HTTP GET Request Incorrectly Sends Body, Causing 422 Error with Fal.ai

Questions
1

Hi everyone,

I’m having a persistent issue with an HTTP Request node and would appreciate any help you can offer.

My Goal: I’m building a workflow to use an asynchronous image generation API from Fal.ai. The process is:

  1. An HTTP Request (POST) node starts a job. This works perfectly and returns a response_url.

  2. After a “Wait” node, a second HTTP Request (GET) node uses the response_url to fetch the final image file.

The Problem: The second GET request consistently fails with a 422 Unprocessable Entity error. The error message from the server is: Input should be a valid dictionary or object to extract fields from.

The detailed error response shows that my GET request is being sent with a JSON body (containing the data from the previous node), which is invalid for a GET request and is causing the server to reject it.

The Core Issue: The problem is that the GET request is sending a body, even though I have configured it not to. The node’s settings in my editor and the actual request being made do not match.

What I’ve Tried: I have spent a lot of time debugging this and have tried every possible solution I can think of, including:

  • Ensuring the Method is GET.

  • Setting Send Body to OFF.

  • Setting Response Format to File.

  • Deleting and completely recreating the node from scratch to avoid any stuck/cached settings.

  • Saving the workflow and running the active version in a new incognito window after every change.

  • As an unconventional test, I even tried setting Send Body to ON and sending an empty JSON body ({}). The server still received the full data payload from the previous node, not the empty body.

No matter what I do, the server’s response proves that a body is always being sent.

My Environment:

  • n8n Version: 1.111.1 (Self Hosted)

Has anyone encountered this behavior before? I have confirmed my node’s settings are correct, but the execution engine seems to be ignoring them. Could this be a bug in this specific n8n version, or is there something else in a self-hosted environment I should be checking?

Thank you for your help!

2

Hey @Sifat_Oni hope all is good. Would you like to share your workflow?

This way we can look at the requests you send and think of the reason they may fail.

3

Yep ive been experencing this - its funny because i get this same error yet fal is charging me and generating random videos within my dashboard. im currently looking for an alternative - They dont even have a discord or customer support aside from email. Total scam

4

I get the same 422 error when trying to get the result back from Kling Video-to-Audio api. Post and status check work while Get the result fails with this 422 error and no details. This was reported previously but no solution was offered. The issue was just closed.

It’s not JSON body being sent as HTTP request works fine with other APIs but only fails with particular ones. It must be on the API provider’s side.