> curl --data @- -X POST --dump - http://localhost:8529/_api/graph/graph1/vertex
{"_key" : "v1", "optional1" : "val1", "optional2" : "val2"}

HTTP/1.1 201 Created
content-type: application/json; charset=utf-8
etag: 24332177

{
  "vertex": {
    "_id": "v/v1",
    "_rev": "24332177",
    "_key": "v1",
    "optional1": "val1",
    "optional2": "val2"
  },
  "error": false,
  "code": 201
}