discourse/spec/requests/api/schemas/json/user_update_avatar_request.json

{
  "additionalProperties": false,
  "properties": {
    "upload_id": {
      "type": "integer"
    },
    "type": {
      "type": "string",
      "enum": [
        "uploaded",
        "custom",
        "gravatar",
        "system"
      ]
    }
  },
  "required": [
    "upload_id",
    "type"
  ]
}