[Feature Request] Support per-part Content-Type in HTTP Request node multipart/form-data

Feature Requests Nodes
,
1

It would help if there was a node for:

Enhancement to the existing HTTP Request node to support specifying Content-Type for individual parts in multipart/form-data requests.

My use case:

I need to send a multipart/form-data request with both a file and JSON data, where the JSON part requires an explicit Content-Type: application/json header. Currently, the HTTP Request node doesn’t provide a way to set Content-Type for individual form parts.

Current behavior:
When using the HTTP Request node with multipart/form-data, the generated request looks like:
------WebKitFormBoundary…
Content-Disposition: form-data; name=“request”

{“baseTextMatch”:{},“options”:{}}
------WebKitFormBoundary…
Content-Disposition: form-data; name=“image”; filename=“file.jpg”
Content-Type: image/jpeg

[binary data]

Expected behavior:
Some APIs require explicit Content-Type for non-file parts:
------WebKitFormBoundary…
Content-Disposition: form-data; name=“request”
Content-Type: application/json ← This is needed!

{“baseTextMatch”:{},“options”:{}}
------WebKitFormBoundary…
Content-Disposition: form-data; name=“image”; filename=“file.jpg”
Content-Type: image/jpeg

[binary data]

Proposed solution:
Add an optional Content-Type field for each Body Parameter in the HTTP Request node:

Body Parameters:
Parameter 1:

  • Name: request
  • Value: {“baseTextMatch”:{},“options”:{}}
  • Content-Type: application/json ← New optional field
Parameter 2:
  - Type: Binary Data
  - Name: image
  - Input Data Field Name: data
  - Content-Type: image/jpeg  ← Already inferred, but make it configurable

Current workaround:
I had to use a Code node to manually construct the multipart/form-data body with correct Content-Type headers for each part, which
defeats the purpose of having a user-friendly HTTP Request node.

Real-world example:
This is required when integrating with APIs that strictly validate multipart Content-Type headers, such as:

  • Document processing APIs (OCR, PDF conversion)
  • File upload APIs that also accept metadata as JSON
  • APIs following strict OpenAPI/Swagger specifications

Any resources to support this?

  • cURL equivalent (which works):
curl --location 'https://api.example.com/upload' \
  --header 'Authorization: Bearer token' \
  --form 'metadata="{\"key\":\"value\"}";type=application/json' \
  --form 'file=@"/path/to/file.jpg"'
Note the ;type=application/json part in the metadata field.

- Postman supports this via the "Content Type" dropdown for each form-data parameter
- RFC 7578 (Multipart/Form-Data): https://datatracker.ietf.org/doc/html/rfc7578#section-4.4
  - Section 4.4 states: "Each part MAY have an (optional) "Content-Type" header field"

Are you willing to work on this?

I’m willing to contribute if guidance is provided on:

  1. Where in the codebase the HTTP Request node multipart body generation happens
  2. How to extend the parameter schema to include optional Content-Type field
  3. Testing requirements for this feature