What is CAPI? How it's work?

What is CAPI / Server-Side Tracking?

Traditionally, tracking was done using browser-based pixels (JavaScript).
But now many browsers block cookies, pixels, and trackers.

👉 CAPI solves this problem by sending conversion data directly from your server to the ad platform.

Simple definition:

Server-side tracking sends user action data (purchase, lead, signup) from your website server to Facebook/Google servers securely.

Why CAPI is Important?

Browser tracking problems:

Ad blockers ❌

iOS privacy (ATT) ❌

Cookie blocking ❌

Data loss ❌

CAPI benefits:

✅ More accurate tracking

✅ Higher event match quality

✅ Better ad optimization

✅ Works even if pixel is blocked

✅ Improves ROAS

How CAPI Works (Step-by-Step)
1️⃣ User Action

A user visits your website and:

Makes a purchase

Submits a form

Clicks “Contact”

Adds to cart

2️⃣ Data Collected

Your server collects:

Event name (Purchase, Lead, etc.)

Time of event

User data (hashed):

Email

Phone

IP

User agent

Order value / currency

⚠️ User data is hashed (SHA-256) for privacy

3️⃣ Server Sends Data

Your server sends this data via API request to:

Meta (Facebook) Conversion API

Google Enhanced Conversions

TikTok Events API

4️⃣ Platform Matches User

The ad platform matches:

Server data

Pixel data (if available)

👉 This is called Event Deduplication

5️⃣ Conversion Recorded

The platform records:

Accurate conversion

Better attribution

Smarter ad optimization

Pixel vs CAPI (Quick Comparison)
Feature Pixel (Browser) CAPI (Server)
Blocked by ad blockers Yes ❌ No ✅
iOS tracking accuracy Low ❌ High ✅
Data reliability Medium High
Security Low High
Recommended ❌ Alone ✅ With Pixel

👉 Best practice: Use Pixel + CAPI together

How to Set Up CAPI
Option 1: Google Tag Manager (Server-Side)

Create server container

Connect Meta / Google / TikTok

Recommended for professionals

Option 2: Platform Integrations

Shopify (built-in)

WooCommerce plugins

Custom CMS APIs

Option 3: Manual API (Developers)

Backend coding (Node, PHP, Python)

Who Should Use CAPI?

E-commerce stores 🛒

Lead generation websites 📋

High ad spenders 💰

Facebook / Google advertisers

Anyone facing tracking issues

Simple Example

Purchase happens →

Website Server → Facebook CAPI → Conversion recorded


Even if the pixel fails ✔️

Final Summary

CAPI = Server-side conversion tracking

Sends data directly from server

More accurate than pixels

Essential for modern digital marketing

Best used with browser pixel

If you want, I can:

Explain Meta CAPI only

Show real-life setup flow

Provide diagram

Explain in Bangla

Guide setup for Shopify / WooCommerce

Just tell me 👍