Certain product data like price and availability naturally changes over time, so you will need to maintain your product feed to keep this information up-to-date. This section discusses how to provide updated information about your products.
The preferred avenue for providing updated price, availability, and sale information is the Inventory service provided by the Content API for Shopping. See the automatic steps section for more information.
An alternative method for providing this information is to use supplemental feeds. Supplemental feeds can only be registered using the Merchant Center, not the Content API for Shopping.
You can also use automatic item updates to help keep price and availability information up-to-date. The Merchant Center can use embedded structured data in your website to update products appropriately if the price or availability of a product on your landing page differs from the information currently stored in the Merchant Center.
To create a supplemental feed, see the Create a feed article. Note that supplemental feeds must be linked to a primary feed.
For what you need to enable automatic item updates, see the article on automatic item updates.
To update prices, availability, and information on sales with the Content API, use the Inventory.set method. Like product inserts and updates, multiple inventory updates can be batched into a single Content API call using the Inventory.custombatch method.