diff --git a/aiogram/client/bot.py b/aiogram/client/bot.py
index a4a56127..1c6de27c 100644
--- a/aiogram/client/bot.py
+++ b/aiogram/client/bot.py
@@ -20,7 +20,9 @@ from typing import (
 import aiofiles
 
 from aiogram.utils.token import extract_bot_id, validate_token
-
+from .default import Default, DefaultBotProperties
+from .session.aiohttp import AiohttpSession
+from .session.base import BaseSession
 from ..methods import (
     AddStickerToSet,
     AnswerCallbackQuery,
@@ -165,7 +167,6 @@ from ..types import (
     ChatMemberOwner,
     ChatMemberRestricted,
     ChatPermissions,
-    DateTime,
     Downloadable,
     File,
     ForceReply,
@@ -234,9 +235,6 @@ from ..types import (
     UserProfilePhotos,
     WebhookInfo,
 )
-from .default import Default, DefaultBotProperties
-from .session.aiohttp import AiohttpSession
-from .session.base import BaseSession
 
 T = TypeVar("T")
 
@@ -2895,7 +2893,7 @@ class Bot:
         explanation_parse_mode: Optional[Union[str, Default]] = Default("parse_mode"),
         explanation_entities: Optional[List[MessageEntity]] = None,
         open_period: Optional[int] = None,
-        close_date: Optional[DateTime] = None,
+        close_date: Optional[Union[datetime.datetime, datetime.timedelta, int]] = None,
         is_closed: Optional[bool] = None,
         disable_notification: Optional[bool] = None,
         protect_content: Optional[Union[bool, Default]] = Default("protect_content"),
diff --git a/aiogram/types/base.py b/aiogram/types/base.py
index 4fbe7113..e251cfa0 100644
--- a/aiogram/types/base.py
+++ b/aiogram/types/base.py
@@ -45,7 +45,7 @@ class TelegramObject(BotContextController, BaseModel):
         Replacing `Default` placeholders with actual values from bot defaults.
         Ensures JSON serialization backward compatibility by handling non-standard objects.
         """
-        if isinstance(self, BotContextController) and isinstance(self, BaseModel):
+        if isinstance(self, TelegramObject):
             properties = self.bot.default if self.bot else DefaultBotProperties()
             default_fields = {
                 key: properties[value.name] for key, value in self if isinstance(value, Default)
diff --git a/aiogram/types/input_media_animation.py b/aiogram/types/input_media_animation.py
index ac05dbbe..9dcf0a9e 100644
--- a/aiogram/types/input_media_animation.py
+++ b/aiogram/types/input_media_animation.py
@@ -20,7 +20,7 @@ class InputMediaAnimation(InputMedia):
 
     type: Literal[InputMediaType.ANIMATION] = InputMediaType.ANIMATION
     """Type of the result, must be *animation*"""
-    media: Union[InputFile, str]
+    media: Union[str, InputFile]
     """File to send. Pass a file_id to send a file that exists on the Telegram servers (recommended), pass an HTTP URL for Telegram to get a file from the Internet, or pass 'attach://<file_attach_name>' to upload a new one using multipart/form-data under <file_attach_name> name. :ref:`More information on Sending Files » <sending-files>`"""
     thumbnail: Optional[InputFile] = None
     """*Optional*. Thumbnail of the file sent; can be ignored if thumbnail generation for the file is supported server-side. The thumbnail should be in JPEG format and less than 200 kB in size. A thumbnail's width and height should not exceed 320. Ignored if the file is not uploaded using multipart/form-data. Thumbnails can't be reused and can be only uploaded as a new file, so you can pass 'attach://<file_attach_name>' if the thumbnail was uploaded using multipart/form-data under <file_attach_name>. :ref:`More information on Sending Files » <sending-files>`"""
@@ -47,7 +47,7 @@ class InputMediaAnimation(InputMedia):
             __pydantic__self__,
             *,
             type: Literal[InputMediaType.ANIMATION] = InputMediaType.ANIMATION,
-            media: Union[InputFile, str],
+            media: Union[str, InputFile],
             thumbnail: Optional[InputFile] = None,
             caption: Optional[str] = None,
             parse_mode: Optional[Union[str, Default]] = Default("parse_mode"),
diff --git a/aiogram/types/input_media_audio.py b/aiogram/types/input_media_audio.py
index bb551c90..c3722011 100644
--- a/aiogram/types/input_media_audio.py
+++ b/aiogram/types/input_media_audio.py
@@ -20,7 +20,7 @@ class InputMediaAudio(InputMedia):
 
     type: Literal[InputMediaType.AUDIO] = InputMediaType.AUDIO
     """Type of the result, must be *audio*"""
-    media: Union[InputFile, str]
+    media: Union[str, InputFile]
     """File to send. Pass a file_id to send a file that exists on the Telegram servers (recommended), pass an HTTP URL for Telegram to get a file from the Internet, or pass 'attach://<file_attach_name>' to upload a new one using multipart/form-data under <file_attach_name> name. :ref:`More information on Sending Files » <sending-files>`"""
     thumbnail: Optional[InputFile] = None
     """*Optional*. Thumbnail of the file sent; can be ignored if thumbnail generation for the file is supported server-side. The thumbnail should be in JPEG format and less than 200 kB in size. A thumbnail's width and height should not exceed 320. Ignored if the file is not uploaded using multipart/form-data. Thumbnails can't be reused and can be only uploaded as a new file, so you can pass 'attach://<file_attach_name>' if the thumbnail was uploaded using multipart/form-data under <file_attach_name>. :ref:`More information on Sending Files » <sending-files>`"""
@@ -45,7 +45,7 @@ class InputMediaAudio(InputMedia):
             __pydantic__self__,
             *,
             type: Literal[InputMediaType.AUDIO] = InputMediaType.AUDIO,
-            media: Union[InputFile, str],
+            media: Union[str, InputFile],
             thumbnail: Optional[InputFile] = None,
             caption: Optional[str] = None,
             parse_mode: Optional[Union[str, Default]] = Default("parse_mode"),
diff --git a/aiogram/types/input_media_document.py b/aiogram/types/input_media_document.py
index 100f66b8..7c24b929 100644
--- a/aiogram/types/input_media_document.py
+++ b/aiogram/types/input_media_document.py
@@ -20,7 +20,7 @@ class InputMediaDocument(InputMedia):
 
     type: Literal[InputMediaType.DOCUMENT] = InputMediaType.DOCUMENT
     """Type of the result, must be *document*"""
-    media: Union[InputFile, str]
+    media: Union[str, InputFile]
     """File to send. Pass a file_id to send a file that exists on the Telegram servers (recommended), pass an HTTP URL for Telegram to get a file from the Internet, or pass 'attach://<file_attach_name>' to upload a new one using multipart/form-data under <file_attach_name> name. :ref:`More information on Sending Files » <sending-files>`"""
     thumbnail: Optional[InputFile] = None
     """*Optional*. Thumbnail of the file sent; can be ignored if thumbnail generation for the file is supported server-side. The thumbnail should be in JPEG format and less than 200 kB in size. A thumbnail's width and height should not exceed 320. Ignored if the file is not uploaded using multipart/form-data. Thumbnails can't be reused and can be only uploaded as a new file, so you can pass 'attach://<file_attach_name>' if the thumbnail was uploaded using multipart/form-data under <file_attach_name>. :ref:`More information on Sending Files » <sending-files>`"""
@@ -41,7 +41,7 @@ class InputMediaDocument(InputMedia):
             __pydantic__self__,
             *,
             type: Literal[InputMediaType.DOCUMENT] = InputMediaType.DOCUMENT,
-            media: Union[InputFile, str],
+            media: Union[str, InputFile],
             thumbnail: Optional[InputFile] = None,
             caption: Optional[str] = None,
             parse_mode: Optional[Union[str, Default]] = Default("parse_mode"),
diff --git a/aiogram/types/input_media_photo.py b/aiogram/types/input_media_photo.py
index db00a72f..ecb3c91d 100644
--- a/aiogram/types/input_media_photo.py
+++ b/aiogram/types/input_media_photo.py
@@ -20,7 +20,7 @@ class InputMediaPhoto(InputMedia):
 
     type: Literal[InputMediaType.PHOTO] = InputMediaType.PHOTO
     """Type of the result, must be *photo*"""
-    media: Union[InputFile, str]
+    media: Union[str, InputFile]
     """File to send. Pass a file_id to send a file that exists on the Telegram servers (recommended), pass an HTTP URL for Telegram to get a file from the Internet, or pass 'attach://<file_attach_name>' to upload a new one using multipart/form-data under <file_attach_name> name. :ref:`More information on Sending Files » <sending-files>`"""
     caption: Optional[str] = None
     """*Optional*. Caption of the photo to be sent, 0-1024 characters after entities parsing"""
@@ -39,7 +39,7 @@ class InputMediaPhoto(InputMedia):
             __pydantic__self__,
             *,
             type: Literal[InputMediaType.PHOTO] = InputMediaType.PHOTO,
-            media: Union[InputFile, str],
+            media: Union[str, InputFile],
             caption: Optional[str] = None,
             parse_mode: Optional[Union[str, Default]] = Default("parse_mode"),
             caption_entities: Optional[List[MessageEntity]] = None,
diff --git a/aiogram/types/input_media_video.py b/aiogram/types/input_media_video.py
index 5ffbe640..b44f6a76 100644
--- a/aiogram/types/input_media_video.py
+++ b/aiogram/types/input_media_video.py
@@ -20,7 +20,7 @@ class InputMediaVideo(InputMedia):
 
     type: Literal[InputMediaType.VIDEO] = InputMediaType.VIDEO
     """Type of the result, must be *video*"""
-    media: Union[InputFile, str]
+    media: Union[str, InputFile]
     """File to send. Pass a file_id to send a file that exists on the Telegram servers (recommended), pass an HTTP URL for Telegram to get a file from the Internet, or pass 'attach://<file_attach_name>' to upload a new one using multipart/form-data under <file_attach_name> name. :ref:`More information on Sending Files » <sending-files>`"""
     thumbnail: Optional[InputFile] = None
     """*Optional*. Thumbnail of the file sent; can be ignored if thumbnail generation for the file is supported server-side. The thumbnail should be in JPEG format and less than 200 kB in size. A thumbnail's width and height should not exceed 320. Ignored if the file is not uploaded using multipart/form-data. Thumbnails can't be reused and can be only uploaded as a new file, so you can pass 'attach://<file_attach_name>' if the thumbnail was uploaded using multipart/form-data under <file_attach_name>. :ref:`More information on Sending Files » <sending-files>`"""
@@ -49,7 +49,7 @@ class InputMediaVideo(InputMedia):
             __pydantic__self__,
             *,
             type: Literal[InputMediaType.VIDEO] = InputMediaType.VIDEO,
-            media: Union[InputFile, str],
+            media: Union[str, InputFile],
             thumbnail: Optional[InputFile] = None,
             caption: Optional[str] = None,
             parse_mode: Optional[Union[str, Default]] = Default("parse_mode"),
diff --git a/aiogram/utils/media_group.py b/aiogram/utils/media_group.py
index ebe04667..e4277d2f 100644
--- a/aiogram/utils/media_group.py
+++ b/aiogram/utils/media_group.py
@@ -63,7 +63,7 @@ class MediaGroupBuilder:
         self,
         *,
         type: Literal[InputMediaType.AUDIO],
-        media: Union[InputFile, str],
+        media: Union[str, InputFile],
         caption: Optional[str] = None,
         parse_mode: Optional[str] = UNSET_PARSE_MODE,
         caption_entities: Optional[List[MessageEntity]] = None,
@@ -79,7 +79,7 @@ class MediaGroupBuilder:
         self,
         *,
         type: Literal[InputMediaType.PHOTO],
-        media: Union[InputFile, str],
+        media: Union[str, InputFile],
         caption: Optional[str] = None,
         parse_mode: Optional[str] = UNSET_PARSE_MODE,
         caption_entities: Optional[List[MessageEntity]] = None,
@@ -93,7 +93,7 @@ class MediaGroupBuilder:
         self,
         *,
         type: Literal[InputMediaType.VIDEO],
-        media: Union[InputFile, str],
+        media: Union[str, InputFile],
         thumbnail: Optional[Union[InputFile, str]] = None,
         caption: Optional[str] = None,
         parse_mode: Optional[str] = UNSET_PARSE_MODE,
@@ -112,7 +112,7 @@ class MediaGroupBuilder:
         self,
         *,
         type: Literal[InputMediaType.DOCUMENT],
-        media: Union[InputFile, str],
+        media: Union[str, InputFile],
         thumbnail: Optional[Union[InputFile, str]] = None,
         caption: Optional[str] = None,
         parse_mode: Optional[str] = UNSET_PARSE_MODE,
@@ -144,7 +144,7 @@ class MediaGroupBuilder:
 
     def add_audio(
         self,
-        media: Union[InputFile, str],
+        media: Union[str, InputFile],
         thumbnail: Optional[InputFile] = None,
         caption: Optional[str] = None,
         parse_mode: Optional[str] = UNSET_PARSE_MODE,
@@ -194,7 +194,7 @@ class MediaGroupBuilder:
 
     def add_photo(
         self,
-        media: Union[InputFile, str],
+        media: Union[str, InputFile],
         caption: Optional[str] = None,
         parse_mode: Optional[str] = UNSET_PARSE_MODE,
         caption_entities: Optional[List[MessageEntity]] = None,
@@ -233,7 +233,7 @@ class MediaGroupBuilder:
 
     def add_video(
         self,
-        media: Union[InputFile, str],
+        media: Union[str, InputFile],
         thumbnail: Optional[InputFile] = None,
         caption: Optional[str] = None,
         parse_mode: Optional[str] = UNSET_PARSE_MODE,
@@ -295,7 +295,7 @@ class MediaGroupBuilder:
 
     def add_document(
         self,
-        media: Union[InputFile, str],
+        media: Union[str, InputFile],
         thumbnail: Optional[InputFile] = None,
         caption: Optional[str] = None,
         parse_mode: Optional[str] = UNSET_PARSE_MODE,
diff --git a/aiogram/webhook/aiohttp_server.py b/aiogram/webhook/aiohttp_server.py
index b1f34ddc..7a60c06d 100644
--- a/aiogram/webhook/aiohttp_server.py
+++ b/aiogram/webhook/aiohttp_server.py
@@ -8,6 +8,7 @@ from aiohttp import MultipartWriter, web
 from aiohttp.abc import Application
 from aiohttp.typedefs import Handler
 from aiohttp.web_middlewares import middleware
+from pydantic_core import from_json, to_json
 
 from aiogram import Bot, Dispatcher, loggers
 from aiogram.client.form import extract_files, form_serialize
@@ -141,11 +142,11 @@ class BaseRequestHandler(ABC):
 
     async def _handle_request_background(self, bot: Bot, request: web.Request) -> web.Response:
         feed_update_task = asyncio.create_task(
-            self._background_feed_update(bot=bot, update=await request.json())
+            self._background_feed_update(bot=bot, update=await request.json(loads=from_json))
         )
         self._background_feed_update_tasks.add(feed_update_task)
         feed_update_task.add_done_callback(self._background_feed_update_tasks.discard)
-        return web.json_response({})
+        return web.json_response({})  # TODO
 
     def _build_response_writer(
         self, bot: Bot, result: Optional[TelegramMethod[TelegramType]]
diff --git a/tests/test_api/test_client/test_session/test_base_session.py b/tests/test_api/test_client/test_session/test_base_session.py
index 0ab9b77d..b90b500e 100644
--- a/tests/test_api/test_client/test_session/test_base_session.py
+++ b/tests/test_api/test_client/test_session/test_base_session.py
@@ -122,7 +122,7 @@ class TestBaseSession:
                 ),
                 "1494994302",
             ],
-            [LinkPreviewOptions(is_disabled=True, url=None), '{"is_disabled":true}'],
+            [LinkPreviewOptions(is_disabled=True), '{"is_disabled":true}'],
             [Default("parse_mode"), "HTML"],
             [Default("protect_content"), "true"],
             [Default("link_preview_is_disabled"), "true"],
diff --git a/tests/test_api/test_methods/test_base.py b/tests/test_api/test_methods/test_base.py
index 66cfd101..07dedc77 100644
--- a/tests/test_api/test_methods/test_base.py
+++ b/tests/test_api/test_methods/test_base.py
@@ -20,15 +20,15 @@ class TestTelegramMethodRemoveUnset:
     )
     @pytest.mark.parametrize("obj", [TelegramMethod, TelegramObject])
     def test_remove_unset(self, values, names, obj):
-        validated = obj.remove_unset(values)
+        validated = obj.remove_unset.wrapped(values)
         assert set(validated.keys()) == names
 
     @pytest.mark.parametrize("obj", [TelegramMethod, TelegramObject])
     def test_remove_unset_non_dict(self, obj):
-        assert obj.remove_unset("") == ""
+        assert obj.remove_unset.wrapped("") == ""
 
 
-class TestTelegramMethodJsonSerialize:
+class TestTelegramMethodModelDumpJson:
     @pytest.mark.parametrize(
         "obj",
         [
@@ -39,7 +39,7 @@ class TestTelegramMethodJsonSerialize:
             LinkPreviewOptions(),
         ],
     )
-    def test_json_serialize(self, obj):
+    def test_model_dump_json(self, obj):
         def has_defaults(dump: Dict[str, Any]) -> bool:
             return any(isinstance(value, Default) for value in dump.values())
 
diff --git a/tests/test_api/test_types/test_input_file.py b/tests/test_api/test_types/test_input_file.py
index fa7a267b..c5cfcb04 100644
--- a/tests/test_api/test_types/test_input_file.py
+++ b/tests/test_api/test_types/test_input_file.py
@@ -99,3 +99,5 @@ class TestInputFile:
                 assert chunk_size == 1
                 size += chunk_size
             assert size == 10
+
+    # TODO: used_valid_bot