GraphQL provides a live schema via introspection of the API endpoint. That's a nerdy way of saying the available fields are always up to date and you don't have to worry about the documentation being stale!

How to View the Schema

Head to the Tooling page and follow the instructions listed there to view the schema docs via the Insomnia Client.

Check out the Graph behind the GraphQL here: https://graph.fast-weigh.dev/

Making Sense of the Schema

GraphQL queries are based on "Types". These types are similar to a SQL Table.

A "Customer" database table, for example, becomes a "Customer" type in GraphQL.

Root type:

First, you'll need to drill into a "root" type, two of which are available:

• query_root
• subscription_root

In the vast majority of cases, query_root is what you're after. It's equivalent to a SELECT query in SQL.

The subscription_root is useful for programmers wanting a live websocket connection to the data.

If you're following along, click into the query_root to continue.

Exploring a GraphQL type:

Inside the query_root you'll see a list of available Types to explore.

Let's click into the Customer type.

Here, you'll see a link to view the fields available on the Customer type at the top.

You'll also see a list of arguments that can be passed into the type to filter or order the results returned.

For example, the limit argument tells you that you can pass an integer to limit the number of results.

query GetOneHundredCustomers {
  Customer(limit: 100) {
    CustomerID
  }
}

Arguments/filters are covered further in our GraphQL Crash Course.

Clicking inside the actual Customer type at the top reveals the fields available to you within that type.

Object relationships:

Object relationships on a type are 1:1 relationships with another type.

On the Customer type, if you scroll to the bottom, you'll see the TaxCode field. This is listed as an object type, meaning that if you query for the Customer's TaxCode the result will be a single TaxCode object.

Array relationships:

Array relationships on a type are 1:N relationships with another type.

On the Customer type, you can find the Orders field. This is listed as an array type, meaning that querying for Orders will return a nested array of Orders for the Customer(s) you are filtering for.