I have not used Relay before, but I will look it up.
I will circle back on this after looking up relay, but Slash GraphQL does generate a full spec compliant GraphQL API endpoint.
Hasura can be loosely compared because it generated an API off from a database schema where Slash GraphQL generates the API & graph database from asimplified GraphQL schema of types.
Update: Relay, from my limited understanding is a client side Javascript framework for React applications. It has requirements for a GraphQL API such as pagination, normalized mutation, and globally unique identifiers. Dgraph’s GraphQL API endpoint does all of these things. I am still unsure if you have to create a Node interface that is implemented by all types or if that is just recommended. Either way though, Dgraph’s Slash GraphQL can be used with Relay’s framework.
In my opinion though, Relay looks very complicated and doesn’t add much value in a tech stack that can’t be achieved easier with Apollo Client and graphql-codegen