cities.json

{
  "Nicosia": {
    "__typename": "City",
    "name": "Nicosia"
  }
}

cms.graphql

scalar DateTime

type CityTranslation {
  language: String!
  name: String
}

type City @GQLifyModel(dataSource: "firestore", key: "cities") {
  name: String! @unique @ID
  timezone: String!
  translation: [CityTranslation]
  events: [Event]
}

type Tag @GQLifyModel(dataSource: "firestore", key: "tags") {
  name: String! @unique @ID
  emoji: String
  events: [Event]
}

type EventThumbnail {
  url: String
}

type Event @GQLifyModel(dataSource: "firestore", key: "events") {
  title: String!
  description: String!
  location: String!
  address: String!
  dateStart: DateTime!
  dateEnd: DateTime
  url: String! @unique
  translated: Boolean
  ready: Boolean
  loaded: Boolean
  tags: [Tag!]
  city: City
  thumbnail: EventThumbnail
  contact: String
}

event.json

{
  "__typename": "Event",
  "address": "address",
  "city": "Nicosia",
  "dateEnd": "",
  "dateStart": "",
  "description": "test",
  "language": "",
  "loaded": false,
  "location": "location",
  "ready": false,
  "source": "",
  "tags": {
    "AErGsXIuh2z4Pux0RX2e": true,
    "XGtMxNrR8iCPGRPsDMv3": true,
  }
}

query-response.json

{
  "data": {
    "events": [
      {
        "title": "title",
        "tags": [],
        "city": null
      }
    ]
  }
}

query.graphql

# Write your query or mutation here
query {
  events {
    title
    tags {
      name
    }
    city {
      name
    }
  }
}

tags.json

{
  "AErGsXIuh2z4Pux0RX2e": {
    "__typename": "Tag",
    "name": "music"
  },
  "XGtMxNrR8iCPGRPsDMv3": {
    "__typename": "Tag",
    "name": "kids"
  }
}

I'm missing the resolved relations in https://gist.github.com/valentinalexeev/9d98076d2903b2a09b84ee0fef1493af#file-query-response-json-L6-L7