FAQ
Does it work with CS-Cart and Multi-Vendor?
Section titled “Does it work with CS-Cart and Multi-Vendor?”Yes. The add-on supports CS-Cart (including Ultimate storefronts) and Multi-Vendor. In Multi-Vendor vendors manage the labels of their own products only; the marketplace owner can use one EPREL key for everyone or let each vendor save their own.
Which CS-Cart versions are supported?
Section titled “Which CS-Cart versions are supported?”Tested on CS-Cart 4.17.2 (Ultimate and Multi-Vendor). The code and templates are written for 4.17.2 to 4.21.x and PHP 7.4 to 8.3 (the Smarty 5 compile and the PHP 8.1 / 8.3 checks pass), but the add-on has not yet been run on a 4.21 store.
Do I need an EPREL API key?
Section titled “Do I need an EPREL API key?”No. Without a key you type the class (or import it from CSV) and the label and sheet are linked at EPREL from the registration number. With a key the cron job reads class, model and label for you. The Commission issues keys on request; read their API terms first.
Is the EPREL address the add-on uses official?
Section titled “Is the EPREL address the add-on uses official?”The Commission documents that APIs exist and publishes the key request page, but the endpoint reference is available to key holders only. The add-on’s default addresses were checked read-only against the live register on 2026-11-07 (see the developer notes); you can change them in the settings. The arrow itself does not depend on them.
Does it make my shop compliant?
Section titled “Does it make my shop compliant?”No. It helps you show the arrow, the label and the information sheet in the way the regulation describes for the internet. Which rules apply to which product, whether your data is right and whether your page design meets the regulation (for example the letter size relative to your price) remain your responsibility. This is not legal advice.
Why is the arrow letter white on yellow?
Section titled “Why is the arrow letter white on yellow?”The regulation prescribes a white class letter with a black border around the arrow, so the add-on follows it for every class.
Does the label load from EPREL when the page opens?
Section titled “Does the label load from EPREL when the page opens?”No. The label picture is requested only when a shopper opens it (or served from your own domain when a copy is stored or uploaded).
Where is my API key stored?
Section titled “Where is my API key stored?”In your own database, encrypted. The key is derived from your store’s secret in config.php, so a database dump alone does not reveal it. It is never shown again after saving and is sent to eprel.ec.europa.eu only.
Does it send data to Kavio Labs?
Section titled “Does it send data to Kavio Labs?”No. The add-on talks to EPREL only (when a key is set). The license check sends your domain name to the Kavio Labs license server once a day (Kavio Labs downloads).
What happens when EPREL is down or answers “too many requests”?
Section titled “What happens when EPREL is down or answers “too many requests”?”The job waits and is retried (5 minutes up to 12 hours, or the time EPREL asks). Your stored data keeps showing.
What happens when the license expires?
Section titled “What happens when the license expires?”The storefront arrows, labels and sheet links are hidden until the license is valid; your data is kept.
Does it work with full page cache?
Section titled “Does it work with full page cache?”It is built for it: the output depends on the product and the settings, not on the visitor, so a cached page is the same for everyone. It has not yet been tested on CS-Cart 4.21 with the full page cache switched on.
How do I get updates and support?
Section titled “How do I get updates and support?”Install the new package over the old one (see Installation). Contact us through https://cs-cart.kaviolabs.com.
My license shows “Pending verification”
Section titled “My license shows “Pending verification””This status appears in older add-on versions when you use a CS-Cart Marketplace license number that our license server has not matched with the Marketplace yet. The add-on is fully working in this state: no feature is switched off and you do not need to do anything. Newer versions show it as Active (Marketplace license). We confirm Marketplace numbers on our side; click Check now on the add-on’s License tab (Add-ons → Manage add-ons → the add-on) a little later and it shows Active. If it has not changed after 24 hours, contact support with your Marketplace order number.
Still stuck?
Section titled “Still stuck?”Work through the troubleshooting guide, then contact support with your CS-Cart version, edition, PHP version and the add-on version (1.0.0).