GraphiQL

https://www.electronjs.org/apps/graphiql

Variables

mutation addPost($post: PostInput!, $user: UserInput!) {
  addPost(post:$post, user:$user) {
    id
    text
    user {
      username
      avatar
    }
  }
}

Query variables:

{
  "post": {
    "text": "You just added a post."
  },
  "user": {
    "avatar": "/uploads/avatar3.png",
    "username": "Fake User"
  }
}