# Quickstart

🤗 Optimum Neuron makes AWS accelerator adoption seamless for Hugging Face users with **drop-in replacements** for standard training and inference components.

***🚀 Need to set up your environment first?** Check out our [Getting Started on EC2](getting-started-on-ec2) page for complete installation and AWS setup instructions.*

**Key Features:**
- 🔄 **Drop-in replacement** for standard Transformers training and inference
- ⚡ **Distributed training** support with minimal code changes  
- 🎯 **Optimized models** for AWS accelerators
- 📈 **Production-ready** inference with compiled models

## Training

Training on AWS Trainium requires minimal changes to your existing code - just swap in Optimum Neuron's drop-in replacements:

```python
import torch
import torch_xla.runtime as xr

from datasets import load_dataset
from transformers import AutoTokenizer

# Optimum Neuron's drop-in replacements for standard training components
from optimum.neuron import NeuronSFTConfig, NeuronSFTTrainer, NeuronTrainingArguments
from optimum.neuron.models.training import NeuronModelForCausalLM


def format_dolly_dataset(example):
    """Format Dolly dataset into instruction-following format."""
    instruction = f"### Instruction\n{example['instruction']}"
    context = f"### Context\n{example['context']}" if example["context"] else None
    response = f"### Answer\n{example['response']}"
    
    # Combine all parts with double newlines
    parts = [instruction, context, response]
    return "\n\n".join(part for part in parts if part)


def main():
    # Load instruction-following dataset
    dataset = load_dataset("databricks/databricks-dolly-15k", split="train")
    
    # Model configuration
    model_id = "Qwen/Qwen3-1.7B"
    output_dir = "qwen3-1.7b-finetuned"
    
    # Setup tokenizer
    tokenizer = AutoTokenizer.from_pretrained(model_id)
    tokenizer.pad_token = tokenizer.eos_token
    
    # Configure training for Trainium
    training_args = NeuronTrainingArguments(
        learning_rate=1e-4,
        tensor_parallel_size=8,  # Split model across 8 accelerators
        per_device_train_batch_size=1,  # Batch size per device
        gradient_accumulation_steps=8,
        logging_steps=1,
        output_dir=output_dir,
    )
    
    # Load model optimized for Trainium
    model = NeuronModelForCausalLM.from_pretrained(
        model_id,
        training_args.trn_config,
        dtype=torch.bfloat16,
        attn_implementation="flash_attention_2",  # Enable flash attention
    )
    
    # Setup supervised fine-tuning
    sft_config = NeuronSFTConfig(
        max_seq_length=2048,
        packing=True,  # Pack multiple samples for efficiency
        **training_args.to_dict(),
    )
    
    # Initialize trainer and start training
    trainer = NeuronSFTTrainer(
        model=model,
        args=sft_config,
        tokenizer=tokenizer,
        train_dataset=dataset,
        formatting_func=format_dolly_dataset,
    )
    
    trainer.train()
    
    # Share your model with the community
    trainer.push_to_hub(
        commit_message="Fine-tuned on Databricks Dolly dataset",
        blocking=True,
        model_name=output_dir,
    )
    
    if xr.local_ordinal() == 0:
        print(f"Training complete! Model saved to {output_dir}")


if __name__ == "__main__":
    main()
```

This example demonstrates supervised fine-tuning on the [Databricks Dolly dataset](https://huggingface.co/datasets/databricks/databricks-dolly-15k) using `NeuronSFTTrainer` and `NeuronModelForCausalLM` - the Trainium-optimized versions of standard Transformers components.

### Running Training

**Compilation** (optional for first run):
```bash
NEURON_CC_FLAGS="--model-type transformer" neuron_parallel_compile torchrun --nproc_per_node 32 sft_finetune_qwen3.py
```

**Training:**
```bash
NEURON_CC_FLAGS="--model-type transformer" torchrun --nproc_per_node 32 sft_finetune_qwen3.py
```

## Inference

Optimized inference requires two steps: **export** your model to Neuron format, then **run** it with `NeuronModelForXXX` classes.

### 1. Export Your Model

```bash
optimum-cli export neuron \
  --model distilbert-base-uncased-finetuned-sst-2-english \
  --batch_size 1 \
  --sequence_length 32 \
  --auto_cast matmul \
  --auto_cast_type bf16 \
  distilbert_base_uncased_finetuned_sst2_english_neuron/
```

This exports the model with optimized settings: static shapes (`batch_size=1`, `sequence_length=32`) and BF16 precision for `matmul` operations. Check out the [exporter guide](https://huggingface.co/docs/optimum-neuron/guides/export_model) for more compilation options.

### 2. Run Inference

```python
from transformers import AutoTokenizer
from optimum.neuron import NeuronModelForSequenceClassification

# Load the compiled Neuron model
model = NeuronModelForSequenceClassification.from_pretrained(
    "distilbert_base_uncased_finetuned_sst2_english_neuron"
)

# Setup tokenizer (same as original model)
tokenizer = AutoTokenizer.from_pretrained("distilbert-base-uncased-finetuned-sst-2-english")

# Run inference
inputs = tokenizer("Hamilton is considered to be the best musical of past years.", return_tensors="pt")
logits = model(**inputs).logits

print(model.config.id2label[logits.argmax().item()])
# 'POSITIVE'
```

The `NeuronModelForXXX` classes work as drop-in replacements for their `AutoModelForXXX` counterparts, making migration seamless.

## Next Steps

Ready to dive deeper? Check out our comprehensive guides:

- 📚 **[Getting Started](getting-started)** - Complete setup and installation
- 🏋️ **[Training Tutorials](training_tutorials/notebooks)** - End-to-end training examples
- 🔧 **[Export Guide](guides/export_model)** - Advanced model compilation options