Add anonymous chat access feature

- Allow users to chat without creating an account
- Add choice page for selecting access mode (anonymous vs authenticated)
- Implement session-based chat storage for anonymous users
- Add rate limiting (20 messages/hour) for anonymous users
- Add message length limits (2000 chars) for anonymous users
- Update UI to show anonymous user indicators and session warnings
- Maintain backward compatibility with existing authenticated flow

.gitignore

@@ -0,0 +1,67 @@
+# Claude
+.claude
+.swarm
+.claude-flow/metrics
+.kiro
+
+# Environment variables
+.env
+.env.local
+.env.production
+
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# Virtual environments
+atlas_env/
+venv/
+env/
+ENV/
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Logs
+*.log
+
+# Test files (exclude from root, but allow in tests/ folder)
+/test_*.py
+/debug_*.py
+/validate_*.py
+/deployment_check.py
+
+# MongoDB local data
+*.json
+*.bson
+
+# API Keys (backup protection)
+*.key
+*.pem
+api_keys.txt

CLAUDE.md

@@ -0,0 +1,193 @@
+# Chatty - Ethics Chat Application Context
+
+## Project Overview
+Chatty is a secure web-based chat interface that connects to the findEthics-Atlas API for ethical discussions and guidance. Originally a Gradio chatbot template, it has been transformed into a full Flask web application with user authentication, chat history persistence, and deployment on Hugging Face Spaces.
+
+## Architecture
+
+### Tech Stack
+- **Backend**: Flask 3.0.0 (Python web framework)
+- **Database**: MongoDB Atlas (user accounts & chat history)
+- **Authentication**: Flask-Login with JWT tokens for stateless auth
+- **Security**: CSRF protection (disabled for HF Spaces), rate limiting, secure password hashing (Werkzeug PBKDF2)
+- **Frontend**: HTML, CSS (minimal design), JavaScript (vanilla ES6)
+- **Deployment**: Hugging Face Spaces (primary), supports Docker and traditional servers
+- **API Integration**: findEthics-Atlas API at https://findEthics-Atlas.hf.space/chat
+
+### Project Structure
+```
+Chatty/
+├── app.py                 # Main Flask application with routes and JWT auth
+├── config.py              # Environment-based configuration management
+├── auth.py                # Authentication utilities & Flask-Login setup
+├── models.py              # MongoDB models (User, ChatSession)
+├── database.py            # MongoDB connection and collection utilities
+├── deploy.py              # Deployment tools and configuration helpers
+├── requirements.txt       # Python dependencies
+├── start.sh               # Application startup script
+├── templates/             # HTML templates
+│   ├── base.html         # Base template with navigation
+│   ├── login.html        # Login form
+│   ├── register.html     # Registration form
+│   ├── index.html        # Main chat interface
+│   └── errors/           # Error page templates (400, 401, 429, 500)
+├── static/               # Static assets
+│   ├── css/
+│   │   ├── style.css     # Main stylesheet
+│   │   └── auth.css      # Authentication form styles
+│   └── js/
+│       └── chat.js       # Frontend chat functionality
+├── Test/                 # Test suite
+└── Documentation/
+    ├── README.md         # Main documentation with HF Spaces YAML header
+    ├── HUGGINGFACE_DEPLOYMENT_CHECKLIST.md
+    ├── PRODUCTION_DEPLOYMENT.md
+    └── instructions.md   # Original requirements
+```
+
+## Key Features
+1. **User Authentication**: Secure registration/login with email validation
+2. **Personalized Chat History**: Each user's conversations saved in MongoDB
+3. **Stateless JWT Auth**: For Hugging Face Spaces compatibility
+4. **Real-time Chat**: Instant messaging with ethics AI
+5. **Security Features**: Rate limiting, secure sessions, password hashing
+6. **Responsive Design**: Mobile-friendly minimal UI
+
+## API Integration
+
+### findEthics-Atlas API
+- **Endpoint**: https://findEthics-Atlas.hf.space/chat
+- **Method**: POST
+- **Request Format**:
+```json
+{
+  "prompt": "user message",
+  "history": []
+}
+```
+- **Response Format**:
+```json
+{
+  "response": "AI response text",
+  "search_results": []
+}
+```
+
+## Database Schema
+
+### Users Collection
+```javascript
+{
+  _id: ObjectId,
+  email: String (lowercase, unique),
+  password_hash: String (Werkzeug PBKDF2),
+  created_at: DateTime,
+  is_active: Boolean
+}
+```
+
+### Chat Sessions Collection
+```javascript
+{
+  _id: ObjectId,
+  user_id: ObjectId (reference to Users),
+  message: String,
+  response: String,
+  timestamp: DateTime,
+  session_data: Object (metadata)
+}
+```
+
+## Recent Updates
+- **Stateless JWT Authentication**: Implemented for Hugging Face Spaces compatibility
+- **Session Persistence Fixes**: Resolved load balancing issues on HF Spaces
+- **CSRF Protection**: Disabled for HF Spaces deployment (iframe/proxy limitations)
+- **Cookie Configuration**: Adjusted for HF Spaces environment
+
+## Deployment Configuration
+
+### Hugging Face Spaces
+- **FLASK_ENV**: huggingface
+- **Port**: 7860
+- **CSRF**: Disabled (WTF_CSRF_ENABLED=false)
+- **Session Cookies**: Secure=false (for HF proxy)
+- **JWT Tokens**: 48-hour expiry for stateless auth
+
+### Environment Variables
+Required:
+- `SECRET_KEY`: 64-character secure key
+- `MONGODB_URL`: MongoDB Atlas connection string
+- `MONGODB_DATABASE`: Atlas
+
+Security (HF Spaces optimized):
+- `SESSION_COOKIE_SECURE`: false
+- `WTF_CSRF_ENABLED`: false
+- `MAX_LOGIN_ATTEMPTS`: 3
+- `RATE_LIMIT_WINDOW`: 1800
+
+## Security Considerations
+1. **Password Security**: PBKDF2 hashing via Werkzeug
+2. **Rate Limiting**: Login attempt limiting (5 attempts default)
+3. **JWT Tokens**: Stateless authentication for distributed deployment
+4. **Input Validation**: Server and client-side validation
+5. **HTTPS**: Provided by Hugging Face Spaces
+
+## Testing
+- **Test Suite**: Located in Test/ directory
+- **Coverage**: Unit tests, integration tests, auth flow tests
+- **Run Tests**: `python Test/run_tests.py`
+
+## Development Workflow
+
+### Local Development
+```bash
+# Setup virtual environment
+python -m venv atlas_env
+source atlas_env/bin/activate
+
+# Install dependencies
+pip install -r requirements.txt
+
+# Configure environment
+python deploy.py setup-dev
+
+# Run application
+./start.sh
+```
+
+### Production Deployment
+```bash
+# Check production readiness
+python deploy.py check-prod
+
+# Generate secure key
+python deploy.py gen-secret
+
+# Deploy to HF Spaces
+git push origin main
+```
+
+## Important Notes
+1. **CSRF Protection**: Disabled for HF Spaces due to iframe limitations
+2. **Session Management**: Uses JWT tokens for stateless operation
+3. **Database**: Requires MongoDB Atlas with proper network access
+4. **API Dependency**: Relies on findEthics-Atlas API availability
+5. **Minimal UI**: Intentionally basic design per requirements
+
+## Common Issues & Solutions
+1. **Session Persistence**: Resolved with JWT tokens
+2. **CSRF Errors on HF**: Disabled CSRF for HF environment
+3. **Database Connection**: Ensure MongoDB Atlas allows HF IP ranges
+4. **Cookie Issues**: Configured for HF Spaces proxy environment
+
+## Maintenance Tasks
+- Monitor MongoDB Atlas usage and performance
+- Check API endpoint availability
+- Review authentication logs for security
+- Update dependencies regularly
+- Backup database periodically
+
+## Contact & Support
+- Deployment issues: Check HUGGINGFACE_DEPLOYMENT_CHECKLIST.md
+- Production setup: See PRODUCTION_DEPLOYMENT.md
+- Test failures: Review Test/TEST_SUMMARY.md

app.py

@@ -20,6 +20,8 @@ from config import get_config, validate_environment
 from auth import init_login_manager, authenticate_user, create_user_account
 from models import User, ChatSession
 from functools import wraps
+import secrets
+import string
 
 # Validate configuration before starting
 if not validate_environment():
@@ -175,6 +177,66 @@ def record_login_attempt(ip_address):
 API_URL = app.config['API_URL']
 TIMEOUT = app.config['API_TIMEOUT']
 
+# Anonymous user session management
+def generate_anonymous_id():
+    """Generate a unique anonymous user ID"""
+    random_string = ''.join(secrets.choice(string.ascii_lowercase + string.digits) for _ in range(8))
+    return f"anon_{random_string}"
+
+def init_anonymous_session():
+    """Initialize session for anonymous user"""
+    session.permanent = True
+    session['is_anonymous'] = True
+    session['anonymous_id'] = generate_anonymous_id()
+    session['anonymous_chat_history'] = []
+    session['anonymous_message_count'] = 0
+    session['anonymous_first_message_time'] = None
+    app.logger.info(f"Initialized anonymous session: {session['anonymous_id']}")
+    return session['anonymous_id']
+
+def get_anonymous_chat_history():
+    """Get chat history from session for anonymous user"""
+    return session.get('anonymous_chat_history', [])
+
+def add_anonymous_message(message, response):
+    """Add message and response to anonymous session history"""
+    if 'anonymous_chat_history' not in session:
+        session['anonymous_chat_history'] = []
+    
+    session['anonymous_chat_history'].append({
+        'user': message,
+        'assistant': response
+    })
+    
+    # Keep only last 20 messages for anonymous users
+    if len(session['anonymous_chat_history']) > 20:
+        session['anonymous_chat_history'] = session['anonymous_chat_history'][-20:]
+
+def check_anonymous_rate_limit():
+    """Check if anonymous user has exceeded rate limit"""
+    current_time = time.time()
+    
+    # Initialize rate limit tracking
+    if 'anonymous_first_message_time' not in session or session.get('anonymous_first_message_time') is None:
+        session['anonymous_first_message_time'] = current_time
+        session['anonymous_message_count'] = 0
+    
+    # Check if rate limit window has passed
+    time_since_first = current_time - session['anonymous_first_message_time']
+    if time_since_first > app.config['ANONYMOUS_RATE_LIMIT_WINDOW']:
+        # Reset rate limit window
+        session['anonymous_first_message_time'] = current_time
+        session['anonymous_message_count'] = 0
+    
+    # Check if limit exceeded
+    if session.get('anonymous_message_count', 0) >= app.config['ANONYMOUS_RATE_LIMIT']:
+        time_remaining = app.config['ANONYMOUS_RATE_LIMIT_WINDOW'] - time_since_first
+        return False, f"Rate limit exceeded. Please wait {int(time_remaining/60)} minutes."
+    
+    # Increment message count
+    session['anonymous_message_count'] = session.get('anonymous_message_count', 0) + 1
+    return True, None
+
 def make_api_request(message, history=None):
     """
     Make POST request to the findEthics-Atlas API
@@ -235,11 +297,16 @@ def make_api_request(message, history=None):
 @app.route('/')
 def index():
     """
-    Main route - redirect to login if not authenticated, otherwise show chat
+    Main route - show choice page for non-authenticated users
     """
     if current_user.is_authenticated:
         return redirect(url_for('chat_interface'))
-    return redirect(url_for('login'))
+    
+    # Check if anonymous access is enabled
+    if app.config.get('ANONYMOUS_ENABLED', True):
+        return redirect(url_for('choose'))
+    else:
+        return redirect(url_for('login'))
 
 @app.route('/register', methods=['GET', 'POST'])
 def register():
@@ -396,6 +463,42 @@ def logout():
         
         return response
 
+@app.route('/choose')
+def choose():
+    """
+    Access mode selection page - choose between anonymous or authenticated access
+    """
+    # If user is already logged in, redirect to chat
+    if current_user.is_authenticated:
+        return redirect(url_for('chat_interface'))
+    
+    # Check if anonymous access is enabled
+    if not app.config.get('ANONYMOUS_ENABLED', True):
+        return redirect(url_for('login'))
+    
+    return render_template('choose.html')
+
+@app.route('/anonymous')
+def anonymous():
+    """
+    Anonymous chat interface - no authentication required
+    """
+    # If user is authenticated, redirect to authenticated chat
+    if current_user.is_authenticated:
+        return redirect(url_for('chat_interface'))
+    
+    # Check if anonymous access is enabled
+    if not app.config.get('ANONYMOUS_ENABLED', True):
+        flash('Anonymous access is not available. Please login or register.', 'info')
+        return redirect(url_for('login'))
+    
+    # Initialize anonymous session if not already done
+    if not session.get('is_anonymous'):
+        init_anonymous_session()
+    
+    # Render chat interface in anonymous mode
+    return render_template('index.html', is_anonymous=True)
+
 @app.route('/chat')
 @hf_login_required
 def chat_interface():
@@ -411,14 +514,16 @@ def chat_interface():
     return render_template('index.html')
 
 @app.route('/api/chat', methods=['POST'])
-@hf_login_required
 def chat():
     """
-    Protected API route to handle chat requests
+    API route to handle chat requests - supports both authenticated and anonymous users
     """
     try:
-        # Check if user session is still valid
-        if not current_user.is_authenticated:
+        # Check if user is anonymous
+        is_anonymous = session.get('is_anonymous', False)
+        
+        # If not anonymous and not authenticated, require login
+        if not is_anonymous and not current_user.is_authenticated:
             return jsonify({
                 "success": False,
                 "error": "Your session has expired. Please log in again.",
@@ -440,47 +545,68 @@ def chat():
                 "error": "Your message cannot be empty. Please type something."
             }), 400
         
-        # Check message length (reasonable limit)
-        if len(message) > 5000:
+        # Check message length (different limits for anonymous vs authenticated)
+        max_length = app.config['ANONYMOUS_MAX_MESSAGE_LENGTH'] if is_anonymous else 5000
+        if len(message) > max_length:
             return jsonify({
                 "success": False,
-                "error": "Your message is too long. Please keep it under 5000 characters."
+                "error": f"Your message is too long. Please keep it under {max_length} characters."
             }), 400
         
-        # Get user's chat history for context
-        user_history = ChatSession.get_session_context(current_user.id, limit=10)
+        # Check rate limit for anonymous users
+        if is_anonymous:
+            allowed, error_msg = check_anonymous_rate_limit()
+            if not allowed:
+                return jsonify({
+                    "success": False,
+                    "error": error_msg
+                }), 429
+        
+        # Get chat history for context
+        if is_anonymous:
+            user_history = get_anonymous_chat_history()
+        else:
+            user_history = ChatSession.get_session_context(current_user.id, limit=10)
         
         # Make request to the external API
         result = make_api_request(message, user_history)
         
-        # If successful, save the message and response to database
+        # If successful, save the message and response
         if result.get('success'):
             response_text = result.get('response', '')
             
-            # Save to database with user_id
-            session_metadata = {
-                'timestamp': datetime.utcnow().isoformat(),
-                'api_url': API_URL,
-                'user_agent': request.headers.get('User-Agent', ''),
-                'ip_address': request.environ.get('HTTP_X_FORWARDED_FOR', request.remote_addr)
-            }
-            
-            save_success = ChatSession.save_message(
-                user_id=current_user.id,
-                message=message,
-                response=response_text,
-                session_metadata=session_metadata
-            )
-            
-            if not save_success:
-                # Log the error but don't fail the request
-                app.logger.warning(f"Failed to save chat message for user {current_user.id}")
-                # Optionally notify user that history wasn't saved
-                result['history_saved'] = False
+            if is_anonymous:
+                # Save to session for anonymous users
+                add_anonymous_message(message, response_text)
+                result['history_saved'] = False  # Indicate temporary storage
+                result['user_id'] = session.get('anonymous_id', 'anonymous')
+                result['is_anonymous'] = True
             else:
-                result['history_saved'] = True
-            
-            result['user_id'] = current_user.id
+                # Save to database for authenticated users
+                session_metadata = {
+                    'timestamp': datetime.utcnow().isoformat(),
+                    'api_url': API_URL,
+                    'user_agent': request.headers.get('User-Agent', ''),
+                    'ip_address': request.environ.get('HTTP_X_FORWARDED_FOR', request.remote_addr)
+                }
+                
+                save_success = ChatSession.save_message(
+                    user_id=current_user.id,
+                    message=message,
+                    response=response_text,
+                    session_metadata=session_metadata
+                )
+                
+                if not save_success:
+                    # Log the error but don't fail the request
+                    app.logger.warning(f"Failed to save chat message for user {current_user.id}")
+                    # Optionally notify user that history wasn't saved
+                    result['history_saved'] = False
+                else:
+                    result['history_saved'] = True
+                
+                result['user_id'] = current_user.id
+                result['is_anonymous'] = False
         else:
             # Enhance error messages from API
             error_msg = result.get('error', 'Unknown error occurred')
@@ -494,7 +620,8 @@ def chat():
         return jsonify(result)
         
     except Exception as e:
-        app.logger.error(f"Chat API error for user {current_user.id if current_user.is_authenticated else 'unknown'}: {str(e)}")
+        user_identifier = session.get('anonymous_id', 'unknown') if is_anonymous else (current_user.id if current_user.is_authenticated else 'unknown')
+        app.logger.error(f"Chat API error for user {user_identifier}: {str(e)}")
         return jsonify({
             "success": False,
             "error": "We're experiencing technical difficulties. Please try again in a few moments."

config.py

@@ -39,6 +39,13 @@ class Config:
     MAX_LOGIN_ATTEMPTS = int(os.environ.get('MAX_LOGIN_ATTEMPTS', 5))
     RATE_LIMIT_WINDOW = int(os.environ.get('RATE_LIMIT_WINDOW', 900))  # 15 minutes
     
+    # Anonymous User Configuration
+    ANONYMOUS_ENABLED = os.environ.get('ANONYMOUS_ENABLED', 'True').lower() == 'true'
+    ANONYMOUS_RATE_LIMIT = int(os.environ.get('ANONYMOUS_RATE_LIMIT', 20))  # messages per hour
+    ANONYMOUS_RATE_LIMIT_WINDOW = int(os.environ.get('ANONYMOUS_RATE_LIMIT_WINDOW', 3600))  # 1 hour
+    ANONYMOUS_SESSION_TIMEOUT = int(os.environ.get('ANONYMOUS_SESSION_TIMEOUT', 3600))  # 1 hour
+    ANONYMOUS_MAX_MESSAGE_LENGTH = int(os.environ.get('ANONYMOUS_MAX_MESSAGE_LENGTH', 2000))  # characters
+    
     # API Configuration
     API_URL = os.environ.get('API_URL', 'https://findEthics-Atlas.hf.space/chat')
     API_TIMEOUT = int(os.environ.get('API_TIMEOUT', 30))
@@ -72,6 +79,7 @@ class DevelopmentConfig(Config):
     DEBUG = True
     SESSION_COOKIE_SECURE = False
     WTF_CSRF_SSL_STRICT = False
+    WTF_CSRF_ENABLED = False  # Disable CSRF for testing
     LOG_LEVEL = 'DEBUG'
 
 class ProductionConfig(Config):

static/css/style.css

@@ -542,4 +542,227 @@ uch and interaction improvements */
         border: 1px solid #ccc;
         page-break-inside: avoid;
     }
+}
+
+/* Choice Page Styles */
+.choose-container {
+    width: 100%;
+    min-height: calc(100vh - 60px);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    padding: 2rem;
+    background: linear-gradient(135deg, #f5f5f5 0%, #ffffff 100%);
+}
+
+.choose-wrapper {
+    max-width: 900px;
+    width: 100%;
+    text-align: center;
+}
+
+.choose-title {
+    font-size: 2.5rem;
+    margin-bottom: 0.5rem;
+    color: black;
+}
+
+.choose-subtitle {
+    font-size: 1.2rem;
+    color: #666;
+    margin-bottom: 3rem;
+}
+
+.choose-options {
+    display: grid;
+    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
+    gap: 2rem;
+    margin-bottom: 2rem;
+}
+
+.choose-option {
+    background: white;
+    border: 2px solid #e5e5e5;
+    border-radius: 12px;
+    padding: 2rem;
+    transition: all 0.3s ease;
+    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
+}
+
+.choose-option:hover {
+    border-color: #000;
+    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
+}
+
+.choose-option h2 {
+    margin-bottom: 1.5rem;
+    font-size: 1.5rem;
+    color: black;
+}
+
+.option-features ul {
+    list-style: none;
+    padding: 0;
+    margin-bottom: 1.5rem;
+    text-align: left;
+}
+
+.option-features li {
+    padding: 0.5rem 0;
+    padding-left: 1.5rem;
+    position: relative;
+}
+
+.option-features li:before {
+    content: "✓";
+    position: absolute;
+    left: 0;
+    color: #10b981;
+    font-weight: bold;
+}
+
+.privacy-notice {
+    background: #fef3c7;
+    border: 1px solid #fbbf24;
+    border-radius: 8px;
+    padding: 1rem;
+    margin-bottom: 1.5rem;
+    font-size: 0.9rem;
+    text-align: left;
+}
+
+.privacy-notice p {
+    margin: 0;
+    color: #92400e;
+}
+
+.choose-button {
+    display: inline-block;
+    padding: 0.75rem 2rem;
+    background: black;
+    color: white;
+    text-decoration: none;
+    border-radius: 8px;
+    font-weight: 500;
+    transition: all 0.3s ease;
+    border: 2px solid black;
+    margin: 0.5rem;
+}
+
+.choose-button:hover {
+    background: white;
+    color: black;
+    transform: translateY(-2px);
+}
+
+.anonymous-button {
+    background: #6b7280;
+    border-color: #6b7280;
+}
+
+.anonymous-button:hover {
+    background: white;
+    color: #6b7280;
+}
+
+.register-button {
+    background: #10b981;
+    border-color: #10b981;
+}
+
+.register-button:hover {
+    background: white;
+    color: #10b981;
+}
+
+.auth-buttons {
+    display: flex;
+    justify-content: center;
+    gap: 1rem;
+    flex-wrap: wrap;
+}
+
+.choose-footer {
+    margin-top: 3rem;
+    color: #666;
+    font-size: 0.9rem;
+}
+
+/* Anonymous User Styles */
+.anonymous-user {
+    color: #6b7280;
+    font-style: italic;
+}
+
+.session-warning {
+    background: #fef3c7;
+    border-bottom: 2px solid #fbbf24;
+    padding: 0.75rem;
+    text-align: center;
+    color: #92400e;
+}
+
+.warning-content {
+    max-width: 800px;
+    margin: 0 auto;
+}
+
+.warning-content a {
+    color: #92400e;
+    font-weight: bold;
+}
+
+.session-expiry-warning {
+    position: fixed;
+    top: 0;
+    left: 0;
+    right: 0;
+    background: #ef4444;
+    color: white;
+    padding: 1rem;
+    text-align: center;
+    z-index: 10000;
+    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
+}
+
+.session-expiry-warning button {
+    background: white;
+    color: #ef4444;
+    border: none;
+    padding: 0.5rem 1rem;
+    margin: 0 0.5rem;
+    border-radius: 4px;
+    cursor: pointer;
+    font-weight: bold;
+}
+
+.session-expiry-warning button:hover {
+    background: #fee2e2;
+}
+
+/* System message styles */
+.message.system .message-content {
+    background: #f3f4f6;
+    color: #4b5563;
+    border: 1px solid #d1d5db;
+    font-style: italic;
+}
+
+/* Mobile responsive for choice page */
+@media (max-width: 768px) {
+    .choose-options {
+        grid-template-columns: 1fr;
+    }
+    
+    .choose-title {
+        font-size: 2rem;
+    }
+    
+    .auth-buttons {
+        flex-direction: column;
+    }
+    
+    .choose-button {
+        width: 100%;
+    }
 }

static/js/chat.js

@@ -23,6 +23,11 @@ class ChatApp {
         this.historyLoaded = false;
         this.sessionWarningShown = false;
         
+        // Check if anonymous mode
+        this.isAnonymous = window.chatConfig && window.chatConfig.isAnonymous;
+        this.anonymousRateLimit = window.chatConfig ? window.chatConfig.anonymousRateLimit : 0;
+        this.anonymousId = window.chatConfig ? window.chatConfig.anonymousId : '';
+        
         this.init();
     }
     
@@ -151,7 +156,11 @@ class ChatApp {
                 this.handleSessionExpiry();
                 this.showError('Your session has expired. Please log in again to continue.');
             } else if (error.message.includes('429')) {
-                this.showError('You are sending messages too quickly. Please wait a moment and try again.');
+                if (this.isAnonymous) {
+                    this.showError(`Rate limit exceeded. Anonymous users are limited to ${this.anonymousRateLimit} messages per hour.`);
+                } else {
+                    this.showError('You are sending messages too quickly. Please wait a moment and try again.');
+                }
             } else if (error.message.includes('400')) {
                 this.showError('There was a problem with your message. Please check it and try again.');
             } else if (error.message.includes('500')) {
@@ -251,6 +260,14 @@ class ChatApp {
     }
     
     async loadChatHistory() {
+        // Skip loading history for anonymous users (they start fresh)
+        if (this.isAnonymous) {
+            this.historyLoaded = true;
+            // Show welcome message for anonymous users
+            this.showAnonymousWelcome();
+            return;
+        }
+        
         try {
             // Show loading state
             this.showHistoryLoading(true);
@@ -407,12 +424,25 @@ class ChatApp {
         // Create session expiry warning banner
         const warningDiv = document.createElement('div');
         warningDiv.className = 'session-expiry-warning';
-        warningDiv.innerHTML = `
-            Your session has expired. Please log in again to continue chatting.
-            <button onclick="window.location.href='/login?next=' + encodeURIComponent(window.location.pathname)">
-                Login Again
-            </button>
-        `;
+        
+        if (this.isAnonymous) {
+            warningDiv.innerHTML = `
+                Your anonymous session has expired. 
+                <button onclick="window.location.href='/anonymous'">
+                    Start New Session
+                </button>
+                <button onclick="window.location.href='/register'">
+                    Create Account
+                </button>
+            `;
+        } else {
+            warningDiv.innerHTML = `
+                Your session has expired. Please log in again to continue chatting.
+                <button onclick="window.location.href='/login?next=' + encodeURIComponent(window.location.pathname)">
+                    Login Again
+                </button>
+            `;
+        }
         
         // Insert at top of page
         document.body.insertBefore(warningDiv, document.body.firstChild);
@@ -420,7 +450,7 @@ class ChatApp {
         // Disable chat interface
         this.messageInput.disabled = true;
         this.sendButton.disabled = true;
-        this.messageInput.placeholder = 'Session expired - please log in again';
+        this.messageInput.placeholder = this.isAnonymous ? 'Session expired - start a new anonymous session' : 'Session expired - please log in again';
     }
     
     showSessionWarning(message) {
@@ -450,6 +480,12 @@ class ChatApp {
             }
         }, 5000);
     }
+    
+    showAnonymousWelcome() {
+        // Show welcome message for anonymous users
+        const welcomeMessage = `Welcome to Anonymous Chat! You can send up to ${this.anonymousRateLimit} messages per hour. Your chat history is temporary and will be lost when you close your browser.`;
+        this.addMessage(welcomeMessage, 'system', false);
+    }
 }
 
 // Initialize the chat application when the page loads

task_list.md

@@ -122,4 +122,143 @@ Transform the current Gradio chatbot template into a web app that uses the API "
 - [x] UI is minimal and basic as requested
 - [x] Chat functionality works with conversation history
 - [x] App can be deployed as a Hugging Face space
-- [x] Error handling is implemented for API failures 
+- [x] Error handling is implemented for API failures
+
+---
+
+# Anonymous Chat Access Implementation Tasks
+
+## Overview
+Add anonymous chat functionality alongside existing authenticated access, allowing users to chat without creating an account while maintaining the option for registered users.
+
+## Task List
+
+### Phase 1: Backend Infrastructure
+
+- [x] **Task 1: Update config.py with anonymous user settings**
+  - Add ANONYMOUS_ENABLED flag
+  - Add ANONYMOUS_RATE_LIMIT (messages per hour)
+  - Add ANONYMOUS_SESSION_TIMEOUT
+  - Add ANONYMOUS_MAX_MESSAGE_LENGTH
+  - **Status: COMPLETED**
+  - **Assignee: Backend Coder Agent**
+
+- [x] **Task 2: Create anonymous session management functions in app.py**
+  - Generate anonymous user IDs (e.g., anon_<hash>)
+  - Implement session-based chat history storage
+  - Add session validation functions
+  - **Status: COMPLETED**
+  - **Assignee: Backend Coder Agent**
+
+- [x] **Task 3: Update app.py index route to show choice page**
+  - Modify `/` route to show choice instead of redirect
+  - Handle authenticated user redirect
+  - **Status: COMPLETED**
+  - **Assignee: Backend Coder Agent**
+
+- [x] **Task 4: Add /choose route for access mode selection**
+  - Create route handler
+  - Implement GET method for displaying choice page
+  - **Status: COMPLETED**
+  - **Assignee: Backend Coder Agent**
+
+- [x] **Task 5: Add /anonymous route for anonymous chat interface**
+  - Create route for anonymous chat
+  - Set up anonymous session
+  - Render chat template with anonymous mode
+  - **Status: COMPLETED**
+  - **Assignee: Backend Coder Agent**
+
+- [x] **Task 6: Update /api/chat endpoint to handle anonymous users**
+  - Detect anonymous vs authenticated users
+  - Handle session-based chat history for anonymous
+  - Skip MongoDB saves for anonymous users
+  - Implement different rate limiting
+  - **Status: COMPLETED**
+  - **Assignee: Backend Coder Agent**
+
+- [x] **Task 7: Implement rate limiting for anonymous users**
+  - Track message count per session
+  - Use IP + session combo for tracking
+  - Return 429 errors when exceeded
+  - **Status: COMPLETED**
+  - **Assignee: Backend Coder Agent**
+
+### Phase 2: Frontend Updates
+
+- [x] **Task 8: Create choose.html template**
+  - Design landing page with two options
+  - "Chat Anonymously" button
+  - "Login/Register" section
+  - Include privacy notice
+  - **Status: COMPLETED**
+  - **Assignee: Frontend Coder Agent**
+
+- [x] **Task 9: Update base.html to handle anonymous users**
+  - Conditional navigation for anonymous users
+  - Show "Anonymous User" instead of email
+  - Different logout/exit behavior
+  - **Status: COMPLETED**
+  - **Assignee: Frontend Coder Agent**
+
+- [x] **Task 10: Update index.html for anonymous mode**
+  - Add session warning banner
+  - Include "Create Account" prompt
+  - Display anonymous user indicator
+  - **Status: COMPLETED**
+  - **Assignee: Frontend Coder Agent**
+
+- [x] **Task 11: Update chat.js for anonymous mode support**
+  - Detect anonymous mode from page data
+  - Handle session expiry warnings
+  - Modify API calls for anonymous users
+  - Add upgrade prompts
+  - **Status: COMPLETED**
+  - **Assignee: Frontend Coder Agent**
+
+- [x] **Task 12: Add CSS styles for choice page**
+  - Style choice buttons
+  - Add anonymous mode indicators
+  - Style session warnings
+  - **Status: COMPLETED**
+  - **Assignee: Frontend Coder Agent**
+
+### Phase 3: Testing & Documentation
+
+- [ ] **Task 13: Test anonymous chat functionality**
+  - Test anonymous chat flow
+  - Verify rate limiting
+  - Test session expiry
+  - Test switching between modes
+  - **Status: PENDING**
+  - **Assignee: Testing Agent**
+
+- [ ] **Task 14: Update CLAUDE.md with anonymous feature**
+  - Document new architecture
+  - Add anonymous mode details
+  - Update configuration section
+  - **Status: PENDING**
+  - **Assignee: Documentation Agent**
+
+- [ ] **Task 15: Update README.md**
+  - Add anonymous mode to features
+  - Document usage instructions
+  - Add configuration details
+  - **Status: PENDING**
+  - **Assignee: Documentation Agent**
+
+## Implementation Order
+1. Backend configuration (Tasks 1-2)
+2. Core routes (Tasks 3-5)
+3. API updates (Tasks 6-7)
+4. Frontend templates (Tasks 8-10)
+5. JavaScript updates (Task 11)
+6. Styling (Task 12)
+7. Testing (Task 13)
+8. Documentation (Tasks 14-15)
+
+## Notes
+- Maintain backward compatibility with existing authenticated flow
+- Anonymous sessions are temporary and not persisted to database
+- Stricter rate limits for anonymous users to prevent abuse
+- Clear privacy notices about session-only storage 

templates/base.html

@@ -27,6 +27,10 @@
                             {% endif %}
                             <button type="submit" class="nav-button logout-button">Logout</button>
                         </form>
+                    {% elif is_anonymous %}
+                        <span class="user-info anonymous-user">Anonymous User</span>
+                        <a href="{{ url_for('login') }}" class="nav-button">Login</a>
+                        <a href="{{ url_for('register') }}" class="nav-button">Create Account</a>
                     {% else %}
                         <a href="{{ url_for('login') }}" class="nav-button">Login</a>
                         <a href="{{ url_for('register') }}" class="nav-button">Register</a>

templates/choose.html

@@ -0,0 +1,75 @@
+{% extends "base.html" %}
+
+{% block title %}Choose Access Mode - Chatty{% endblock %}
+
+{% block content %}
+<div class="choose-container">
+    <div class="choose-wrapper">
+        <h1 class="choose-title">Welcome to Chatty</h1>
+        <p class="choose-subtitle">Ethics Chat Application</p>
+        
+        <div class="choose-options">
+            <!-- Anonymous Access Option -->
+            <div class="choose-option anonymous-option">
+                <h2>Chat Anonymously</h2>
+                <div class="option-features">
+                    <ul>
+                        <li>No registration required</li>
+                        <li>Start chatting immediately</li>
+                        <li>Session-based conversation</li>
+                        <li>Limited to {{ config.ANONYMOUS_RATE_LIMIT }} messages per hour</li>
+                    </ul>
+                </div>
+                <div class="privacy-notice">
+                    <p><strong>Privacy Notice:</strong> Your chat history will be stored temporarily in your browser session and will be lost when you close the browser or after {{ config.ANONYMOUS_SESSION_TIMEOUT // 3600 }} hour(s) of inactivity.</p>
+                </div>
+                <a href="{{ url_for('anonymous') }}" class="choose-button anonymous-button">
+                    Start Anonymous Chat
+                </a>
+            </div>
+            
+            <!-- Authenticated Access Option -->
+            <div class="choose-option auth-option">
+                <h2>Login or Register</h2>
+                <div class="option-features">
+                    <ul>
+                        <li>Save your chat history permanently</li>
+                        <li>Access conversations from any device</li>
+                        <li>No message limits</li>
+                        <li>Personalized experience</li>
+                    </ul>
+                </div>
+                <div class="auth-buttons">
+                    <a href="{{ url_for('login') }}" class="choose-button login-button">
+                        Login
+                    </a>
+                    <a href="{{ url_for('register') }}" class="choose-button register-button">
+                        Create Account
+                    </a>
+                </div>
+            </div>
+        </div>
+        
+        <div class="choose-footer">
+            <p>By using this service, you agree to our ethical guidelines and responsible AI usage.</p>
+        </div>
+    </div>
+</div>
+{% endblock %}
+
+{% block scripts %}
+<script>
+document.addEventListener('DOMContentLoaded', function() {
+    // Add hover effects
+    const options = document.querySelectorAll('.choose-option');
+    options.forEach(option => {
+        option.addEventListener('mouseenter', function() {
+            this.style.transform = 'translateY(-5px)';
+        });
+        option.addEventListener('mouseleave', function() {
+            this.style.transform = 'translateY(0)';
+        });
+    });
+});
+</script>
+{% endblock %}

templates/index.html

@@ -4,6 +4,15 @@
 
 {% block content %}
 <div class="chat-container">
+            {% if is_anonymous %}
+            <div class="session-warning">
+                <div class="warning-content">
+                    <strong>Anonymous Session:</strong> Your chat history is temporary and will be lost when you close your browser. 
+                    <a href="{{ url_for('register') }}">Create an account</a> to save your conversations permanently.
+                </div>
+            </div>
+            {% endif %}
+            
             <div class="chat-messages" id="chatMessages">
                 <!-- Messages will be dynamically added here -->
             </div>
@@ -33,5 +42,13 @@
 {% endblock %}
 
 {% block scripts %}
+<script>
+    // Pass server-side variables to JavaScript
+    window.chatConfig = {
+        isAnonymous: {{ 'true' if is_anonymous else 'false' }},
+        anonymousRateLimit: {{ config.ANONYMOUS_RATE_LIMIT if is_anonymous else 0 }},
+        anonymousId: "{{ session.get('anonymous_id', '') if is_anonymous else '' }}"
+    };
+</script>
 <script src="{{ url_for('static', filename='js/chat.js') }}"></script>
 {% endblock %}