Bagel Labs is a physical AI research lab based in San Francisco and Toronto. It has developed an architecture that uses dramatically less data and compute to train while delivering a state-of-the-art model-size/performance tradeoff. WorldDiT demonstrates the model advantage; Paris 1.0 and Paris 2.0 demonstrate the training advantage.
Bagel Labs
WorldDiT: A Unified Diffusion Backbone for World and Action Modeling
WorldDiT couples continuous action generation with auxiliary future normalized
RGB patch prediction in one diffusion transformer. The architecture is designed
as a general backbone for world and action modeling, while the current release
evaluates it on LIBERO and provides four checkpoints, a self contained
inference runtime, and an evaluator.
See WorldDiT act
The four clips below show successful rollouts from the released checkpoints.
Each clip covers a different LIBERO suite and camera view.
94.9 percent mean success 1,898 of 2,000 successful episodes
399.084 million total parameters 135.107 million trainable parameters
98.0 percent Spatial 97.0 percent Object
Three observation steps Seven predicted actions
92.8 percent Goal 91.8 percent Long
Three actions executed before replanning Seven action dimensions
Checkpoints
Runtime
Encoders and environment
Spatial Object Goal Long
inference.py eval.py config.json
MAE ViT B OpenAI CLIP ViT B 32 SafeTensors and pinned requirements
The repository is self contained for WorldDiT inference. LIBERO provides the
benchmark environments, assets, task definitions, and initial states.
The released runtime and checkpoints were revalidated from a clean installation
on eight RTX Pro 6000 Blackwell GPUs. The reported aggregate covers five
hundred simulator episodes per suite. Three hundred episodes per suite informed
staged checkpoint selection, while two hundred episodes per suite were disjoint
from selection.
Parameter count and reported success
Among methods with complete four suite averages, WorldDiT lies on the reported
Pareto frontier for total model parameters and mean LIBERO success.
Reported mean LIBERO success against total instantiated model parameters
Reported LIBERO success against total model parameters for 24 methods. The line connects methods on the Pareto frontier with complete four suite averages. Because the methods follow different published evaluation protocols, the figure summarizes published results rather than a direct comparison under one common evaluation protocol.
Run a smoke test
Download the repository and create a clean Python 3.12 environment.
A successful smoke test confirms that the environment, checkpoint, visual
encoders, simulator, and rendering path load together. Full benchmark reporting
uses complete suite evaluations.
How WorldDiT works
Each of three recent observation steps contributes primary and wrist images
together with robot state, while one language instruction conditions the
sequence. During training, one diffusion transformer backbone learns a seven
step action chunk together with an auxiliary future normalized RGB patch
target. At deployment, the encoded history conditions the action velocity field
directly. RGB patch token construction and RGB prediction head evaluation
remain outside the inference graph, concentrating computation on action
generation. The controller executes the first three predicted actions, observes
again, and replans.
WorldDiT inference pipeline
WorldDiT inference pipeline. The encoded observation history conditions action generation through twenty flow steps. The controller executes the first three actions from each seven action chunk, then updates the window and replans.
Training
Deployment
Action and future normalized RGB patch targets are learned by one backbone
Encoded history conditions the action velocity field
Seven action steps are supervised
Seven actions are predicted
Future normalized RGB patch supervision is present
RGB patch tokens and the RGB prediction head remain outside the inference graph
Each GPU receives an independent progress bar. After all workers finish, rank 0
prints per task and overall success rates and writes a structured
results.json. Use a new output directory for each evaluation to preserve
earlier results.
dependencies/ contains the frozen visual and language encoder weights needed
by the released WorldDiT runtime. The repository contains every model weight
required for inference.
Evaluation uses the final temporal slot of the predicted action tensor.
Architecture details
Component
Specification
Backbone
WorldDiT diffusion transformer
Observation context
3 observation steps
Action horizon
7 actions
Action dimension
7
Action aggregation
Temporal ensembling
Language encoder
OpenAI CLIP ViT-B/32
Visual encoder
MAE ViT-B
Evaluation
Headless LIBERO with EGL
Checkpoint format
SafeTensors
Use and scope
Intended use
Scope of the release
Research on world and action modeling for language conditioned robot manipulation. The architecture supports continuous action generation with auxiliary future normalized RGB patch prediction.
The current release evaluates WorldDiT in LIBERO simulation under the released protocol and provides checkpoints for all four suites.
Architecture research, reproduction, and evaluation of multimodal diffusion backbones for robot manipulation.
Real robot reliability, safety, and transfer across embodiments require dedicated future evaluation. The present experiments evaluate the integrated WorldDiT system. Targeted ablations are required to attribute performance to the future normalized RGB patch objective. Total instantiated parameter count characterizes model scale. Training cost, deployment latency, and runtime efficiency require dedicated measurements.
Citation
If you use WorldDiT in your research, please cite the paper.
bibtex
1@article{260723909,
2 title={{WorldDiT: A Unified Diffusion Architecture for World and Action Modeling}},
3 author={Sen Wang and R. Gnana Praveen and Bidhan Roy and Marcos Villagra},
4 year={{2026}},
5 eprint={{2607.23909}},
6 archivePrefix={{arXiv}}
7}
License
The WorldDiT checkpoints, model card, and original release materials are
licensed under Creative Commons Attribution 4.0
International. You may copy,
redistribute, and adapt them, including commercially, with appropriate credit
to Bagel Labs and the WorldDiT authors, a link to the license, and an indication
of any changes. Third party dependencies and assets remain governed by their
upstream licenses.
Authors and contact
WorldDiT is developed by Sen Wang, Praveen Rajasekhar, Bidhan Roy, and Marcos
Villagra at Bagel Labs. Questions can be sent to research@bagel.com.