Meta Pixel and CAPI Event Deduplication: Implementation Guide

What to do first

Generate the event ID once after a validated lead submission or confirmed order, then retain it with that record.

Implementation and review

1. Pass the same ID and event name to the browser event and the server request; keep access tokens on the server.
2. Inspect test-event diagnostics and check that retries preserve the original event identity.

What to watch for

Generating separate IDs in the browser and server defeats matching. Server-side collection also remains subject to permissions and platform requirements.

Event identity example

This illustrative mapping shows the same business event on both paths. It is not a complete API implementation; server authentication and required fields must follow the current provider documentation.

{
  "submission_id": "form-unique-record-id",
  "browser": {"event_name": "Lead", "event_id": "form-unique-record-id"},
  "server": {"event_name": "Lead", "event_id": "form-unique-record-id"}
}

A practical example to work through

The server should receive the identifier attached to the confirmed business event rather than constructing a new unrelated identifier for the same submission. A retry should reuse that identity. In test diagnostics, look for whether the browser and server records form the intended pair. This is separate from customer-information matching and should be validated as its own part of the implementation.

References and further reading

• GA4 event setup
• Server-side GTM overview

References explain platform behavior; they are not independent verification of portfolio results. Check current documentation before implementation.