It depends on the backend that powers your GraphQL API, some are much easier than others, but all are doable. Which backend are you using?
We have already done a lot of the groundwork, embedding other GraphQL APIs like GitHub's into OneGraph. We're careful to namespace all of the types so that there will be no collisions.
I'm using apollo-server-hapi. I've briefly looked into schema stitching before but haven't done that recently. Is that something that you'd recommend doing with OneGraph?
We have already done a lot of the groundwork, embedding other GraphQL APIs like GitHub's into OneGraph. We're careful to namespace all of the types so that there will be no collisions.