# ComfyUI WanVideo Save Merged Model

A ComfyUI custom node that saves a [WanVideo Wrapper](https://github.com/kijai/ComfyUI-WanVideoWrapper) diffusion model — including merged LoRAs — as a standalone `.safetensors` checkpoint.

This lets you bake LoRA weights into a base model once and reload the result directly, without re-merging every time.

## Installation

Clone or copy this repository into your ComfyUI `custom_nodes` directory:

```bash
cd ComfyUI/custom_nodes
git clone <repo-url> Comfyui_WW_msave
```

Restart ComfyUI. The node will appear under the **WanVideoWrapper** category.

## Node: WanVideo Save Merged Model

### Inputs

| Input | Type | Required | Description |
|-------|------|----------|-------------|
| `model` | `WANVIDEOMODEL` | Yes | Model output from the **WanVideo Model Loader** node (with LoRA merged) |
| `filename_prefix` | `STRING` | Yes | Filename for the saved file (default: `merged_wanvideo`) |
| `save_dtype` | Dropdown | No | Cast weights before saving: `same`, `bf16`, `fp16`, `fp32`. Defaults to `same` (keeps current dtype). Set explicitly if the model was loaded in fp8. |
| `custom_path` | `STRING` | No | Absolute path to a save directory. Leave empty to save in `ComfyUI/models/diffusion_models/` |

### Usage

1. Set up the **WanVideo Model Loader** with a base model and one or more LoRAs (with `merge_loras` enabled)
2. Connect the `model` output to **WanVideo Save Merged Model**
3. Set a filename prefix and optionally choose a dtype and save path
4. Queue the prompt — the merged checkpoint will be saved as `<filename_prefix>.safetensors`

```
[WanVideo Lora Select] --> lora
                             |
[WanVideo Model Loader] --> model --> [WanVideo Save Merged Model]
```

The saved file can then be loaded directly by the WanVideo Model Loader as a regular diffusion model, without needing the original LoRA files.

### Metadata

The saved `.safetensors` file includes metadata for traceability:

- `source_model` — name of the base model
- `merged_loras` — JSON list of merged LoRA names and strengths
- `save_dtype` — dtype used when saving

You can inspect this metadata with any safetensors viewer or with Python:

```python
from safetensors import safe_open
with safe_open("merged_wanvideo.safetensors", framework="pt") as f:
    print(f.metadata())
```

### Notes

- Existing files are never overwritten — a counter suffix (`_1`, `_2`, ...) is appended automatically
- The `custom_path` input only accepts absolute paths; relative paths are ignored and the default location is used
- Saving a 14B model in bf16 produces a ~28 GB file — make sure you have enough disk space
- If the model was quantized to fp8, use `save_dtype` to cast back to `bf16` or `fp16` for a more portable checkpoint

## Requirements

- [ComfyUI](https://github.com/comfyanonymous/ComfyUI)
- [ComfyUI-WanVideoWrapper](https://github.com/kijai/ComfyUI-WanVideoWrapper)

## License

MIT