You have to set categories and attributes when adding your Magento products as new listings to the OnBuy catalog. Products without the category and related attributes can’t be listed on the OnBuy marketplace as new items.
By providing this information, you can ensure your products are accurately categorized and described. This also helps enhance product visibility and appeal on the OnBuy marketplace.
ℹ️ Setting category is only available when adding new products to the OnBuy catalog.
Assign categories #
Once you’ve selected products to be added to your M2E OnBuy Listing and confirmed new OnBuy product creation, you will need to assign them to the appropriate category. For that, choose the preferred category settings first.

All Products same Category #
The same category settings will be applied to all products in M2E OnBuy Listing. Click the Edit button to start assigning the OnBuy category to your products.

You can choose from the previously saved categories or browse through the category tree to find the most suitable one. Confirm your choice to proceed.

Set Manually for each Product #
Set a relevant OnBuy category manually for each of the selected products.

Click Edit Category to assign the corresponding OnBuy category to your product. You can choose from the previously saved categories or browse through the category tree to find the most suitable one. Confirm your choice to proceed.
Assign attributes #
Once the category is set, you should assign product attributes (specifics) per category. Attributes define such product details as size, color, brand, style, etc., and help customers make informed purchasing decisions.
Click Edit to start assigning the attributes.

In the Mode section, select one of the available options from the drop-down menu:
- OnBuy Recommended – OnBuy recommends specific characteristics for your product. Choose the most appropriate one from the drop-down menu.
- Custom Value – allows you to enter information about your product manually, rather than selecting from a list. This is useful if the OnBuy recommended option doesn't include information about the items you're selling.
- Custom Attribute – manually enter the relevant value for the attribute.
Once selected, save the settings.

Product data validation #
OnBuy assigns specific attributes to each product category, so your product data must match these to ensure proper classification and visibility. M2E OnBuy Connect automatically validates this data whenever you assign or edit a Category for a not listed product in a Listing.
The system checks that Magento attributes mapped to OnBuy fields meet format, data type, and value requirements. For example, if a category requires a specific size, the value must fall within OnBuy’s accepted range. Any validation errors must be fixed by updating or adding the correct attributes.

After successful validation, M2E OnBuy Connect submits the data to OnBuy, where it’s reviewed before listing. Additional adjustments may be needed during this review.
Edit categories and attributes #
At any time, you can modify category and attribute settings for your OnBuy products. Navigate to your M2E OnBuy Listing and switch to the Settings View Mode on top of the grid. Select the needed products you want to update and submit the Edit Category Settings > Categories & Specifics action.
