The stored_fields parameter is about fields that are explicitly marked as stored in the mapping, which is off by default and generally not recommended. Use source filtering instead to select subsets of the original source document to be returned.

Allows to selectively load specific stored fields for each document represented by a search hit.

GET /_search
{
    "stored_fields" : ["user", "postDate"],
    "query" : {
        "term" : { "user" : "kimchy" }
    }
}

* can be used to load all stored fields from the document.

An empty array will cause only the _id and _type for each hit to be returned, for example:

GET /_search
{
    "stored_fields" : [],
    "query" : {
        "term" : { "user" : "kimchy" }
    }
}

If the requested fields are not stored (store mapping set to false), they will be ignored.

Stored field values fetched from the document itself are always returned as an array. On the contrary, metadata fields like _routing are never returned as an array.

Also only leaf fields can be returned via the field option. So object fields can’t be returned and such requests will fail.

Script fields can also be automatically detected and used as fields, so things like _source.obj1.field1 can be used, though not recommended, as obj1.field1 will work as well.

Disable stored fields entirely

To disable the stored fields (and metadata fields) entirely use: _none_:

GET /_search
{
    "stored_fields": "_none_",
    "query" : {
        "term" : { "user" : "kimchy" }
    }
}

_source and version parameters cannot be activated if _none_ is used.