Brevo Webhooks + Event Tracking - Wiring Real-Time Email Data Into Your App

The killer feature nobody talks about in Brevo is the webhook system. When set up correctly, you can react to opens, clicks, bounces and unsubscribes in real time — inside your own product. Here is how I wire it up in a Next.js app.

Which events matter?

• delivered — email accepted by the recipient server.
• opened — the recipient loaded the tracking pixel.
• clicked — a link in the email was clicked.
• hard_bounce / soft_bounce — permanent or temporary delivery failure.
• unsubscribed — the recipient opted out.
• spam — recipient marked the email as spam (fix your list immediately).

Step 1 — Create the webhook endpoint

js
// /app/api/brevo-webhook/route.js
import { NextResponse } from "next/server";

export async function POST(req) {
  const events = await req.json(); // Brevo posts JSON array
  for (const e of events) {
    // e.event: "delivered" | "opened" | "click" | "bounce" | "unsubscribed" | "spam"
    // e.email: recipient
    // e.message-id: your message id
    await recordEvent(e);
  }
  return NextResponse.json({ ok: true });
}

Step 2 — Register the URL in Brevo

Dashboard → Transactional → Settings → Webhook. Add https://yourdomain.com/api/brevo-webhook and tick the events you care about. Save.

Step 3 — Idempotency (do this)

Brevo occasionally retries a webhook. Use the message-id + event type as an idempotency key and skip duplicates. Otherwise you will double-count opens and confuse your analytics.

Step 4 — Wire it into your product

• Update user records — mark "email_verified" on first successful delivered event.
• Suppress future sends automatically on hard_bounce.
• Trigger a follow-up campaign after a specific click.
• Alert your team in Slack when spam rate crosses 0.1%.

The compound effect

Once webhooks feed your product database, your onboarding, retention and reactivation campaigns get 3-5× smarter. This is the single biggest lever in modern email — and Brevo gives it away for free.