Getting Apollo Rover with a rust subgraph to work with _service endpoint

I’m trying to configure my Rust subgraph to work with Rover to generate my queryPlan, and although the async-graphql library for rust says it supports _service, to query the sdl file, it does not work out of the box, the closest I can get to work is to just print this the console…

let schema = Schema::build(Query, EmptyMutation, EmptySubscription).finish();
println!("{}", &schema.sdl());

I am looking to be able to support this GraphQL endpoint in async-graphl, to return my formatted SDL file, so rover will work please.

{ "query": "query Query {\n _service {\n sdl\n }\n}", "variables": {} }

Thank you

I see this module in rust, but there’s no explanation of how to use this anywhere.

The problem is that I forgot this call in building my schema

 let schema = Schema::build(Query, EmptyMutation, EmptySubscription)

The documentation is pretty light on this this crate, although the library seems like a full-featured thing