Publish a product to Google Merchant Center using the Merchant API v1 products.productInputs resource

Verified steps

1. Enable the Merchant API in your Google Cloud project and authorize with OAuth 2.0 using the https://www.googleapis.com/auth/content scope; Merchant API v1 is GA as of summer 2025.
2. Retrieve your primary dataSource ID: GET https://merchantapi.googleapis.com/products/v1/accounts/{merchantId}/dataSources — look for the dataSource with type 'PRIMARY' and note its name (in the format accounts/{id}/dataSources/{dataSourceId}).
3. Build a productInput object with at minimum: offerId (your unique product ID), title, description, link, imageLink, availability ('in_stock', 'out_of_stock', 'preorder'), price {amountMicros, currencyCode}, condition, and a Google product category string.
4. Insert the product: POST https://merchantapi.googleapis.com/products/v1/{parent=accounts/*/dataSources/*}/productInputs:insert?dataSource={dataSourceName} with the productInput body.
5. Check processing status: GET https://merchantapi.googleapis.com/products/v1/accounts/{merchantId}/products/{productId} — the productStatus.destinationStatuses array shows whether the product is approved for Shopping ads and free listings.
6. For bulk inserts, use the productInputs.insert endpoint in a loop or batch wrapper; Google Merchant API does not have a dedicated batch endpoint analogous to Content API's custombatch — rely on concurrent API calls with appropriate rate-limit handling.