Sample requests:
{
  "id": 1,
  "get_buffer_request": {
    "line_range": {
      "screen_contents_only": true
    }
  }
}

{
  "id": 1,
  "get_prompt_request": {
  }
}

{
  "id": 1,
  "transaction_request": { "begin": true }
}

{
  "id": 1,
  "transaction_request": { "begin": false }
}

{
  "id": 1,
  "register_tool_request": {
    "identifier": "com.iterm2.mytool",
    "name": "Wikipedia",
    "url": "https://en.wikipedia.org/"
  }
}

{
  "id": 1,
  "set_profile_property_request": {
    "key": "Badge Color",
     "json_value": "{\"Red Component\": 1, \"Green Component\": 0, \"Blue Component\": 0, \"Alpha Component\": 1}"
  }
}

// Keystroke
{
  "id": 1,
  "notification_request": { "subscribe": true, "notification_type": 1 }
}

// Screen update
{
  "id": 1,
  "notification_request": { "subscribe": true, "notification_type": 2 }
}

// Prompt
{
  "id": 1,
  "notification_request": { "subscribe": true, "notification_type": 3 }
}

// Location change
{
  "id": 1,
  "notification_request": { "subscribe": true, "notification_type": 4 }
}