> curl -X GET --dump - http://localhost:8529/_api/index?collection=115221776

HTTP/1.1 200 OK
content-type: application/json

{
  "code": 200,
  "indexes": [
    {
      "fields": [
        "_id"
      ],
      "id": "115221776/0",
      "type": "primary"
    }
  ],
  "error": false,
  "identifiers": {
    "115221776/0": {
      "fields": [
        "_id"
      ],
      "id": "115221776/0",
      "type": "primary"
    }
  }
}