diff --git a/basecamp_client.py b/basecamp_client.py
new file mode 100644
index 0000000..750cb86
--- /dev/null
+++ b/basecamp_client.py
@@ -0,0 +1,332 @@
+import os
+import requests
+from dotenv import load_dotenv
+
+class BasecampClient:
+    """
+    Client for interacting with Basecamp 3 API using Basic Authentication or OAuth 2.0.
+    """
+    
+    def __init__(self, username=None, password=None, account_id=None, user_agent=None, 
+                 access_token=None, auth_mode="basic"):
+        """
+        Initialize the Basecamp client with credentials.
+        
+        Args:
+            username (str, optional): Basecamp username (email) for Basic Auth
+            password (str, optional): Basecamp password for Basic Auth
+            account_id (str, optional): Basecamp account ID
+            user_agent (str, optional): User agent for API requests
+            access_token (str, optional): OAuth access token for OAuth Auth
+            auth_mode (str, optional): Authentication mode ('basic' or 'oauth')
+        """
+        # Load environment variables if not provided directly
+        load_dotenv()
+        
+        self.auth_mode = auth_mode.lower()
+        self.account_id = account_id or os.getenv('BASECAMP_ACCOUNT_ID')
+        self.user_agent = user_agent or os.getenv('USER_AGENT')
+        
+        # Set up authentication based on mode
+        if self.auth_mode == 'basic':
+            self.username = username or os.getenv('BASECAMP_USERNAME')
+            self.password = password or os.getenv('BASECAMP_PASSWORD')
+            
+            if not all([self.username, self.password, self.account_id, self.user_agent]):
+                raise ValueError("Missing required credentials for Basic Auth. Set them in .env file or pass them to the constructor.")
+            
+            self.auth = (self.username, self.password)
+            self.headers = {
+                "User-Agent": self.user_agent,
+                "Content-Type": "application/json"
+            }
+        
+        elif self.auth_mode == 'oauth':
+            self.access_token = access_token or os.getenv('BASECAMP_ACCESS_TOKEN')
+            
+            if not all([self.access_token, self.account_id, self.user_agent]):
+                raise ValueError("Missing required credentials for OAuth. Set them in .env file or pass them to the constructor.")
+            
+            self.auth = None  # No basic auth needed for OAuth
+            self.headers = {
+                "User-Agent": self.user_agent,
+                "Content-Type": "application/json",
+                "Authorization": f"Bearer {self.access_token}"
+            }
+        
+        else:
+            raise ValueError("Invalid auth_mode. Must be 'basic' or 'oauth'")
+        
+        # Basecamp 3 uses a different URL structure
+        self.base_url = f"https://3.basecampapi.com/{self.account_id}"
+    
+    def test_connection(self):
+        """Test the connection to Basecamp API."""
+        response = self.get('projects.json')
+        if response.status_code == 200:
+            return True, "Connection successful"
+        else:
+            return False, f"Connection failed: {response.status_code} - {response.text}"
+    
+    def get(self, endpoint, params=None):
+        """Make a GET request to the Basecamp API."""
+        url = f"{self.base_url}/{endpoint}"
+        return requests.get(url, auth=self.auth, headers=self.headers, params=params)
+    
+    def post(self, endpoint, data=None):
+        """Make a POST request to the Basecamp API."""
+        url = f"{self.base_url}/{endpoint}"
+        return requests.post(url, auth=self.auth, headers=self.headers, json=data)
+    
+    def put(self, endpoint, data=None):
+        """Make a PUT request to the Basecamp API."""
+        url = f"{self.base_url}/{endpoint}"
+        return requests.put(url, auth=self.auth, headers=self.headers, json=data)
+    
+    def delete(self, endpoint):
+        """Make a DELETE request to the Basecamp API."""
+        url = f"{self.base_url}/{endpoint}"
+        return requests.delete(url, auth=self.auth, headers=self.headers)
+    
+    # Project methods
+    def get_projects(self):
+        """Get all projects."""
+        response = self.get('projects.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get projects: {response.status_code} - {response.text}")
+    
+    def get_project(self, project_id):
+        """Get a specific project by ID."""
+        response = self.get(f'projects/{project_id}.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get project: {response.status_code} - {response.text}")
+    
+    # To-do list methods
+    def get_todosets(self, project_id):
+        """Get the todoset for a project (Basecamp 3 has one todoset per project)."""
+        response = self.get(f'projects/{project_id}/todoset.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get todoset: {response.status_code} - {response.text}")
+    
+    def get_todolists(self, project_id):
+        """Get all todolists for a project."""
+        # First get the todoset ID for this project
+        todoset = self.get_todosets(project_id)
+        todoset_id = todoset['id']
+        
+        # Then get all todolists in this todoset
+        response = self.get(f'todolists.json', {'todoset_id': todoset_id})
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get todolists: {response.status_code} - {response.text}")
+    
+    def get_todolist(self, todolist_id):
+        """Get a specific todolist."""
+        response = self.get(f'todolists/{todolist_id}.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get todolist: {response.status_code} - {response.text}")
+    
+    # To-do methods
+    def get_todos(self, todolist_id):
+        """Get all todos in a todolist."""
+        response = self.get(f'todolists/{todolist_id}/todos.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get todos: {response.status_code} - {response.text}")
+    
+    def get_todo(self, todo_id):
+        """Get a specific todo."""
+        response = self.get(f'todos/{todo_id}.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get todo: {response.status_code} - {response.text}")
+    
+    # People methods
+    def get_people(self):
+        """Get all people in the account."""
+        response = self.get('people.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get people: {response.status_code} - {response.text}")
+            
+    # Campfire (chat) methods
+    def get_campfires(self, project_id):
+        """Get the campfire for a project."""
+        response = self.get(f'buckets/{project_id}/chats.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get campfire: {response.status_code} - {response.text}")
+    
+    def get_campfire_lines(self, project_id, campfire_id):
+        """Get chat lines from a campfire."""
+        response = self.get(f'buckets/{project_id}/chats/{campfire_id}/lines.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get campfire lines: {response.status_code} - {response.text}")
+            
+    # Message board methods
+    def get_message_board(self, project_id):
+        """Get the message board for a project."""
+        response = self.get(f'projects/{project_id}/message_board.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get message board: {response.status_code} - {response.text}")
+            
+    def get_messages(self, project_id):
+        """Get all messages for a project."""
+        # First get the message board ID
+        message_board = self.get_message_board(project_id)
+        message_board_id = message_board['id']
+        
+        # Then get all messages
+        response = self.get('messages.json', {'message_board_id': message_board_id})
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get messages: {response.status_code} - {response.text}")
+    
+    # Schedule methods
+    def get_schedule(self, project_id):
+        """Get the schedule for a project."""
+        response = self.get(f'projects/{project_id}/schedule.json')
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get schedule: {response.status_code} - {response.text}")
+    
+    def get_schedule_entries(self, project_id):
+        """
+        Get schedule entries for a project.
+        
+        Args:
+            project_id (int): Project ID
+            
+        Returns:
+            list: Schedule entries
+        """
+        try:
+            endpoint = f"buckets/{project_id}/schedules.json"
+            schedule = self.get(endpoint)
+            
+            if isinstance(schedule, list) and len(schedule) > 0:
+                schedule_id = schedule[0]['id']
+                entries_endpoint = f"buckets/{project_id}/schedules/{schedule_id}/entries.json"
+                return self.get(entries_endpoint)
+            else:
+                return []
+        except Exception as e:
+            raise Exception(f"Failed to get schedule: {str(e)}")
+    
+    # Comments methods
+    def get_comments(self, recording_id, bucket_id=None):
+        """
+        Get all comments for a recording (todo, message, etc.).
+        
+        Args:
+            recording_id (int): ID of the recording (todo, message, etc.)
+            bucket_id (int, optional): Project/bucket ID. If not provided, it will be extracted from the recording ID.
+            
+        Returns:
+            list: Comments for the recording
+        """
+        if bucket_id is None:
+            # Try to get the recording first to extract the bucket_id
+            raise ValueError("bucket_id is required")
+            
+        endpoint = f"buckets/{bucket_id}/recordings/{recording_id}/comments.json"
+        response = self.get(endpoint)
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get comments: {response.status_code} - {response.text}")
+            
+    def create_comment(self, recording_id, bucket_id, content):
+        """
+        Create a comment on a recording.
+        
+        Args:
+            recording_id (int): ID of the recording to comment on
+            bucket_id (int): Project/bucket ID
+            content (str): Content of the comment in HTML format
+            
+        Returns:
+            dict: The created comment
+        """
+        endpoint = f"buckets/{bucket_id}/recordings/{recording_id}/comments.json"
+        data = {"content": content}
+        response = self.post(endpoint, data)
+        if response.status_code == 201:
+            return response.json()
+        else:
+            raise Exception(f"Failed to create comment: {response.status_code} - {response.text}")
+            
+    def get_comment(self, comment_id, bucket_id):
+        """
+        Get a specific comment.
+        
+        Args:
+            comment_id (int): Comment ID
+            bucket_id (int): Project/bucket ID
+            
+        Returns:
+            dict: Comment details
+        """
+        endpoint = f"buckets/{bucket_id}/comments/{comment_id}.json"
+        response = self.get(endpoint)
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get comment: {response.status_code} - {response.text}")
+    
+    def update_comment(self, comment_id, bucket_id, content):
+        """
+        Update a comment.
+        
+        Args:
+            comment_id (int): Comment ID
+            bucket_id (int): Project/bucket ID
+            content (str): New content for the comment in HTML format
+            
+        Returns:
+            dict: Updated comment
+        """
+        endpoint = f"buckets/{bucket_id}/comments/{comment_id}.json"
+        data = {"content": content}
+        response = self.put(endpoint, data)
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to update comment: {response.status_code} - {response.text}")
+    
+    def delete_comment(self, comment_id, bucket_id):
+        """
+        Delete a comment.
+        
+        Args:
+            comment_id (int): Comment ID
+            bucket_id (int): Project/bucket ID
+            
+        Returns:
+            bool: True if successful
+        """
+        endpoint = f"buckets/{bucket_id}/comments/{comment_id}.json"
+        response = self.delete(endpoint)
+        if response.status_code == 204:
+            return True
+        else:
+            raise Exception(f"Failed to delete comment: {response.status_code} - {response.text}") 
\ No newline at end of file
diff --git a/basecamp_oauth.py b/basecamp_oauth.py
new file mode 100644
index 0000000..03ba687
--- /dev/null
+++ b/basecamp_oauth.py
@@ -0,0 +1,134 @@
+"""
+Basecamp 3 OAuth 2.0 Authentication Module
+
+This module provides the functionality to authenticate with Basecamp 3
+using OAuth 2.0, which is necessary when using Google Authentication (SSO).
+"""
+
+import os
+import requests
+from urllib.parse import urlencode
+from dotenv import load_dotenv
+
+# Load environment variables
+load_dotenv()
+
+# OAuth 2.0 endpoints for Basecamp - these stay the same for Basecamp 2 and 3
+AUTH_URL = "https://launchpad.37signals.com/authorization/new"
+TOKEN_URL = "https://launchpad.37signals.com/authorization/token"
+IDENTITY_URL = "https://launchpad.37signals.com/authorization.json"
+
+class BasecampOAuth:
+    """
+    OAuth 2.0 client for Basecamp 3.
+    """
+    
+    def __init__(self, client_id=None, client_secret=None, redirect_uri=None, user_agent=None):
+        """Initialize the OAuth client with credentials."""
+        self.client_id = client_id or os.getenv('BASECAMP_CLIENT_ID')
+        self.client_secret = client_secret or os.getenv('BASECAMP_CLIENT_SECRET')
+        self.redirect_uri = redirect_uri or os.getenv('BASECAMP_REDIRECT_URI')
+        self.user_agent = user_agent or os.getenv('USER_AGENT')
+        
+        if not all([self.client_id, self.client_secret, self.redirect_uri, self.user_agent]):
+            raise ValueError("Missing required OAuth credentials. Set them in .env file or pass them to the constructor.")
+    
+    def get_authorization_url(self, state=None):
+        """
+        Get the URL to redirect the user to for authorization.
+        
+        Args:
+            state (str, optional): A random string to maintain state between requests
+            
+        Returns:
+            str: The authorization URL
+        """
+        params = {
+            'type': 'web_server',
+            'client_id': self.client_id,
+            'redirect_uri': self.redirect_uri
+        }
+        
+        if state:
+            params['state'] = state
+            
+        return f"{AUTH_URL}?{urlencode(params)}"
+    
+    def exchange_code_for_token(self, code):
+        """
+        Exchange the authorization code for an access token.
+        
+        Args:
+            code (str): The authorization code received after user grants permission
+            
+        Returns:
+            dict: The token response containing access_token and refresh_token
+        """
+        data = {
+            'type': 'web_server',
+            'client_id': self.client_id,
+            'redirect_uri': self.redirect_uri,
+            'client_secret': self.client_secret,
+            'code': code
+        }
+        
+        headers = {
+            'User-Agent': self.user_agent
+        }
+        
+        response = requests.post(TOKEN_URL, data=data, headers=headers)
+        
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to exchange code for token: {response.status_code} - {response.text}")
+    
+    def refresh_token(self, refresh_token):
+        """
+        Refresh an expired access token.
+        
+        Args:
+            refresh_token (str): The refresh token from the original token response
+            
+        Returns:
+            dict: The new token response containing a new access_token
+        """
+        data = {
+            'type': 'refresh',
+            'client_id': self.client_id,
+            'client_secret': self.client_secret,
+            'refresh_token': refresh_token
+        }
+        
+        headers = {
+            'User-Agent': self.user_agent
+        }
+        
+        response = requests.post(TOKEN_URL, data=data, headers=headers)
+        
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to refresh token: {response.status_code} - {response.text}")
+    
+    def get_identity(self, access_token):
+        """
+        Get the identity and account information for the authenticated user.
+        
+        Args:
+            access_token (str): The OAuth access token
+            
+        Returns:
+            dict: The identity and account information
+        """
+        headers = {
+            'User-Agent': self.user_agent,
+            'Authorization': f"Bearer {access_token}"
+        }
+        
+        response = requests.get(IDENTITY_URL, headers=headers)
+        
+        if response.status_code == 200:
+            return response.json()
+        else:
+            raise Exception(f"Failed to get identity: {response.status_code} - {response.text}") 
\ No newline at end of file