HTTP POST Request

If HTTPGet is how ComfyUI reads the world, HTTP POST Request is how it writes back. POST is the "create something" method - submit a job, send a caption, upload a file, call an LLM's completion endpoint - and this node handles all four body styles you'll ever need: JSON, form-encoded, raw text, and multipart form data. It's the second half of any real automation workflow, and the only node in the pack that can carry a generated image out the door.

How it works

Two required inputs: url and content_type. The content_type choice decides which body input to fill:

• json (default) - type a JSON object into json_data; it's sent with Content-Type: application/json. The default for talking to REST APIs and LLM endpoints.
• form - json_data is sent as application/x-www-form-urlencoded. For classic web forms.
• raw - send raw_data as-is, for anything that isn't JSON, like a plain text body.
• form-data - multipart. This is where the form nodes come in: plug an HTTP_FORM_DATA object (from HTTP Form Data) into the form_data input, and any files/images it carries go out as multipart fields.

Optional inputs: session, auth, headers, cookies, timeout, verify_ssl, allow_redirects, proxy_url - the standard set, working exactly as they do on HTTPGet.

Four outputs: status_code, headers, content, json (the body, pretty-printed if it parses as JSON).

The combo that makes it special

HTTPPost is the only place an HTTP_FORM_DATA object plugs in, which means it's the terminal node of the upload pipeline:

[VAE Decode] → [HTTP Form Image Item] ─┐
                                        ├→ [HTTP Form Data] → [HTTPPost: form-data]
[prompt] → [HTTP Form Text Item] ───────┘

A rendered image plus its metadata, in one request, with no temp files. That's the workflow this pack exists for.

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 model downloads; plain requests.

Where people get burned

The #1 mistake is picking json and then typing invalid JSON into json_data - the node logs a warning and sends the raw string instead, which most APIs reject. Use HTTP Convert JSON's minify/format if you're unsure of your payload. Second: for form-data uploads, if the form_data input is empty the node falls back to sending json_data as a plain form body - so a disconnected form node silently produces a body with no file in it. And as always, a failed request returns status_code = 0 with the error in content rather than erroring - check it.