Markproof

Markproof for ComfyUI

Mark the images your workflows generate for the EU AI Act's Article 50, using Markproof: an invisible watermark plus signed C2PA Content Credentials, saved straight from ComfyUI.

Nodes

Markproof: Mark & Save (category Markproof)

Use it in place of Save Image. It marks each image and saves the marked PNG to your output folder, and outputs:

• images: the marked images, for previews or further nodes;
• watermark_codes and verify_urls: one per line, for example https://markproof.co/v/57CR5KMW.

Set generator_name (default ComfyUI) and model_name (for example your checkpoint) to record them in the C2PA manifest.

Why not Save Image? ComfyUI's Save Image re-encodes images, which strips the C2PA manifest. The watermark survives (it's in the pixels), but the signed Content Credentials don't. Mark & Save writes the exact file Markproof returns, so both layers stay intact.

Markproof: Verify Image

Checks images for a Markproof watermark and outputs all_marked (true or false), the codes, and a per-image summary. ComfyUI images carry pixels only, so it can't check C2PA metadata; drop the saved file into markproof.co/check for the full check.

Install

1. Install the node pack, either way:

   • ComfyUI-Manager: search for Markproof and click Install.
   • comfy-cli: comfy node install comfyui-markproof
   • Manually: cd ComfyUI/custom_nodes && git clone https://github.com/Ajinkya710/comfyui-markproof

   No extra Python packages are needed.

2. Create an API key on your Markproof dashboard (250 free calls a month).

3. Start ComfyUI with the key in the environment:

   MARKPROOF_API_KEY=lt_live_... python main.py
   

   On Windows (PowerShell): $env:MARKPROOF_API_KEY = "lt_live_..."; python main.py

The key is read from the environment on purpose. ComfyUI saves node settings into images and workflow files, so a key typed into a node would leak whenever you shared one.

Good to know

• Each image is one API call against your plan. Marking takes a few seconds per image.
• Images are processed in the EU and not stored by Markproof.
• If the console reports that a watermark may not survive heavy editing, the image was very smooth or featureless. It's still marked and signed; rely on the C2PA manifest for it.

Development

cd tests && python -m pytest   # runs against a local fake of the API