Merchant API

What it is

Merchant API is a family of REST endpoints that let a retailer or an agency create, update and read the data Google holds about their products and merchant account. It covers areas such as product inputs and data sources, local and online inventory, promotions, account settings, and reporting. It replaces the older Content API for Shopping, which Google has been phasing out in favour of this modular design.

Why it matters

Product data quality decides whether items are eligible to appear in Shopping surfaces, free product listings and shopping-related answers in AI assistants. Feeds that go stale on price or stock create disapprovals and mismatched results, which costs visibility and trust. An API connection lets stock and pricing changes reach Google in near real time rather than waiting for the next scheduled crawl or file upload.

How it works

Practitioners authenticate against a Merchant Center account, register a data source, then push product inputs and inventory updates from the commerce platform or a middleware layer. Teams typically combine a primary data source for core attributes with supplemental updates for volatile fields such as price and availability, and pull reporting endpoints to monitor disapprovals and product-level performance. Migration work usually means mapping existing Content API calls and feed logic to the newer sub-API structure.

When it applies

It applies to any retailer running Shopping ads or free product listings at a scale where manual feeds and spreadsheets break down, and to anyone still on the Content API for Shopping who needs to migrate.

Examples

• A fashion retailer pushes size-level availability updates through the inventory endpoints each time a warehouse order is picked, so sold-out variants stop being advertised.
• An agency pulls product-level reporting nightly into a warehouse to flag which SKUs are disapproved and which are losing impression share on price.
• A multi-country store uses account and data source endpoints to manage separate feeds per market with local currency and shipping settings.

How it is measured

• Share of catalogue active and approved in Merchant Center, and disapproval reasons by count
• Latency between a price or stock change in the commerce platform and the update being live in Merchant Center
• Impressions and clicks from free product listings and Shopping ads at SKU level
• Rate of price and availability mismatch warnings over time