ChatGPT Ads module for PrestaShop: conversions, add to cart and CAPI

What the module does, event by event

The module maps the PrestaShop purchase journey to the standard events defined by OpenAI:

• contents_viewed on the product page, with the ID, name and price of the displayed combination;
• items_added on add to cart, including AJAX adds from a product list or the theme’s modal window;
• checkout_started when entering the checkout;
• order_created on purchase, sent both by the pixel on the confirmation page and by the server;
• registration_completed on customer account creation, and lead_created on the contact form if you want it.

The purchase event matters most: it is the one you will choose as the goal of a conversion-optimised campaign. It leaves the server as soon as PrestaShop confirms the order, through the actionValidateOrder hook, whether or not the customer comes back from the payment page. For deferred payment methods such as bank transfer or cheque, we decide together which order status counts.

oppref, deduplication and the data sent

When a visitor arrives from an ad, the URL carries an oppref parameter. The pixel stores it in the __oppref cookie, but the Conversions API does not read it by itself. So the module captures it on arrival, links it to the PrestaShop cart and then to the order, and attaches it to the server call along with the obref browser identifier. A customer who comes back three days later to complete their cart stays linked to their click.

For deduplication, the module generates an opaque identifier when the order is created and uses it on both sides: event_id in the pixel, id in the Conversions API, with the same Pixel ID and the same event name. OpenAI then keeps a single sale. The amount is sent as an integer in the minor unit of the order currency, as the documentation requires.

Customer emails and phone numbers never leave the shop in clear text: they are normalised and then hashed with SHA-256 before sending. The Conversions API key stays on the server, in the module configuration, never in the theme JavaScript.

Consent, GDPR and banner tools

Nothing is loaded or sent before the visitor consents: no script, no __oppref or __obref cookie, no server call. The module is compatible with tarteaucitron.js, where the pixel is declared as a custom service, and with Axeptio, Cookiebot, Didomi, CookieYes or Complianz, where it is tied to the marketing purpose. It can also read the ad storage signal from Google Consent Mode when the banner publishes it.

The consent state is stored with the order: a customer who refused will not be sent through the Conversions API. I give you the exact list of data sent, for your privacy policy and your record of processing; choosing the legal basis remains yours or your DPO’s.

PrestaShop compatibility

The module is designed for PrestaShop 1.7, 8 and 9. It relies on standard hooks rather than core overrides: it changes neither PrestaShop classes nor theme files, and uninstalls cleanly. In multistore, each shop can have its own Pixel ID and key; with multiple currencies, each order is sent in its own currency. A log available from the back office records server calls and OpenAI’s responses, so a gap can be checked without opening server files.

A heavily customised theme or a third-party one-page checkout may need an adjustment: that is precisely why I do the installation myself rather than leaving you a file to upload. For the overall logic of ChatGPT Ads tracking, read the complete guide to the OpenAI pixel, the Conversions API and consent.