mutation {
  updateAuthor(relativePath: "napolean.json", params: {name: "Napolean", avatar: "https://path.to/my-avatar.jpg"}) {
    name
    avatar
  }
}

{
  "data": {
    "updateAuthor": {
      "name": "Napolean",
      "avatar": "https://path.to/my-avatar.jpg"
    }
  }
}

mutation {
  updatePost(relativePath: "voteForPedro.json", params: {title: "Vote For Napolean Instead", category: "politics", author: "content/authors/napolean.json"}) {
    title
    category
    author {
      ... on Author {
        id
      }
    }
  }
}

{
  "data": {
    "updatePost": {
      "title": "Vote For Napolean Instead",
      "category": "politics",
      "author": {
        "id": "content/authors/napolean.json"
      }
    }
  }
}