Countly Server-Side vs Client-Side Tracking

Tracking Approaches

Countly supports both client-side and server-side tracking. Choose based on your requirements.

Client-Side Tracking

When to Use

• Web and mobile applications
• Real-time session tracking
• Automatic device/browser detection
• Crash reporting
• Push notifications

Implementation

// Browser
Countly.init({
  app_key: 'YOUR_APP_KEY',
  url: 'https://your-server.com'
});

Countly.track_sessions();
Countly.add_event({ key: 'button_click' });

Advantages

• Automatic device info collection
• Session management built-in
• Crash/error reporting
• Heatmaps and scrollmaps
• Real-time capabilities

Disadvantages

• Can be blocked by ad blockers
• Requires JavaScript
• Client-side code is visible

Server-Side Tracking

When to Use

• Backend events (API calls, webhooks)
• Ad blocker immunity
• Sensitive data processing
• Batch processing
• IoT/embedded devices

HTTP API

curl -X POST "https://your-countly-server.com/i" \
  -d "app_key=YOUR_APP_KEY" \
  -d "device_id=server_device_123" \
  -d "events=[{\"key\":\"api_call\",\"count\":1}]"

Node.js SDK

const Countly = require('countly-sdk-nodejs');

Countly.init({
  app_key: 'YOUR_APP_KEY',
  url: 'https://your-server.com',
  device_id: 'server_instance_1'
});

Countly.add_event({
  key: 'backend_process',
  count: 1,
  segmentation: {
    status: 'completed',
    duration_ms: 150
  }
});

Python

import requests

def track_event(device_id, event_key, count=1, segmentation=None):
    payload = {
        'app_key': 'YOUR_APP_KEY',
        'device_id': device_id,
        'events': json.dumps([{
            'key': event_key,
            'count': count,
            'segmentation': segmentation or {}
        }])
    }
    requests.post('https://your-countly-server.com/i', data=payload)

track_event('user_123', 'purchase', 1, {'product': 'premium'})

Advantages

• Cannot be blocked by browsers
• Full control over data
• Better for sensitive operations
• Works without JavaScript

Disadvantages

• No automatic session tracking
• Manual device info required
• More implementation effort
• No crash reporting

Hybrid Approach

Combine both for complete coverage:

// Client-side: User interactions
Countly.track_sessions();
Countly.add_event({ key: 'page_view' });

// Server-side: Critical events
app.post('/api/purchase', (req, res) => {
  // Process purchase...

  // Server-side tracking (guaranteed)
  serverCountly.add_event({
    key: 'purchase_confirmed',
    sum: order.total,
    segmentation: { order_id: order.id }
  });
});

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