The more like this (mlt) API allows to get documents that are “like” a specified document. Here is an example:
$ curl -XGET 'http://localhost:9200/twitter/tweet/1/_mlt?fields=tag,content&min_doc_freq=1'
The API simply results in executing a search request with moreLikeThis query (http parameters match the parameters to the more_like_this query). This means that the body of the request can optionally include all the request body options in the search API (facets, from/to and so on).
Rest parameters relating to search are also allowed, including search_type, search_indices, search_types, and search_scroll.
When no fields are specified, all the fields of the document will be used in the more_like_this query generated.