I was looking for JsonApi.org request and response format support in all of four actions (CRUD) while using restmod. I am seeing that "relationships" tag in json is not handled by response decoder and is placed as it is in resource object.

{
  "data": {
    "type": "articles",
    "id": "1",
    "attributes": {
    },
    "relationships": {
      // ... this is not being handled properly and left as it is in response
    }
  }
}