---
license: apache-2.0
library_name: custom
base_model: robbyant/lingbot-va-posttrain-robotwin
datasets:
- robbyant/robotwin-clean-and-aug-lerobot
pipeline_tag: robotics
language:
- en
tags:
- robotics
- embodied-ai
- world-action-model
- world-model
- diffusion
- step-distillation
- lingbot-va
- robotwin
- arxiv:2606.05254
---

# Flash-WAM RoboTwin: Distilled World-Action Model

[Project page](https://flashwam.github.io/) ·
[Paper](https://arxiv.org/abs/2606.05254) ·
[Code](https://github.com/NU-World-Model-Embodied-AI/Flash-WAM) ·
[LingBot-VA](https://github.com/Robbyant/lingbot-va)

This repository contains the complete RoboTwin checkpoint for **Flash-WAM:
Modality-Aware Distillation for World Action Models**. Flash-WAM distills the
joint video and action streams of LingBot-VA with consistency functions matched
to their different noise regimes.

The released student supports one-step video and one-step action generation.
Under the paper's RoboTwin 2.0 setup on a single NVIDIA L40S, this reduces
per-chunk latency from **8.1 seconds to 348 milliseconds**, a **23.3× speedup**.

> **Important:** this is a custom joint video-action robotics model, not a
> generic text-to-image or video `DiffusionPipeline`. Do not use
> `DiffusionPipeline.from_pretrained(...)`. Install the Flash-WAM/LingBot-VA
> code and use their RoboTwin server/client evaluation path.

## Model details

| Field | Value |
| --- | --- |
| Base model | [LingBot-VA RoboTwin post-training checkpoint](https://huggingface.co/robbyant/lingbot-va-posttrain-robotwin) |
| Task | Joint future-video and robot-action prediction |
| Benchmark | RoboTwin 2.0 |
| Released student | 1 video step / 1 action step |
| Action dimension | 30 in the released transformer config |
| Reported latency hardware | 1 × NVIDIA L40S |
| Checkpoint license | Apache-2.0 |

## Repository contents

| Directory | Description |
| --- | --- |
| `transformer/` | Distilled Flash-WAM student, approximately 10 GB |
| `vae/` | VAE inherited from the LingBot-VA teacher, approximately 2.8 GB |
| `text_encoder/` | UMT5-XXL text encoder, approximately 11.3 GB |
| `tokenizer/` | T5 tokenizer files |

The full snapshot is approximately 24 GB.

## Download

```bash
pip install -U huggingface_hub

hf download NU-World-Model-Embodied-AI/FlashWAM-RoboTwin \
  --local-dir ./FlashWAM-RoboTwin
```

To inspect configs without downloading the weights:

```bash
hf download NU-World-Model-Embodied-AI/FlashWAM-RoboTwin \
  README.md \
  transformer/config.json vae/config.json text_encoder/config.json \
  tokenizer/tokenizer_config.json \
  --local-dir ./FlashWAM-RoboTwin-config
```

## Environment and evaluation

Flash-WAM uses the LingBot-VA environment and the same RoboTwin server/client
evaluation pipeline:

1. Follow the [LingBot-VA installation and RoboTwin evaluation
   instructions](https://github.com/Robbyant/lingbot-va).
2. Clone the [Flash-WAM repository](https://github.com/NU-World-Model-Embodied-AI/Flash-WAM)
   so the custom `wan_va` model implementation is available.
3. Download this snapshot and set the model path in the LingBot-VA/Flash-WAM
   evaluation configuration to the local snapshot directory.
4. For training or distillation, use the released commands in the Flash-WAM
   repository; this checkpoint is the already-distilled student.

The public Flash-WAM repository does not yet include the real-world Unitree G1
deployment setup. Do not infer a supported real-robot deployment command from
the checkpoint layout alone.

## Optional component-loading check

After installing the LingBot-VA environment and making the Flash-WAM repository
available on `PYTHONPATH`, the released helper functions can load the individual
components:

```python
from pathlib import Path
import torch

from wan_va.modules.utils import (
    load_text_encoder,
    load_tokenizer,
    load_transformer,
    load_vae,
)

root = Path("/path/to/FlashWAM-RoboTwin")
device = "cuda"
dtype = torch.bfloat16

tokenizer = load_tokenizer(root / "tokenizer")
text_encoder = load_text_encoder(root / "text_encoder", dtype, device)
vae = load_vae(root / "vae", dtype, device)
transformer = load_transformer(root / "transformer", dtype, device)
```

This verifies component compatibility; it is not a complete policy rollout.
Use the upstream server/client evaluation path for observations, action
normalization, temporal caching, and environment interaction.

## Reported results

### RoboTwin 2.0

| Method | Video steps | Action steps | Average success | Speedup |
| --- | ---: | ---: | ---: | ---: |
| LingBot-VA teacher | 25 | 50 | 91.25% | 1.0× |
| Naive joint LCM | 1 | 2 | 23.97% | — |
| **Flash-WAM** | **1** | **2** | **85.54%** | **19.0×** |
| Naive joint LCM | 1 | 1 | 36.32% | — |
| **Flash-WAM** | **1** | **1** | **81.41%** | **23.3×** |

### LIBERO

| Method | Video steps | Action steps | Average success | Speedup |
| --- | ---: | ---: | ---: | ---: |
| LingBot-VA teacher | 20 | 50 | 98.6% | 1.0× |
| **Flash-WAM** | **1** | **2** | **95.7%** | **13.7×** |
| **Flash-WAM** | **1** | **1** | **95.1%** | **16.3×** |

### Real-world Unitree G1

Three manipulation tasks were evaluated with 10 rollouts per task:

| Method | Video/action steps | T1 | T2 | T3 | Average |
| --- | ---: | ---: | ---: | ---: | ---: |
| LingBot-VA | 3 / 10 | 50% | 70% | 80% | 66.7% |
| **Flash-WAM** | **1 / 2** | **50%** | **60%** | **70%** | **60.0%** |
| **Flash-WAM** | **1 / 1** | **40%** | **50%** | **60%** | **50.0%** |

The fastest 1-video/1-action-step configuration and the 60% real-world result
are **not the same configuration**. Report step budgets together with every
success-rate or latency claim.

## Intended use

This checkpoint is intended for:

- research on step distillation for joint video-action models;
- reproducing the reported RoboTwin results;
- comparing modality-aware and naive joint consistency objectives;
- studying latency/task-success trade-offs in world-action models.

It is not a drop-in controller for an arbitrary robot or task. Deployment on
physical robots requires task-specific observation processing, action
normalization, safety constraints, control integration, and validation.

## Limitations and safety

- Results are specific to LingBot-VA, the released RoboTwin checkpoint, and the
  paper's evaluation settings.
- Latency depends on GPU, software stack, precision, resolution, horizon, and
  server/client overhead; 348 ms is not a universal runtime guarantee.
- The real-world evaluation covers three tasks and 30 rollouts per method.
- One-step generation still reduces task success relative to the teacher.
- Generated actions may be unsafe or incorrect. Use independent safeguards,
  workspace limits, emergency stops, and supervised testing before any
  physical deployment.
- The real-world G1 deployment setup is not included in the public code release.

## Licenses

The **checkpoint in this Hugging Face repository** is released under
Apache-2.0. It includes components derived from LingBot-VA, whose released
model and bundled upstream components are also Apache-2.0.

The separate [Flash-WAM GitHub repository](https://github.com/NU-World-Model-Embodied-AI/Flash-WAM)
uses different terms for different parts: the authors' distillation code,
documentation, and demo videos are CC BY-NC 4.0, while the bundled `wan_va/`
components remain Apache-2.0. Downloading this checkpoint does not replace the
license notices of the code or other assets used with it.

## Citation

```bibtex
@misc{akbari2026flashwammodalityawaredistillationworld,
  title         = {Flash-WAM: Modality-Aware Distillation for World Action Models},
  author        = {Arman Akbari and Ci Zhang and Arash Akbari and Lin Zhao and Yixiao Chen and Weiwei Chen and Xuan Zhang and Geng Yuan and Yanzhi Wang},
  year          = {2026},
  eprint        = {2606.05254},
  archivePrefix = {arXiv},
  primaryClass  = {cs.LG},
  url           = {https://arxiv.org/abs/2606.05254}
}
```