Mepi Save Image

Where your image lands when you press go

Mepi Save Image is the end of the line in ComfyMepi, a small mobile frontend for ComfyUI by rhplus0831. It's the pack's terminal node - an output node with no outputs - and it does exactly what its description says: saves the input images to your ComfyUI output directory. In practice it's a near-copy of ComfyUI's built-in Save Image node, so if you've used that, you already know this one. The mobile UI just needs its own copy so it can point the workflow at a filename it controls.

What you set

Two inputs, both required:

• images (IMAGE) - the batch of images to save, typically straight out of VAE Decode.
• filename_prefix (STRING, default ComfyUI) - the prefix for saved files. The author's own tooltip spells out the fun part: it supports formatting tokens like %date:yyyy-MM-dd% to stamp the date, and even pulls values from other nodes via %Empty Latent Image.width%. So mepi_%date:yyyy-MM-dd% turns into mepi_2026-08-16_00001_.png.

Files land in ComfyUI/output/ as PNGs, with the subfolder/counter naming scheme core Save Image uses. No outputs to wire - it's a sink.

The part people don't notice: it embeds your workflow

Here's the mechanism worth caring about. When it saves, Mepi Save Image writes the full workflow JSON - the prompt plus any extra PNG info - into the PNG metadata. That's the same trick core ComfyUI uses, and it's why "workflow included" is a whole culture in this ecosystem: someone posts an image, you drag it into ComfyUI, and the entire graph reconstructs. Images saved by this node carry that metadata too, so a workflow you build around Mepi Save Image stays recoverable from the file itself.

That metadata disappears if you launch ComfyUI with the --disable-metadata flag - the node checks that flag and skips embedding. Fine if you want privacy, annoying if you later want to rebuild a workflow from an old output.

Install

No dependencies and nothing to download, like the rest of the pack. Via ComfyUI Manager: Install Custom Nodes → search "ComfyMepi". Or manually:

cd ComfyUI/custom_nodes
git clone https://github.com/rhplus0831/ComfyMepi

Restart ComfyUI. There's no requirements.txt; the node only uses ComfyUI's own PIL/numpy code paths.

Troubleshooting

• "Where did my image go?" Check ComfyUI/output/ (or wherever your output dir points), and look for your prefix plus a counter. If you used a %date% token, the folder may contain dated subfolders.
• "The saved file won't reconstruct my workflow." You either launched with --disable-metadata, or the image was re-saved somewhere that stripped the PNG info. Re-generate with metadata on.
• "Why use this over core Save Image?" You mostly shouldn't, unless the Mepi mobile UI is your driver. On desktop, the built-in node is identical and better supported. This one exists so the phone's workflow has a consistent save point.

The usual pack caveat applies: personal project, no community presence, light maintenance. But since it's a copy of a core node, the failure modes are the well-trodden ComfyUI ones, not novel surprises.