analytics/examples/nestjs-backend/README.md

NestJS Backend Integration

Server-side analytics tracking for NestJS applications.

Use Cases

• Track events from server-side rendered pages
• Track API events (signups, purchases, etc.)
• Add analytics context via interceptors
• Automatic request tracking with decorators

Files

• analytics.module.ts - Module setup
• analytics.interceptor.ts - Automatic request tracking
• track-analytics.decorator.ts - Method-level tracking
• user.controller.ts - Example controller with tracking
• order.service.ts - Example service with tracking

Key Concepts

1. Backend Client

The BackendAnalyticsClient is designed for server-side use:

• Generates its own session IDs (from headers or fresh)
• No browser APIs required
• Batch processing for performance

2. Interceptor vs Decorator

• Interceptor: Automatic tracking on all routes (or specific ones)
• Decorator: Explicit tracking on specific methods

3. Request Context

Pass request headers to extract:

• Session ID (x-session-id header from client)
• User ID (from auth middleware)
• IP address (for geolocation)
• User agent (for device detection)