diff --git a/.github/workflows/python-quality.yml b/.github/workflows/python-quality.yml
index e1bbbba..8db5c5a 100644
--- a/.github/workflows/python-quality.yml
+++ b/.github/workflows/python-quality.yml
@@ -6,7 +6,7 @@ on:
       - 'backend/**'
 
 jobs:
-  black-check:
+  python-check:
     runs-on: ubuntu-latest
     steps:
     - name: Check out code
@@ -17,11 +17,14 @@ jobs:
       with:
         python-version: '3.8'
 
-    - name: Install Black
-      run: pip install black flake8
+    - name: Install dependencies
+      run: pip install black flake8 mypy
 
     - name: Check Python code formatting with Black
       run: black --check backend/
 
     - name: Check Python code style with Flake8
       run: flake8 backend/
+
+    - name: Run Mypy Type Checking
+      run: mypy backend/
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 3d8c455..e28c0ea 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -10,3 +10,10 @@ repos:
     hooks:
     -   id: flake8
         files: ^backend/  # Run flake8 only on files in the backend/ directory
+
+-   repo: https://github.com/pre-commit/mirrors-mypy
+    rev: 'v1.7.1'  # Use the latest version
+    hooks:
+    -   id: mypy
+        files: ^backend/
+
diff --git a/backend/databases/chat_history_manager.py b/backend/databases/chat_history_manager.py
index 5ce3935..7ce9ac9 100644
--- a/backend/databases/chat_history_manager.py
+++ b/backend/databases/chat_history_manager.py
@@ -1,8 +1,10 @@
-from sqlalchemy.orm import Session
-from models.chat_history import ChatHistory  # Replace with your actual import
+from typing import Optional
 
 import json
 
+from sqlalchemy.orm import Session
+from models.chat_history import ChatHistory  # Replace with your actual import
+
 
 class ChatHistoryManager:
     """
@@ -41,14 +43,16 @@ def get_new_chat_id(self) -> int:
         """
         Get a new chat id. Used for storing a new chat.
         """
-        latest_chat = (
+        latest_chat: Optional[ChatHistory] = (
             self.session.query(ChatHistory).order_by(ChatHistory.chat_id.desc()).first()
         )
 
         if not latest_chat:  # If there are no chats in database
             return 0
 
-        return latest_chat.chat_id + 1
+        new_chat_id: int = latest_chat.chat_id + 1
+
+        return new_chat_id
 
     def get_llm_chat_history_for_user(self, user_id: int, llm_type: str):
         """
diff --git a/backend/databases/dashboard_manager.py b/backend/databases/dashboard_manager.py
index 7476508..d1139d4 100644
--- a/backend/databases/dashboard_manager.py
+++ b/backend/databases/dashboard_manager.py
@@ -43,10 +43,12 @@ def get_dashboards(self) -> List[Dashboard]:
             List[Dashboard]: List of Dashboard objects.
         """
         try:
-            return self.db_session.query(Dashboard).all()
+            dashboards: List[Dashboard] = self.db_session.query(Dashboard).all()
+            return dashboards
         except Exception as e:
             # Handle exception
             print(f"Database error: {str(e)}")
+            return []
 
     def save_dashboard(self, dashboard: Dashboard):
         self.db_session.add(dashboard)
diff --git a/backend/databases/sql_executor.py b/backend/databases/sql_executor.py
index 29bd937..198ba3b 100644
--- a/backend/databases/sql_executor.py
+++ b/backend/databases/sql_executor.py
@@ -1,5 +1,6 @@
 from sqlalchemy import inspect, text
 from sqlalchemy.orm import Session
+from typing import List
 
 import pandas as pd
 
@@ -71,16 +72,16 @@ def get_all_table_names_as_str(self) -> str:
             print(f"An error occurred: {e}")
             raise
 
-    def get_all_table_names_as_list(self) -> list:
+    def get_all_table_names_as_list(self) -> List:
         try:
             # Using the engine from the session to get table names
-            table_names = self.session.bind.table_names()
+            table_names: List = self.session.bind.table_names()
             return table_names
         except Exception as e:
             print(f"An error occurred: {e}")
             raise
 
-    def get_table_columns(self, table_name: str) -> list:
+    def get_table_columns(self, table_name: str) -> List:
         try:
             engine = self.session.bind
             inspector = inspect(engine)
diff --git a/backend/databases/table_manager.py b/backend/databases/table_manager.py
index 2f17cce..20715e9 100644
--- a/backend/databases/table_manager.py
+++ b/backend/databases/table_manager.py
@@ -106,7 +106,7 @@ def determine_table(self, sample_content: str, extra_desc: str) -> str:
                 table_metadata
             )
 
-        table_name = self.llm.fetch_table_name_from_sample(
+        table_name: str = self.llm.fetch_table_name_from_sample(
             sample_content, extra_desc, formatted_table_metadata
         )
         return table_name
diff --git a/backend/databases/table_metadata_manager.py b/backend/databases/table_metadata_manager.py
index c19ed98..4a025cc 100644
--- a/backend/databases/table_metadata_manager.py
+++ b/backend/databases/table_metadata_manager.py
@@ -32,10 +32,14 @@ def get_all_metadata(self) -> List[TableMetadata]:
             List[TableMetadata]: List of TableMetadata objects.
         """
         try:
-            return self.db_session.query(TableMetadata).all()
+            table_metadatas: List[TableMetadata] = self.db_session.query(
+                TableMetadata
+            ).all()
+            return table_metadatas
         except Exception as e:
             # Handle exception
             print(f"Database error: {str(e)}")
+            return []
 
     def get_metadata(self, table_name: str) -> TableMetadata:
         """Retrieve metadata for a single table"""
diff --git a/backend/databases/user_manager.py b/backend/databases/user_manager.py
index e0797a2..4731005 100644
--- a/backend/databases/user_manager.py
+++ b/backend/databases/user_manager.py
@@ -2,6 +2,8 @@
 This module provides a UserManager class that handles database operations related to the User model.
 It uses SQLAlchemy for ORM operations and facilitates CRUD operations on user data.
 """
+from typing import Optional
+
 from sqlalchemy.orm import Session
 from models.user import User
 
@@ -95,10 +97,10 @@ def get_users_without_password(self, skip: int = 0, limit: int = 10):
     def update_user(
         self,
         user_id: int,
-        email: str = None,
-        organization_id: int = None,
-        role: str = None,
-        refresh_token: str = None,
+        email: Optional[str],
+        organization_id: Optional[int],
+        role: Optional[str],
+        refresh_token: Optional[str],
     ):
         """
         Update a user's details in the database.
diff --git a/backend/llms/base.py b/backend/llms/base.py
index 1f48297..a7d3433 100644
--- a/backend/llms/base.py
+++ b/backend/llms/base.py
@@ -11,17 +11,21 @@ def generate_text(self, prompt: str) -> str:
         """
         raise NotImplementedError("This method should be overridden by subclass")
 
-    def generate_create_statement(
-        self, sample_content: str, existing_table_names: str, extra_desc: str
+    async def generate_create_statement(
+        self,
+        sample_content: str,
+        header: str,
+        existing_table_names: str,
+        extra_desc: str,
     ) -> str:
         raise NotImplementedError
 
-    def generate_table_desc(
+    async def generate_table_desc(
         self, create_query: str, sample_content: str, extra_desc: str
     ) -> str:
         raise NotImplementedError
 
     def fetch_table_name_from_sample(
         self, sample_content: str, extra_desc: str, table_metadata: str
-    ):
+    ) -> str:
         raise NotImplementedError
diff --git a/backend/llms/gpt.py b/backend/llms/gpt.py
index 61965da..12da75e 100644
--- a/backend/llms/gpt.py
+++ b/backend/llms/gpt.py
@@ -1,3 +1,10 @@
+from openai import ChatCompletion
+from typing import Optional
+
+import json
+import openai
+import tiktoken
+
 from .base import BaseLLM
 from databases.chat_history_manager import ChatHistoryManager
 from databases.database_manager import DatabaseManager
@@ -5,10 +12,6 @@
 from settings import OPENAI_API_KEY
 from utils.nivo_assistant import NivoAssistant
 
-import json
-import openai
-import tiktoken
-
 
 class GPTLLM(BaseLLM):
     """
@@ -21,7 +24,7 @@ class GPTLLM(BaseLLM):
 
     def __init__(
         self,
-        chat_id: int = None,
+        chat_id: Optional[int],
         user: User = None,
         store_history: bool = False,
         llm_type: str = "generic",
@@ -77,12 +80,14 @@ def _set_response_format(self, is_json: bool):
 
     async def _api_call(self, payload: dict) -> str:
         """Make an API call to get a response based on the conversation history."""
-        completion = await openai.ChatCompletion.acreate(
+        completion: ChatCompletion = await openai.ChatCompletion.acreate(
             model=self.model,
             messages=payload["messages"],
             response_format=self.response_format,
         )
-        return completion.choices[0].message.content
+        return str(
+            completion.choices[0].message.content
+        )  # TODO: Typecasting is not recommended for mypy
 
     def _count_tokens(self, text: str) -> int:
         """Count the number of tokens in the given text."""
@@ -181,7 +186,7 @@ def _add_system_message(self, assistant_type: str) -> None:
 
         self.llm_type = assistant_type
 
-    async def _send_and_receive_message(self, prompt: str):
+    async def _send_and_receive_message(self, prompt: str) -> str:
         user_message = self._create_message("user", prompt)
         self.history.append(user_message)
 
@@ -196,7 +201,7 @@ async def _send_and_receive_message(self, prompt: str):
         self.history.append(assistant_message)
 
         if self.store_history:
-            self._save_messages()
+            self._save_messages(user_message, assistant_message)
 
         return assistant_message_content
 
@@ -276,7 +281,7 @@ async def generate_create_statement(
                 f"\n\nAdditional information about the sample data: \n{extra_desc}"
             )
 
-        gpt_response = await self._send_and_receive_message(prompt)
+        gpt_response: str = await self._send_and_receive_message(prompt)
 
         return gpt_response
 
diff --git a/backend/routes/chart_routes.py b/backend/routes/chart_routes.py
index c4f665c..3b42ace 100644
--- a/backend/routes/chart_routes.py
+++ b/backend/routes/chart_routes.py
@@ -8,6 +8,7 @@
 from llms.gpt import GPTLLM
 from models.user import User
 from models.chart import Chart, ChartCreate
+from models.table_metadata import TableMetadata
 from security import get_current_user
 from utils.nivo_assistant import NivoAssistant
 from utils.utils import execute_select_query
@@ -58,7 +59,7 @@ async def create_chart_config(
     chat_id = request.chat_id
     msg = request.msg
     chart_config = request.chart_config
-    table_name = chart_config.get("table")
+    table_name = chart_config.get("table", "")
     chart_type = chart_config.get("type")
     nivo_config = chart_config.get("nivoConfig")
     table_metadata = get_table_metadata(table_name)
@@ -85,7 +86,9 @@ async def create_chart_config(
     return updated_chart_config, gpt.chat_id
 
 
-def get_table_metadata(table_name: str, current_user: User = Depends(get_current_user)):
+def get_table_metadata(
+    table_name: str, current_user: User = Depends(get_current_user)
+) -> TableMetadata:
     """Get table metadata"""
     with DatabaseManager() as session:
         metadata_manager = TableMetadataManager(session)
diff --git a/backend/security.py b/backend/security.py
index 0f6de36..b41f602 100644
--- a/backend/security.py
+++ b/backend/security.py
@@ -109,7 +109,7 @@ def create_token(data: dict, expires_delta: timedelta) -> str:
     to_encode = data.copy()
     expire = datetime.utcnow() + expires_delta
     to_encode.update({"exp": expire})
-    encoded_jwt = jwt.encode(to_encode, JWT_SECRET_KEY, algorithm=ALGORITHM)
+    encoded_jwt: str = jwt.encode(to_encode, JWT_SECRET_KEY, algorithm=ALGORITHM)
     return encoded_jwt
 
 
@@ -191,7 +191,7 @@ def set_tokens_in_cookies(response: Response, access_token: str, refresh_token:
         httponly=True,
         max_age=1800,
         secure=True,
-        samesite="Lax",
+        samesite="lax",
     )
     response.set_cookie(
         key="refresh_token",
@@ -199,7 +199,7 @@ def set_tokens_in_cookies(response: Response, access_token: str, refresh_token:
         httponly=True,
         max_age=60 * 60 * 24 * 7,
         secure=True,
-        samesite="Lax",
+        samesite="lax",
     )
 
 
diff --git a/backend/utils/sql_string_manipulator.py b/backend/utils/sql_string_manipulator.py
index e57fdb5..b528183 100644
--- a/backend/utils/sql_string_manipulator.py
+++ b/backend/utils/sql_string_manipulator.py
@@ -70,5 +70,6 @@ def extract_sql_query_from_text(self) -> Optional[str]:
         match = re.findall(r"CREATE TABLE [^;]+;", self.sql_string)
         if match:
             # Extract only the last "CREATE TABLE" statement and add a space after "CREATE TABLE"
-            last_statement = match[-1]
+            last_statement: str = match[-1]
             return "CREATE TABLE " + last_statement.split("CREATE TABLE")[-1].strip()
+        return None
diff --git a/backend/utils/utils.py b/backend/utils/utils.py
index b54d601..565d053 100644
--- a/backend/utils/utils.py
+++ b/backend/utils/utils.py
@@ -1,7 +1,7 @@
 from csv import Sniffer
 from fastapi import File, UploadFile
 from io import StringIO
-from typing import Any
+from typing import Any, Dict, Optional
 
 import logging
 import os
@@ -30,10 +30,18 @@ def process_file(file: UploadFile, encoding: str) -> Any:
     Returns:
         Any: Processed content of the file.
     """
+    if file.filename is None:
+        raise ValueError("File must have a filename")
+
     # Find file type by file extension
     file_type = file.filename.split(".")[-1].lower()
 
-    files = {"processed_df": None, "sample_file_content": None}
+    # Define the dictionary with types for values
+    files: Dict[str, Optional[str]] = {
+        "processed_df": None,
+        "sample_file_content_str": None,
+        "header_str": None,
+    }
 
     if file_type == "csv":
         # Sniff the first 1024 bytes to check for a header
diff --git a/mypy.ini b/mypy.ini
new file mode 100644
index 0000000..1efd6c8
--- /dev/null
+++ b/mypy.ini
@@ -0,0 +1,8 @@
+[mypy]
+python_version = 3.8
+check_untyped_defs = True
+ignore_missing_imports = True
+warn_redundant_casts = True
+warn_unused_ignores = True
+warn_return_any = True
+no_implicit_optional = True