See: https://api-university.com/books/graphql-api-design/tutorial/

• Install npm
  • Check installation npm -v
    • If not found: brew install npm
    • If version printed: brew upgrade npm
• Install node.js
  • Check installation node -v
    • If not found: brew install node
    • If version printed: brew upgrade node
• Download the tutorial sources, go to the directory and fetch the dependencies:
  • npm install -save graphql express graphql-server-express body-parser graphql-tools graphql-subscriptions subscriptions-transport-ws

In order to run the server, simply execute npm start which should print out the following:

> [email protected] start /Users/cpickl/Dev/graphql-book
> node ./server.js

GraphQL on port 4000

The address http://localhost:4000/ should return a simple "Hello World!", whereas the well-known GraphiQL is available at: http://localhost:4000/graphiql

Point your browser to http://localhost:4001/client.html to run a sample client.

Read all books:

query readAllBooks {
  books {
    id
    title
    authors {
      id
      name
    }
  }
}

Read a single book:

query readBook {
  book(title: "ReSTful Services") {
    id
    title
  }
}