You can use Apollo GraphQL https://www.apollographql.com/ on the front-end(Apollo Client). Not sure about your server implementation. You are using sockets, that is used only with subscriptions in GraphQL context and you are using it for several things. You have to move all that logic to Dgraph Schema model (and in the end, you won’t need a node.js server). That requires a deeper look, you might end up needing some lambda or something.
You should start here https://dgraph.io/docs/graphql/overview/ and then you can go to Slash.