---
tags:
- flux
- quantization
- modelopt
- fp8
- nvfp4
- int8
license: apache-2.0
---

# Quantized FLUX.2 Klein 4B Transformer (ModelOpt)

This repo stores NVIDIA Model Optimizer checkpoints for FLUX.2 Klein 4B transformer quantization variants.

## Contents

- `fp8/transformer_modelopt.pt`
- `fp8/transformer_modelopt_meta.json`
- `w8a8/transformer_modelopt.pt`
- `w8a8/transformer_modelopt_meta.json`
- `nvfp4/transformer_modelopt.pt`
- `nvfp4/transformer_modelopt_meta.json`

## Restore into pipeline

```python
import modelopt.torch.opt as mto
from klein_pipeline import Flux2KleinPipeline
import torch

pipe = Flux2KleinPipeline.from_pretrained(
    "black-forest-labs/FLUX.2-klein-4B", torch_dtype=torch.bfloat16
).to("cuda")

ckpt = "fp8/transformer_modelopt.pt"  # or w8a8 / nvfp4
mto.restore(pipe.transformer, ckpt)
pipe.transformer.eval()
```

Uploaded from Modal volume `klein4B-assets`.