curl copy of a mutation?

request

curl 'http://localhost:4000/graphql' -X POST -H 'Pragma: no-cache' -H 'Origin: http://localhost:4000' -H 'Accept-Encoding: gzip, deflate' -H 'Accept-Language: en-US,en;q=0.8' -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36' -H 'content-type: application/json' -H 'Accept: */*' -H 'Cache-Control: no-cache' -H 'Referer: http://localhost:4000/?' -H 'Connection: keep-alive' -H 'Content-Length: 280' --compressed

response

{
  "data": {
    "uploadFileByUrl": null
  },
  "errors": [
    {
      "message": "Unknown affix declaration: [object Object]",
      "locations": [
        {
          "line": 1,
          "column": 64
        }
      ]
    }
  ]
}