Merchant API v1beta discontinued on February 28, 2026; all calls must target v1 or v1alpha

Google set February 28, 2026 as the shutdown date for Merchant API v1beta across the Accounts, Conversions, Data sources, Inventories, Products, Promotions and Reports sub-APIs; the May 2026 release notes confirmed v1beta was discontinued. January 2026 also added the FREE_LISTINGS_UCP_CHECKOUT reporting context, YouTube Shopping Affiliates reporting (v1alpha), ErrorInfo error metadata and InventoryLoyaltyProgram.

The v1beta discontinuation was first flagged in the November 2025 release notes. Month-level date from Google's latest-updates page.