alert when finished

FastBlend passes and long video2video runs can take a while, and staring at a progress bar for ten minutes to catch the exact moment it finishes is a bad use of your time. alert when finished is a tripwire: drop it at the end of your graph, point it at a sound file, and it plays that sound the moment ComfyUI actually reaches it. It doesn't touch your images at all - it's a pure side-effect node, added by the author alongside FastBlend specifically for this pack's long-running video jobs.

How it works

It's about as simple as custom nodes get. The node takes an image input purely as a trigger - something has to flow into it before ComfyUI will execute it - and a path to a sound file. When execution hits this node, it plays that sound. There's nothing downstream to wire, because there's nothing to pass on: it's marked as an output node, meaning it's meant to sit at the end of a branch, not the middle.

The inputs and outputs that matter

Just two inputs, no outputs:

• images (IMAGE) - your final output. This is what makes the node fire; it doesn't modify these images, so this can be your last Save Image's input duplicated into this node, or you can chain it before the save.
• sound_path (STRING, default "sound_path") - the full filesystem path to a sound file to play. That default value is a placeholder, not a working path - you're meant to replace it. The pack ships an example: drop.wav, sitting in the pack's own folder, and the README's own example format is a full absolute path like ...\...\custom_nodes\ComfyUI-fastblend\drop.wav.

No outputs at all - this is a dead end by design, is_output_node: true.

How to install it

Same pack as everything else here. Via ComfyUI Manager: search "ComfyUI-fastblend," install, restart. Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/AInseven/ComfyUI-fastblend

Restart ComfyUI. The example drop.wav file comes with the repo, so you don't need to source your own sound to try it - just point sound_path at wherever it landed on your disk.

Common issues & troubleshooting

No sound plays, no error either. Almost always a bad sound_path. The default string isn't a real path, and a relative path (just drop.wav) generally won't resolve - use the full absolute path to the file, exactly like the README's own example.

It works on your desktop but does nothing when ComfyUI runs elsewhere. This is the one to actually understand: the sound plays on the machine running the ComfyUI Python process, not in your browser. If you're running ComfyUI on a remote box, a cloud GPU, or any headless/serverless setup, the audio plays on hardware you're not sitting in front of - there's no speaker to hear it from. This node is built for the classic "ComfyUI running on your own desktop, you've tabbed away to do something else" case; it's not a notification system for a remote server.

Wrong file format. The README only confirms .wav via its own example. If you swap in another format and get silence or an error, go back to .wav first before troubleshooting anything else.