Tracking snippets

Three scripts, for three different jobs on your own pages. You get the exact snippet for your account, with ids filled in, from Direct Links and Landing Pages in the app — this page is the reference for what each option does.

The JavaScript objects are named PropelDirect and PropelConvert, and the HTML attributes are data-propel-*. Those names date from the platform's original working title. They are part of the public interface of code already running on live landing pages, so they cannot be renamed without breaking those pages. Type them exactly as shown.

Which one you need#

The first two are alternatives to each other. The third is independent, and only needed when your offer source is not sending postbacks for you.

Cookie enrichment#

For the normal flow, where your ad points at a PostbackX tracking link that redirects to your landing page.

Facebook writes two cookies in the visitor's browser, _fbp and _fbc, that can only be read client-side. They materially improve Facebook's ability to match a conversion to a person, so this script reads them and attaches them to the click record.

<script src="https://propel-lander-api.propelsys.workers.dev/snippet.js"></script>
<script>
  Propel.init({
    landerId: 'YOUR_LANDER_ID',
    delay: 2500
  })
</script>

The delay matters: read the cookies too early and the pixel has not written them yet. If your pixel loads slowly, raise it.

Without writing any JavaScript#

Put the attributes on any element instead, and the script initializes itself:

<script src="https://propel-lander-api.propelsys.workers.dev/snippet.js"></script>
<div data-propel-auto-init
     data-propel-lander-id="YOUR_LANDER_ID"
     data-propel-click-param="click_id"
     data-propel-delay="2500"></div>

Direct links#

For when your ad points directly at your own landing page. There is no redirect, so nothing has created a click record yet — this script creates it from the page itself.

The trade-off: you keep full control of the URL in your ad and drop a redirect hop, but click recording now depends on the visitor's browser running your script.

<script src="https://propel-lander-api.propelsys.workers.dev/direct-snippet.js"></script>
<script>
  PropelDirect.init({
    trackingId: 'YOUR_CAMPAIGN_TRACKING_ID',
    offerId: 'YOUR_OFFER_ID',
    apiUrl: 'https://propel-lander-api.propelsys.workers.dev'
  })
</script>

When it creates a click, and when it reuses one#

In order, stopping at the first that applies:

1. A click_id is in the page URL. The visitor arrived through a redirect that

already created the click. It is reused, not duplicated.

1. A _propel_click_id cookie exists and the visitor's attribution has not

changed. The same click is reused — a returning visitor is not a new click.

1. Otherwise, a new click record is created.

"Attribution has not changed" means the ad parameters in the URL are the same. A visitor who comes back through a different ad gets a new click, because they are genuinely new traffic.

Outbound links#

Any anchor carrying data-propel-link is rewritten to a tracked redirect, with the click id attached:

<a href="#" data-propel-link="/offer">See your quote</a>

Rewritten anchors are marked data-propel-resolved="true". Links added to the page later are picked up automatically, so this works with content rendered after load.

The script also injects the click id into forms on the page, so a form submission carries it to your backend.

Everflow#

If you use Everflow's own SDK alongside PostbackX, pass its ids and both are fired together:

PropelDirect.init({
  trackingId: 'YOUR_CAMPAIGN_TRACKING_ID',
  offerId: 'YOUR_OFFER_ID',
  apiUrl: 'https://propel-lander-api.propelsys.workers.dev',
  everflow: {
    offer_id: 123,
    affiliate_id: 456
  }
})

offer_id and affiliate_id are required when the everflow block is present. uid, and sub1 through sub4, are optional overrides.

The PostbackX click id is passed to Everflow as sub5. When you configure Everflow's postback, its click id macro is therefore {sub5} — see postback parameters.

What it stores in the browser#

Conversion firing#

For when the conversion happens on your page rather than the offer's, and no offer source is going to send a postback for it.

Add this to the thank-you or confirmation page — the page a visitor only reaches after converting:

<script src="https://propel-lander-api.propelsys.workers.dev/conversion-snippet.js"></script>
<script>
  PropelConvert.fire({
    postbackUrl: 'https://postbacks.postbackx.com',
    payout: 0,
    eventName: 'lead'
  })
</script>

postbackUrl takes the host with no path: the script appends /postback itself. Passing https://postbacks.postbackx.com/postback produces a doubled path and the conversion is lost.

Left to itself, the script finds the click id in this order: the clickId you passed, then the _propel_click_id cookie, then localStorage, then a click_id parameter in the page URL.

Because this fires from a browser, treat it as best-effort: a visitor who closes the tab early never runs it. Where your offer source can send a real postback, prefer that.