### What does this PR do?
Type of change: new example
Adds an end-to-end Cosmos3 Nano DFlash training recipe for multimodal
speculative decoding.
- Adds a notebook that prepares data, launches synthetic generation in
Slurm, trains a DFlash draft model, exports it, and provides a vLLM
smoke-test command.
- Adds PAI-Understanding, VQA v2, and multilingual prompt sharding and
distributed-generation helpers.
- Adds an atomic, multimodal-safe merge and conservative deduplication
flow.
- Extends the VLM data collator to handle structured image/video
messages, configurable visual bounds, and fixed DFlash sequence lengths.
- Hardens generation launch scripts and preserves truncated generated
responses.
### Usage
```bash
cd examples/speculative_decoding/recipes
export MODEL_PATH=/path/to/cosmos3-nano
export
PLAIN_TEXT_INPUT=/path/to/nemotron-chat-or-approved-user-data.jsonl
jupyter lab train_dflash_cosmos3_nano.ipynb
Run the notebook in order:
1. Configure paths.
2. Prepare prompts on a CPU-only node and generate target completions in
a Slurm GPU allocation.
3. Merge the four required sources and submit training.
4. Export a saved checkpoint and run the vLLM deployment smoke test.
### Testing
- jq empty
examples/speculative_decoding/recipes/train_dflash_cosmos3_nano.ipynb
- bash -n on the modified launch, worker, and recipe shell scripts.
- Ran a two-step Cosmos3 Nano DFlash Slurm smoke job; it completed and
wrote modelopt_state.pth.
- Not run: pytest
tests/unit/torch/speculative/plugins/test_hf_speculative_offline.py
(pytest is unavailable in the current environment).
### Before your PR is "Ready for review"
- Is this change backward compatible?: ✅
- If you copied code from any other sources or added a new PIP
dependency, did you follow guidance in CONTRIBUTING.md?: N/A
- Did you write any new necessary tests?: ✅
- Did you update CHANGELOG.rst?: N/A
- Did you get Claude approval on this PR?: N/A
### Additional Information
Security follow-up required before marking ready: the notebook hardcodes
model.trust_remote_code=true and --trust_remote_code. Either
parameterize
this with a default of false, or obtain and document a security
exception.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Added end-to-end multimodal workflows for dataset preparation,
distributed generation, result merging, training, export, and deployment
testing.
* Added support for image and video inputs, multiple dataset formats,
resumable JSONL generation, configurable serving, and parallel
processing.
* Added configurable prompt, media, token, sequence, temperature, and
tensor-parallel settings.
* **Bug Fixes**
* Improved truncated-response handling, assistant-label processing,
validation, health checks, cleanup, deduplication, media resolution,
atomic outputs, and failure reporting.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Signed-off-by: Slawomir Kierat <skierat@nvidia.com>
## What does this PR do?
**Type of change:** New feature, new tests; <!-- Use one of the
following: Bug fix, new feature, new example, new tests, documentation.
-->
**Overview:**
- Add conversion scripts for eagle3 llm-compressor style checkpoint
- Jira Ticket: https://jirasw.nvidia.com/browse/OMNIML-2866
- Add unit tests for `ar_validate.py`, `export_hf_checkpoint.py`, and
`convert_to_vllm_ckpt.py`.
## Usage
<!-- You can potentially add a usage example below. -->
```python
python scripts/convert_to_vllm_ckpt.py --input <eagle3 ckpt> --verifier <base model> --output <path>
```
## Testing
<!-- Mention how have you tested your change if applicable. -->
## Before your PR is "*Ready for review*"
<!-- If you haven't finished some of the above items you can still open
`Draft` PR. -->
- **Make sure you read and follow [Contributor
guidelines](https://github.com/NVIDIA/TensorRT-Model-Optimizer/blob/main/CONTRIBUTING.md)**
and your commits are signed.
- **Is this change backward compatible?**: Yes/No <!--- If No, explain
why. -->
- **Did you write any new necessary tests?**: Yes/No
- **Did you add or update any necessary documentation?**: Yes/No
- **Did you update
[Changelog](https://github.com/NVIDIA/TensorRT-Model-Optimizer/blob/main/CHANGELOG.rst)?**:
Yes/No <!--- Only for new features, API changes, critical bug fixes or
bw breaking changes. -->
## Additional Information
<!-- E.g. related issue. -->
---------
Signed-off-by: h-guo18 <67671475+h-guo18@users.noreply.github.com>
skierat