Min Aggregation

More info about min aggregation is in the official elasticsearch docs

A single-value metrics aggregation that keeps track and returns the minimum value among numeric values extracted from the aggregated documents.

Simple example

{
    "aggregations" : {
        "min_price" : { "min" : { "field" : "price" } }
    }
}

And now the query via DSL:

$minAggregation = new MinAggregation('min_price', 'price');

$search = new Search();
$search->addAggregation($minAggregation);

$queryArray = $search->toArray();