API – error 400Solved

Participant
Discussion
2 days ago Jan 14, 2026

Hi everyone,
I’m trying to call a Hexnode API endpoint using the HTTP action in Power Automate, but I keep getting an Error 400.

The request is definitely reaching the server, but something seems off. I’ve worked with APIs before, so I’m assuming it’s a formatting issue on my end. Has anyone run into this?

Replies (2)

Marked SolutionPending Review
Participant
2 days ago Jan 14, 2026
Marked SolutionPending Review

I have seen that before I think.
Usually when I get a 400 it’s like… something’s off in the request but it’s not super obvious. Maybe headers? Or like the JSON body being picky? I’d double-check the method too, just in case.

Marked SolutionPending Review
Hexnode Expert
2 days ago Jan 14, 2026
Marked SolutionPending Review

Hi @jayceon,

The Error 400 (Bad Request) indicates that the Hexnode server received the request, but the syntax or data in the request is invalid.

Based on the API documentation, please verify the following common causes:

  • Missing or Incorrect Headers
    Ensure the header Authorization: is included exactly as required.
  • Content-Type Header
    Confirm that Content-Type: application/json is present in the Headers section.
  • JSON Body Syntax
    Check for trailing commas, missing quotes, or malformed JSON. Power Automate is very sensitive to JSON formatting.
    Also ensure any dynamic content (variables) passed into the body does not contain special characters that could break the JSON string.
  • Correct HTTP Method
    Verify that you are using the appropriate method (GET, POST, PUT, etc.) for the endpoint.
  • URL Formatting
    Make sure the URL does not contain accidental double slashes (for example: …/api/v1//devices/).

Reviewing these items typically resolves most 400 errors in Power Automate. Please let us know if you have any further questions or require clarification.

Regards,
Sienna Carter
Hexnode UEM

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