* feat: add LLaDA2 and BlockRefinement pipelines for discrete text diffusion Add support for LLaDA2/LLaDA2.1 discrete diffusion text generation: - BlockRefinementPipeline: block-wise iterative refinement with confidence-based token commitment, supporting editing threshold for LLaDA2.1 models - LLaDA2Pipeline: convenience wrapper with LLaDA2-specific defaults - DiscreteDiffusionPipelineMixin: shared SAR sampling utilities (top-k, top-p, temperature) and prompt/prefix helpers - compute_confidence_aware_loss: CAP-style training loss - Examples: sampling scripts for LLaDA2 and block refinement, training scripts with Qwen causal LM - Docs and tests included * feat: add BlockRefinementScheduler for commit-by-confidence scheduling Extract the confidence-based token commit logic from BlockRefinementPipeline into a dedicated BlockRefinementScheduler, following diffusers conventions. The scheduler owns: - Transfer schedule computation (get_num_transfer_tokens) - Timestep management (set_timesteps) - Step logic: confidence-based mask-filling and optional token editing The pipeline now delegates scheduling to self.scheduler.step() and accepts a scheduler parameter in __init__. * test: add unit tests for BlockRefinementScheduler 12 tests covering set_timesteps, get_num_transfer_tokens, step logic (confidence-based commits, threshold behavior, editing, prompt masking, batched inputs, tuple output). * docs: add toctree entries and standalone scheduler doc page - Add BlockRefinement and LLaDA2 to docs sidebar navigation - Add BlockRefinementScheduler to schedulers sidebar navigation - Move scheduler autodoc to its own page under api/schedulers/ * feat: add --revision flag and fix dtype deprecation in sample_llada2.py - Add --revision argument for loading model revisions from the Hub - Replace deprecated torch_dtype with dtype for transformers 5.x compat * fix: use 1/0 attention mask instead of 0/-inf for LLaDA2 compat LLaDA2 models expect a boolean-style (1/0) attention mask, not an additive (0/-inf) mask. The model internally converts to additive, so passing 0/-inf caused double-masking and gibberish output. * refactor: consolidate training scripts into single train_block_refinement.py - Remove toy train_block_refinement_cap.py (self-contained demo with tiny model) - Rename train_block_refinement_qwen_cap.py to train_block_refinement.py (already works with any causal LM via AutoModelForCausalLM) - Fix torch_dtype deprecation and update README with correct script names * fix formatting * docs: improve LLaDA2 and BlockRefinement documentation - Add usage examples with real model IDs and working code - Add recommended parameters table for LLaDA2.1 quality/speed modes - Note that editing is LLaDA2.1-only (not for LLaDA2.0 models) - Remove misleading config defaults section from BlockRefinement docs * feat: set LLaDA2Pipeline defaults to recommended model parameters - threshold: 0.95 -> 0.7 (quality mode) - max_post_steps: 0 -> 16 (recommended for LLaDA2.1, harmless for 2.0) - eos_early_stop: False -> True (stop at EOS token) block_length=32, steps=32, temperature=0.0 were already correct. editing_threshold remains None (users enable for LLaDA2.1 models). * feat: default editing_threshold=0.5 for LLaDA2.1 quality mode LLaDA2.1 is the current generation. Users with LLaDA2.0 models can disable editing by passing editing_threshold=None. * fix: align sampling utilities with official LLaDA2 implementation - top_p filtering: add shift-right to preserve at least one token above threshold (matches official code line 1210) - temperature ordering: apply scaling before top-k/top-p filtering so filtering operates on scaled logits (matches official code lines 1232-1235) - greedy branch: return argmax directly when temperature=0 without filtering (matches official code lines 1226-1230) * refactor: remove duplicate prompt encoding, reuse mixin's _prepare_input_ids LLaDA2Pipeline._prepare_prompt_ids was a near-copy of DiscreteDiffusionPipelineMixin._prepare_input_ids. Remove the duplicate and call the mixin method directly. Also simplify _extract_input_ids since we always pass return_dict=True. * formatting * fix: replace deprecated torch_dtype with dtype in examples and docstrings - Update EXAMPLE_DOC_STRING to use dtype= and LLaDA2.1-mini model ID - Fix sample_block_refinement.py to use dtype= * remove BlockRefinementPipeline * cleanup * fix readme * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: YiYi Xu <yixu310@gmail.com> * removed DiscreteDiffusionPipelineMixin * add support for 2d masks for flash attn * Update src/diffusers/training_utils.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/training_utils.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * fix issues from review * added tests * formatting * add check_eos_finished to scheduler * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/schedulers/scheduling_block_refinement.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/schedulers/scheduling_block_refinement.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * fix renaming issues and types * remove duplicate check * Update docs/source/en/api/pipelines/llada2.md Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> * Update src/diffusers/pipelines/llada2/pipeline_llada2.py Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com> --------- Co-authored-by: YiYi Xu <yixu310@gmail.com> Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com>
π€ Diffusers is the go-to library for state-of-the-art pretrained diffusion models for generating images, audio, and even 3D structures of molecules. Whether you're looking for a simple inference solution or training your own diffusion models, π€ Diffusers is a modular toolbox that supports both. Our library is designed with a focus on usability over performance, simple over easy, and customizability over abstractions.
π€ Diffusers offers three core components:
- State-of-the-art diffusion pipelines that can be run in inference with just a few lines of code.
- Interchangeable noise schedulers for different diffusion speeds and output quality.
- Pretrained models that can be used as building blocks, and combined with schedulers, for creating your own end-to-end diffusion systems.
Installation
We recommend installing π€ Diffusers in a virtual environment from PyPI or Conda. For more details about installing PyTorch, please refer to their official documentation.
PyTorch
With pip (official package):
pip install --upgrade diffusers[torch]
With conda (maintained by the community):
conda install -c conda-forge diffusers
Apple Silicon (M1/M2) support
Please refer to the How to use Stable Diffusion in Apple Silicon guide.
Quickstart
Generating outputs is super easy with π€ Diffusers. To generate an image from text, use the from_pretrained method to load any pretrained diffusion model (browse the Hub for 30,000+ checkpoints):
from diffusers import DiffusionPipeline
import torch
pipeline = DiffusionPipeline.from_pretrained("stable-diffusion-v1-5/stable-diffusion-v1-5", torch_dtype=torch.float16)
pipeline.to("cuda")
pipeline("An image of a squirrel in Picasso style").images[0]
You can also dig into the models and schedulers toolbox to build your own diffusion system:
from diffusers import DDPMScheduler, UNet2DModel
from PIL import Image
import torch
scheduler = DDPMScheduler.from_pretrained("google/ddpm-cat-256")
model = UNet2DModel.from_pretrained("google/ddpm-cat-256").to("cuda")
scheduler.set_timesteps(50)
sample_size = model.config.sample_size
noise = torch.randn((1, 3, sample_size, sample_size), device="cuda")
input = noise
for t in scheduler.timesteps:
with torch.no_grad():
noisy_residual = model(input, t).sample
prev_noisy_sample = scheduler.step(noisy_residual, t, input).prev_sample
input = prev_noisy_sample
image = (input / 2 + 0.5).clamp(0, 1)
image = image.cpu().permute(0, 2, 3, 1).numpy()[0]
image = Image.fromarray((image * 255).round().astype("uint8"))
image
Check out the Quickstart to launch your diffusion journey today!
How to navigate the documentation
| Documentation | What can I learn? |
|---|---|
| Tutorial | A basic crash course for learning how to use the library's most important features like using models and schedulers to build your own diffusion system, and training your own diffusion model. |
| Loading | Guides for how to load and configure all the components (pipelines, models, and schedulers) of the library, as well as how to use different schedulers. |
| Pipelines for inference | Guides for how to use pipelines for different inference tasks, batched generation, controlling generated outputs and randomness, and how to contribute a pipeline to the library. |
| Optimization | Guides for how to optimize your diffusion model to run faster and consume less memory. |
| Training | Guides for how to train a diffusion model for different tasks with different training techniques. |
Contribution
We β€οΈ contributions from the open-source community! If you want to contribute to this library, please check out our Contribution guide. You can look out for issues you'd like to tackle to contribute to the library.
- See Good first issues for general opportunities to contribute
- See New model/pipeline to contribute exciting new diffusion models / diffusion pipelines
- See New scheduler
Also, say π in our public Discord channel . We discuss the hottest trends about diffusion models, help each other with contributions, personal projects or just hang out β.
Popular Tasks & Pipelines
| Task | Pipeline | π€ Hub |
|---|---|---|
| Unconditional Image Generation | DDPM | google/ddpm-ema-church-256 |
| Text-to-Image | Stable Diffusion Text-to-Image | stable-diffusion-v1-5/stable-diffusion-v1-5 |
| Text-to-Image | unCLIP | kakaobrain/karlo-v1-alpha |
| Text-to-Image | DeepFloyd IF | DeepFloyd/IF-I-XL-v1.0 |
| Text-to-Image | Kandinsky | kandinsky-community/kandinsky-2-2-decoder |
| Text-guided Image-to-Image | ControlNet | lllyasviel/sd-controlnet-canny |
| Text-guided Image-to-Image | InstructPix2Pix | timbrooks/instruct-pix2pix |
| Text-guided Image-to-Image | Stable Diffusion Image-to-Image | stable-diffusion-v1-5/stable-diffusion-v1-5 |
| Text-guided Image Inpainting | Stable Diffusion Inpainting | stable-diffusion-v1-5/stable-diffusion-inpainting |
| Image Variation | Stable Diffusion Image Variation | lambdalabs/sd-image-variations-diffusers |
| Super Resolution | Stable Diffusion Upscale | stabilityai/stable-diffusion-x4-upscaler |
| Super Resolution | Stable Diffusion Latent Upscale | stabilityai/sd-x2-latent-upscaler |
Popular libraries using 𧨠Diffusers
- https://github.com/microsoft/TaskMatrix
- https://github.com/invoke-ai/InvokeAI
- https://github.com/InstantID/InstantID
- https://github.com/apple/ml-stable-diffusion
- https://github.com/Sanster/lama-cleaner
- https://github.com/IDEA-Research/Grounded-Segment-Anything
- https://github.com/ashawkey/stable-dreamfusion
- https://github.com/deep-floyd/IF
- https://github.com/bentoml/BentoML
- https://github.com/bmaltais/kohya_ss
- +14,000 other amazing GitHub repositories πͺ
Thank you for using us β€οΈ.
Credits
This library concretizes previous work by many different authors and would not have been possible without their great research and implementations. We'd like to thank, in particular, the following implementations which have helped us in our development and without which the API could not have been as polished today:
- @CompVis' latent diffusion models library, available here
- @hojonathanho original DDPM implementation, available here as well as the extremely useful translation into PyTorch by @pesser, available here
- @ermongroup's DDIM implementation, available here
- @yang-song's Score-VE and Score-VP implementations, available here
We also want to thank @heejkoo for the very helpful overview of papers, code and resources on diffusion models, available here as well as @crowsonkb and @rromb for useful discussions and insights.
Citation
@misc{von-platen-etal-2022-diffusers,
author = {Patrick von Platen and Suraj Patil and Anton Lozhkov and Pedro Cuenca and Nathan Lambert and Kashif Rasul and Mishig Davaadorj and Dhruv Nair and Sayak Paul and William Berman and Yiyi Xu and Steven Liu and Thomas Wolf},
title = {Diffusers: State-of-the-art diffusion models},
year = {2022},
publisher = {GitHub},
journal = {GitHub repository},
howpublished = {\url{https://github.com/huggingface/diffusers}}
}
