How to convert a json response to graphql SQLAlchemyObjectType

I am trying to build an application with graphene_sqlalchemy to manage quite a few micro-services. I have the data models (SQLAlchemyObjectType) of each micro-service, and want to reuse them so that I don't need to duplicate data models. But the challenge is how to convert json responses from micro-services to graphql SQLAlchemyObjectType. Is there any reference? Or do I have to redefine data models for graphql? Thank you!