How to send a multipart form-data request in webMethods using pub.mime?

Product: webMethods . io Integration version:

Question: How to send a multipart form-data request in webMethods HTTP Request (pub.client:http).

For instance, in Python this can be done like this

import requests
url = '
headers = {
    'Authorization': 'Bearer 12345'
files = {
    'file': ('TEST.csv', open(r'C:\Users\ME\Desktop\TEST.csv', 'rb')),
    'FileName': 'TEST'
response =, headers=headers, files=files)

In Postman it can be done by selecting “form-data” as the payload type and entering the key “file” with a value of the uploaded CSV file and another key “FileName” with a value of the name of the file.

I have followed the other answers (i.e. How to send a mimestream using pub.client:http - #6 by Martin_Gawantka) but they do not specify how to attach the “file” and “FileName” expected keys with respective values. Same issues on cloud and webMethods on-prem. I understand we must use pub.mime to complete this but I would like to know more about adding the headers.

1 Like

Hi @GMook ,
I have created the sample to handle the mime data on Integration.
Created the flow service how you can submit the mime data using Http request.
For testing purpose I am using azure storage to get the stream data and.

Attaching the sample for same. (10.7 KB)

Let me know if this helps.

Vikash Sharma

1 Like

Thanks for the reply,

Unfortunately, the sample Service provided titled SubmitCSVMimeData used a “Content-Type” header of “multipart/form-data”. However, the way we built out the integration in the call it does not accept that giving a error message of

MIME part of type “multipart/form-data” contains object of type instead of MimeMultipart

When trying to use Content-Type of text/csv the endpoint gives a status code of 415 for Unsupported Media Type. The Content-Type of application/json gives status code of 400 for Bad Request.

For the “Content-Disposition ” header I was told to do form-data; name=“file”; filename=“CSVDataSample.csv”. However, I do not exactly see how that matches the required key-value headers of the key “file” having a value of the actual file contents and then the key “FileName” having the name of the file itself.

The documentation from SoftwareAG on MIME messages does not cover this use case provided by the Postman Proof Of Concept attached above in the original message.

Look forward for more information to hopefully get this resolved asap.

Thank you,

hi @GMook ,
Can you please share the service you are trying .
We can look into it.

Vikash Sharma

hi @GMook,
We resolved the issue by using the workflow.

Vikash Sharma


hi Garret/Vikash,

Hope you are doing good . I am also facing the similar issue in and my requirement is to send to CSV data through HTPP post. Let me know if you have found the solution

If i set the Content-Type field in mimeHeader as text/csv the endpoint gives a status code of 415 for Unsupported and If i set the content-type in mimeHeader as multipart/form-data the below error is received
error received : MIME part of type “multipart/form-data” contains object of type instead of MimeMultipart.

Pls note that , the implementation is done as below

  • Initialize the mime header
  • Mime CreateMimeData
  • Convert the CSV string into stream through StringToStream service
  • Mime AddBodyPart
  • MIme GetEnvelopStream


hi @Sunil_Salian ,
Can you please refer to this article for same.

Let me know if you face any difficulty.

Vikash Sharma

hi Vikash,

I have referred the approach and still facing the issue . So planning to write the csv file into directory (home/sagadmin/flow/user_data) workflow and do the HTTP post instead of mime approach . So could you please let me is there any file size limitation if we write the file into home/sagadmin/flow/user_data?


Hi Sunil,
I am not sure why it is not working.
Anyways when you are submitting the request from flow service to workflow.
In the workflow we can submit max up to 10 mb data.

Vikash Sharma