web
You’re offline. This is a read only version of the page.
close
Skip to main content

Notifications

Announcements

Community site session details

Community site session details

Session Id :
Power Platform Community / Forums / Power Automate / Invoke Web Service Act...
Power Automate
Unanswered

Invoke Web Service Action Issue: Multiple Headers

(2) ShareShare
ReportReport
Posted on by 139

Hello,

We can successfully use the Invoke Web Service action when an API requires only one item in the Custom headers field (like "Authorization"), but when two items are required, the connection attempt fails due to an "invalid credentials" error.  Using the same header items, the connection is successful in the Postman app so we feel they are correct.   

 

We feel that Power Automate Desktop may be incorrectly formatting the header values when it sends the request or we are incorrectly formatting them in the Custom headers field.  To add to this concern, one of the headers requires a space in its value ("Authorization: Bearer [KEY]"):

 

drake_1-1623276047918.png

 

The credentials have to be base 64 encoded, so using the HTTP Authentication section does not appear to be an option:

 

drake_0-1623275945137.png

 

We have no way to viewing the request that is actually being sent out by Power Automate Desktop (I don't believe this is possible to see from within the app), but again the request works fine from Postman.  We have attempted using commas, semicolons, newlines, etc. to delimit the two header lines.  We have also attempted to include the header string in a variable and then reference the variable from the Custom headers field.  Unfortunately, nothing has worked so far.

 

Is anyone aware of how to view a request, how to format the text in the Custom headers field when there are more than one header and a space in value, or any other idea for how to resolve this issue?  Thanks!

I have the same question (0)
  • richgunk Profile Picture
    9 on at

    Did you ever get this to work? 

    With our old automation app we had to prepend the base 64 string with "basic ".  I'm still troubleshooting our issue but I believe it is a server authentication issue.

     

  • yoko2020 Profile Picture
    495 on at

    @drake 


    @drake wrote:

     

    Is anyone aware of how to view a request, how to format the text in the Custom headers field when there are more than one header and a space in value, or any other idea for how to resolve this issue?  Thanks!

     

    Use Fiddler https://www.telerik.com/fiddler/fiddler-classic


     

  • richgunk Profile Picture
    9 on at

    Add an & sign between items.  If you have a sniffer/WireShark you can see exactly what is being sent.

  • drake Profile Picture
    139 on at

    @yoko2020 Check the body text in an app like NotePad++, with "View All Characters" turned on.  There is a chance there is character in the string causing this, that is not visible in "regular" mode.  Remove all extraneous characters (e.g. linefeed).

  • drake Profile Picture
    139 on at

    @yoko2020  Also, replace semicolons with a newline character for new lines.

  • yoko2020 Profile Picture
    495 on at

    @drake 

    I am answering your question, not asking a question. 🤔

  • Community Power Platform Member Profile Picture
    on at

    Hi is this issue got solved ? i am facing the same issue 

     

  • Suggested answer
    WhiteHat Profile Picture
    25 on at
    separate multiple custom headers with a space character
     
    example:
    Authorization:Basic %HTTPAuthorization% dispatcherGUID:%DispatcherGUID%
     

Under review

Thank you for your reply! To ensure a great experience for everyone, your content is awaiting approval by our Community Managers. Please check back later.

Helpful resources

Quick Links

Forum hierarchy changes are complete!

In our never-ending quest to improve we are simplifying the forum hierarchy…

Ajay Kumar Gannamaneni – Community Spotlight

We are honored to recognize Ajay Kumar Gannamaneni as our Community Spotlight for December…

Leaderboard > Power Automate

#1
Michael E. Gernaey Profile Picture

Michael E. Gernaey 538 Super User 2025 Season 2

#2
Tomac Profile Picture

Tomac 405 Moderator

#3
abm abm Profile Picture

abm abm 252 Most Valuable Professional

Last 30 days Overall leaderboard