Add additional attributes to an existing document elasticsearch

I think it is possible with the update api. Check this :

https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-update.html#_update_part_of_a_document

and scroll down to "add a new field to the document".

Regards

I know this is an old post but i think it can be handy

POST /twitter/tweet/1/_update
{
  "doc": {
    "new_attribute":""
  }
}