diff --git a/docs/.vuepress/public/logo.png b/docs/.vuepress/public/logo.png
index 45857ada..2b7e3815 100644
Binary files a/docs/.vuepress/public/logo.png and b/docs/.vuepress/public/logo.png differ
diff --git a/nonebot/adapters/__init__.py b/nonebot/adapters/__init__.py
index f7e6a3bd..1ce77bc0 100644
--- a/nonebot/adapters/__init__.py
+++ b/nonebot/adapters/__init__.py
@@ -4,10 +4,9 @@
 import abc
 from functools import reduce
 from dataclasses import dataclass, field
-from nonebot.rule import notice
 
 from nonebot.config import Config
-from nonebot.typing import Dict, Union, Iterable, WebSocket
+from nonebot.typing import Dict, Union, Optional, Iterable, WebSocket
 
 
 class BaseBot(abc.ABC):
@@ -49,32 +48,32 @@ class BaseEvent(abc.ABC):
 
     @property
     @abc.abstractmethod
-    def type(self):
+    def type(self) -> str:
         raise NotImplementedError
 
     @type.setter
     @abc.abstractmethod
-    def type(self, value):
+    def type(self, value) -> None:
         raise NotImplementedError
 
     @property
     @abc.abstractmethod
-    def detail_type(self):
+    def detail_type(self) -> str:
         raise NotImplementedError
 
     @detail_type.setter
     @abc.abstractmethod
-    def detail_type(self, value):
+    def detail_type(self, value) -> None:
         raise NotImplementedError
 
     @property
     @abc.abstractmethod
-    def sub_type(self):
+    def sub_type(self) -> Optional[str]:
         raise NotImplementedError
 
     @sub_type.setter
     @abc.abstractmethod
-    def sub_type(self, value):
+    def sub_type(self, value) -> None:
         raise NotImplementedError
 
 
diff --git a/nonebot/adapters/cqhttp.py b/nonebot/adapters/cqhttp.py
index ee109468..ce68977a 100644
--- a/nonebot/adapters/cqhttp.py
+++ b/nonebot/adapters/cqhttp.py
@@ -58,14 +58,11 @@ class Bot(BaseBot):
 
     @overrides(BaseBot)
     async def handle_message(self, message: dict):
-        # TODO: convert message into event
-        event = Event(message)
-
-        if not event:
+        if not message:
             return
 
-        # if "message" in event.keys():
-        #     event["message"] = Message(event["message"])
+        # TODO: convert message into event
+        event = Event(message)
 
         await handle_event(self, event)
 
@@ -98,37 +95,39 @@ class Bot(BaseBot):
 class Event(BaseEvent):
 
     def __init__(self, raw_event: dict):
+        if "message" in raw_event:
+            raw_event["message"] = Message(raw_event["message"])
 
         super().__init__(raw_event)
 
     @property
     @overrides(BaseEvent)
-    def type(self):
+    def type(self) -> str:
         return self._raw_event["post_type"]
 
     @type.setter
     @overrides(BaseEvent)
-    def type(self, value):
+    def type(self, value) -> None:
         self._raw_event["post_type"] = value
 
     @property
     @overrides(BaseEvent)
-    def detail_type(self):
+    def detail_type(self) -> str:
         return self._raw_event[f"{self.type}_type"]
 
     @detail_type.setter
     @overrides(BaseEvent)
-    def detail_type(self, value):
+    def detail_type(self, value) -> None:
         self._raw_event[f"{self.type}_type"] = value
 
     @property
     @overrides(BaseEvent)
-    def sub_type(self):
-        return self._raw_event["sub_type"]
+    def sub_type(self) -> Optional[str]:
+        return self._raw_event.get("sub_type")
 
     @type.setter
     @overrides(BaseEvent)
-    def sub_type(self, value):
+    def sub_type(self, value) -> None:
         self._raw_event["sub_type"] = value