Reddit Pixel Shopify Server-Side Tracking

Server-side conversion tracking for Reddit Ads using Shopify webhooks and Reddit Conversions API. This implementation bypasses browser-based tracking limitations (ad blockers, privacy settings, iOS restrictions) to capture conversions that client-side pixels miss.

Why Server-Side Tracking?

Reddit officially recommends using both Pixel and Conversions API together for optimal tracking accuracy. According to their documentation:

"CAPI is more resilient to signal loss because it operates server-side, making it less susceptible to ad blockers and browser restrictions."

Client-side pixel tracking loses 30-50% of conversions due to:

• Ad blockers
• Browser privacy settings (Safari, Firefox)
• iOS App Tracking Transparency
• Third-party cookie blocking

This server-side implementation captures conversions that browser-based tracking misses by sending data directly from your server to Reddit's API.

Features

• ✅ Production-ready Docker setup
• ✅ HMAC webhook verification (Shopify security)
• ✅ PII hashing (SHA-256 for privacy)
• ✅ Event deduplication (PostgreSQL)
• ✅ Automatic retry logic with exponential backoff
• ✅ Rate limiting handling (429 responses)
• ✅ Comprehensive logging (Winston)
• ✅ Health check endpoint
• ✅ SSL/HTTPS support (Nginx reverse proxy example)

Quick Start

Prerequisites:

• Linux server with Docker installed
• Domain/subdomain pointing to your server
• Reddit Ads account with Pixel created
• Shopify store with admin access

Installation (5 minutes):

# Clone repository
git clone https://github.com/91369673/reddit-pixel-shopify-server-side-tracking.git
cd reddit-pixel-shopify-server-side-tracking

# Copy environment template
cp .env.example .env

# Edit .env with your credentials
nano .env

# Start services
docker compose up -d

# Check logs
docker compose logs -f reddit-capi

Configuration

1. Reddit Ads Manager

1. Go to Reddit Ads Manager → Events Manager
2. Create new Pixel
3. Copy Pixel ID (format: t2_abc123)
4. Go to Settings → Conversions API
5. Generate Access Token
6. Add to .env:

REDDIT_PIXEL_ID=t2_your_pixel_id
REDDIT_ACCESS_TOKEN=your_access_token_here

2. Shopify Webhooks

1. Shopify Admin → Settings → Notifications → Webhooks
2. Create webhook:
   • Event: Order creation
   • Format: JSON
   • URL: https://your-domain.com/webhooks/shopify
   • API version: Latest
3. Copy Signing Secret → add to .env:

SHOPIFY_WEBHOOK_SECRET=your_webhook_secret

4. Restart: docker compose restart reddit-capi

3. Nginx Reverse Proxy (Optional but Recommended)

Create /etc/nginx/sites-available/reddit-tracking.conf:

server {
    listen 443 ssl http2;
    server_name your-domain.com;

    ssl_certificate /etc/letsencrypt/live/your-domain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/your-domain.com/privkey.pem;

    location / {
        proxy_pass http://127.0.0.1:3000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;
    }
}

Enable and reload:

ln -s /etc/nginx/sites-available/reddit-tracking.conf /etc/nginx/sites-enabled/
nginx -t
systemctl reload nginx

Architecture

Shopify Store (order created)
    |
    v
Shopify Webhook (HTTPS POST)
    |
    v
Nginx Reverse Proxy (SSL termination)
    |
    v
Node.js Application (Docker container)
    |
    v
1. HMAC Verification
2. Event Transformation
3. PII Hashing (SHA-256)
4. Deduplication Check
5. Send to Reddit CAPI
6. Log Result
    |
    v
Reddit Ads Platform

Environment Variables

Variable	Required	Description	Example
SHOPIFY_WEBHOOK_SECRET	Yes	Shopify webhook signing secret	ba32d1d12da1ffc...
REDDIT_PIXEL_ID	Yes	Reddit Pixel ID from Events Manager	t2_abc123
REDDIT_ACCESS_TOKEN	Yes	Reddit Conversions API access token	eyJhbGciOiJSUzI1...
DB_PASSWORD	Yes	PostgreSQL database password	strong_password
PORT	No	Application port (default: 3000)	3000

Testing

Health check:

curl https://your-domain.com/health

Expected response:

{
  "status": "healthy",
  "timestamp": "2025-11-22T12:00:00.000Z",
  "uptime": 12345.67,
  "database": "connected"
}

Send test webhook from Shopify:

1. Shopify Admin → Settings → Notifications → Webhooks
2. Click on your webhook
3. "Send test notification"
4. Check logs: docker compose logs -f reddit-capi

Verify in Reddit:

1. Reddit Ads Manager → Events Manager
2. Click your Pixel → "Test Events" tab
3. Event should appear within a few minutes

Monitoring

View logs:

docker compose logs -f reddit-capi

Check recent events:

docker compose exec postgres psql -U reddit_capi -d reddit_capi -c \
  "SELECT event_id, event_type, status, created_at FROM events ORDER BY created_at DESC LIMIT 10;"

Failed events:

docker compose exec postgres psql -U reddit_capi -d reddit_capi -c \
  "SELECT event_id, error_message FROM events WHERE status = 'failed';"

Troubleshooting

Events Not Appearing in Reddit

Check logs for API errors:

docker compose logs reddit-capi | grep "Reddit API error"

Common errors:

Error	Cause	Solution
"unexpected type number"	Value sent as decimal	Verify multiplication by 100 in transformer
"unknown field event_id"	Invalid field in payload	Remove event_id from Reddit event object
401 Unauthorized	Invalid access token	Regenerate token in Reddit Events Manager
429 Too Many Requests	Rate limiting	Handled automatically with retry logic

HMAC Verification Failed

# Check if secret matches
docker compose exec reddit-capi printenv SHOPIFY_WEBHOOK_SECRET

# Update .env and restart
docker compose restart reddit-capi

Database Connection Issues

# Check PostgreSQL status
docker compose ps postgres

# Test connection
docker compose exec postgres pg_isready -U reddit_capi

Database Schema

CREATE TABLE events (
  event_id VARCHAR(255) PRIMARY KEY,
  event_type VARCHAR(50) NOT NULL,
  shopify_id VARCHAR(255) NOT NULL,
  shopify_payload JSONB,
  reddit_payload JSONB,
  reddit_response JSONB,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  sent_at TIMESTAMP,
  status VARCHAR(20) DEFAULT 'pending',
  error_message TEXT
);

Security Features

1. HMAC Verification: Every webhook validated with SHA-256 HMAC
2. HTTPS Only: TLS 1.2/1.3 encryption
3. Localhost Binding: Container only accessible via reverse proxy
4. PII Hashing: Email/phone SHA-256 hashed before sending to Reddit
5. Environment Secrets: All sensitive data in .env (git-ignored)

Advanced Configuration

Multi-Currency Support

The implementation automatically handles different currencies. For currencies with non-standard decimal places:

// Zero-decimal currencies (JPY, KRW): multiply by 1
// Standard currencies (USD, EUR): multiply by 100
// Three-decimal currencies (BHD, KWD): multiply by 1000

value: Math.round(parseFloat(order.total_price) * 100)

Additional Event Types

Extend src/services/shopifyTransformer.js for more events:

export function transformProductView(product) {
  return {
    event_at: new Date().toISOString(),
    event_type: { tracking_type: 'ViewContent' },
    // ... user data
    event_metadata: {
      conversion_id: `product_${product.id}_${Date.now()}`,
      item_id: String(product.id),
    },
  };
}

License

MIT License - see LICENSE file for details.

Contributing

Contributions welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Test your changes
4. Submit a pull request

Support

• Issues: GitHub Issues
• Documentation: Full setup guide
• Reddit API Docs: Reddit Conversions API

Acknowledgments

Based on production implementation for live Shopify stores. Tested with:

• Reddit Conversions API v2.0
• Shopify API 2025-01
• Docker Compose v2.x
• PostgreSQL 16
• Node.js 18

---

⭐ If this helped you, consider starring the repo!