Introspection system

• Query information about a GraphQL schema – features it supports.
• According to Merriam-Webster “introspection” means a reflective looking inward.
• A special kind of query.
• Allow you to learn about a GraphQL API’s schema.

[!TIP]

GraphQL APIs designed exclusively for in-house applications, we typically won’t add introspection service in production env. In fact disabling introspection service can be considered part of a security strategy.

To disable it you can use 3rd-party libs such as graphql-disable-introspection.

__typename

• Ask GraphQL to tell us about the type of object.
• Can be added to any object.

__schema

• Returns available types.
• Always available on the query root operation type.

Operation	Response
	Types defined by us: Robot, SearchResult, Mutation, EventSource, etc. Built-in scalars Types preceded/prefixed with a double underscore which are part of the introspection system itself: __Schema. __Type. __TypeKin. __Field. __InputValue. __EnumValue. __Directive. __DirectiveLocation.
	The response in JSON format look like this. The entrypoint of available queries which is usually called Query.
	The response in JSON format look like this. Essentially it is an array of fields with filed name inside it.