GraphQL schema are generated dynamically, on configuration, as a convenience in order to distinguish schema for key authentication (non-nullable input field 'key') and JWT token (no such field). It is preferable to generate schema statically, during installation of the debian package vyos-1x, as one can then apply code generation tools for client types and operations. Consequently, use nullable field 'key' and generate schema in vyos-1x.postinst.