Input objects
@Input follows the same class metadata contract as @Type, but its fields are
compiled as GraphQL input fields and cannot have output resolvers.
Interfaces and unions
Enums and scalars
@Enum maps Python enum members to GraphQL enum values. @Scalar or Scalar(...)
defines custom serialization and parsing. Include non-root types explicitly in
build_schema(types=[...]) when they are not reachable through a root field.