ReverseDiffusion – ComfyUI API

Install

npm install npm run dev

Setup

1. Start ComfyUI portable with CORS enabled

From the root of your ComfyUI_windows_portable folder, run:

.\python_embeded\python.exe -s ComfyUI\main.py --windows-standalone-build --listen --enable-cors-header

This launches ComfyUI with:

• --windows-standalone-build for the portable Windows build
• --listen to expose the local server
• --enable-cors-header to allow requests from the browser

2. Add your workflows

Place your ComfyUI workflow JSON files in the /workflows folder of this project.

Example:

/workflows/my-workflow.json

3. Check the API URL

Default URL in api.js:

const COMFY_URL = "http://127.0.0.1:8188";

If ComfyUI is running on another port or address, update this value.

4. Workflow output

The workflow must output a Base64 string.

Run

Once ComfyUI is running and your workflow is in place:

npm run dev

Then open the local Vite app in your browser.

Notes

• ComfyUI must be started before the web app sends requests
• CORS must be enabled, otherwise browser requests will be blocked
• The workflow must output a Base64 string, not only save an image to disk
• The web app communicates with ComfyUI through its API at http://127.0.0.1:8188

---

Matthieu Minguet
ECAL
Mars 2026