Federation schema spec SDL

[Barry-Zou]

Hi I am using gqlgen with federation. I have enabled gqlgen federation on my SDL and it was able to generate all the boilerplates + necessary entity resolver signatures. After filling in the resolvers, _entities queries are working again my subgraph.

Now that my subgraph runtime is working federation wise, do I need to add the fields necessary according to https://www.apollographql.com/docs/federation/federation-spec/ manually back to my SDL when publishing to Apollo?

Or is there a way to get that from gqlgen, because I did notice that the generated schema.go by gqlgen around where
var sources = []*ast.Source {....
contains some of the necessary federation spec fields (_Any, _entities, _Service, union _Entity ....)

any info appreciated thanks!