Meta Conversions API Explained

If you’re running Meta Ads, you’ve probably heard about the Conversions API (CAPI). But what is it, and why should you care?

The Browser Tracking Problem

Traditional Meta Pixel tracking works like this:

1. User visits your website
2. Meta Pixel (JavaScript) fires in their browser
3. Browser sends event data to Meta

The problem: This breaks constantly.

• Ad blockers — Block the Pixel entirely
• iOS 14+ — App Tracking Transparency limits tracking
• Browser privacy — Safari, Firefox block third-party cookies
• VPNs — Mask user identity

Studies show browser-based tracking misses 20-40% of conversions.

Enter the Conversions API

CAPI takes a different approach:

1. User takes an action on your site
2. Your server sends the event to Meta
3. Meta receives 100% of server-sent events

Server-side = no browser required.

Ad blockers can’t block server-to-server communication. iOS privacy doesn’t affect it. VPNs don’t matter.

How CAPI Works

Here’s the technical flow:

User Action → Your Server → Meta API → Events Manager

You send a POST request to Meta’s API with:

• Event type (Lead, Purchase, etc.)
• Event time
• User data (hashed email, phone, etc.)
• Attribution data (fbc and fbp cookies)

Meta uses this data to:

1. Attribute the conversion to an ad click
2. Update your campaign optimization
3. Build better audiences

CAPI vs Pixel: Which to Use?

Use both. Meta recommends “redundant” tracking:

Meta deduplicates automatically using event IDs.

For Telegram Marketers

Here’s the challenge: when users click your ad and join Telegram, the Pixel can’t track it. Telegram opens in a different app/browser.

CAPI solves this:

1. User clicks ad → lands on your page
2. You capture the fbclid
3. They join your Telegram channel
4. Your server detects the join
5. Server sends CAPI event to Meta

The entire conversion journey is tracked, even though it crosses platforms.

Setting Up CAPI

Prerequisites

• Meta Business Manager account
• Meta Pixel
• Server or service to send events

Step 1: Create a System User

1. Go to Business Settings
2. Navigate to System Users
3. Create new system user
4. Assign pixel access

Step 2: Generate Access Token

1. Select your system user
2. Click “Generate Token”
3. Select required permissions
4. Save the token securely

Step 3: Send Events

Here’s a simplified example:

// POST to Meta Conversions API
fetch('https://graph.facebook.com/v21.0/{pixel_id}/events', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'Authorization': 'Bearer your_access_token'
  },
  body: JSON.stringify({
    data: [{
      event_name: 'Lead',
      event_time: Math.floor(Date.now() / 1000),
      action_source: 'website',
      user_data: {
        fbc: 'fb.1.1234567890.abcdef...',
        fbp: 'fb.1.1234567890.987654321'
      }
    }]
  })
});

Or Use a Tool

Services like AdTarget handle CAPI integration automatically:

1. Connect your Pixel
2. Add your access token
3. Events are sent when conversions happen

No code required.

Event Match Quality

Meta scores your events based on how well they can match users:

Improving Match Quality

Send more user data (PII fields must be SHA-256 hashed):

• Email address (hashed)
• Phone number (hashed)
• First/last name (hashed)
• IP address (sent as-is)
• User agent (sent as-is)

The more data, the better matching.

Common CAPI Mistakes

1. Not sending fbc — Critical for click attribution. The fbc cookie contains the fbclid from the ad click.
2. Missing event_id — Causes duplicate counting
3. Wrong event_time — Must be Unix timestamp
4. Unhashed PII — Meta requires SHA-256 hashing for PII fields (email, phone, name); IP and user agent are sent as-is

CAPI for Different Use Cases

E-commerce

PageView → AddToCart → InitiateCheckout → Purchase

Send full funnel events with order value.

Lead Generation

PageView → Lead

Send when form is submitted or meeting booked.

Telegram/App Growth

PageView → Lead (on channel join)

This is where AdTarget shines—tracking off-site conversions.

Measuring CAPI Effectiveness

In Events Manager, compare:

• Browser (Pixel) events
• Server (CAPI) events
• Deduplicated total

If CAPI is adding 20%+ events, it’s working.

The Future of Tracking

Privacy regulations are tightening. Browser tracking will only get worse.

Server-side tracking is the future:

• More accurate data
• Better optimization
• Compliant with privacy laws

Start using CAPI now, before your competitors figure it out.

Need CAPI for Telegram conversions? AdTarget  handles it automatically—no coding required.