diff --git a/src/api/dependacies/db_dep.py b/src/api/dependacies/db_dep.py
index 3be1e5d..df46f22 100644
--- a/src/api/dependacies/db_dep.py
+++ b/src/api/dependacies/db_dep.py
@@ -4,7 +4,7 @@ from fastapi import Depends
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from src.core.database import async_session_maker
-from src.utils.db_manager import DBManager
+from src.core.db_manager import DBManager
 
 
 async def get_db() -> AsyncGenerator[AsyncSession, None]:
@@ -13,5 +13,3 @@ async def get_db() -> AsyncGenerator[AsyncSession, None]:
 
 
 sessionDep = Annotated[AsyncSession, Depends(get_db)]
-
-
diff --git a/src/utils/db_manager.py b/src/core/db_manager.py
similarity index 100%
rename from src/utils/db_manager.py
rename to src/core/db_manager.py
diff --git a/src/core/interfaces.py b/src/core/interfaces.py
new file mode 100644
index 0000000..fcf1383
--- /dev/null
+++ b/src/core/interfaces.py
@@ -0,0 +1,16 @@
+from typing import Protocol
+
+from src.repository.users import UsersRepo
+
+
+class IUnitOfWork(Protocol):
+    user: UsersRepo
+
+    async def __aenter__(self) -> "IUnitOfWork":
+        ...
+
+    async def __aexit__(self, exc_type, exc_val, exc_tb) -> None:
+        ...
+
+    async def commit(self) -> None:
+        ...
\ No newline at end of file
diff --git a/src/schemas/users.py b/src/schemas/users.py
index 1ee78b0..745d20f 100644
--- a/src/schemas/users.py
+++ b/src/schemas/users.py
@@ -17,4 +17,3 @@ class UserRequest(BaseModel):
     username: str
     email: EmailStr | None = None
     password: str
-
diff --git a/src/services/base.py b/src/services/base.py
index 9451e22..04ff0ab 100644
--- a/src/services/base.py
+++ b/src/services/base.py
@@ -1,9 +1,8 @@
-from src.utils.db_manager import DBManager
+from src.core.interfaces import IUnitOfWork
 
 
 class BaseService:
-    session: DBManager | None
+    session: IUnitOfWork | None
 
-    def __init__(self, session: DBManager):
+    def __init__(self, session: "IUnitOfWork"):
         self.session = session
-