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HTTPCaller - Dynamic Headers

  • January 5, 2026
  • 2 replies
  • 48 views

jeand
Contributor
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Hi,

In the headers section, it seems it’s mandatory to define the header parameter immediately.

Is there any way to push a Json or a FME attribute to define a dynamic header to use?

My issue is, the client API Rest has many methods with different header parameter. I’m trying to setup a custom transformer that will be able to handle dynamically the header to set. But it doesn’t seem possible to do it right now?

Any workaround to achieve it?

Regards,

Jean

 

 

2 replies

hkingsbury
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  • Celebrity
  • January 7, 2026

You can dynamically set a defined number of parameters by using attribute values
 

 

But I agree that you can’t set them ‘dynamically’.

I think this would be worth submitting an idea for - https://community.safe.com/ideas 

Something similar to how a schema feature contains a list of the schema. You could have a list that contains each of the headers - similar to how the Requests Module in Python works with a dictionary

headers = {
"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64)",
"Accept": "application/json",
"Accept-Language": "en-US,en;q=0.9",
"Connection": "keep-alive"
}



 


jeand
Contributor
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  • Author
  • Contributor
  • January 13, 2026

Hi ​@hkingsbury, exactly. That would be awesome to prepare all the headers in JSON format to use during the HTTPCaller.