Comment by bastawhiz

tRPC sort of does this (there's no spec, but you don't need a spec because the interface is managed by tRPC on both sides). But it loses the real main defining quality of gql: not needing subsequent requests.

If I need more information about a resource that an endpoint exposes, I need another request. If I'm looking at a podcast episode, I might want to know the podcast network that the show belongs to. So first I have to look up the podcast from the id on the episode. Then I have to look up the network by the id on the podcast. Now, two requests later, I can get the network details. GQL gives that to me in one query, and the fundamental properties of what makes GQL GQL are what enables that.

Yes, you can jam podcast data on the episode, and network data inside of that. But now I need a way to not request all that data so I'm not fetching it in all the places where I don't need it. So maybe you have an "expand" parameter: this is what Stripe does. And really, you've just invented a watered down, bespoke GraphQL.