Hi,
I am trying to use HTTP action in Power Automate to post a file to a third party API. The request can be successfully proceeded if it is sent via Postman. And the captured request looks like this.
In Power Automate, I used below JSON to build the same.
However, the request cannot be proceeded by the target API as it returns 400 bad request. Checked with the vendor and they do not have much clue on what is the issue. Therefore, I have used the same webhook to capture the HTTP request sent via Power Automate, which looks like below.
I actually do not see too much differences of the two requests (Postman / Power Automate) except the "boundary" generated in Power Automate is quoted. And I am wondering if this is the cause of API processing failure.
So my questions:
1) Does anyone know if this boundary thing will cause issues?
2) How can we specify the boundary value in Power Automate manually, instead of letting the HTTP action generate it?
Thanks in advance!
Hello Khaos C, I am facing the same issue. Have you found a solution for this?
Thanks for posting this! You answered part of my own question in your screenshot.
Sometimes file encoding can cause problems with these APIs. I see yours says "Output" which I assume is Text and not a File? I was researching the Power BI API and dealing with the File was painful. I wrote a working example here:
stampcoin
14
Churchy
12
rzaneti
10
Super User 2025 Season 1