Stripe to Meta Conversions API: every sale in Meta Ads

1. What you need from Meta

• Your pixel (dataset) ID: Events Manager → your pixel → Settings.
• A Conversions API access token: same Settings page → Conversions API → Generate access token. Keep it on your server, never in the browser.

2. Which Stripe events become which Meta events

3. Keep the buyer’s ids at checkout

The webhook arrives from Stripe’s servers, not from the buyer’s browser, so it carries no cookies. Read them when your server creates the Checkout session and keep them with it:

const session = await stripe.checkout.sessions.create({
  // …your line_items, mode, customer_email…
  success_url: 'https://yourbusiness.com/thanks?session_id={CHECKOUT_SESSION_ID}',
  metadata: {
    fbp: req.cookies._fbp || '',
    fbc: req.cookies._fbc || '',   // or build it from ?fbclid= on the landing page
    ga: req.cookies._ga || '',     // for GA4, see the GA4 guide
  },
})

Stripe hands the same metadata back in checkout.session.completed. For renewals, keep them against the Stripe customer too, since the invoice won’t carry the session’s metadata.

4. Send the Purchase from your webhook

After your handler checks Stripe’s signature. Email is normalised (trimmed, lower-case) and SHA-256 hashed; Meta refuses it in plain text.

import { createHash } from 'node:crypto'
const sha = (s) => createHash('sha256').update(s).digest('hex')

const s = event.data.object // a paid checkout.session.completed
await fetch(`https://graph.facebook.com/v27.0/${PIXEL_ID}/events?access_token=${META_TOKEN}`, {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    data: [{
      event_name: 'Purchase',
      event_time: event.created,
      event_id: s.id,                       // same id as the pixel's Purchase on /thanks
      action_source: 'website',
      event_source_url: 'https://yourbusiness.com/pricing/',
      user_data: {
        em: [sha(s.customer_details.email.trim().toLowerCase())],
        external_id: [sha(s.customer)],
        fbp: s.metadata.fbp || undefined,
        fbc: s.metadata.fbc || undefined,
      },
      custom_data: { value: s.amount_total / 100, currency: s.currency.toUpperCase() },
    }],
    // test_event_code: 'TEST12345',      // while you check it in Test Events
  }),
})

Meta takes events up to 7 days old. With action_source: 'website' it also wants the buyer’s IP and user agent for best matching; keep them at checkout with the cookies if you can.

5. Check it in Test Events

Events Manager → your pixel → Test events. Copy the code into test_event_code, send one event, and it shows there with the keys Meta matched on. If your thank-you page also fires the pixel, you should see the browser and server events paired, not counted twice. Then remove the test code.

Or: forward the event and let FloorSync do 3–5

FloorSync takes the verified Stripe event from your webhook and does the rest: hashes, ids kept from checkout (POST /api/v1/attribution), renewals matched to the first buyer, one send per event id, retries, and a log of every answer Meta gave. Python, from the docs:

import hashlib, os, requests

# payload: the raw body bytes you passed to stripe.Webhook.construct_event(...)
try:
    requests.post('https://floorsync.towers.app/api/v1/events/stripe', data=payload, timeout=10, headers={
        'Content-Type': 'application/json',
        'X-Floor-Key': os.environ['FLOORSYNC_KEY'],
        'x-amz-content-sha256': hashlib.sha256(payload).hexdigest(),
    })
except requests.RequestException:
    pass

See what Meta would get, right here

This runs FloorSync’s mapping in your browser. Start with the renewal: it has no browser, so watch what it matches on. Nothing is sent.

Sources: Meta’s Conversions API docs; Tracking Consulting’s Stripe → Meta guide (on {CHECKOUT_SESSION_ID} as event_id and on renewals). Checked November 2026.

More

• Stripe sales missing in Meta or GA4? A 5-step check
• Stripe to GA4 with the Measurement Protocol
• FloorSync vs Tracklution · vs Admaxxer · vs Stape