Indicating deprecation of a field in a GraphQL Schema

The GraphQL Schema Language provides a very handy feature to indicate that a field has been deprecated. This will show as a prominent text box on auto-complete in the query builder in GraphiQL, as well as in the documentation explorer. This is a great way to indicate to developers using your GraphQL API that code using a field should  ideally be changed. The reason for deprecation can be included as an annotation right in the schema itself!

In the following schema, we have indicated that the field topic is deprecated for the Book type:

type Book {
   id: Int!,
   title: String,
   topic: String @deprecated (reason: "Field is no longer needed")

When we explore the schema with GraphiQL, the deprecation message will display when viewing the field.