Provcheck Adds a C2PA Watermark Node for ComfyUI
Provcheck v1.4.0 brings an offline C2PA signing node to ComfyUI: neural watermarks for image and audio, plus Content Credentials bound to your Bluesky handle.
Provcheck verifies and produces C2PA Content Credentials fully offline, and v1.4.0 ships that pipeline as a ComfyUI node.
Sign your outputs without leaving the graph
Provcheck, an offline C2PA verifier and signing kit written in Rust, shipped its v1.4.0 release with a new ComfyUI node. Drop the node at the end of any workflow, after an image, audio or video generator, and it handles two things locally: it embeds an open neural watermark into the media (TrustMark for images, SilentCipher for audio), and it optionally attaches a C2PA Content Credentials signature bound to your public Bluesky/AT Protocol handle, so anyone can verify through a third party that the output came from you.
The node also has a Read mode: feed it any file and it decodes existing marks and reports whether a watermark survived export, compression, or a third-party edit. Everything runs offline with no accounts; detector weights download once per family only when you explicitly install it.
What ships in the open core
| Component | License | Notes |
|---|---|---|
| C2PA verifier + creator kit | Apache-2.0 | CLI + GUI for Windows, Linux, macOS |
| TrustMark / SilentCipher / AudioSeal / WavMark / SynthID-text detectors | Open | Six detector families across image, audio, video, text |
| Backfire keyed watermark | Source-available (opt-in) | Not bundled with the ComfyUI node |
Two honest caveats from the maintainer: the ComfyUI node only includes open detector families, and it is not a deepfake detector. Provcheck tells you whether a file carries a valid watermark and signature, not whether arbitrary unlabeled media is AI-generated.
Availability
The node source lives under Apps/comfyui-node in the provcheck repository, with example workflows included. The standalone verifier and signing kit ship as release binaries for Windows, Linux and macOS, or via cargo install provcheck-cli.
Comments
Sign in with GitHub to join the discussion.