NeMo Automodel

NeMo Automodel is an open-source PyTorch DTensor-native training library from NVIDIA. It supports large and small scale pretraining and fine-tuning for LLMs and VLMs for fast experimentation in research and production environments, with parallelism strategies including FSDP2, tensor, pipeline, expert, and context parallelism. For high throughput, it integrates kernels from DeepEP and TransformerEngine.

Define your training run in a YAML config file (see full config file).

# Instantiate a Nemotron V3 Nano model
model:
  _target_: nemo_automodel.NeMoAutoModelForCausalLM.from_pretrained
  pretrained_model_name_or_path: nvidia/NVIDIA-Nemotron-3-Nano-30B-A3B-BF16

# Run SFT on HellaSwag
dataset:
  _target_: nemo_automodel.components.datasets.llm.hellaswag.HellaSwag
  path_or_dataset: rowan/hellaswag
  split: train

# Train PEFT adapters
peft:
  _target_: nemo_automodel.components._peft.lora.PeftConfig
  exclude_modules: ["*.out_proj"]  # mamba layers use custom kernels that take in the out_proj.weight directly, thus lora doesn't work here.
  dim: 8
  alpha: 32
  use_triton: True

# Use EP + FSDP2 for training
distributed:
  strategy: fsdp2
  dp_size: none
  tp_size: 1
  cp_size: 1
  ep_size: 4

# ... other parameters

Launch training with torchrun using the command below.

torchrun -–nproc-per-node=4 examples/llm_finetune/finetune.py -c /path/to/yaml

Transformers integration

Any LLM or VLM supported in Transformers can also be instantiated through NeMo Automodel. See the full model coverage.
Built on top of Hugging Face models with AutoModel.from_pretrained(), with dynamic high-performance layer swaps and support for more refined parallelisms like Expert Parallelism (EP).
Detects the architecture field in AutoConfig.from_pretrained() to automatically load custom implementations like Nemotron Nano V3.
Follows the Transformers API closely for drop-in compatibility.

Resources

NeMo Automodel
NeMo Transformers API
NeMo Automodel dense models and Mixture-of-Expert (MoE) benchmarks
See the NeMo pretraining guide to learn how to use NeMo for pretraining

Update on GitHub