Email Security Backend

Backend service for Gmail-integrated email ingestion, analysis, and realtime updates. It provides Google OAuth login, email fetch/send APIs, asynchronous analysis via Celery, and WebSocket push notifications via Redis Pub/Sub.

Components

• FastAPI app: API endpoints, OAuth flow, Gmail integration, and WebSocket gateways in main.py.
• Database layer: SQLAlchemy engine/session setup in database.py and ORM models in models.py.
• Task queue: Celery app and routing in celery_app.py.
• Email analysis tasks: URL, body, headers, and attachment processing in tasks/.
• Analysis service: External analysis API client stubs in services/analysis_service.py.
• Message queue producer: Celery task enqueue in message_queue/producer.py.
• Realtime updates: Redis Pub/Sub publisher in redis_pubsub.py and WebSocket manager in websocket/manager.py.
• API docs: Endpoint reference in API_doc.md.

Requirements

• Python 3.10+ recommended
• RabbitMQ (Celery broker)
• Redis (Pub/Sub)

Installation

1. Create and activate a virtual environment.
2. Install dependencies:

pip install -r requirements.txt

3. Create a .env file in the project root with the variables below.

Environment Variables

# OAuth / Google
GOOGLE_CLIENT_ID=your-google-client-id
GOOGLE_CLIENT_SECRET=your-google-client-secret
GOOGLE_REDIRECT_URI=http://localhost:8000/auth/google/callback
GCP_PUBSUB_SUBSCRIPTION=your-GCP_PUBSUB_SUBSCRIPTION
GCP_PUBSUB_TOPIC=your-GCP_PUBSUB_SUBSCRIPTION

# JWT
JWT_SECRET=change-this

# Database
DATABASE_URL=sqlite:///./test.db

# Celery / RabbitMQ
CELERY_BROKER_URL=amqp://guest:guest@localhost:5672//
CELERY_RESULT_BACKEND=cache+memory://

# Redis
REDIS_URL=redis://localhost:6379/0
REDIS_WS_CHANNEL=ws_updates

Running

1. Open Command Prompt in the project folder

2. Activate the virtual environment:

   venv\Scripts\activate

3. Start Celery workers (in one terminal):

   celery -A celery_app.celery_app worker -Q url_queue,body_queue,headers_queue,attachments_queue --loglevel=info --pool=solo --concurrency=1 --without-mingle --without-gossip

4. Set up ngrok (in a separate command prompt):

   • Navigate to the folder where ngrok is stored
   • Run:

     ngrok http 8000

5. Run the project (in the project terminal):

   uvicorn main:app --reload

Notes

• OAuth login starts at GET /auth/google/login, and Google redirects to GOOGLE_REDIRECT_URI.
• WebSocket endpoints expect JWT in the query string, for example: /ws/emails?token=....
• Analysis tasks currently use stubbed API calls in services/analysis_service.py. Replace them with your deployed analysis services if needed.

API Reference

See API_doc.md for endpoint details and examples.