Consumer Proxy Server

The consumer proxy server is a Node.js Express application that acts as an intermediary between the frontend client and the paywall API service, managing API key authentication and providing a clean interface for content consumption.

Architecture

Core Components

• Express Proxy Server - Lightweight Node.js server with CORS support
• API Key Management - Embedded API key handling for paywall service authentication
• Request Proxying - Transparent request forwarding with authentication injection
• Stream Processing - Efficient streaming of video and image content
• Error Handling - Comprehensive error management and client feedback

Features

Proxy Functionality

• Transparent Proxying - Seamlessly forwards requests to paywall API
• Authentication Injection - Automatically adds API keys to paywall requests
• Stream Support - Efficiently streams large video files without memory buffering
• Error Translation - Converts paywall API errors to client-friendly responses

Content Support

• HTML Content - Proxy HTML articles and documents
• Image Streaming - Stream images with proper content headers
• Video Streaming - Support for segmented video delivery with range requests
• Content Listing - Proxy content catalog and duration options

Configuration Management

• Environment Variables - Configurable paywall API endpoint and port
• API Key Storage - Secure API key management for paywall authentication
• Request Timeout - Configurable timeout for paywall requests
• CORS Configuration - Flexible cross-origin request handling

API Endpoints

All endpoints proxy to the corresponding paywall API endpoints:

Content Management

• GET /api/content/list - List all available content
• GET /api/content/durations - Get available duration options

Content Delivery

• GET /api/html/:id - Proxy HTML content from paywall
• GET /api/image/:id - Stream image content with proper headers
• GET /api/video/:id - Stream video segments with range support

Video Control

• DELETE /api/video/:id/progress - Reset video progress

System

• GET /health - Health check endpoint

Configuration

Environment variables:

• PORT - Server port (default: 4006)
• PAYWALL_API_URL - Paywall service endpoint (default: http://localhost:4005)
• API_KEY - API key for paywall authentication (default: test-key-123)
• REQUEST_TIMEOUT - Request timeout in milliseconds

Development

# Install dependencies
npm install

# Development server with auto-reload
npm run dev

# Production server
npm start

Architecture Benefits

Security

• API Key Encapsulation - Frontend never needs to know paywall API keys
• Request Validation - Server-side validation of requests before proxying
• Error Sanitization - Prevents sensitive paywall error details from reaching client

Performance

• Stream Processing - Videos and images streamed without memory buffering
• Connection Pooling - Efficient HTTP connection reuse to paywall API
• Request Optimization - Single hop between frontend and proxy

Maintainability

• Clean Separation - Clear separation between client and paywall concerns
• Centralized Configuration - Single point for API endpoint and key management
• Modular Design - Easy to extend with additional proxy functionality

Request Flow

1. Client Request - Frontend makes request to proxy server
2. Authentication - Proxy adds API key header for paywall authentication
3. Forwarding - Request forwarded to paywall service with authentication
4. Response Processing - Paywall response processed and streamed back to client
5. Error Handling - Any errors converted to client-appropriate responses

Stream Management

• Automatic Cleanup - Stream resources automatically cleaned up on client disconnect
• Memory Efficiency - Large files streamed without loading into memory
• Range Request Support - HTTP range requests passed through for video seeking
• Content Headers - Proper content-type and caching headers maintained