I am trying to create an Envelope in DocuSign with multiple documents using the DocuSign REST API, I\'m using a multipart/form-data request, I use JSON to define the attribu
You shouldn't need these lines that define a second boundary (or any of the subsequent references to that second boundary):
Content-Disposition: form-data
Content-Type: multipart/mixed; boundary=e8bc9555e9634110bba63547b2552460
Try removing that (and all subsequent references to boundary e8bc9555e9634110bba63547b2552460), so that your request looks like this:
POST https://demo.docusign.net/restapi/v2/accounts/295724/envelopes HTTP/1.1
X-DocuSign-Authentication: {"Username":"email","Password":"password","IntegratorKey":"key"}
Content-Type: multipart/form-data; boundary=9a56da749dc04804819460f6499ab80b
Accept: application/json
Host: demo.docusign.net
Content-Length: 31476
Expect: 100-continue
--9a56da749dc04804819460f6499ab80b
Content-Type: application/json
Content-Disposition: form-data
JSON_REQUEST_BODY_HERE
--9a56da749dc04804819460f6499ab80b
Content-Type:application/pdf
Content-Disposition: file; filename="ABC.pdf"; documentid=1
DOCUMENT_1_BYTES_HERE
--9a56da749dc04804819460f6499ab80b
Content-Type:application/pdf
Content-Disposition: file; filename="AB.pdf"; documentid=2
DOCUMENT_2_BYTES_HERE
--9a56da749dc04804819460f6499ab80b--