the fans are on based on the statemachine."""
     entity_id = entity_id or ENTITY_ID_ALL_FANS
     state = hass.states.get(entity_id)
@@ -149,12 +150,12 @@ class FanEntity(ToggleEntity):
         return self.hass.async_add_job(self.set_direction, direction)
 
     # pylint: disable=arguments-differ
-    def turn_on(self, speed: str = None, **kwargs) -> None:
+    def turn_on(self, speed: Optional[str] = None, **kwargs) -> None:
         """Turn on the fan."""
         raise NotImplementedError()
 
     # pylint: disable=arguments-differ
-    def async_turn_on(self, speed: str = None, **kwargs):
+    def async_turn_on(self, speed: Optional[str] = None, **kwargs):
         """Turn on the fan.
 
         This method must be run in the event loop and returns a coroutine.
@@ -180,7 +181,7 @@ class FanEntity(ToggleEntity):
         return self.speed not in [SPEED_OFF, None]
 
     @property
-    def speed(self) -> str:
+    def speed(self) -> Optional[str]:
         """Return the current speed."""
         return None
 
@@ -190,7 +191,7 @@ class FanEntity(ToggleEntity):
         return []
 
     @property
-    def current_direction(self) -> str:
+    def current_direction(self) -> Optional[str]:
         """Return the current direction of the fan."""
         return None
 
diff --git a/homeassistant/components/frontend/__init__.py b/homeassistant/components/frontend/__init__.py
index b769d6b9aea..d8790b746be 100644
--- a/homeassistant/components/frontend/__init__.py
+++ b/homeassistant/components/frontend/__init__.py
@@ -22,6 +22,8 @@ from homeassistant.loader import bind_hass
 from .storage import async_setup_frontend_storage
 
 
+# mypy: allow-incomplete-defs, allow-untyped-defs, no-check-untyped-defs
+
 # Fix mimetypes for borked Windows machines
 # https://github.com/home-assistant/home-assistant-polymer/issues/3336
 mimetypes.add_type("text/css", ".css")
@@ -45,7 +47,14 @@ MANIFEST_JSON = {
     "description": "Home automation platform that puts local control and privacy first.",
     "dir": "ltr",
     "display": "standalone",
-    "icons": [],
+    "icons": [
+        {
+            "src": "/static/icons/favicon-{size}x{size}.png".format(size=size),
+            "sizes": "{size}x{size}".format(size=size),
+            "type": "image/png",
+        }
+        for size in (192, 384, 512, 1024)
+    ],
     "lang": "en-US",
     "name": "Home Assistant",
     "short_name": "Assistant",
@@ -53,15 +62,6 @@ MANIFEST_JSON = {
     "theme_color": DEFAULT_THEME_COLOR,
 }
 
-for size in (192, 384, 512, 1024):
-    MANIFEST_JSON["icons"].append(
-        {
-            "src": "/static/icons/favicon-{size}x{size}.png".format(size=size),
-            "sizes": "{size}x{size}".format(size=size),
-            "type": "image/png",
-        }
-    )
-
 DATA_PANELS = "frontend_panels"
 DATA_JS_VERSION = "frontend_js_version"
 DATA_EXTRA_HTML_URL = "frontend_extra_html_url"
diff --git a/homeassistant/components/frontend/storage.py b/homeassistant/components/frontend/storage.py
index 56f23da5253..75b7b356ef9 100644
--- a/homeassistant/components/frontend/storage.py
+++ b/homeassistant/components/frontend/storage.py
@@ -4,6 +4,9 @@ import voluptuous as vol
 
 from homeassistant.components import websocket_api
 
+
+# mypy: allow-untyped-calls, allow-untyped-defs
+
 DATA_STORAGE = "frontend_storage"
 STORAGE_VERSION_USER_DATA = 1
 STORAGE_KEY_USER_DATA = "frontend.user_data_{}"
diff --git a/homeassistant/components/geo_location/__init__.py b/homeassistant/components/geo_location/__init__.py
index 869f96901c1..3c270f2c521 100644
--- a/homeassistant/components/geo_location/__init__.py
+++ b/homeassistant/components/geo_location/__init__.py
@@ -11,6 +11,9 @@ from homeassistant.helpers.config_validation import (  # noqa
 from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.entity_component import EntityComponent
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 ATTR_DISTANCE = "distance"
diff --git a/homeassistant/components/history/__init__.py b/homeassistant/components/history/__init__.py
index d402aceaa40..a2285da4e80 100644
--- a/homeassistant/components/history/__init__.py
+++ b/homeassistant/components/history/__init__.py
@@ -21,6 +21,9 @@ from homeassistant.const import ATTR_HIDDEN
 from homeassistant.components.recorder.util import session_scope, execute
 import homeassistant.helpers.config_validation as cv
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 DOMAIN = "history"
diff --git a/homeassistant/components/http/__init__.py b/homeassistant/components/http/__init__.py
index 6d31c3fc700..5e474dafa07 100644
--- a/homeassistant/components/http/__init__.py
+++ b/homeassistant/components/http/__init__.py
@@ -27,6 +27,9 @@ from .real_ip import setup_real_ip
 from .static import CACHE_HEADERS, CachingStaticResource
 from .view import HomeAssistantView  # noqa
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 DOMAIN = "http"
 
 CONF_API_PASSWORD = "api_password"
diff --git a/homeassistant/components/http/auth.py b/homeassistant/components/http/auth.py
index c65cb6a2e94..4ff581aef02 100644
--- a/homeassistant/components/http/auth.py
+++ b/homeassistant/components/http/auth.py
@@ -14,6 +14,9 @@ from homeassistant.util import dt as dt_util
 
 from .const import KEY_AUTHENTICATED, KEY_HASS_USER, KEY_REAL_IP
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 DATA_API_PASSWORD = "api_password"
diff --git a/homeassistant/components/http/ban.py b/homeassistant/components/http/ban.py
index db8d2ade959..71e7ff38924 100644
--- a/homeassistant/components/http/ban.py
+++ b/homeassistant/components/http/ban.py
@@ -3,6 +3,7 @@ from collections import defaultdict
 from datetime import datetime
 from ipaddress import ip_address
 import logging
+from typing import List, Optional
 
 from aiohttp.web import middleware
 from aiohttp.web_exceptions import HTTPForbidden, HTTPUnauthorized
@@ -16,6 +17,9 @@ from homeassistant.util.yaml import dump
 
 from .const import KEY_REAL_IP
 
+
+# mypy: allow-incomplete-defs, allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 KEY_BANNED_IPS = "ha_banned_ips"
@@ -155,7 +159,7 @@ async def process_success_login(request):
 class IpBan:
     """Represents banned IP address."""
 
-    def __init__(self, ip_ban: str, banned_at: datetime = None) -> None:
+    def __init__(self, ip_ban: str, banned_at: Optional[datetime] = None) -> None:
         """Initialize IP Ban object."""
         self.ip_address = ip_address(ip_ban)
         self.banned_at = banned_at or datetime.utcnow()
@@ -163,7 +167,7 @@ class IpBan:
 
 async def async_load_ip_bans_config(hass: HomeAssistant, path: str):
     """Load list of banned IPs from config file."""
-    ip_list = []
+    ip_list: List[IpBan] = []
 
     try:
         list_ = await hass.async_add_executor_job(load_yaml_config_file, path)
diff --git a/homeassistant/components/http/cors.py b/homeassistant/components/http/cors.py
index 19fe88c5cde..39ff45fd4e4 100644
--- a/homeassistant/components/http/cors.py
+++ b/homeassistant/components/http/cors.py
@@ -5,6 +5,9 @@ from aiohttp.hdrs import ACCEPT, CONTENT_TYPE, ORIGIN, AUTHORIZATION
 from homeassistant.const import HTTP_HEADER_HA_AUTH, HTTP_HEADER_X_REQUESTED_WITH
 from homeassistant.core import callback
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 ALLOWED_CORS_HEADERS = [
     ORIGIN,
     ACCEPT,
diff --git a/homeassistant/components/http/data_validator.py b/homeassistant/components/http/data_validator.py
index 8d6ac0b1ceb..634a96aa312 100644
--- a/homeassistant/components/http/data_validator.py
+++ b/homeassistant/components/http/data_validator.py
@@ -4,6 +4,9 @@ import logging
 
 import voluptuous as vol
 
+
+# mypy: allow-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 
diff --git a/homeassistant/components/http/real_ip.py b/homeassistant/components/http/real_ip.py
index c38e5d0b592..f327c86a4c1 100644
--- a/homeassistant/components/http/real_ip.py
+++ b/homeassistant/components/http/real_ip.py
@@ -9,6 +9,9 @@ from homeassistant.core import callback
 from .const import KEY_REAL_IP
 
 
+# mypy: allow-untyped-defs
+
+
 @callback
 def setup_real_ip(app, use_x_forwarded_for, trusted_proxies):
     """Create IP Ban middleware for the app."""
diff --git a/homeassistant/components/http/static.py b/homeassistant/components/http/static.py
index f78ce81d884..76844407f7d 100644
--- a/homeassistant/components/http/static.py
+++ b/homeassistant/components/http/static.py
@@ -6,6 +6,9 @@ from aiohttp.web import FileResponse
 from aiohttp.web_exceptions import HTTPNotFound, HTTPForbidden
 from aiohttp.web_urldispatcher import StaticResource
 
+
+# mypy: allow-untyped-defs
+
 CACHE_TIME = 31 * 86400  # = 1 month
 CACHE_HEADERS = {hdrs.CACHE_CONTROL: "public, max-age={}".format(CACHE_TIME)}
 
@@ -39,7 +42,8 @@ class CachingStaticResource(StaticResource):
         if filepath.is_dir():
             return await super()._handle(request)
         if filepath.is_file():
-            return FileResponse(
+            # type ignore: https://github.com/aio-libs/aiohttp/pull/3976
+            return FileResponse(  # type: ignore
                 filepath, chunk_size=self._chunk_size, headers=CACHE_HEADERS
             )
         raise HTTPNotFound
diff --git a/homeassistant/components/http/view.py b/homeassistant/components/http/view.py
index 35e74b7c2c0..66864eba55e 100644
--- a/homeassistant/components/http/view.py
+++ b/homeassistant/components/http/view.py
@@ -2,6 +2,7 @@
 import asyncio
 import json
 import logging
+from typing import List, Optional
 
 from aiohttp import web
 from aiohttp.web_exceptions import (
@@ -22,11 +23,14 @@ from .const import KEY_AUTHENTICATED, KEY_HASS, KEY_REAL_IP
 _LOGGER = logging.getLogger(__name__)
 
 
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
+
 class HomeAssistantView:
     """Base view for all views."""
 
-    url = None
-    extra_urls = []
+    url: Optional[str] = None
+    extra_urls: List[str] = []
     # Views inheriting from this class can override this
     requires_auth = True
     cors_allowed = False
diff --git a/homeassistant/components/image_processing/__init__.py b/homeassistant/components/image_processing/__init__.py
index 1f106e12dcd..b1c167a4175 100644
--- a/homeassistant/components/image_processing/__init__.py
+++ b/homeassistant/components/image_processing/__init__.py
@@ -14,6 +14,9 @@ from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.entity_component import EntityComponent
 from homeassistant.util.async_ import run_callback_threadsafe
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 DOMAIN = "image_processing"
diff --git a/homeassistant/components/integration/sensor.py b/homeassistant/components/integration/sensor.py
index 006e0fe9a41..d24b70c4be0 100644
--- a/homeassistant/components/integration/sensor.py
+++ b/homeassistant/components/integration/sensor.py
@@ -16,6 +16,9 @@ from homeassistant.core import callback
 from homeassistant.helpers.event import async_track_state_change
 from homeassistant.helpers.restore_state import RestoreEntity
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 ATTR_SOURCE_ID = "source"
diff --git a/homeassistant/components/light/__init__.py b/homeassistant/components/light/__init__.py
index 7ac46d1237d..c70a209a35a 100644
--- a/homeassistant/components/light/__init__.py
+++ b/homeassistant/components/light/__init__.py
@@ -4,6 +4,7 @@ import csv
 from datetime import timedelta
 import logging
 import os
+from typing import Dict, Optional, Tuple
 
 import voluptuous as vol
 
@@ -29,6 +30,9 @@ from homeassistant.helpers import intent
 from homeassistant.loader import bind_hass
 import homeassistant.util.color as color_util
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 DOMAIN = "light"
 SCAN_INTERVAL = timedelta(seconds=30)
 
@@ -344,7 +348,7 @@ async def async_unload_entry(hass, entry):
 class Profiles:
     """Representation of available color profiles."""
 
-    _all = None
+    _all: Optional[Dict[str, Tuple[float, float, int]]] = None
 
     @classmethod
     async def load_profiles(cls, hass):
diff --git a/homeassistant/components/light/device_automation.py b/homeassistant/components/light/device_automation.py
index 26ddef16aae..ed75b5f906f 100644
--- a/homeassistant/components/light/device_automation.py
+++ b/homeassistant/components/light/device_automation.py
@@ -14,6 +14,9 @@ import homeassistant.helpers.config_validation as cv
 from homeassistant.helpers.entity_registry import async_entries_for_device
 from . import DOMAIN
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 CONF_TURN_OFF = "turn_off"
 CONF_TURN_ON = "turn_on"
 
diff --git a/homeassistant/components/lock/__init__.py b/homeassistant/components/lock/__init__.py
index a2205ccbf46..503bd3a8c78 100644
--- a/homeassistant/components/lock/__init__.py
+++ b/homeassistant/components/lock/__init__.py
@@ -25,6 +25,9 @@ from homeassistant.const import (
 )
 from homeassistant.components import group
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 ATTR_CHANGED_BY = "changed_by"
 
 DOMAIN = "lock"
diff --git a/homeassistant/components/mailbox/__init__.py b/homeassistant/components/mailbox/__init__.py
index 08853a4edce..1252036e1b2 100644
--- a/homeassistant/components/mailbox/__init__.py
+++ b/homeassistant/components/mailbox/__init__.py
@@ -16,6 +16,9 @@ from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.entity_component import EntityComponent
 from homeassistant.setup import async_prepare_setup_platform
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 DOMAIN = "mailbox"
diff --git a/homeassistant/components/media_player/__init__.py b/homeassistant/components/media_player/__init__.py
index 8334577ac30..791dacb7024 100644
--- a/homeassistant/components/media_player/__init__.py
+++ b/homeassistant/components/media_player/__init__.py
@@ -97,6 +97,9 @@ from .const import (
     SUPPORT_VOLUME_STEP,
 )
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 _RND = SystemRandom()
 
diff --git a/homeassistant/components/media_player/reproduce_state.py b/homeassistant/components/media_player/reproduce_state.py
index a926274e641..4eba4657d95 100644
--- a/homeassistant/components/media_player/reproduce_state.py
+++ b/homeassistant/components/media_player/reproduce_state.py
@@ -36,6 +36,9 @@ from .const import (
 )
 
 
+# mypy: allow-incomplete-defs, allow-untyped-defs
+
+
 async def _async_reproduce_states(
     hass: HomeAssistantType, state: State, context: Optional[Context] = None
 ) -> None:
diff --git a/homeassistant/components/mqtt/__init__.py b/homeassistant/components/mqtt/__init__.py
index af2fbac9639..75552d1d14b 100644
--- a/homeassistant/components/mqtt/__init__.py
+++ b/homeassistant/components/mqtt/__init__.py
@@ -416,7 +416,7 @@ async def async_subscribe(
     topic: str,
     msg_callback: MessageCallbackType,
     qos: int = DEFAULT_QOS,
-    encoding: str = "utf-8",
+    encoding: Optional[str] = "utf-8",
 ):
     """Subscribe to an MQTT topic.
 
@@ -829,7 +829,11 @@ class MQTT:
         return self.hass.async_add_job(stop)
 
     async def async_subscribe(
-        self, topic: str, msg_callback: MessageCallbackType, qos: int, encoding: str
+        self,
+        topic: str,
+        msg_callback: MessageCallbackType,
+        qos: int,
+        encoding: Optional[str] = None,
     ) -> Callable[[], None]:
         """Set up a subscription to a topic with the provided qos.
 
diff --git a/homeassistant/components/notify/__init__.py b/homeassistant/components/notify/__init__.py
index 8483b703a70..773c08808c3 100644
--- a/homeassistant/components/notify/__init__.py
+++ b/homeassistant/components/notify/__init__.py
@@ -2,6 +2,7 @@
 import asyncio
 import logging
 from functools import partial
+from typing import Optional
 
 import voluptuous as vol
 
@@ -10,8 +11,12 @@ from homeassistant.exceptions import HomeAssistantError
 import homeassistant.helpers.config_validation as cv
 from homeassistant.const import CONF_NAME, CONF_PLATFORM
 from homeassistant.helpers import config_per_platform, discovery
+from homeassistant.helpers.typing import HomeAssistantType
 from homeassistant.util import slugify
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 # Platform specific data
@@ -164,7 +169,7 @@ async def async_setup(hass, config):
 class BaseNotificationService:
     """An abstract class for notification services."""
 
-    hass = None
+    hass: Optional[HomeAssistantType] = None
 
     def send_message(self, message, **kwargs):
         """Send a message.
diff --git a/homeassistant/components/proximity/__init__.py b/homeassistant/components/proximity/__init__.py
index d563314225a..e9b85f79084 100644
--- a/homeassistant/components/proximity/__init__.py
+++ b/homeassistant/components/proximity/__init__.py
@@ -10,6 +10,9 @@ from homeassistant.helpers.event import track_state_change
 from homeassistant.util.distance import convert
 from homeassistant.util.location import distance
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 ATTR_DIR_OF_TRAVEL = "dir_of_travel"
diff --git a/homeassistant/components/remote/__init__.py b/homeassistant/components/remote/__init__.py
index e495874f339..450b1c123c3 100644
--- a/homeassistant/components/remote/__init__.py
+++ b/homeassistant/components/remote/__init__.py
@@ -22,6 +22,9 @@ from homeassistant.helpers.config_validation import (  # noqa
     PLATFORM_SCHEMA_BASE,
 )
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 ATTR_ACTIVITY = "activity"
diff --git a/homeassistant/components/scene/__init__.py b/homeassistant/components/scene/__init__.py
index 5ddb1116d8f..1f71a24c304 100644
--- a/homeassistant/components/scene/__init__.py
+++ b/homeassistant/components/scene/__init__.py
@@ -12,6 +12,9 @@ from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.entity_component import EntityComponent
 from homeassistant.helpers.state import HASS_DOMAIN
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 DOMAIN = "scene"
 STATE = "scening"
 STATES = "states"
diff --git a/homeassistant/components/sensor/__init__.py b/homeassistant/components/sensor/__init__.py
index cc460cdd4a9..9ca11b5266a 100644
--- a/homeassistant/components/sensor/__init__.py
+++ b/homeassistant/components/sensor/__init__.py
@@ -21,6 +21,9 @@ from homeassistant.helpers.config_validation import (  # noqa
 )
 from homeassistant.helpers.entity_component import EntityComponent
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 DOMAIN = "sensor"
diff --git a/homeassistant/components/switch/__init__.py b/homeassistant/components/switch/__init__.py
index a52380882db..348c2a8616b 100644
--- a/homeassistant/components/switch/__init__.py
+++ b/homeassistant/components/switch/__init__.py
@@ -20,6 +20,9 @@ from homeassistant.const import (
 )
 from homeassistant.components import group
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 DOMAIN = "switch"
 SCAN_INTERVAL = timedelta(seconds=30)
 
diff --git a/homeassistant/components/switch/light.py b/homeassistant/components/switch/light.py
index 38c66854a0b..0b1094c0dd9 100644
--- a/homeassistant/components/switch/light.py
+++ b/homeassistant/components/switch/light.py
@@ -1,5 +1,6 @@
 """Light support for switch entities."""
 import logging
+from typing import cast
 
 import voluptuous as vol
 
@@ -18,6 +19,9 @@ from homeassistant.helpers.typing import ConfigType, HomeAssistantType
 
 from homeassistant.components.light import PLATFORM_SCHEMA, Light
 
+
+# mypy: allow-incomplete-defs, allow-untyped-calls, allow-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 DEFAULT_NAME = "Light Switch"
@@ -35,7 +39,7 @@ async def async_setup_platform(
 ) -> None:
     """Initialize Light Switch platform."""
     async_add_entities(
-        [LightSwitch(config.get(CONF_NAME), config[CONF_ENTITY_ID])], True
+        [LightSwitch(cast(str, config.get(CONF_NAME)), config[CONF_ENTITY_ID])], True
     )
 
 
diff --git a/homeassistant/components/systemmonitor/sensor.py b/homeassistant/components/systemmonitor/sensor.py
index 207440a6646..446a36ec350 100644
--- a/homeassistant/components/systemmonitor/sensor.py
+++ b/homeassistant/components/systemmonitor/sensor.py
@@ -12,6 +12,9 @@ from homeassistant.helpers.entity import Entity
 import homeassistant.helpers.config_validation as cv
 import homeassistant.util.dt as dt_util
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 CONF_ARG = "arg"
diff --git a/homeassistant/components/tts/__init__.py b/homeassistant/components/tts/__init__.py
index 862c5e9cf9a..77d24fd7aab 100644
--- a/homeassistant/components/tts/__init__.py
+++ b/homeassistant/components/tts/__init__.py
@@ -8,6 +8,7 @@ import logging
 import mimetypes
 import os
 import re
+from typing import Optional
 
 from aiohttp import web
 import voluptuous as vol
@@ -25,8 +26,12 @@ from homeassistant.core import callback
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers import config_per_platform
 import homeassistant.helpers.config_validation as cv
+from homeassistant.helpers.typing import HomeAssistantType
 from homeassistant.setup import async_prepare_setup_platform
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 ATTR_CACHE = "cache"
@@ -461,8 +466,8 @@ class SpeechManager:
 class Provider:
     """Represent a single TTS provider."""
 
-    hass = None
-    name = None
+    hass: Optional[HomeAssistantType] = None
+    name: Optional[str] = None
 
     @property
     def default_language(self):
diff --git a/homeassistant/components/vacuum/__init__.py b/homeassistant/components/vacuum/__init__.py
index ea2f29ed225..598c068aad5 100644
--- a/homeassistant/components/vacuum/__init__.py
+++ b/homeassistant/components/vacuum/__init__.py
@@ -27,6 +27,9 @@ from homeassistant.helpers.entity_component import EntityComponent
 from homeassistant.helpers.entity import ToggleEntity, Entity
 from homeassistant.helpers.icon import icon_for_battery_level
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 DOMAIN = "vacuum"
diff --git a/homeassistant/components/water_heater/__init__.py b/homeassistant/components/water_heater/__init__.py
index d4402eec3b5..c41381fe5fa 100644
--- a/homeassistant/components/water_heater/__init__.py
+++ b/homeassistant/components/water_heater/__init__.py
@@ -27,6 +27,9 @@ from homeassistant.const import (
     TEMP_FAHRENHEIT,
 )
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 DEFAULT_MIN_TEMP = 110
 DEFAULT_MAX_TEMP = 140
 
diff --git a/homeassistant/components/weather/__init__.py b/homeassistant/components/weather/__init__.py
index 0bd22304119..8f276279ee5 100644
--- a/homeassistant/components/weather/__init__.py
+++ b/homeassistant/components/weather/__init__.py
@@ -11,6 +11,9 @@ from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.entity_component import EntityComponent
 from homeassistant.helpers.temperature import display_temp as show_temp
 
+
+# mypy: allow-untyped-defs, no-check-untyped-defs
+
 _LOGGER = logging.getLogger(__name__)
 
 ATTR_CONDITION_CLASS = "condition_class"
diff --git a/homeassistant/data_entry_flow.py b/homeassistant/data_entry_flow.py
index 789093cc49c..7ce27d404cf 100644
--- a/homeassistant/data_entry_flow.py
+++ b/homeassistant/data_entry_flow.py
@@ -175,11 +175,11 @@ class FlowHandler:
     """Handle the configuration flow of a component."""
 
     # Set by flow manager
-    flow_id = None
-    hass = None
+    flow_id: Optional[str] = None
+    hass: Optional[HomeAssistant] = None
     handler = None
-    cur_step = None
-    context = None  # type: Optional[Dict]
+    cur_step: Optional[Dict[str, str]] = None
+    context: Optional[Dict] = None
 
     # Set by _async_create_flow callback
     init_step = "init"
diff --git a/homeassistant/scripts/check_config.py b/homeassistant/scripts/check_config.py
index e8493822771..28734b30fcc 100644
--- a/homeassistant/scripts/check_config.py
+++ b/homeassistant/scripts/check_config.py
@@ -28,7 +28,7 @@ MOCKS = {
 }  # type: Dict[str, Tuple[str, Callable]]
 SILENCE = ("homeassistant.scripts.check_config.yaml_loader.clear_secret_cache",)
 
-PATCHES = {}
+PATCHES: Dict[str, Any] = {}
 
 C_HEAD = "bold"
 ERROR_STR = "General Errors"
diff --git a/mypyrc b/mypyrc
index ece4678abe6..f3866f40e57 100644
--- a/mypyrc
+++ b/mypyrc
@@ -1,5 +1,32 @@
 homeassistant/*.py
 homeassistant/auth/
+homeassistant/components/*.py
+homeassistant/components/automation/
+homeassistant/components/binary_sensor/
+homeassistant/components/calendar/
+homeassistant/components/camera/
+homeassistant/components/cover/
+homeassistant/components/frontend/
+homeassistant/components/geo_location/
+homeassistant/components/history/
+homeassistant/components/http/
+homeassistant/components/image_processing/
+homeassistant/components/integration/
+homeassistant/components/light/
+homeassistant/components/lock/
+homeassistant/components/mailbox/
+homeassistant/components/media_player/
+homeassistant/components/notify/
+homeassistant/components/proximity/
+homeassistant/components/remote/
+homeassistant/components/scene/
+homeassistant/components/sensor/
+homeassistant/components/switch/
+homeassistant/components/systemmonitor/
+homeassistant/components/tts/
+homeassistant/components/vacuum/
+homeassistant/components/water_heater/
+homeassistant/components/weather/
 homeassistant/helpers/
 homeassistant/scripts/
 homeassistant/util/