diff --git a/backend/alembic/env.py b/backend/alembic/env.py
index 4770a9c..c9fe209 100644
--- a/backend/alembic/env.py
+++ b/backend/alembic/env.py
@@ -7,22 +7,15 @@ from sqlalchemy import pool
 
 from alembic import context
 
+from core.database import Base # Import your Base
+
+
 # --- Add project root to sys.path ---
 # This assumes alembic/env.py is one level down from the project root (backend/)
 PROJECT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 sys.path.insert(0, PROJECT_DIR)
 # -----------------------------------
 
-# --- Import Base and Models ---
-from core.database import Base # Import your Base
-# Import all your models here so Base registers them
-from modules.auth.models import User # Example: Import User model
-from modules.calendar.models import CalendarEvent # Example: Import CalendarEvent model
-from modules.nlp.models import ChatMessage # Import the new ChatMessage model
-from modules.todo.models import Todo # Import the new Todo model
-# Add imports for any other models you have
-# ----------------------------
-
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.
 config = context.config
diff --git a/backend/alembic/versions/69069d6184b3_initial_migration_with_existing_tables.py b/backend/alembic/versions/69069d6184b3_initial_migration_with_existing_tables.py
index c74bf5b..6dece1c 100644
--- a/backend/alembic/versions/69069d6184b3_initial_migration_with_existing_tables.py
+++ b/backend/alembic/versions/69069d6184b3_initial_migration_with_existing_tables.py
@@ -7,8 +7,6 @@ Create Date: 2025-04-21 01:14:33.233195
 """
 from typing import Sequence, Union
 
-from alembic import op
-import sqlalchemy as sa
 
 
 # revision identifiers, used by Alembic.
diff --git a/backend/alembic/versions/9a82960db482_add_todo_table.py b/backend/alembic/versions/9a82960db482_add_todo_table.py
index fea09ee..c264d75 100644
--- a/backend/alembic/versions/9a82960db482_add_todo_table.py
+++ b/backend/alembic/versions/9a82960db482_add_todo_table.py
@@ -7,8 +7,6 @@ Create Date: 2025-04-21 20:33:27.028529
 """
 from typing import Sequence, Union
 
-from alembic import op
-import sqlalchemy as sa
 
 
 # revision identifiers, used by Alembic.
diff --git a/backend/core/__pycache__/config.cpython-312.pyc b/backend/core/__pycache__/config.cpython-312.pyc
index 1ae3b10..fbfe8fd 100644
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diff --git a/backend/core/__pycache__/database.cpython-312.pyc b/backend/core/__pycache__/database.cpython-312.pyc
index bd6580d..300d627 100644
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diff --git a/backend/core/config.py b/backend/core/config.py
index 05f3642..c6b88b2 100644
--- a/backend/core/config.py
+++ b/backend/core/config.py
@@ -1,6 +1,5 @@
 # core/config.py
 from pydantic_settings import BaseSettings
-from pydantic import Field # Import Field for potential default values if needed
 import os
 
 DOTENV_PATH = os.path.join(os.path.dirname(__file__), "../.env")
diff --git a/backend/core/database.py b/backend/core/database.py
index 33c63f6..4897177 100644
--- a/backend/core/database.py
+++ b/backend/core/database.py
@@ -19,7 +19,7 @@ def get_engine():
         _engine = create_engine(settings.DB_URL)
         try:
             _engine.connect()
-        except Exception as e:
+        except Exception:
             raise Exception("Database connection failed. Is the database server running?")
         Base.metadata.create_all(_engine)  # Create tables here
     return _engine
diff --git a/backend/main.py b/backend/main.py
index 29719b3..5af39b7 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -1,7 +1,7 @@
 # main.py
 from contextlib import _AsyncGeneratorContextManager, asynccontextmanager
 from typing import Any, Callable
-from fastapi import FastAPI, Depends
+from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from core.database import get_engine, Base
 from modules import router
@@ -9,9 +9,6 @@ import logging
 
 
 # import all models to ensure they are registered before create_all
-from modules.calendar.models import CalendarEvent
-from modules.auth.models import User
-from modules.todo.models import Todo # Import the new Todo model
 
 
 logging.getLogger('passlib').setLevel(logging.ERROR) # fix bc package logging is broken
diff --git a/backend/modules/admin/__pycache__/api.cpython-312.pyc b/backend/modules/admin/__pycache__/api.cpython-312.pyc
index 06c11ba..6207da4 100644
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diff --git a/backend/modules/admin/api.py b/backend/modules/admin/api.py
index 63990fa..120ab82 100644
--- a/backend/modules/admin/api.py
+++ b/backend/modules/admin/api.py
@@ -1,10 +1,9 @@
 # modules/admin/api.py
 from typing import Annotated
-from fastapi import APIRouter, Depends, Body # Import Body
+from fastapi import APIRouter, Depends # Import Body
 from pydantic import BaseModel # Import BaseModel
 from sqlalchemy.orm import Session
-from core.database import Base, get_db
-from modules.auth.models import User, UserRole
+from core.database import get_db
 from modules.auth.dependencies import admin_only
 from .tasks import cleardb
 
diff --git a/backend/modules/auth/__pycache__/api.cpython-312.pyc b/backend/modules/auth/__pycache__/api.cpython-312.pyc
index edff5ae..b69dc64 100644
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diff --git a/backend/modules/auth/__pycache__/dependencies.cpython-312.pyc b/backend/modules/auth/__pycache__/dependencies.cpython-312.pyc
index b6e718c..bce2297 100644
Binary files a/backend/modules/auth/__pycache__/dependencies.cpython-312.pyc and b/backend/modules/auth/__pycache__/dependencies.cpython-312.pyc differ
diff --git a/backend/modules/auth/api.py b/backend/modules/auth/api.py
index 696c8c6..d959e6b 100644
--- a/backend/modules/auth/api.py
+++ b/backend/modules/auth/api.py
@@ -1,5 +1,5 @@
 # modules/auth/api.py
-from fastapi import APIRouter, Cookie, Depends, HTTPException, status, Request, Response
+from fastapi import APIRouter, Depends, HTTPException, status
 from fastapi.security import OAuth2PasswordRequestForm
 from jose import JWTError
 from modules.auth.models import User
@@ -7,7 +7,7 @@ from modules.auth.schemas import UserCreate, UserResponse, Token, RefreshTokenRe
 from modules.auth.services import create_user
 from modules.auth.security import TokenType, get_current_user, oauth2_scheme, create_access_token, create_refresh_token, verify_token, authenticate_user, blacklist_tokens
 from sqlalchemy.orm import Session
-from typing import Annotated, Optional
+from typing import Annotated
 from core.database import get_db
 from datetime import timedelta
 from core.config import settings  # Assuming settings is defined in core.config
diff --git a/backend/modules/auth/dependencies.py b/backend/modules/auth/dependencies.py
index ee42a7b..b8eb91c 100644
--- a/backend/modules/auth/dependencies.py
+++ b/backend/modules/auth/dependencies.py
@@ -1,5 +1,5 @@
 # modules/auth/dependencies.py
-from fastapi import Depends, HTTPException, status
+from fastapi import Depends
 from modules.auth.security import get_current_user
 from modules.auth.schemas import UserRole
 from modules.auth.models import User
diff --git a/backend/modules/calendar/__pycache__/api.cpython-312.pyc b/backend/modules/calendar/__pycache__/api.cpython-312.pyc
index b276969..2c590a4 100644
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diff --git a/backend/modules/calendar/__pycache__/service.cpython-312.pyc b/backend/modules/calendar/__pycache__/service.cpython-312.pyc
index 4b3a1bc..725eba9 100644
Binary files a/backend/modules/calendar/__pycache__/service.cpython-312.pyc and b/backend/modules/calendar/__pycache__/service.cpython-312.pyc differ
diff --git a/backend/modules/calendar/api.py b/backend/modules/calendar/api.py
index 81ecc15..fdf079c 100644
--- a/backend/modules/calendar/api.py
+++ b/backend/modules/calendar/api.py
@@ -5,7 +5,6 @@ from datetime import datetime
 from typing import List, Optional
 from modules.auth.dependencies import get_current_user
 from core.database import get_db
-from core.exceptions import not_found_exception
 from modules.auth.models import User
 from modules.calendar.schemas import CalendarEventCreate, CalendarEventUpdate, CalendarEventResponse
 from modules.calendar.service import create_calendar_event, get_calendar_event_by_id, get_calendar_events, update_calendar_event, delete_calendar_event
diff --git a/backend/modules/calendar/service.py b/backend/modules/calendar/service.py
index 5b2c27f..d973aca 100644
--- a/backend/modules/calendar/service.py
+++ b/backend/modules/calendar/service.py
@@ -46,9 +46,9 @@ def get_calendar_events(db: Session, user_id: int, start: datetime | None, end:
         query = query.filter(
             or_(
                 # Case 1: Event has duration and overlaps
-                (CalendarEvent.end != None) & (CalendarEvent.start < end) & (CalendarEvent.end > start),
+                (CalendarEvent.end is not None) & (CalendarEvent.start < end) & (CalendarEvent.end > start),
                 # Case 2: Event is a point event within the range
-                (CalendarEvent.end == None) & (CalendarEvent.start >= start) & (CalendarEvent.start < end)
+                (CalendarEvent.end is None) & (CalendarEvent.start >= start) & (CalendarEvent.start < end)
             )
         )
     # If only start is provided, filter events starting on or after start
@@ -63,9 +63,9 @@ def get_calendar_events(db: Session, user_id: int, start: datetime | None, end:
          query = query.filter(
             or_(
                 # Event ends before the specified end time
-                (CalendarEvent.end != None) & (CalendarEvent.end <= end),
+                (CalendarEvent.end is not None) & (CalendarEvent.end <= end),
                 # Point event occurs before the specified end time
-                (CalendarEvent.end == None) & (CalendarEvent.start < end)
+                (CalendarEvent.end is None) & (CalendarEvent.start < end)
             )
         )
         # Alternative interpretation for "ending before end": include events that *start* before end
diff --git a/backend/modules/nlp/__pycache__/api.cpython-312.pyc b/backend/modules/nlp/__pycache__/api.cpython-312.pyc
index 054df8c..b18dfb9 100644
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diff --git a/backend/modules/nlp/__pycache__/models.cpython-312.pyc b/backend/modules/nlp/__pycache__/models.cpython-312.pyc
index 9536465..4eebfa5 100644
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diff --git a/backend/modules/nlp/api.py b/backend/modules/nlp/api.py
index 8f0587c..14e3b8a 100644
--- a/backend/modules/nlp/api.py
+++ b/backend/modules/nlp/api.py
@@ -11,7 +11,6 @@ from modules.auth.models import User
 from modules.nlp.service import process_request, ask_ai, save_chat_message, get_chat_history, MessageSender
 # Import the response schema and the new ChatMessage model for response type hinting
 from modules.nlp.schemas import ProcessCommandRequest, ProcessCommandResponse
-from modules.nlp.models import ChatMessage # Import ChatMessage model
 from modules.calendar.service import create_calendar_event, get_calendar_events, update_calendar_event, delete_calendar_event
 from modules.calendar.models import CalendarEvent
 from modules.calendar.schemas import CalendarEventCreate, CalendarEventUpdate
@@ -19,7 +18,18 @@ from modules.calendar.schemas import CalendarEventCreate, CalendarEventUpdate
 from modules.todo import service as todo_service
 from modules.todo.models import Todo
 from modules.todo.schemas import TodoCreate, TodoUpdate
+from pydantic import BaseModel
+from datetime import datetime
 
+class ChatMessageResponse(BaseModel):
+    id: int
+    sender: MessageSender # Use the enum directly
+    text: str
+    timestamp: datetime
+
+    class Config:
+        from_attributes = True # Allow Pydantic to work with ORM models
+        
 router = APIRouter(prefix="/nlp", tags=["nlp"])
 
 # Helper to format calendar events (expects list of CalendarEvent models)
@@ -217,20 +227,6 @@ def process_command(request_data: ProcessCommandRequest, current_user: User = De
         # ----------------------------------
         return ProcessCommandResponse(responses=[error_response])
 
-# --- New Endpoint for Chat History ---
-# Define a Pydantic schema for the response (optional but good practice)
-from pydantic import BaseModel
-from datetime import datetime
-
-class ChatMessageResponse(BaseModel):
-    id: int
-    sender: MessageSender # Use the enum directly
-    text: str
-    timestamp: datetime
-
-    class Config:
-        from_attributes = True # Allow Pydantic to work with ORM models
-
 @router.get("/history", response_model=List[ChatMessageResponse])
 def read_chat_history(current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
     """Retrieves the last 50 chat messages for the current user."""
diff --git a/backend/modules/nlp/models.py b/backend/modules/nlp/models.py
index b92a1bc..ddeba47 100644
--- a/backend/modules/nlp/models.py
+++ b/backend/modules/nlp/models.py
@@ -1,6 +1,6 @@
 \
 # /home/cdp/code/MAIA/backend/modules/nlp/models.py
-from sqlalchemy import Column, Integer, String, Text, DateTime, ForeignKey, Enum as SQLEnum
+from sqlalchemy import Column, Integer, Text, DateTime, ForeignKey, Enum as SQLEnum
 from sqlalchemy.orm import relationship
 from sqlalchemy.sql import func
 import enum
diff --git a/backend/modules/todo/__pycache__/models.cpython-312.pyc b/backend/modules/todo/__pycache__/models.cpython-312.pyc
index 32eb8e9..54ad666 100644
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diff --git a/backend/modules/todo/models.py b/backend/modules/todo/models.py
index 2b09fdd..dc702b5 100644
--- a/backend/modules/todo/models.py
+++ b/backend/modules/todo/models.py
@@ -2,7 +2,6 @@
 from sqlalchemy import Column, Integer, String, Boolean, DateTime, ForeignKey
 from sqlalchemy.orm import relationship
 from core.database import Base
-import datetime
 
 class Todo(Base):
     __tablename__ = "todos"
diff --git a/backend/modules/user/__pycache__/api.cpython-312.pyc b/backend/modules/user/__pycache__/api.cpython-312.pyc
index 73019e3..8b37d05 100644
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diff --git a/backend/modules/user/api.py b/backend/modules/user/api.py
index 964b891..1804394 100644
--- a/backend/modules/user/api.py
+++ b/backend/modules/user/api.py
@@ -4,7 +4,7 @@ from fastapi import APIRouter, Depends
 from sqlalchemy.orm import Session
 
 from core.database import get_db
-from core.exceptions import unauthorized_exception, not_found_exception, forbidden_exception
+from core.exceptions import not_found_exception, forbidden_exception
 from modules.auth.schemas import UserPatch, UserResponse
 from modules.auth.dependencies import get_current_user
 from modules.auth.models import User
diff --git a/backend/tests/__pycache__/test_admin.cpython-312-pytest-8.3.5.pyc b/backend/tests/__pycache__/test_admin.cpython-312-pytest-8.3.5.pyc
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diff --git a/backend/tests/__pycache__/test_main.cpython-312-pytest-8.3.5.pyc b/backend/tests/__pycache__/test_main.cpython-312-pytest-8.3.5.pyc
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diff --git a/backend/tests/__pycache__/test_nlp.cpython-312-pytest-8.3.5.pyc b/backend/tests/__pycache__/test_nlp.cpython-312-pytest-8.3.5.pyc
index 454d395..b0d485d 100644
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diff --git a/backend/tests/__pycache__/test_todo.cpython-312-pytest-8.3.5.pyc b/backend/tests/__pycache__/test_todo.cpython-312-pytest-8.3.5.pyc
index c7a6b6e..32d3066 100644
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diff --git a/backend/tests/test_admin.py b/backend/tests/test_admin.py
index 3885fd2..3dc906a 100644
--- a/backend/tests/test_admin.py
+++ b/backend/tests/test_admin.py
@@ -1,11 +1,9 @@
-import pytest
 from fastapi import status
 from fastapi.testclient import TestClient
 from sqlalchemy.orm import Session
 from unittest.mock import patch
 
 from tests.helpers import generators
-from modules.auth.models import UserRole
 
 # Test admin routes require admin privileges
 
diff --git a/backend/tests/test_calendar.py b/backend/tests/test_calendar.py
index da0eec6..5e250d9 100644
--- a/backend/tests/test_calendar.py
+++ b/backend/tests/test_calendar.py
@@ -1,4 +1,3 @@
-import pytest
 from fastapi import status
 from fastapi.testclient import TestClient
 from sqlalchemy.orm import Session
diff --git a/backend/tests/test_main.py b/backend/tests/test_main.py
index 2401a93..22c5cf6 100644
--- a/backend/tests/test_main.py
+++ b/backend/tests/test_main.py
@@ -1,4 +1,3 @@
-import pytest
 from fastapi.testclient import TestClient
 
 # No database needed for this simple test
diff --git a/backend/tests/test_nlp.py b/backend/tests/test_nlp.py
index 28f39e3..ab770fd 100644
--- a/backend/tests/test_nlp.py
+++ b/backend/tests/test_nlp.py
@@ -6,7 +6,7 @@ from unittest.mock import patch, MagicMock
 from datetime import datetime
 
 from tests.helpers import generators
-from modules.nlp.schemas import ProcessCommandRequest, ProcessCommandResponse
+from modules.nlp.schemas import ProcessCommandResponse
 from modules.nlp.models import MessageSender, ChatMessage # Import necessary models/enums
 
 # --- Mocks ---
diff --git a/backend/tests/test_todo.py b/backend/tests/test_todo.py
index 573ea76..7497a57 100644
--- a/backend/tests/test_todo.py
+++ b/backend/tests/test_todo.py
@@ -1,11 +1,9 @@
-import pytest
 from fastapi import status
 from fastapi.testclient import TestClient
 from sqlalchemy.orm import Session
 from datetime import date
 
 from tests.helpers import generators
-from modules.todo import schemas # Import schemas
 
 # Helper Function
 def _login_user(db: Session, client: TestClient):