Usage and Merchant Center setup

Overview · Installation · Configuration · Developer notes · FAQ

Daily workflow

1. Generate: feeds in On request mode rebuild themselves when Google fetches them and the cache is older than its lifetime. Feeds in Scheduled mode are rebuilt by cron. Generate now in a feed’s gear menu rebuilds it at once.
2. Check: open Validation report for the feed. The cards show items in the feed, products with errors, products with warnings only, and skipped or excluded products. The table lists every issue per attribute with a product count and a hint on how to fix it. Click an issue to see the products, then click a product to edit it.
3. Fix: fill in the product data, map categories, add a rule or a product override, then click Validate now.

Issues checked

Issue	Severity	Meaning
Missing required attribute	Error	id, title, description, link, image_link, availability or price is empty.
Price is zero	Error	Google rejects zero prices.
Duplicate item ID	Error	Two products share the same product code.
Item ID longer than 50 characters	Error	Shorten the code or use product IDs.
Brand is missing	Warning	Required for new products (except media).
GTIN is missing	Warning	Strongly recommended for products with a barcode.
Invalid GTIN	Warning	Wrong length or check digit. The value is left out.
Google product category is missing	Warning	Map the category or set a feed default.
Required for apparel	Warning	Apparel & Accessories needs color, gender and age_group. Clothing and shoes also need size.
Value not allowed	Warning	E.g. gender boys cannot be normalized. The value is left out.
Too long	Warning	The value was shortened at the Google limit (title 150, description 5000, brand 70, labels 100…).
Title mostly in capital letters	Warning	Google disapproves excessive capitalization.

Items with errors are left out of the feed when Leave out items with errors is on (default), so the rest of the feed is accepted.

Merchant Center setup

These steps follow the Merchant Center interface as of 2026. Menu names can differ slightly between accounts.

1. Prepare the account

1. Sign in to Merchant Center with the Google account that manages your store.
2. Under Settings > Business info, verify and claim your website domain (for example with the HTML tag or Google Search Console). Feed links must be on this domain.
3. Under Settings > Shipping and returns, add shipping services for each country you sell to, unless you send shipping costs in the feed. Add a return policy.
4. Under Settings > Tax (US only), configure sales tax, or leave tax to Google’s automatic settings.

2. Create the feed in CS-Cart

1. Marketing > Google Merchant feeds > + > Add product feed.
2. Choose the Target country, the Language of your product texts and the Currency of that country.
3. Choose XML (recommended) and On request, cached for up to a few thousand products, or Scheduled (cron) for larger catalogs.
4. Set up Category mapping, check the Attributes tab (brand, GTIN, condition), and generate the feed.
5. Open the Validation report and fix the errors.
6. Copy the Feed URL from the feed page.

3. Add the data source

1. In Merchant Center, open Products > Data sources (older accounts: Products > Feeds) and click Add product source.
2. Choose Add products from a file and then Enter a link to your file (scheduled fetch).
3. Paste the feed URL from CS-Cart. The URL contains the access key. No user name or password is needed.
4. Select the country (or countries) and the language that match the feed settings, and the destinations (Shopping ads, free listings…).
5. Set the fetch frequency to daily and pick a time. For scheduled feeds, run cron 1-2 hours before that time.
6. Save, then click Fetch now for the first import.

Repeat for every country: one CS-Cart feed per country and currency, one data source per feed.

4. Check the result

• Products > All products shows approved, limited and disapproved items after processing (minutes to a few hours).
• Products > Needs attention lists the issues Google found. Most of them should already appear in the CS-Cart validation report.
• Variants: items with the same item_group_id are shown as one product with variants.

5. Promotions (optional)

1. In CS-Cart, create a feed with + > Add promotions feed (same country and currency as the product feed).
2. Its Promotions tab lists the cart promotions that will be sent, and the skipped ones with the reason (for example user-group conditions or bundles, which Google cannot express).
3. In the product feed, keep Link cart promotions (promotion_id) on, so products of product- or category-specific promotions get promotion_id.
4. In Merchant Center, open Marketing > Promotions. Add a promotions source with the promotions feed URL (scheduled fetch), if your account and country support promotions.
5. Google reviews each promotion before it shows.

Catalog promotions are not sent as promotions. They already appear as sale_price in the product feed.

6. Custom labels in Google Ads

The default mapping fills:

Label	Default source	Values
custom_label_0	Price band	0-25, 25-50, …
custom_label_1	Bestseller	bestseller or empty
custom_label_2	Margin band	margin 20-40% (needs a cost feature)
custom_label_3	Top-level category	e.g. Electronics
custom_label_4	Not sent	Use it for your own values or rules

In Google Ads, use them to subdivide Shopping or Performance Max listing groups, for example to bid more on bestsellers or high-margin products.

Multi-Vendor

• Marketplace feed: set Vendor to All vendors. All vendor products are included. Use Only these vendors to limit the feed.
• Feed for one vendor (admin): select the vendor in the feed. Only that vendor’s products are included.
• Self-service vendor feeds: turn on Allow vendors to manage their own feeds. Vendors open Marketing > Google Merchant feeds in the vendor panel, create feeds that include only their own products, generate them and see their validation report. Vendors cannot change the category mapping or rules; the administrator manages them for all feeds.
• When the Common products for vendors (master products) add-on is active, common products are skipped and the vendors’ own offers are sent.

CS-Cart Ultimate (multiple storefronts)

Every feed belongs to one storefront. Its products are the products of that storefront’s categories, and links use the storefront’s URL. Category mapping is filtered by the selected storefront.