diff --git a/.claude/commands/commit.md b/.claude/commands/commit.md
index e5903cf..51cbddd 100644
--- a/.claude/commands/commit.md
+++ b/.claude/commands/commit.md
@@ -1,10 +1,4 @@
-Your goal is to write a commit message and open a pull request.
+Your goal is to write a commit message.
 
 1) Write a clear and concise commit message that follows conventional commit format (if applicable). It should explain what was changed and why.
-
-2) Create a pull request with:
-* A descriptive title
-* A summary of changes
-* Any relevant context or background
-* Linked issues (if any)
-* Checklist of tasks done (tests, docs, etc.)
\ No newline at end of file
+2) Take a look to the branch name to understand context of the issue/feature
\ No newline at end of file
diff --git a/.claude/commands/commit_and_pr.md b/.claude/commands/commit_and_pr.md
new file mode 100644
index 0000000..e5903cf
--- /dev/null
+++ b/.claude/commands/commit_and_pr.md
@@ -0,0 +1,10 @@
+Your goal is to write a commit message and open a pull request.
+
+1) Write a clear and concise commit message that follows conventional commit format (if applicable). It should explain what was changed and why.
+
+2) Create a pull request with:
+* A descriptive title
+* A summary of changes
+* Any relevant context or background
+* Linked issues (if any)
+* Checklist of tasks done (tests, docs, etc.)
\ No newline at end of file
diff --git a/.claude/commands/create_pr.md b/.claude/commands/create_pr.md
new file mode 100644
index 0000000..eaa0f63
--- /dev/null
+++ b/.claude/commands/create_pr.md
@@ -0,0 +1,8 @@
+Your goal is to analyze this branch and open a pull request.
+
+1Create a pull request with:
+* A descriptive title
+* A summary of changes
+* Any relevant context or background
+* Linked issues (if any)
+* Checklist of tasks done (tests, docs, etc.)
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index 6e95b12..ed1a5dd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,5 +17,6 @@ dependencies = [
     "pyyaml>=6.0.2",
     "ruff>=0.12.5",
     "sqlalchemy>=2.0.41",
+    "ty>=0.0.1a16",
     "uvicorn>=0.35.0",
 ]
diff --git a/src/application/auth/tg.py b/src/application/auth/tg.py
index 0c75cd8..35f8a6e 100644
--- a/src/application/auth/tg.py
+++ b/src/application/auth/tg.py
@@ -2,7 +2,7 @@
 
 from src.application.common.interactor import Interactor
 from src.application.common.transaction import TransactionManager
-from src.application.interfaces.auth import AuthService, InitDataDTO
+from src.application.interfaces.auth import AuthService
 from src.domain.user import (
     CreateUserDTO,
     UserRepository,
@@ -30,11 +30,10 @@ def __init__(
         self.transaction_manager = transaction_manager
         self.auth_service = auth_service
 
-
     async def __call__(self, data: AuthTgInputDTO) -> AuthTgOutputDTO:
         parsed_data = self.auth_service.validate_init_data(data.init_data)
 
-        user = await self.user_repository.get_user(parsed_data.user_id, by='id')
+        user = await self.user_repository.get_user(parsed_data.user_id, by="id")
         if user is None:
             await self.user_repository.create_user(
                 CreateUserDTO(
diff --git a/src/application/interfaces/auth.py b/src/application/interfaces/auth.py
index e341626..b959eaa 100644
--- a/src/application/interfaces/auth.py
+++ b/src/application/interfaces/auth.py
@@ -12,7 +12,7 @@ class InitDataDTO:
     is_premium: bool
     start_param: str | None
     photo_url: str
-    ui_language_code: str
+    ui_language_code: str | None
 
 
 class AuthService(Protocol):
diff --git a/src/domain/user/__init__.py b/src/domain/user/__init__.py
index 8ab80d8..fac0da7 100644
--- a/src/domain/user/__init__.py
+++ b/src/domain/user/__init__.py
@@ -1,2 +1,9 @@
 from .entity import User
-from .repository import UserRepository, CreateUserDTO
\ No newline at end of file
+from .repository import UserRepository, CreateUserDTO
+
+
+__all__ = [
+    "User",
+    "CreateUserDTO",
+    "UserRepository",
+]
diff --git a/src/domain/user/repository.py b/src/domain/user/repository.py
index f1f5d54..2c2f0c6 100644
--- a/src/domain/user/repository.py
+++ b/src/domain/user/repository.py
@@ -11,6 +11,7 @@ class CreateUserDTO(TypedDict):
     is_premium: bool
     photo_url: str
 
+
 class UpdateUserDTO(TypedDict):
     username: str | None
     first_name: str
@@ -28,7 +29,9 @@ async def get_user(self, identifier: str) -> User: ...
     async def get_user(self, identifier: int, by: str = Literal["id"]) -> User: ...
 
     @overload
-    async def get_user(self, identifier: str, by: str = Literal["username"]) -> User: ...
+    async def get_user(
+        self, identifier: str, by: str = Literal["username"]
+    ) -> User: ...
 
     @abstractmethod
     async def get_user(
diff --git a/src/infrastructure/auth.py b/src/infrastructure/auth.py
index 19f18e5..357e555 100644
--- a/src/infrastructure/auth.py
+++ b/src/infrastructure/auth.py
@@ -15,8 +15,10 @@ def __init__(self, config: Config) -> None:
     def validate_init_data(self, init_data: str) -> InitDataDTO:
         # todo - cover with tests
         try:
-            parsed_data = safe_parse_webapp_init_data(self.config.telegram.bot_token, init_data)
-        except ValueError as e:
+            parsed_data = safe_parse_webapp_init_data(
+                self.config.telegram.bot_token, init_data
+            )
+        except ValueError:
             error_msg = f"Invalid init data '{init_data}'"
             raise ValidationError(message=error_msg)
 
@@ -32,14 +34,17 @@ def validate_init_data(self, init_data: str) -> InitDataDTO:
             is_premium=parsed_data.user.is_premium or False,
             start_param=parsed_data.start_param,
             photo_url=parsed_data.user.photo_url,
-            ui_language_code=parsed_data.user.language_code,
+            ui_language_code=parsed_data.user.language_code
+            if parsed_data.user.language_code
+            else None,
         )
 
     def create_access_token(self, user_id: int) -> str:
         # todo - cover with tests
         to_encode = {
             "sub": str(user_id),
-            "exp": datetime.now(UTC) + timedelta(minutes=self.config.auth.access_token_expire_minutes),
+            "exp": datetime.now(UTC)
+            + timedelta(minutes=self.config.auth.access_token_expire_minutes),
         }
         encoded_jwt = encode(
             to_encode,
diff --git a/src/infrastructure/config.py b/src/infrastructure/config.py
index a27f750..19b5ead 100644
--- a/src/infrastructure/config.py
+++ b/src/infrastructure/config.py
@@ -29,6 +29,7 @@ class AuthConfig(BaseModel):
     algorithm: str
     access_token_expire_minutes: int
 
+
 class TelegramConfig(BaseModel):
     bot_token: str
 
diff --git a/src/infrastructure/db/models/user.py b/src/infrastructure/db/models/user.py
index 488f186..9f2f85a 100644
--- a/src/infrastructure/db/models/user.py
+++ b/src/infrastructure/db/models/user.py
@@ -1,6 +1,5 @@
 from typing import Optional
 
-from sqlalchemy import Column
 from sqlalchemy.orm import Mapped, mapped_column
 
 from src.domain.user.entity import User
@@ -19,7 +18,7 @@ class UserModel(BaseORMModel):
     username: Mapped[Optional[Username]] = mapped_column(
         UsernameType, nullable=True, unique=False
     )
-    bio: Mapped[Optional[Bio]] = Column(BioType, nullable=True)
+    bio: Mapped[Bio | None] = mapped_column(BioType, nullable=True)
 
     def to_domain(self) -> User:
         return User(
diff --git a/src/infrastructure/db/repos/__init__.py b/src/infrastructure/db/repos/__init__.py
index 2ad3043..6df7de9 100644
--- a/src/infrastructure/db/repos/__init__.py
+++ b/src/infrastructure/db/repos/__init__.py
@@ -2,5 +2,5 @@
 
 
 __all__ = [
-    'UserRepositoryImpl',
+    "UserRepositoryImpl",
 ]
diff --git a/src/infrastructure/db/repos/user.py b/src/infrastructure/db/repos/user.py
index 848639b..0659dda 100644
--- a/src/infrastructure/db/repos/user.py
+++ b/src/infrastructure/db/repos/user.py
@@ -25,24 +25,32 @@ async def get_user(
         return user_model.to_domain() if user_model else None
 
     async def create_user(self, user: CreateUserDTO) -> User:
-        stmt = insert(UserModel).values(
-            id=user["id"],
-            username=user["username"],
-            first_name=user["first_name"],
-            last_name=user["last_name"],
-        ).returning(UserModel)
+        stmt = (
+            insert(UserModel)
+            .values(
+                id=user["id"],
+                username=user["username"],
+                first_name=user["first_name"],
+                last_name=user["last_name"],
+            )
+            .returning(UserModel)
+        )
 
         result = await self._session.execute(stmt)
         orm_model = result.scalar_one()
         return orm_model.to_domain()
 
     async def update_user(self, user_id: int, **fields: Unpack[UpdateUserDTO]) -> User:
-        stmt = update(UserModel).values(
-            id=user_id,
-            username=fields["username"],
-            first_name=fields["first_name"],
-            last_name=fields["last_name"],
-        ).returning(UserModel)
+        stmt = (
+            update(UserModel)
+            .values(
+                id=user_id,
+                username=fields["username"],
+                first_name=fields["first_name"],
+                last_name=fields["last_name"],
+            )
+            .returning(UserModel)
+        )
         result = await self._session.execute(stmt)
         orm_model = result.scalar_one()
         return orm_model.to_domain()
diff --git a/src/presentation/api/app.py b/src/presentation/api/app.py
index 3c6781d..d087f8d 100644
--- a/src/presentation/api/app.py
+++ b/src/presentation/api/app.py
@@ -24,7 +24,7 @@ def create_app() -> Litestar:
         exception_handlers={
             Exception: custom_exception_handler,
             ValidationError: validation_error_handler,
-        }
+        },
     )
 
     container = make_async_container(
diff --git a/src/presentation/api/exception.py b/src/presentation/api/exception.py
index e6e5e0d..8e7a347 100644
--- a/src/presentation/api/exception.py
+++ b/src/presentation/api/exception.py
@@ -8,11 +8,20 @@
 logger = logging.getLogger(__name__)
 
 
-def custom_exception_handler(_: Request[Any, Any, Any], exc: Exception) -> Response[Any]:
+def custom_exception_handler(
+    _: Request[Any, Any, Any], exc: Exception
+) -> Response[Any]:
     logger.exception(exc)
-    return Response({"detail": "Internal Server Error", "status_code": 500}, status_code=500)
+    return Response(
+        {"detail": "Internal Server Error", "status_code": 500}, status_code=500
+    )
 
 
-def validation_error_handler(_: Request[Any, Any, Any], exc: ValidationError) -> Response[Any]:
+def validation_error_handler(
+    _: Request[Any, Any, Any], exc: ValidationError
+) -> Response[Any]:
     logger.exception(exc)
-    return Response({"detail": exc.message, "status_code": exc.status_code}, status_code=exc.status_code)
+    return Response(
+        {"detail": exc.message, "status_code": exc.status_code},
+        status_code=exc.status_code,
+    )
diff --git a/src/presentation/api/health/__init__.py b/src/presentation/api/health/__init__.py
index ccc2cd9..b22a756 100644
--- a/src/presentation/api/health/__init__.py
+++ b/src/presentation/api/health/__init__.py
@@ -1,5 +1,5 @@
 from .router import health_router
 
 __all__ = [
-    'health_router',
-]
\ No newline at end of file
+    "health_router",
+]
diff --git a/uv.lock b/uv.lock
index 16a4fa9..d1aa7e8 100644
--- a/uv.lock
+++ b/uv.lock
@@ -135,6 +135,7 @@ dependencies = [
     { name = "pyyaml" },
     { name = "ruff" },
     { name = "sqlalchemy" },
+    { name = "ty" },
     { name = "uvicorn" },
 ]
 
@@ -152,6 +153,7 @@ requires-dist = [
     { name = "pyyaml", specifier = ">=6.0.2" },
     { name = "ruff", specifier = ">=0.12.5" },
     { name = "sqlalchemy", specifier = ">=2.0.41" },
+    { name = "ty", specifier = ">=0.0.1a16" },
     { name = "uvicorn", specifier = ">=0.35.0" },
 ]
 
@@ -819,6 +821,31 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/1c/fc/9ba22f01b5cdacc8f5ed0d22304718d2c758fce3fd49a5372b886a86f37c/sqlalchemy-2.0.41-py3-none-any.whl", hash = "sha256:57df5dc6fdb5ed1a88a1ed2195fd31927e705cad62dedd86b46972752a80f576", size = 1911224 },
 ]
 
+[[package]]
+name = "ty"
+version = "0.0.1a16"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/ca/62/f021cdbdda9dbd553be4b841c2e9329ecd3ddc630a17c1ab5179832fbca8/ty-0.0.1a16.tar.gz", hash = "sha256:9ade26904870dc9bd988e58bad4382857f75ae05edb682ee0ba2f26fcc2d4c0f", size = 3961822 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/c8/8d/fe6a4161ee493005d2d59bb02c37a746723eb65e45740cc8aa2367da5ddb/ty-0.0.1a16-py3-none-linux_armv6l.whl", hash = "sha256:dfb55d28df78ca40f8aff91ec3ae01f4b7bc23aa04c72ace7ec00fbc5e0468c0", size = 7840414 },
+    { url = "https://files.pythonhosted.org/packages/88/85/70bef8b680216276e941480a0bac3d00b89d1d64d4e281bd3daaa85fc5ed/ty-0.0.1a16-py3-none-macosx_10_12_x86_64.whl", hash = "sha256:5a0e9917efadf2ec173ee755db3653243b64fa8b26fa4d740dea68e969a99898", size = 7979261 },
+    { url = "https://files.pythonhosted.org/packages/5a/07/400b56734c7b8a29ea1d6927f36dd75bf263c8a223ea4bd05e25bdbbc8a2/ty-0.0.1a16-py3-none-macosx_11_0_arm64.whl", hash = "sha256:9253cb8b5c4052337b1600f581ecd8e6929e635a07ec9e8dc5cc2fa4008e6b3b", size = 7567959 },
+    { url = "https://files.pythonhosted.org/packages/02/c9/095cb09e33a4d547a71f4f698d09f3f9edc92746e029945fe8412f59d421/ty-0.0.1a16-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:374c059e184f8abc969e07965355ddbbf7205a713721d3867ee42f976249c9ac", size = 7697398 },
+    { url = "https://files.pythonhosted.org/packages/48/39/e2ce5b1151dfc80659486f74113972bc994c39b8f7f39084b271d03c4b04/ty-0.0.1a16-py3-none-manylinux_2_17_armv7l.manylinux2014_armv7l.whl", hash = "sha256:c5364c6d1a1a3d5b8e765a730303f8e07094ab9e63682aa82f73755d92749852", size = 7681504 },
+    { url = "https://files.pythonhosted.org/packages/a3/44/5c1158bd3e2e939e5b0ddb6b15c8e158870fa44915b5535909f83d4bd4ed/ty-0.0.1a16-py3-none-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:f201ff0ab3267123b9e42cc8584a193aa76e6e0865003d1b0a41bd025f08229e", size = 8551057 },
+    { url = "https://files.pythonhosted.org/packages/0d/20/2564cd89f1c06ce329ab25d91ce457d2dc00d2559c519111874811250442/ty-0.0.1a16-py3-none-manylinux_2_17_ppc64.manylinux2014_ppc64.whl", hash = "sha256:57f14207d88043ba27f4b84d84dfdaa1bfbcc5170d5f50814d2997cbc3d75366", size = 8999239 },
+    { url = "https://files.pythonhosted.org/packages/41/5f/64b74a8aaa080267c71a9d591b980a9c915b2439034b9075520c56ef1e4b/ty-0.0.1a16-py3-none-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl", hash = "sha256:950c45e1d6c58e61ad77ed5d2d04f091e44b0d13e6d5d79143bb81078ab526b1", size = 8638649 },
+    { url = "https://files.pythonhosted.org/packages/67/c7/80ad1c11d896cd1a52f24f0b3660ed368187ba152337b8f18b2d0591bd02/ty-0.0.1a16-py3-none-manylinux_2_17_s390x.manylinux2014_s390x.whl", hash = "sha256:ad133d0eac5291d738e40052df98ca9f194e0f0433d6086a4890fd6733217969", size = 8443175 },
+    { url = "https://files.pythonhosted.org/packages/94/6c/eb3c214a44bd0f6ad359c1ce28de62cbaecfd5823553a35b0163e9f3e738/ty-0.0.1a16-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:3e59f877ef8b967c06173a7a663271a6e66edb049f0db00f7873be5e41d61d5b", size = 8278214 },
+    { url = "https://files.pythonhosted.org/packages/18/ab/f44474a526f3a1ac770c8839a23fac51f93a4ad5e6ec2770d74e20bd5684/ty-0.0.1a16-py3-none-musllinux_1_2_aarch64.whl", hash = "sha256:4e973b8cb2c382263aaf77a40889ad236bd06ddca671cc973f9e33e8e02f0af1", size = 7591502 },
+    { url = "https://files.pythonhosted.org/packages/b9/d3/825975f1277b097883ed3428c23e0e8f67ed4fffd25d00b8b60650b663cb/ty-0.0.1a16-py3-none-musllinux_1_2_armv7l.whl", hash = "sha256:4a82d9c4b76a73aff60cab93b71f2dd83952c2eb68a86578e1db56aee8f7e338", size = 7715602 },
+    { url = "https://files.pythonhosted.org/packages/f8/f0/2805b4172c46b832c2efa368731d4aa4af0aa35ce120a4726ccdb3b102a0/ty-0.0.1a16-py3-none-musllinux_1_2_i686.whl", hash = "sha256:7993f48def35f1707a2dc675bf7d08906cc5f26204b0b479746664301eda15b9", size = 8156780 },
+    { url = "https://files.pythonhosted.org/packages/25/a5/f47c11a3dc52b3e148aaaa2bf7c37ea75998cfd50ad5f4b56fd2cc79c708/ty-0.0.1a16-py3-none-musllinux_1_2_x86_64.whl", hash = "sha256:d9887ec65984e7dbf3b5e906ef44e8f47ff5351c7ac04d49e793b324d744050f", size = 8350253 },
+    { url = "https://files.pythonhosted.org/packages/1e/e4/498c0bed38385d0c8babfe5707fe157700ae698d77dd9a1a8ffaaa97baea/ty-0.0.1a16-py3-none-win32.whl", hash = "sha256:4113a176a8343196d73145668460873d26ccef8766ff4e5287eec2622ce8754d", size = 7460041 },
+    { url = "https://files.pythonhosted.org/packages/af/9e/5a8a690a5542405fd20cab6b0aa97a5af76de1e39582de545fac48e53f3a/ty-0.0.1a16-py3-none-win_amd64.whl", hash = "sha256:508ba4c50bc88f1a7c730d40f28d6c679696ee824bc09630c7c6763911de862a", size = 8074666 },
+    { url = "https://files.pythonhosted.org/packages/dc/53/2a2eb8cc22b3e12d2040ed78d98842d0dddfa593d824b7ff60e30afe6f41/ty-0.0.1a16-py3-none-win_arm64.whl", hash = "sha256:36f53e430b5e0231d6b6672160c981eaf7f9390162380bcd1096941b2c746b5d", size = 7612948 },
+]
+
 [[package]]
 name = "typing-extensions"
 version = "4.14.1"