Attribute revenue with Stripe Checkout API

Before proceeding, confirm that you have linked your Stripe account.

You no longer need to pass websiteId — Flowsery registers a dedicated webhook URL per website, so payments route to the correct site automatically.

To attribute a payment to the visitor's traffic source, forward the Flowsery cookies (_fs_vid and _fs_sid) into the Checkout Session metadata when you create the session server-side:

import { cookies } from 'next/headers';
 
const cookieStore = await cookies();
 
const session = await stripe.checkout.sessions.create({
  line_items: [...],
  mode: 'payment',
  metadata: {
    fs_visitor_id: cookieStore.get('_fs_vid')?.value,
    fs_session_id: cookieStore.get('_fs_sid')?.value,
  },
});

Flowsery reads fs_visitor_id from the webhook and links the payment to that visitor's journey (referrer, channel, country, device).

Supported Stripe webhook events

• checkout.session.completed
• invoice.payment_succeeded
• charge.refunded

No metadata? Flowsery still attributes when it can

• Stripe Payment Links attribute automatically — the Flowsery script appends the visitor id as client_reference_id. See Payment Links.
• If you call identify(email), Flowsery matches the payment to the visitor by email.
• Otherwise the payment is still recorded as revenue, with an "Unknown" source.