diff --git a/app/dependencies.py b/app/dependencies.py
index 3c95823..3e522b3 100644
--- a/app/dependencies.py
+++ b/app/dependencies.py
@@ -9,7 +9,7 @@ from app.models.admin import Admin, oauth2_scheme
 from app.utils.jwt import get_admin_payload
 
 
-def get_db():  # Dependency
+def get_db():
     with GetDB() as db:
         yield db
 
@@ -27,9 +27,8 @@ def get_admin(
         return
 
     if dbadmin.password_reset_at:
-        if not payload.get("created_at"):
-            return
-        if dbadmin.password_reset_at > payload.get("created_at"):
+        created_at = payload.get("created_at")
+        if not created_at or dbadmin.password_reset_at > created_at:
             return
 
     return Admin.model_validate(dbadmin)
@@ -61,12 +60,13 @@ def get_subscription_user(
     try:
         int(key, 16)
     except ValueError:
-        raise HTTPException(404)
+        raise HTTPException(status_code=404)
 
     db_user = crud.get_user(db, username)
-    if not db_user or db_user.key != key:
-        raise HTTPException(404)
-    return db_user
+    if db_user and db_user.key == key:
+        return db_user
+    else:
+        raise HTTPException(status_code=404)
 
 
 def get_user(
@@ -76,8 +76,7 @@ def get_user(
 ):
     db_user = crud.get_user(db, username)
     if not (
-        admin.is_sudo
-        or (db_user.admin and db_user.admin.username == admin.username)
+        admin.is_sudo or (db_user and db_user.admin.username == admin.username)
     ):
         raise HTTPException(status_code=403, detail="You're not allowed")
 
diff --git a/app/marzneshin.py b/app/marzneshin.py
index 667b949..db50858 100644
--- a/app/marzneshin.py
+++ b/app/marzneshin.py
@@ -3,6 +3,9 @@ import logging
 from datetime import datetime as dt
 from datetime import timedelta as td
 
+from typing import AsyncGenerator
+from contextlib import asynccontextmanager
+
 from apscheduler.schedulers.asyncio import AsyncIOScheduler
 from fastapi import FastAPI, Request, status
 from fastapi.encoders import jsonable_encoder
@@ -40,10 +43,21 @@ from .tasks import (
 
 logger = logging.getLogger(__name__)
 
+
+@asynccontextmanager
+async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
+    await nodes_startup()
+    yield
+    scheduler.shutdown()
+    logger.info("Sending pending notifications before shutdown...")
+    await send_notifications()
+
+
 app = FastAPI(
     title="MarzneshinAPI",
     description="Unified GUI Censorship Resistant Solution Powered by Xray",
     version=__version__,
+    lifespan=lifespan,
     docs_url="/docs" if DOCS else None,
     redoc_url="/redoc" if DOCS else None,
 )
@@ -91,18 +105,6 @@ if WEBHOOK_ADDRESS:
     )
 
 
-@app.on_event("startup")
-async def on_start():
-    await nodes_startup()
-
-
-@app.on_event("shutdown")
-async def on_shutdown():
-    scheduler.shutdown()
-    logger.info("Sending pending notifications before shutdown...")
-    await send_notifications()
-
-
 @app.exception_handler(RequestValidationError)
 def validation_exception_handler(
     request: Request, exc: RequestValidationError
diff --git a/app/routes/admin.py b/app/routes/admin.py
index b3340a1..23e1a09 100644
--- a/app/routes/admin.py
+++ b/app/routes/admin.py
@@ -31,7 +31,7 @@ def authenticate_admin(
 
 
 @router.get("", response_model=Page[Admin])
-def get_admins(db: DBDep, admin: SudoAdminDep, username: str = None):
+def get_admins(db: DBDep, admin: SudoAdminDep, username: str | None = None):
     query = db.query(DBAdmin)
     if username:
         query = query.filter(DBAdmin.username.ilike(f"%{username}%"))
@@ -95,10 +95,10 @@ def modify_admin(
         raise HTTPException(status_code=404, detail="Admin not found")
 
     # If a sudoer admin wants to edit another sudoer
-    if (username != admin.username) and dbadmin.is_sudo:
+    if username != admin.username and dbadmin.is_sudo:
         raise HTTPException(
             status_code=403,
-            detail="You're not allowed to edit another sudoers account. Use marzban-cli instead.",
+            detail="You're not allowed to edit another sudoers account. Use marzneshin-cli instead.",
         )
 
     dbadmin = crud.update_admin(db, dbadmin, modified_admin)
@@ -114,7 +114,7 @@ def remove_admin(username: str, db: DBDep, admin: SudoAdminDep):
     if dbadmin.is_sudo:
         raise HTTPException(
             status_code=403,
-            detail="You're not allowed to delete sudoers accounts. Use marzban-cli instead.",
+            detail="You're not allowed to delete sudoers accounts. Use marzneshin-cli instead.",
         )
 
     crud.remove_admin(db, dbadmin)
diff --git a/app/routes/inbounds.py b/app/routes/inbounds.py
index d96221b..0c1bffc 100644
--- a/app/routes/inbounds.py
+++ b/app/routes/inbounds.py
@@ -84,7 +84,7 @@ def get_inbound(id: int, db: DBDep):
 
 
 @router.get("/{id}/hosts", response_model=Page[InboundHostResponse])
-def get_inbound_hosts(id: int | None, db: DBDep):
+def get_inbound_hosts(id: int, db: DBDep):
     """
     Get hosts of a specific inbound
     """
diff --git a/cli/admin.py b/cli/admin.py
index 492fbd3..5987e96 100644
--- a/cli/admin.py
+++ b/cli/admin.py
@@ -89,7 +89,10 @@ def create_admin(
     with GetDB() as db:
         try:
             crud.create_admin(
-                db, AdminCreate(username=username, password=password, is_sudo=is_sudo)
+                db,
+                AdminCreate(
+                    username=username, password=password, is_sudo=is_sudo
+                ),
             )
             utils.success(f'Admin "{username}" created successfully.')
         except IntegrityError:
@@ -180,16 +183,23 @@ def import_from_env(
                 utils.error("Aborted.")
 
             admin = crud.partial_update_admin(
-                db, current_admin, AdminPartialModify(password=password, is_sudo=True)
+                db,
+                current_admin,
+                AdminPartialModify(password=password, is_sudo=True),
             )
         # If env admin does not exist yet
         else:
             admin = crud.create_admin(
-                db, AdminCreate(username=username, password=password, is_sudo=True)
+                db,
+                AdminCreate(
+                    username=username, password=password, is_sudo=True
+                ),
             )
 
         updated_user_count = (
-            db.query(User).filter_by(admin_id=None).update({"admin_id": admin.id})
+            db.query(User)
+            .filter_by(admin_id=None)
+            .update({"admin_id": admin.id})
         )
         db.commit()
 
diff --git a/cli/subscription.py b/cli/subscription.py
index 4b27c62..f8f03c6 100644
--- a/cli/subscription.py
+++ b/cli/subscription.py
@@ -19,7 +19,9 @@ class ConfigFormat(str, Enum):
 
 
 @app.command(name="get-link")
-def get_link(username: str = typer.Option(..., *utils.FLAGS["username"], prompt=True)):
+def get_link(
+    username: str = typer.Option(..., *utils.FLAGS["username"], prompt=True)
+):
     """
     Prints the given user's subscription link.
 
@@ -27,7 +29,9 @@ def get_link(username: str = typer.Option(..., *utils.FLAGS["username"], prompt=
       in order to work correctly.
     """
     with GetDB() as db:
-        user: UserResponse = UserResponse.from_orm(utils.get_user(db, username))
+        user: UserResponse = UserResponse.from_orm(
+            utils.get_user(db, username)
+        )
         print(user.subscription_url)
 
 
@@ -58,7 +62,9 @@ def get_config(
       otherwise will be shown in the terminal.
     """
     with GetDB() as db:
-        user: UserResponse = UserResponse.from_orm(utils.get_user(db, username))
+        user: UserResponse = UserResponse.from_orm(
+            utils.get_user(db, username)
+        )
         conf: str = generate_subscription(
             user=user, config_format=config_format.name, as_base64=as_base64
         )
diff --git a/cli/user.py b/cli/user.py
index f7bd605..c667415 100644
--- a/cli/user.py
+++ b/cli/user.py
@@ -19,7 +19,9 @@ def list_users(
     username: Optional[List[str]] = typer.Option(
         None, *utils.FLAGS["username"], help="Search by username(s)"
     ),
-    status: Optional[crud.UserStatus] = typer.Option(None, *utils.FLAGS["status"]),
+    status: Optional[crud.UserStatus] = typer.Option(
+        None, *utils.FLAGS["status"]
+    ),
     admin: Optional[str] = typer.Option(
         None, "--admin", "--owner", help="Search by owner admin's username"
     ),
@@ -56,7 +58,11 @@ def list_users(
                     user.username,
                     user.status.value,
                     readable_size(user.used_traffic),
-                    readable_size(user.data_limit) if user.data_limit else "Unlimited",
+                    (
+                        readable_size(user.data_limit)
+                        if user.data_limit
+                        else "Unlimited"
+                    ),
                     user.data_limit_reset_strategy.value,
                     utils.readable_datetime(user.expire, include_time=False),
                     user.admin.username if user.admin else "",
@@ -83,7 +89,8 @@ def set_owner(
     """
     with GetDB() as db:
         user: User = utils.raise_if_falsy(
-            crud.get_user(db, username=username), f'User "{username}" not found.'
+            crud.get_user(db, username=username),
+            f'User "{username}" not found.',
         )
 
         dbadmin = utils.raise_if_falsy(
diff --git a/cli/utils.py b/cli/utils.py
index 0f563c0..3251f1a 100644
--- a/cli/utils.py
+++ b/cli/utils.py
@@ -51,7 +51,9 @@ def get_user(db, username: str) -> User:
 
 
 def print_table(
-    table: Table, rows: Iterable[Iterable[Any]], console: Optional[Console] = None
+    table: Table,
+    rows: Iterable[Iterable[Any]],
+    console: Optional[Console] = None,
 ):
     for row in rows:
         table.add_row(*row)
diff --git a/marzneshin-cli.py b/marzneshin-cli.py
index b904ac8..d416579 100755
--- a/marzneshin-cli.py
+++ b/marzneshin-cli.py
@@ -17,7 +17,9 @@ app.add_typer(cli.user.app, name="user")
 
 # Hidden completion app
 app_completion = typer.Typer(
-    no_args_is_help=True, help="Generate and install completion scripts.", hidden=True
+    no_args_is_help=True,
+    help="Generate and install completion scripts.",
+    hidden=True,
 )
 app.add_typer(app_completion, name="completion")