diff --git a/homeassistant/auth/mfa_modules/notify.py b/homeassistant/auth/mfa_modules/notify.py
index d8c28409b2d..c4e5800821e 100644
--- a/homeassistant/auth/mfa_modules/notify.py
+++ b/homeassistant/auth/mfa_modules/notify.py
@@ -77,10 +77,10 @@ def _verify_otp(secret: str, otp: str, count: int) -> bool:
 class NotifySetting:
     """Store notify setting for one user."""
 
-    secret = attr.ib(type=str, factory=_generate_secret)  # not persistent
-    counter = attr.ib(type=int, factory=_generate_random)  # not persistent
-    notify_service = attr.ib(type=Optional[str], default=None)
-    target = attr.ib(type=Optional[str], default=None)
+    secret: str = attr.ib(factory=_generate_secret)  # not persistent
+    counter: int = attr.ib(factory=_generate_random)  # not persistent
+    notify_service: Optional[str] = attr.ib(default=None)
+    target: Optional[str] = attr.ib(default=None)
 
 
 _UsersDict = Dict[str, NotifySetting]
diff --git a/homeassistant/auth/models.py b/homeassistant/auth/models.py
index 502155df129..e4f31eea330 100644
--- a/homeassistant/auth/models.py
+++ b/homeassistant/auth/models.py
@@ -20,39 +20,35 @@ TOKEN_TYPE_LONG_LIVED_ACCESS_TOKEN = "long_lived_access_token"
 class Group:
     """A group."""
 
-    name = attr.ib(type=Optional[str])
-    policy = attr.ib(type=perm_mdl.PolicyType)
-    id = attr.ib(type=str, factory=lambda: uuid.uuid4().hex)
-    system_generated = attr.ib(type=bool, default=False)
+    name: Optional[str] = attr.ib()
+    policy: perm_mdl.PolicyType = attr.ib()
+    id: str = attr.ib(factory=lambda: uuid.uuid4().hex)
+    system_generated: bool = attr.ib(default=False)
 
 
 @attr.s(slots=True)
 class User:
     """A user."""
 
-    name = attr.ib(type=Optional[str])
-    perm_lookup = attr.ib(type=perm_mdl.PermissionLookup, eq=False, order=False)
-    id = attr.ib(type=str, factory=lambda: uuid.uuid4().hex)
-    is_owner = attr.ib(type=bool, default=False)
-    is_active = attr.ib(type=bool, default=False)
-    system_generated = attr.ib(type=bool, default=False)
+    name: Optional[str] = attr.ib()
+    perm_lookup: perm_mdl.PermissionLookup = attr.ib(eq=False, order=False)
+    id: str = attr.ib(factory=lambda: uuid.uuid4().hex)
+    is_owner: bool = attr.ib(default=False)
+    is_active: bool = attr.ib(default=False)
+    system_generated: bool = attr.ib(default=False)
 
-    groups = attr.ib(type=List[Group], factory=list, eq=False, order=False)
+    groups: List[Group] = attr.ib(factory=list, eq=False, order=False)
 
     # List of credentials of a user.
-    credentials = attr.ib(type=List["Credentials"], factory=list, eq=False, order=False)
+    credentials: List["Credentials"] = attr.ib(factory=list, eq=False, order=False)
 
     # Tokens associated with a user.
-    refresh_tokens = attr.ib(
-        type=Dict[str, "RefreshToken"], factory=dict, eq=False, order=False
+    refresh_tokens: Dict[str, "RefreshToken"] = attr.ib(
+        factory=dict, eq=False, order=False
     )
 
-    _permissions = attr.ib(
-        type=Optional[perm_mdl.PolicyPermissions],
-        init=False,
-        eq=False,
-        order=False,
-        default=None,
+    _permissions: Optional[perm_mdl.PolicyPermissions] = attr.ib(
+        init=False, eq=False, order=False, default=None,
     )
 
     @property
@@ -88,39 +84,38 @@ class User:
 class RefreshToken:
     """RefreshToken for a user to grant new access tokens."""
 
-    user = attr.ib(type=User)
-    client_id = attr.ib(type=Optional[str])
-    access_token_expiration = attr.ib(type=timedelta)
-    client_name = attr.ib(type=Optional[str], default=None)
-    client_icon = attr.ib(type=Optional[str], default=None)
-    token_type = attr.ib(
-        type=str,
+    user: User = attr.ib()
+    client_id: Optional[str] = attr.ib()
+    access_token_expiration: timedelta = attr.ib()
+    client_name: Optional[str] = attr.ib(default=None)
+    client_icon: Optional[str] = attr.ib(default=None)
+    token_type: str = attr.ib(
         default=TOKEN_TYPE_NORMAL,
         validator=attr.validators.in_(
             (TOKEN_TYPE_NORMAL, TOKEN_TYPE_SYSTEM, TOKEN_TYPE_LONG_LIVED_ACCESS_TOKEN)
         ),
     )
-    id = attr.ib(type=str, factory=lambda: uuid.uuid4().hex)
-    created_at = attr.ib(type=datetime, factory=dt_util.utcnow)
-    token = attr.ib(type=str, factory=lambda: secrets.token_hex(64))
-    jwt_key = attr.ib(type=str, factory=lambda: secrets.token_hex(64))
+    id: str = attr.ib(factory=lambda: uuid.uuid4().hex)
+    created_at: datetime = attr.ib(factory=dt_util.utcnow)
+    token: str = attr.ib(factory=lambda: secrets.token_hex(64))
+    jwt_key: str = attr.ib(factory=lambda: secrets.token_hex(64))
 
-    last_used_at = attr.ib(type=Optional[datetime], default=None)
-    last_used_ip = attr.ib(type=Optional[str], default=None)
+    last_used_at: Optional[datetime] = attr.ib(default=None)
+    last_used_ip: Optional[str] = attr.ib(default=None)
 
 
 @attr.s(slots=True)
 class Credentials:
     """Credentials for a user on an auth provider."""
 
-    auth_provider_type = attr.ib(type=str)
-    auth_provider_id = attr.ib(type=Optional[str])
+    auth_provider_type: str = attr.ib()
+    auth_provider_id: Optional[str] = attr.ib()
 
     # Allow the auth provider to store data to represent their auth.
-    data = attr.ib(type=dict)
+    data: dict = attr.ib()
 
-    id = attr.ib(type=str, factory=lambda: uuid.uuid4().hex)
-    is_new = attr.ib(type=bool, default=True)
+    id: str = attr.ib(factory=lambda: uuid.uuid4().hex)
+    is_new: bool = attr.ib(default=True)
 
 
 class UserMeta(NamedTuple):
diff --git a/homeassistant/auth/permissions/models.py b/homeassistant/auth/permissions/models.py
index 1224ea07b23..435d5f2e982 100644
--- a/homeassistant/auth/permissions/models.py
+++ b/homeassistant/auth/permissions/models.py
@@ -13,5 +13,5 @@ if TYPE_CHECKING:
 class PermissionLookup:
     """Class to hold data for permission lookups."""
 
-    entity_registry = attr.ib(type="ent_reg.EntityRegistry")
-    device_registry = attr.ib(type="dev_reg.DeviceRegistry")
+    entity_registry: "ent_reg.EntityRegistry" = attr.ib()
+    device_registry: "dev_reg.DeviceRegistry" = attr.ib()
diff --git a/homeassistant/components/camera/__init__.py b/homeassistant/components/camera/__init__.py
index 2e49b50651b..bdc94b19eb1 100644
--- a/homeassistant/components/camera/__init__.py
+++ b/homeassistant/components/camera/__init__.py
@@ -119,8 +119,8 @@ SCHEMA_WS_CAMERA_THUMBNAIL = websocket_api.BASE_COMMAND_MESSAGE_SCHEMA.extend(
 class Image:
     """Represent an image."""
 
-    content_type = attr.ib(type=str)
-    content = attr.ib(type=bytes)
+    content_type: str = attr.ib()
+    content: bytes = attr.ib()
 
 
 @bind_hass
diff --git a/homeassistant/components/cast/helpers.py b/homeassistant/components/cast/helpers.py
index cc0ec911bbf..0ad13d137d1 100644
--- a/homeassistant/components/cast/helpers.py
+++ b/homeassistant/components/cast/helpers.py
@@ -14,14 +14,14 @@ class ChromecastInfo:
     This also has the same attributes as the mDNS fields by zeroconf.
     """
 
-    services = attr.ib(type=Optional[set])
-    host = attr.ib(type=Optional[str], default=None)
-    port = attr.ib(type=Optional[int], default=0)
-    uuid = attr.ib(
-        type=Optional[str], converter=attr.converters.optional(str), default=None
+    services: Optional[set] = attr.ib()
+    host: Optional[str] = attr.ib(default=None)
+    port: Optional[int] = attr.ib(default=0)
+    uuid: Optional[str] = attr.ib(
+        converter=attr.converters.optional(str), default=None
     )  # always convert UUID to string if not None
-    model_name = attr.ib(type=str, default="")
-    friendly_name = attr.ib(type=Optional[str], default=None)
+    model_name: str = attr.ib(default="")
+    friendly_name: Optional[str] = attr.ib(default=None)
 
     @property
     def is_audio_group(self) -> bool:
diff --git a/homeassistant/components/device_tracker/setup.py b/homeassistant/components/device_tracker/setup.py
index 3b7afbe25ee..6d1d81634bd 100644
--- a/homeassistant/components/device_tracker/setup.py
+++ b/homeassistant/components/device_tracker/setup.py
@@ -35,9 +35,9 @@ class DeviceTrackerPlatform:
         "setup_scanner",
     )
 
-    name = attr.ib(type=str)
-    platform = attr.ib(type=ModuleType)
-    config = attr.ib(type=Dict)
+    name: str = attr.ib()
+    platform: ModuleType = attr.ib()
+    config: Dict = attr.ib()
 
     @property
     def type(self):
diff --git a/homeassistant/components/esphome/entry_data.py b/homeassistant/components/esphome/entry_data.py
index d8453c974f6..8f273b682ff 100644
--- a/homeassistant/components/esphome/entry_data.py
+++ b/homeassistant/components/esphome/entry_data.py
@@ -1,6 +1,6 @@
 """Runtime entry data for ESPHome stored in hass.data."""
 import asyncio
-from typing import Any, Callable, Dict, List, Optional, Set, Tuple
+from typing import TYPE_CHECKING, Any, Callable, Dict, List, Optional, Set, Tuple
 
 from aioesphomeapi import (
     COMPONENT_TYPE_TO_INFO,
@@ -26,6 +26,9 @@ from homeassistant.helpers.dispatcher import async_dispatcher_send
 from homeassistant.helpers.storage import Store
 from homeassistant.helpers.typing import HomeAssistantType
 
+if TYPE_CHECKING:
+    from . import APIClient
+
 DATA_KEY = "esphome"
 
 # Mapping from ESPHome info type to HA platform
@@ -46,26 +49,26 @@ INFO_TYPE_TO_PLATFORM = {
 class RuntimeEntryData:
     """Store runtime data for esphome config entries."""
 
-    entry_id = attr.ib(type=str)
-    client = attr.ib(type="APIClient")
-    store = attr.ib(type=Store)
-    reconnect_task = attr.ib(type=Optional[asyncio.Task], default=None)
-    state = attr.ib(type=Dict[str, Dict[str, Any]], factory=dict)
-    info = attr.ib(type=Dict[str, Dict[str, Any]], factory=dict)
+    entry_id: str = attr.ib()
+    client: "APIClient" = attr.ib()
+    store: Store = attr.ib()
+    reconnect_task: Optional[asyncio.Task] = attr.ib(default=None)
+    state: Dict[str, Dict[str, Any]] = attr.ib(factory=dict)
+    info: Dict[str, Dict[str, Any]] = attr.ib(factory=dict)
 
     # A second list of EntityInfo objects
     # This is necessary for when an entity is being removed. HA requires
     # some static info to be accessible during removal (unique_id, maybe others)
     # If an entity can't find anything in the info array, it will look for info here.
-    old_info = attr.ib(type=Dict[str, Dict[str, Any]], factory=dict)
+    old_info: Dict[str, Dict[str, Any]] = attr.ib(factory=dict)
 
-    services = attr.ib(type=Dict[int, "UserService"], factory=dict)
-    available = attr.ib(type=bool, default=False)
-    device_info = attr.ib(type=DeviceInfo, default=None)
-    cleanup_callbacks = attr.ib(type=List[Callable[[], None]], factory=list)
-    disconnect_callbacks = attr.ib(type=List[Callable[[], None]], factory=list)
-    loaded_platforms = attr.ib(type=Set[str], factory=set)
-    platform_load_lock = attr.ib(type=asyncio.Lock, factory=asyncio.Lock)
+    services: Dict[int, "UserService"] = attr.ib(factory=dict)
+    available: bool = attr.ib(default=False)
+    device_info: Optional[DeviceInfo] = attr.ib(default=None)
+    cleanup_callbacks: List[Callable[[], None]] = attr.ib(factory=list)
+    disconnect_callbacks: List[Callable[[], None]] = attr.ib(factory=list)
+    loaded_platforms: Set[str] = attr.ib(factory=set)
+    platform_load_lock: asyncio.Lock = attr.ib(factory=asyncio.Lock)
 
     @callback
     def async_update_entity(
diff --git a/homeassistant/components/mqtt/__init__.py b/homeassistant/components/mqtt/__init__.py
index ef5bea57bd3..0a35c85d023 100644
--- a/homeassistant/components/mqtt/__init__.py
+++ b/homeassistant/components/mqtt/__init__.py
@@ -612,10 +612,10 @@ async def async_setup_entry(hass, entry):
 class Subscription:
     """Class to hold data about an active subscription."""
 
-    topic = attr.ib(type=str)
-    callback = attr.ib(type=MessageCallbackType)
-    qos = attr.ib(type=int, default=0)
-    encoding = attr.ib(type=str, default="utf-8")
+    topic: str = attr.ib()
+    callback: MessageCallbackType = attr.ib()
+    qos: int = attr.ib(default=0)
+    encoding: str = attr.ib(default="utf-8")
 
 
 class MQTT:
diff --git a/homeassistant/components/mqtt/device_trigger.py b/homeassistant/components/mqtt/device_trigger.py
index 7ff40ffe27d..cf8d0f250d1 100644
--- a/homeassistant/components/mqtt/device_trigger.py
+++ b/homeassistant/components/mqtt/device_trigger.py
@@ -1,6 +1,6 @@
 """Provides device automations for MQTT."""
 import logging
-from typing import Callable, List
+from typing import Callable, List, Optional
 
 import attr
 import voluptuous as vol
@@ -75,10 +75,10 @@ DEVICE_TRIGGERS = "mqtt_device_triggers"
 class TriggerInstance:
     """Attached trigger settings."""
 
-    action = attr.ib(type=AutomationActionType)
-    automation_info = attr.ib(type=dict)
-    trigger = attr.ib(type="Trigger")
-    remove = attr.ib(type=CALLBACK_TYPE, default=None)
+    action: AutomationActionType = attr.ib()
+    automation_info: dict = attr.ib()
+    trigger: "Trigger" = attr.ib()
+    remove: Optional[CALLBACK_TYPE] = attr.ib(default=None)
 
     async def async_attach_trigger(self):
         """Attach MQTT trigger."""
@@ -101,16 +101,16 @@ class TriggerInstance:
 class Trigger:
     """Device trigger settings."""
 
-    device_id = attr.ib(type=str)
-    discovery_data = attr.ib(type=dict)
-    hass = attr.ib(type=HomeAssistantType)
-    payload = attr.ib(type=str)
-    qos = attr.ib(type=int)
-    remove_signal = attr.ib(type=Callable[[], None])
-    subtype = attr.ib(type=str)
-    topic = attr.ib(type=str)
-    type = attr.ib(type=str)
-    trigger_instances = attr.ib(type=[TriggerInstance], default=attr.Factory(list))
+    device_id: str = attr.ib()
+    discovery_data: dict = attr.ib()
+    hass: HomeAssistantType = attr.ib()
+    payload: str = attr.ib()
+    qos: int = attr.ib()
+    remove_signal: Callable[[], None] = attr.ib()
+    subtype: str = attr.ib()
+    topic: str = attr.ib()
+    type: str = attr.ib()
+    trigger_instances: List[TriggerInstance] = attr.ib(factory=list)
 
     async def add_trigger(self, action, automation_info):
         """Add MQTT trigger."""
diff --git a/homeassistant/components/mqtt/models.py b/homeassistant/components/mqtt/models.py
index 1fb6cd28fac..202f457372c 100644
--- a/homeassistant/components/mqtt/models.py
+++ b/homeassistant/components/mqtt/models.py
@@ -1,6 +1,6 @@
 """Modesl used by multiple MQTT modules."""
 import datetime as dt
-from typing import Callable, Union
+from typing import Callable, Optional, Union
 
 import attr
 
@@ -11,12 +11,12 @@ PublishPayloadType = Union[str, bytes, int, float, None]
 class Message:
     """MQTT Message."""
 
-    topic = attr.ib(type=str)
-    payload = attr.ib(type=PublishPayloadType)
-    qos = attr.ib(type=int)
-    retain = attr.ib(type=bool)
-    subscribed_topic = attr.ib(type=str, default=None)
-    timestamp = attr.ib(type=dt.datetime, default=None)
+    topic: str = attr.ib()
+    payload: PublishPayloadType = attr.ib()
+    qos: int = attr.ib()
+    retain: bool = attr.ib()
+    subscribed_topic: Optional[str] = attr.ib(default=None)
+    timestamp: Optional[dt.datetime] = attr.ib(default=None)
 
 
 MessageCallbackType = Callable[[Message], None]
diff --git a/homeassistant/components/mqtt/subscription.py b/homeassistant/components/mqtt/subscription.py
index c1de08d5be8..feccdc33bc2 100644
--- a/homeassistant/components/mqtt/subscription.py
+++ b/homeassistant/components/mqtt/subscription.py
@@ -19,12 +19,12 @@ _LOGGER = logging.getLogger(__name__)
 class EntitySubscription:
     """Class to hold data about an active entity topic subscription."""
 
-    hass = attr.ib(type=HomeAssistantType)
-    topic = attr.ib(type=str)
-    message_callback = attr.ib(type=MessageCallbackType)
-    unsubscribe_callback = attr.ib(type=Optional[Callable[[], None]])
-    qos = attr.ib(type=int, default=0)
-    encoding = attr.ib(type=str, default="utf-8")
+    hass: HomeAssistantType = attr.ib()
+    topic: str = attr.ib()
+    message_callback: MessageCallbackType = attr.ib()
+    unsubscribe_callback: Optional[Callable[[], None]] = attr.ib()
+    qos: int = attr.ib(default=0)
+    encoding: str = attr.ib(default="utf-8")
 
     async def resubscribe_if_necessary(self, hass, other):
         """Re-subscribe to the new topic if necessary."""
diff --git a/homeassistant/components/stream/core.py b/homeassistant/components/stream/core.py
index 153c006ccb2..715ae47e133 100644
--- a/homeassistant/components/stream/core.py
+++ b/homeassistant/components/stream/core.py
@@ -21,19 +21,19 @@ PROVIDERS = Registry()
 class StreamBuffer:
     """Represent a segment."""
 
-    segment = attr.ib(type=io.BytesIO)
+    segment: io.BytesIO = attr.ib()
     output = attr.ib()  # type=av.OutputContainer
     vstream = attr.ib()  # type=av.VideoStream
-    astream = attr.ib(default=None)  # type=av.AudioStream
+    astream = attr.ib(default=None)  # type=Optional[av.AudioStream]
 
 
 @attr.s
 class Segment:
     """Represent a segment."""
 
-    sequence = attr.ib(type=int)
-    segment = attr.ib(type=io.BytesIO)
-    duration = attr.ib(type=float)
+    sequence: int = attr.ib()
+    segment: io.BytesIO = attr.ib()
+    duration: float = attr.ib()
 
 
 class StreamOutput:
diff --git a/homeassistant/components/zha/core/store.py b/homeassistant/components/zha/core/store.py
index 896402703da..ab560820f19 100644
--- a/homeassistant/components/zha/core/store.py
+++ b/homeassistant/components/zha/core/store.py
@@ -4,7 +4,7 @@ from collections import OrderedDict
 import datetime
 import logging
 import time
-from typing import MutableMapping, cast
+from typing import MutableMapping, Optional, cast
 
 import attr
 
@@ -28,9 +28,9 @@ TOMBSTONE_LIFETIME = datetime.timedelta(days=60).total_seconds()
 class ZhaDeviceEntry:
     """Zha Device storage Entry."""
 
-    name = attr.ib(type=str, default=None)
-    ieee = attr.ib(type=str, default=None)
-    last_seen = attr.ib(type=float, default=None)
+    name: Optional[str] = attr.ib(default=None)
+    ieee: Optional[str] = attr.ib(default=None)
+    last_seen: Optional[float] = attr.ib(default=None)
 
 
 class ZhaStorage:
diff --git a/homeassistant/config_entries.py b/homeassistant/config_entries.py
index d707546a8cc..77efc3824df 100644
--- a/homeassistant/config_entries.py
+++ b/homeassistant/config_entries.py
@@ -1025,7 +1025,7 @@ class OptionsFlow(data_entry_flow.FlowHandler):
 class SystemOptions:
     """Config entry system options."""
 
-    disable_new_entities = attr.ib(type=bool, default=False)
+    disable_new_entities: bool = attr.ib(default=False)
 
     def update(self, *, disable_new_entities: bool) -> None:
         """Update properties."""
diff --git a/homeassistant/core.py b/homeassistant/core.py
index fb6db49139d..a8613dade59 100644
--- a/homeassistant/core.py
+++ b/homeassistant/core.py
@@ -456,9 +456,9 @@ class HomeAssistant:
 class Context:
     """The context that triggered something."""
 
-    user_id = attr.ib(type=str, default=None)
-    parent_id = attr.ib(type=Optional[str], default=None)
-    id = attr.ib(type=str, default=attr.Factory(lambda: uuid.uuid4().hex))
+    user_id: str = attr.ib(default=None)
+    parent_id: Optional[str] = attr.ib(default=None)
+    id: str = attr.ib(factory=lambda: uuid.uuid4().hex)
 
     def as_dict(self) -> dict:
         """Return a dictionary representation of the context."""
diff --git a/homeassistant/helpers/area_registry.py b/homeassistant/helpers/area_registry.py
index 58abecffb8b..72f4b2c5e6d 100644
--- a/homeassistant/helpers/area_registry.py
+++ b/homeassistant/helpers/area_registry.py
@@ -25,8 +25,8 @@ SAVE_DELAY = 10
 class AreaEntry:
     """Area Registry Entry."""
 
-    name = attr.ib(type=str, default=None)
-    id = attr.ib(type=str, default=attr.Factory(lambda: uuid.uuid4().hex))
+    name: Optional[str] = attr.ib(default=None)
+    id: str = attr.ib(factory=lambda: uuid.uuid4().hex)
 
 
 class AreaRegistry:
diff --git a/homeassistant/helpers/check_config.py b/homeassistant/helpers/check_config.py
index d876748e8d1..7b71b7aae2b 100644
--- a/homeassistant/helpers/check_config.py
+++ b/homeassistant/helpers/check_config.py
@@ -40,7 +40,7 @@ class CheckConfigError(NamedTuple):
 class HomeAssistantConfig(OrderedDict):
     """Configuration result with errors attribute."""
 
-    errors: List[CheckConfigError] = attr.ib(default=attr.Factory(list))
+    errors: List[CheckConfigError] = attr.ib(factory=list)
 
     def add_error(
         self,
diff --git a/homeassistant/helpers/device_registry.py b/homeassistant/helpers/device_registry.py
index aeee9e802c9..f9a7d6660da 100644
--- a/homeassistant/helpers/device_registry.py
+++ b/homeassistant/helpers/device_registry.py
@@ -57,13 +57,9 @@ class DeletedDeviceEntry:
 class DeviceEntry:
     """Device Registry Entry."""
 
-    config_entries: Set[str] = attr.ib(converter=set, default=attr.Factory(set))
-    connections: Set[Tuple[str, str]] = attr.ib(
-        converter=set, default=attr.Factory(set)
-    )
-    identifiers: Set[Tuple[str, str]] = attr.ib(
-        converter=set, default=attr.Factory(set)
-    )
+    config_entries: Set[str] = attr.ib(converter=set, factory=set)
+    connections: Set[Tuple[str, str]] = attr.ib(converter=set, factory=set)
+    identifiers: Set[Tuple[str, str]] = attr.ib(converter=set, factory=set)
     manufacturer: str = attr.ib(default=None)
     model: str = attr.ib(default=None)
     name: str = attr.ib(default=None)
@@ -72,7 +68,7 @@ class DeviceEntry:
     area_id: str = attr.ib(default=None)
     name_by_user: str = attr.ib(default=None)
     entry_type: str = attr.ib(default=None)
-    id: str = attr.ib(default=attr.Factory(lambda: uuid.uuid4().hex))
+    id: str = attr.ib(factory=lambda: uuid.uuid4().hex)
     # This value is not stored, just used to keep track of events to fire.
     is_new: bool = attr.ib(default=False)
 
diff --git a/homeassistant/helpers/entity_registry.py b/homeassistant/helpers/entity_registry.py
index de4f5eeb297..b9b9af6f5c1 100644
--- a/homeassistant/helpers/entity_registry.py
+++ b/homeassistant/helpers/entity_registry.py
@@ -78,15 +78,14 @@ ENTITY_DESCRIBING_ATTRIBUTES = {
 class RegistryEntry:
     """Entity Registry Entry."""
 
-    entity_id = attr.ib(type=str)
-    unique_id = attr.ib(type=str)
-    platform = attr.ib(type=str)
-    name = attr.ib(type=str, default=None)
-    icon = attr.ib(type=str, default=None)
+    entity_id: str = attr.ib()
+    unique_id: str = attr.ib()
+    platform: str = attr.ib()
+    name: Optional[str] = attr.ib(default=None)
+    icon: Optional[str] = attr.ib(default=None)
     device_id: Optional[str] = attr.ib(default=None)
     config_entry_id: Optional[str] = attr.ib(default=None)
-    disabled_by = attr.ib(
-        type=Optional[str],
+    disabled_by: Optional[str] = attr.ib(
         default=None,
         validator=attr.validators.in_(
             (
@@ -105,7 +104,7 @@ class RegistryEntry:
     # As set by integration
     original_name: Optional[str] = attr.ib(default=None)
     original_icon: Optional[str] = attr.ib(default=None)
-    domain = attr.ib(type=str, init=False, repr=False)
+    domain: str = attr.ib(init=False, repr=False)
 
     @domain.default
     def _domain_default(self) -> str:
diff --git a/homeassistant/helpers/event.py b/homeassistant/helpers/event.py
index a947e6b54b0..e1ef0ed5952 100644
--- a/homeassistant/helpers/event.py
+++ b/homeassistant/helpers/event.py
@@ -400,7 +400,7 @@ track_time_interval = threaded_listener_factory(async_track_time_interval)
 class SunListener:
     """Helper class to help listen to sun events."""
 
-    hass = attr.ib(type=HomeAssistant)
+    hass: HomeAssistant = attr.ib()
     action: Callable[..., None] = attr.ib()
     event: str = attr.ib()
     offset: Optional[timedelta] = attr.ib()
diff --git a/homeassistant/util/color.py b/homeassistant/util/color.py
index 965b5950c93..1e782f0c0f9 100644
--- a/homeassistant/util/color.py
+++ b/homeassistant/util/color.py
@@ -167,8 +167,8 @@ COLORS = {
 class XYPoint:
     """Represents a CIE 1931 XY coordinate pair."""
 
-    x = attr.ib(type=float)  # pylint: disable=invalid-name
-    y = attr.ib(type=float)  # pylint: disable=invalid-name
+    x: float = attr.ib()  # pylint: disable=invalid-name
+    y: float = attr.ib()  # pylint: disable=invalid-name
 
 
 @attr.s()
@@ -176,9 +176,9 @@ class GamutType:
     """Represents the Gamut of a light."""
 
     # ColorGamut = gamut(xypoint(xR,yR),xypoint(xG,yG),xypoint(xB,yB))
-    red = attr.ib(type=XYPoint)
-    green = attr.ib(type=XYPoint)
-    blue = attr.ib(type=XYPoint)
+    red: XYPoint = attr.ib()
+    green: XYPoint = attr.ib()
+    blue: XYPoint = attr.ib()
 
 
 def color_name_to_rgb(color_name: str) -> Tuple[int, int, int]:
diff --git a/script/hassfest/model.py b/script/hassfest/model.py
index e90a08f69fe..bb438f4d84f 100644
--- a/script/hassfest/model.py
+++ b/script/hassfest/model.py
@@ -11,9 +11,9 @@ import attr
 class Error:
     """Error validating an integration."""
 
-    plugin = attr.ib(type=str)
-    error = attr.ib(type=str)
-    fixable = attr.ib(type=bool, default=False)
+    plugin: str = attr.ib()
+    error: str = attr.ib()
+    fixable: bool = attr.ib(default=False)
 
     def __str__(self) -> str:
         """Represent error as string."""
@@ -63,10 +63,10 @@ class Integration:
 
         return integrations
 
-    path = attr.ib(type=pathlib.Path)
-    manifest = attr.ib(type=dict, default=None)
-    errors = attr.ib(type=List[Error], factory=list)
-    warnings = attr.ib(type=List[Error], factory=list)
+    path: pathlib.Path = attr.ib()
+    manifest: Optional[dict] = attr.ib(default=None)
+    errors: List[Error] = attr.ib(factory=list)
+    warnings: List[Error] = attr.ib(factory=list)
 
     @property
     def domain(self) -> str: