`__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.

GraphQL Schema definition

type __Directive {
name: String! 
description: String 
locations: [__DirectiveLocation!]! 
args: [__InputValue!]! 
onOperation: Boolean! @deprecated( reason: "Use `locations`."  )
onFragment: Boolean! @deprecated( reason: "Use `locations`."  )
onField: Boolean! @deprecated( reason: "Use `locations`."  )
}

Require by

__SchemaA GraphQL Schema defines the capabilities of a GraphQL server. It exposes all available types and directives on the server, as well as the entry points for query, mutation, and subscription operations.