slate-doc.json

{
  "object": "value",
  "document": {
    "object": "document",
    "data": {},
    "nodes": [
      {
        "object": "block",
        "type": "heading-three",
        "isVoid": false,
        "data": {},
        "nodes": [
          {
            "object": "text",
            "leaves": [
              {
                "object": "leaf",
                "text": "I love college success!",
                "marks": []
              }
            ]
          }
        ]
      },
      {
        "object": "block",
        "type": "video",
        "isVoid": true,
        "data": {
          "originalUrl": "https://www.youtube.com/watch?v=c1c0a4fo1zo",
          "videoId": "c1c0a4fo1zo",
          "type": "youtube",
          "title": "My kitten video"
        },
        "nodes": [
          {
            "object": "text",
            "leaves": [
              {
                "object": "leaf",
                "text": "",
                "marks": []
              }
            ]
          }
        ]
      },
      {
        "object": "block",
        "type": "paragraph",
        "isVoid": false,
        "data": {},
        "nodes": [
          {
            "object": "text",
            "leaves": [
              {
                "object": "leaf",
                "text": "",
                "marks": []
              }
            ]
          }
        ]
      }
    ]
  }
}

Example of Slate.JS schema