Call this first, before anything else in this server.

It returns a conversationId that every other tool here requires, and — more usefully — what the CloudCart Storefront API's schema does not show: how a signed-in buyer is sent (an argument or @inContext(buyer:), never an Authorization header), that a Nitrogen storefront's checkout is the store's own (cart.checkoutUrl), that the server owns every price and money is shown as formatted, and that a cart is addressed by an unguessable key.

Reading it first is the difference between a storefront that works and one that charges the wrong total.

Look up types, queries and mutations in the CloudCart Storefront schema by name.

Use this when you already know what something is called. When you know what you want to do but not what it is called, read learn_cloudcart_storefront's guide first — it names the operation for each step.

It searches the names of types, queries and mutations, not of fields: look up the type that holds a field.

Results flag fields that only answer when the merchant runs the app behind them, which is the usual explanation for an empty list.

Check GraphQL against the Storefront schema before it reaches a browser.

Always run generated queries and mutations through this. The schema is large and has many close names, and an invented field looks entirely plausible until it fails.

Beyond schema validity it flags mistakes that validate cleanly and still fail at runtime, such as a numeric cart id or reading delivery before the cart has an address, and it answers names borrowed from other storefront APIs with the CloudCart one.