Type Name Introspection

GraphQL supports type name introspection at any point within a query by the meta field__typename: String!when querying against any Object, Interface, or Union. It returns the name of the object type currently being queried.

This is most often used when querying against Interface or Union types to identify which actual type of the possible types has been returned.

This field is implicit and does not appear in the fields list in any defined type.