GraphiQL (A graphical interactive in-browser GraphQL IDE) ... in other words it's a powerful tool to explore your API and interact with them.

GraphQLBundle has a GraphiQL integrated and ready to start using it, the only that you need is add the following route to your routing.yml

api_explore:
      resource: '@YnloGraphQLBundle/Resources/config/routing/explorer.yml'
      prefix:   /explorer
      trailing_slash_on_root: false

The trailing_slash_on_root option was introduced in Symfony 4.1.

Install required javascript and stylesheets:

bin/console assets:install --symlink

If you only need use the GraphiQL tool in a dev environment add the route configuration to routing_dev.yml instead.

Now you can use GraphiQL to interact with your API using the path /explorer in your browser.

By default you can view two queries in the schema, node(id) and nodes(ids)

The following graphql example request for one user with database ID = 1

query node{
  node(id: "VXNlcjox"){
   id
    ... on User{
      username
    }
  }
}

See this documentation to view how encode and decode your database Ids.