shell> curl -X POST --data-binary @- --dump - http://localhost:8529/_api/document?collection=products
{ "Hello": "World" }

HTTP/1.1 202 Accepted
content-type: application/json; charset=utf-8
etag: "1507172653"
location: /_db/_system/_api/document/products/1507172653

{ 
  "error" : false, 
  "_id" : "products/1507172653", 
  "_rev" : "1507172653", 
  "_key" : "1507172653" 
}