I’ve managed to implemented it

It’s open source here: https://github.com/sibelius/relay-modern-network-deep-dive

There is also a medium post about it: https://medium.com/@sibelius/relay-modern-network-deep-dive-ec187629dfd3

now we need to improve Relay official docs

I think we can provide an example of fetch for network using Observable, and explain that this is needed to make poll work

this was a breaking change on this on v2

can we close this?

Hi @Angry-Potato This is a simplified example of my relay environment:

import { graphql } from "graphql";
import { Environment, Network, RecordSource, Store, Observable } from "relay-runtime";
import Schema from "./Schema";

function createFetch(schema) {
  return function fetch(operation) {
    return new Observable(sink => {
      graphql(
        schema,
        operation.text,
      ).then((payload) => {
        if (payload.errors) {
          /* Handle errors */
          sink.error(payload.errors);
        } else {
          /* Handle payload */
          sink.next(payload);
          sink.complete();
        }
      });
    });
  }
}

function createEnvironment() {
  return new Environment({
    network: Network.create(createFetch(Schema)),
    store: new Store(new RecordSource()),
  });
}