OBJECT
__Directive
A Directive provides a way to describe alternate runtime execution and type validation behavior in a GraphQL document.
In some cases, you need to provide options to alter GraphQL's execution behavior in ways field arguments will not suffice, such as conditionally including or skipping a field. Directives provide this by describing additional information to the executor.
link GraphQL Schema definition
1 type __Directive { 2 3 String! : 4 5 String : 6 7 __DirectiveLocation!]! : [ 8 9 __InputValue!]! : [ 10 11 }