Backend Server Configuration

Relevant source files

The following files were used as context for generating this wiki page:

• backend/server.py
• backend_test.py
• test_result.md
• frontend/src/App.js
• frontend/package.json

The NEXUS backend server is a FastAPI-based application designed to manage digital accounts, email addresses, and free trial tracking. It serves as the "Digital Command Center," providing a robust API for the Frontend Application to perform CRUD operations, manage authentication via JWT, and retrieve dashboard statistics.

The server utilizes an asynchronous architecture with motor for MongoDB interactions and incorporates security measures such as bcrypt password hashing and HTTP Bearer token validation.

Sources: backend/server.py:1-25, test_result.md:65-70

Architecture and Core Components

The backend is structured around a central FastAPI instance that handles routing, middleware, and database connectivity. The application logic is divided into specialized routers and dependency-injected authentication helpers.

Technology Stack

Component	Technology	Description
Framework	FastAPI	High-performance Python web framework.
Database	MongoDB	NoSQL database accessed via the motor async driver.
Authentication	JWT & HTTPBearer	Secure token-based access control.
Security	Bcrypt	Password hashing for user credentials.
Schema	Pydantic	Data validation and settings management.

Sources: backend/server.py:1-20, frontend/package.json:65-75

Database Integration

The system connects to MongoDB using environment variables for the connection string (MONGO_URL) and database name (DB_NAME). It uses AsyncIOMotorClient to ensure non-blocking I/O operations.

The diagram shows the relationship between the FastAPI application and the asynchronous MongoDB collections.
Sources: backend/server.py:27-31

Authentication System

The server implements a JWT (JSON Web Token) authentication flow. Users must register or log in to obtain a Bearer token, which is then required for all protected API endpoints.

Authentication Flow

1. Registration/Login: User provides credentials to /api/register or /api/login.
2. Token Generation: Server validates credentials, hashes passwords using bcrypt, and returns an access_token.
3. Verification: Subsequent requests include the token in the Authorization header.
4. Dependency Injection: The get_current_user function uses verify_token to decode the JWT and fetch the user from the database.

This sequence illustrates the login and subsequent protected route access.
Sources: backend/server.py:175-225, backend_test.py:75-125

Configuration Parameters

Parameter	Default Value	Description
SECRET_KEY	nexus-super-secret...	Key used for JWT signature.
ALGORITHM	HS256	Hashing algorithm for tokens.
ACCESS_TOKEN_EXPIRE_MINUTES	30	Token validity duration.

Sources: backend/server.py:39-42

API Modules and Models

The backend exposes several CRUD modules, each governed by specific Pydantic models to ensure data integrity.

Account Management

Manages platform credentials and subscription details.

• Endpoint Prefix: /api/accounts
• Key Fields: platform_name, subscription_type, monthly_cost, two_fa_enabled.

Email Management

Tracks email addresses used for various digital services.

• Endpoint Prefix: /api/emails
• Key Fields: email_address, provider, purpose (Enum: PERSONAL, WORK, TRIALS, etc.).

Trial Tracking

Monitors free trial periods and cancellation deadlines.

• Endpoint Prefix: /api/trials
• Logic: Calculates cancellation_deadline and tracks is_cancelled status.

Sources: backend/server.py:112-168, backend_test.py:130-330

Dashboard Statistics

The /api/dashboard/stats endpoint aggregates data across all collections for the authenticated user to provide a high-level overview of their digital footprint.

Statistic	Calculation Logic
total_accounts	Count of documents in accounts collection for user_id.
monthly_spend	Sum of monthly_cost from all user accounts.
active_trials	Count of trials where is_cancelled is False.
security_score	Placeholder logic (defaulting to 75.0) for future implementation.

Sources: backend/server.py:378-403, backend_test.py:335-355

Middleware and CORS Configuration

The server includes CORSMiddleware to facilitate communication with the React frontend.

• Allowed Origins: Configurable via CORS_ORIGINS environment variable (defaults to *).
• Allowed Methods: Supports all standard HTTP methods (GET, POST, PUT, DELETE).
• Logging: Configured at the INFO level to track requests and system errors.

Sources: backend/server.py:408-423, frontend/src/App.js:7-10

The Backend Server Configuration ensures a secure, scalable, and isolated environment for users to manage their sensitive account data, providing the foundational logic for the NEXUS ecosystem.