AWS Appsync HTTP resolvers alternative

Thank you for the great project!
I currently have an AWS AppSync GraphQL API on top of REST API (golang) using HTTP resolvers: https://docs.aws.amazon.com/appsync/latest/devguide/tutorial-http-resolvers.html and local resolvers for subscriptions:
https://docs.aws.amazon.com/appsync/latest/devguide/tutorial-local-resolvers.html
Could you please advise on the feasibility of replacing AWS AppSync with gqlgen?
The idea is to skip the model generation and proxy the calls to API (either via real HTTP or directly in golang), getting GraphQL API from REST API with subscriptions support.
Thank you!