HTTP Form File Item

Multipart forms often need a file sitting somewhere on disk - a document, a config, an audio clip - alongside their text fields. HTTP Form File Item is the node that picks that file up and turns it into one item of a multipart body. It's the disk-based cousin of HTTP Form Image Item, and the two cover the "send actual bytes" half of form building.

How it works

Two required inputs:

• name - the form field name (defaults to file).
• file_path - the absolute path to the file you want to attach.

And two optional inputs that do most of the convenience work:

• filename - leave it blank and it's taken from the end of file_path automatically.
• content_type - leave it blank and it's auto-detected from the file extension. The mapping covers the usual suspects: text, json, xml, pdf, jpg/png/gif/bmp/webp, mp4/avi, mp3/wav. Anything unknown falls back to application/octet-stream.

One output: form_item (HTTP_FORM_ITEM), which plugs into an HTTP Form Data slot. When the form is sent, the file is read and included in the files part of the multipart body under its name.

The right workflow

[HTTP Form File Item] ─┐
                        ├→ [HTTP Form Data] → [HTTP Post: form-data]
[HTTP Form Text Item] ──┘

The file path matters here - it's whatever path your OS sees, not a ComfyUI input. /path/to/file.txt in the default is a placeholder; put in something real or the upload will quietly fail.

Install

ComfyUI Manager → search "ComfyUI-HTTP" → Install, restart. Manual:

cd ComfyUI/custom_nodes/
git clone https://github.com/wawahuy/ComfyUI-HTTP.git
cd ComfyUI-HTTP
pip install -r requirements.txt

No models, no extra dependencies.

Where people get burned

The big one: a missing or mistyped file_path doesn't error the workflow. The form container catches the read failure and stuffs a File not found: <path> string into the text-data part of the form, and the API receives a text field where it expected a file - usually a confusing 400 or 422. Check paths before you run. Second: while HTTP File Upload (the standalone node) sends one file and some additional_data, this node is the one to use when the file is one of several fields in a bigger form - if your endpoint takes a file plus multiple text fields, go this route.