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Responsive Resident
Responsive Resident

http authentication

My goal tonight was to get my REST calls that work with Postman and .NET console apps to work with Flow, as well.


I'm actually trying to do something i had hoped the Cognitive Services connection would provide, but it does not, yet: Text To Speech.


as i said, the url and three headers (including a Bearer token) work with Postman. but Postman alone isn't enough for me to actually use the media bytes the Bing Speech synthesis resource returens.


in spite of the fact that the same configuration in Postman returns 200 status code, Flow keeps returning 403 errors, usually indicative of not using a working token. I have another Postman call that gets my authentication token (expires every 10 minutes), and i confirm the token works in Postman before i try it in Flow.


I have tried to infer correct usage through reasoning over the various Flow errors and output. I ran out of options when i saw, "The required raw authentication property 'scheme' is missing." All the more obscure because up to that point, I had been working with the following feedback in the Flow editor after failing to run, but "'scheme'" is not in the json (oh, and you can only use either parameter or value, evidently):


"parameter": "*sanitized*",
"value": "*sanitized*",
"type": "Raw"


i've done my research here in Forum tonight, but I didn't see anything that actually helped any of us use HTTP with authentication. I saw a few posts from back in May warning us that we are on the bleeding edge and that we might be better off with Logic apps. I'm about to return to that fold, but thought I'd make one more appeal to the Flow team to give us a complete explanation of using HTTP actions, especially when Authentication is in play.

Community Support
Community Support

Hi Mcorning,

If you are refering to custom APIs, You can connect to any REST API that uses JSON and supports at least one of more than ten authentication methods by creating a Custom API.


The documentation regarding REST API is under Develop part of Flow Documentation:

Start to Build with Microsoft Flow

If I have any misunderstandings, please feel free to let me know.


Community Support Team _ Michael Shao
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

we all need a third option: when a thread is not affirmatively solved (i.e., when we cannot, in goof faith, mark a reply as a Solution), and when an alternative strategy unblocks us, we need to mark the thread with something like "Deferred" (so the product team can see what issues are not work stoppages, just work slowdowns). but we need something so Microsoft doesn't have to worry that a forum member is left in the lurch.


In this thread, for example, i seem to have worked around the blockage by not using HTTP actions when authentication is necessary. Instead, i use HTTP + Swagger. This "solution" requires a new set of skills for me (e.g., understanding swagger v2.0, using, and it requires understanding swagger endpoints (since i couldn't get the hang of that challenge, i now use my Azure Blobs for swagger storage and use the Azure endpoint in the HTTP + Swagger dialog when i add the Action).


Regardless, in its current state, the HTTP action is broken with respect to authentication for the reasons i note above.


Well mcorning,


Thanks for the feedback.

And glad to hear that currently you have a workaround.

I will help to collect this as an idea, and also a feedback for Microsoft Flow forum moderation.



Community Support Team _ Michael Shao
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

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