transformers/docs/source/en/model_doc/opt.md

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*This model was published in HF papers on 2022-05-02 and contributed to Hugging Face Transformers on 2022-05-12.*

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              <img alt="FlashAttention" src="https://img.shields.io/badge/%E2%9A%A1%EF%B8%8E%20FlashAttention-eae0c8?style=flat">
           <img alt="SDPA" src="https://img.shields.io/badge/SDPA-DE3412?style=flat&logo=pytorch&logoColor=white">
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# OPT

[OPT](https://huggingface.co/papers/2205.01068) is a suite of open-source decoder-only pre-trained transformers whose parameters range from 125M to 175B. OPT models are designed for causal language modeling and aim to enable responsible and reproducible research at scale. OPT-175B is comparable in performance to GPT-3 with only 1/7th the carbon footprint.

You can find all the original OPT checkpoints under the [OPT](https://huggingface.co/collections/facebook/opt-66ed00e15599f02966818844) collection.

> [!TIP]
> This model was contributed by [ArthurZ](https://huggingface.co/ArthurZ), [ybelkada](https://huggingface.co/ybelkada), and [patrickvonplaten](https://huggingface.co/patrickvonplaten).
>
> Click on the OPT models in the right sidebar for more examples of how to apply OPT to different language tasks.

The example below demonstrates how to generate text with [`Pipeline`], [`AutoModel`], and from the command line.

<hfoptions id="usage">
<hfoption id="Pipeline">

```python
from transformers import pipeline


pipeline = pipeline(task="text-generation", model="facebook/opt-125m", device=0)
pipeline("Once upon a time, in a land far, far away,", max_length=50, num_return_sequences=1)
```

</hfoption>
<hfoption id="AutoModel">

```python
from transformers import AutoModelForCausalLM, AutoTokenizer


model = AutoModelForCausalLM.from_pretrained("facebook/opt-350m", device_map="auto", attn_implementation="sdpa")
tokenizer = AutoTokenizer.from_pretrained("facebook/opt-350m")

prompt = ("Once upon a time, in a land far, far away, ")

model_inputs = tokenizer([prompt], return_tensors="pt").to(model.device)

generated_ids = model.generate(**model_inputs, max_new_tokens=30, do_sample=False)
tokenizer.batch_decode(generated_ids)[0]
```

</hfoption>
</hfoptions>

Quantization reduces the memory burden of large models by representing the weights in a lower precision. Refer to the [Quantization](../quantization/overview) overview for more available quantization backends.

The example below uses [bitsandbytes](..quantization/bitsandbytes) to quantize the weights to 8-bits.

```python
from transformers import AutoModelForCausalLM, AutoTokenizer, BitsAndBytesConfig


bnb_config = BitsAndBytesConfig(load_in_8bit=True)
model = AutoModelForCausalLM.from_pretrained("facebook/opt-13b", attn_implementation="sdpa", quantization_config=bnb_config, device_map="auto")
tokenizer = AutoTokenizer.from_pretrained("facebook/opt-13b")

prompt = ("Once upon a time, in a land far, far away, ")

model_inputs = tokenizer([prompt], return_tensors="pt").to(model.device)

generated_ids = model.generate(**model_inputs, max_new_tokens=30, do_sample=False)
tokenizer.batch_decode(generated_ids)[0]
```

## Notes

- OPT adds an `EOS` token `</s>` to the beginning of every prompt.

## Resources

- Refer to this [notebook](https://colab.research.google.com/drive/1jCkpikz0J2o20FBQmYmAGdiKmJGOMo-o?usp=sharing) for an example of fine-tuning OPT with PEFT, bitsandbytes, and Transformers.
- The [How 🤗 Accelerate runs very large models thanks to PyTorch](https://huggingface.co/blog/accelerate-large-models) blog post demonstrates how to run OPT for inference.

## OPTConfig

[[autodoc]] OPTConfig

## OPTModel

[[autodoc]] OPTModel
    - forward

## OPTForCausalLM

[[autodoc]] OPTForCausalLM
    - forward

## OPTForSequenceClassification

[[autodoc]] OPTForSequenceClassification
    - forward

## OPTForQuestionAnswering

[[autodoc]] OPTForQuestionAnswering
    - forward