Adding Multiple Documents with Meta Data

We are trying to add multiple documents with Meta Data to the REST API in a single call. We are able to add a single document with meta data using a call like

POST /api/packages/CexKAcIADCrhmET2TheZdEtnnQA=/documents/ HTTP/1.1
Host: sandbox.esignlive.com
Authorization: Basic XXXXXXXXXXXXXXXXXXXXX
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW
Cache-Control: no-cache

------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="payload"

 {
    "description": "A test document 1.",
    "name": "45-Sold Notice.pdf"
  }
------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="file"; filename="3-Sold Notice.pdf"
Content-Type: application/pdf

We are able to add multiple files using a call like

POST /api/packages/CexKAcIADCrhmET2TheZdEtnnQA=/documents/ HTTP/1.1
Host: sandbox.esignlive.com
Authorization: Basic XXXXXXXXXXXXXXXXXXXXXXX
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW

------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="files[]"; filename="3-Sold Notice.pdf"
Content-Type: application/pdf

------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="files[]"; filename="9-Bill Of Sale.pdf"
Content-Type: application/pdf

------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="files[]"; filename="24-Power of Attorney.pdf"
Content-Type: application/pdf

------WebKitFormBoundary7MA4YWxkTrZu0gW--

What we cannot seem to do is add multiple documents to a package in one call. changing the payload to be an array results in an error payload

 {"documents" : [{
    "description": "A test document 1.",
    "name": "45-Sold Notice.pdf"
  }, {
    "description": "A test document 1.",
    "name": "46-Sold Notice.pdf"
  }, {
    "description": "A test document 1.",
    "name": "47-Sold Notice.pdf"
  }
]}

response

{
    "messageKey": "error.validation.addDocument.documentNameEmpty",
    "message": "Document name cannot be empty.",
    "code": 400,
    "name": "Validation Error"
}

we have tried multiple other ways, none with any success.