Google Merchant API
The Merchant API provides programmatic access to manage Merchant Center accounts, products, inventories, promotions, reports, conversions, and order tracking for Google Shopping integration.
Documentation
Documentation
https://developers.google.com/merchant/api/reference/rest
Authentication
https://developers.google.com/merchant/api/guides/authentication
Getting Started
https://developers.google.com/shopping-content/guides/quickstart