Example output from https://github.com/konsumer/rawproto

demo.json

[
  {
    "1": {
      "type": "Buffer",
      "data": [
        1,
        2,
        3,
        4,
        5
      ]
    }
  },
  {
    "2": 1
  },
  {
    "3": "hello"
  },
  {
    "4": [
      {
        "1": 1
      },
      {
        "2": "cool"
      },
      {
        "3": [
          {
            "1": 1
          }
        ]
      }
    ]
  },
  {
    "4": [
      {
        "1": 2
      },
      {
        "2": "awesome"
      },
      {
        "3": [
          {
            "1": 2
          }
        ]
      }
    ]
  },
  {
    "4": [
      {
        "1": 3
      },
      {
        "2": "neat"
      },
      {
        "3": [
          {
            "1": 3
          }
        ]
      }
    ]
  }
]

demo.proto

syntax = "proto3";

MessageRoot {
  string field1 = 1; // could be a repeated-value, string, buffer, or malformed sub-message
  int32 field2 = 2; // could be a int32, int64, uint32, bool, enum, etc, or even a float of some kind
  string field3 = 3; // could be a repeated-value, string, buffer, or malformed sub-message

  Message4 {
    int32 field1 = 1; // could be a int32, int64, uint32, bool, enum, etc, or even a float of some kind
    string field2 = 2; // could be a repeated-value, string, buffer, or malformed sub-message

    Message3 {
      int32 field1 = 1; // could be a int32, int64, uint32, bool, enum, etc, or even a float of some kind
    }
    
    Message3 subMessage3 = 3;
  }
  
  repeated Message4 subMessage4 = 4;
}