transformers/docs/source/model_doc/auto.mdx

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# Auto Classes

In many cases, the architecture you want to use can be guessed from the name or the path of the pretrained model you
are supplying to the `from_pretrained()` method. AutoClasses are here to do this job for you so that you
automatically retrieve the relevant model given the name/path to the pretrained weights/config/vocabulary.

Instantiating one of [`AutoConfig`], [`AutoModel`], and
[`AutoTokenizer`] will directly create a class of the relevant architecture. For instance


```python
model = AutoModel.from_pretrained("bert-base-cased")
```

will create a model that is an instance of [`BertModel`].

There is one class of `AutoModel` for each task, and for each backend (PyTorch, TensorFlow, or Flax).

## Extending the Auto Classes

Each of the auto classes has a method to be extended with your custom classes. For instance, if you have defined a
custom class of model `NewModel`, make sure you have a `NewModelConfig` then you can add those to the auto
classes like this:

```python
from transformers import AutoConfig, AutoModel

AutoConfig.register("new-model", NewModelConfig)
AutoModel.register(NewModelConfig, NewModel)
```

You will then be able to use the auto classes like you would usually do!

<Tip warning={true}>

If your `NewModelConfig` is a subclass of [`~transformer.PretrainedConfig`], make sure its
`model_type` attribute is set to the same key you use when registering the config (here `"new-model"`).

Likewise, if your `NewModel` is a subclass of [`PreTrainedModel`], make sure its
`config_class` attribute is set to the same class you use when registering the model (here
`NewModelConfig`).

</Tip>

## AutoConfig

[[autodoc]] AutoConfig

## AutoTokenizer

[[autodoc]] AutoTokenizer

## AutoFeatureExtractor

[[autodoc]] AutoFeatureExtractor

## AutoProcessor

[[autodoc]] AutoProcessor

## AutoModel

[[autodoc]] AutoModel

## AutoModelForPreTraining

[[autodoc]] AutoModelForPreTraining

## AutoModelForCausalLM

[[autodoc]] AutoModelForCausalLM

## AutoModelForMaskedLM

[[autodoc]] AutoModelForMaskedLM

## AutoModelForSeq2SeqLM

[[autodoc]] AutoModelForSeq2SeqLM

## AutoModelForSequenceClassification

[[autodoc]] AutoModelForSequenceClassification

## AutoModelForMultipleChoice

[[autodoc]] AutoModelForMultipleChoice

## AutoModelForNextSentencePrediction

[[autodoc]] AutoModelForNextSentencePrediction

## AutoModelForTokenClassification

[[autodoc]] AutoModelForTokenClassification

## AutoModelForQuestionAnswering

[[autodoc]] AutoModelForQuestionAnswering

## AutoModelForTableQuestionAnswering

[[autodoc]] AutoModelForTableQuestionAnswering

## AutoModelForImageClassification

[[autodoc]] AutoModelForImageClassification

## AutoModelForVision2Seq

[[autodoc]] AutoModelForVision2Seq

## AutoModelForAudioClassification

[[autodoc]] AutoModelForAudioClassification

## AutoModelForAudioFrameClassification

[[autodoc]] AutoModelForAudioFrameClassification

## AutoModelForCTC

[[autodoc]] AutoModelForCTC

## AutoModelForSpeechSeq2Seq

[[autodoc]] AutoModelForSpeechSeq2Seq

## AutoModelForAudioXVector

[[autodoc]] AutoModelForAudioXVector

## AutoModelForMaskedImageModeling

[[autodoc]] AutoModelForMaskedImageModeling

## AutoModelForObjectDetection

[[autodoc]] AutoModelForObjectDetection

## AutoModelForImageSegmentation

[[autodoc]] AutoModelForImageSegmentation

## AutoModelForSemanticSegmentation

[[autodoc]] AutoModelForSemanticSegmentation

## AutoModelForInstanceSegmentation

[[autodoc]] AutoModelForInstanceSegmentation

## TFAutoModel

[[autodoc]] TFAutoModel

## TFAutoModelForPreTraining

[[autodoc]] TFAutoModelForPreTraining

## TFAutoModelForCausalLM

[[autodoc]] TFAutoModelForCausalLM

## TFAutoModelForImageClassification

[[autodoc]] TFAutoModelForImageClassification

## TFAutoModelForMaskedLM

[[autodoc]] TFAutoModelForMaskedLM

## TFAutoModelForSeq2SeqLM

[[autodoc]] TFAutoModelForSeq2SeqLM

## TFAutoModelForSequenceClassification

[[autodoc]] TFAutoModelForSequenceClassification

## TFAutoModelForMultipleChoice

[[autodoc]] TFAutoModelForMultipleChoice

## TFAutoModelForTableQuestionAnswering

[[autodoc]] TFAutoModelForTableQuestionAnswering

## TFAutoModelForTokenClassification

[[autodoc]] TFAutoModelForTokenClassification

## TFAutoModelForQuestionAnswering

[[autodoc]] TFAutoModelForQuestionAnswering

## TFAutoModelForVision2Seq

[[autodoc]] TFAutoModelForVision2Seq

## TFAutoModelForSpeechSeq2Seq

[[autodoc]] TFAutoModelForSpeechSeq2Seq

## FlaxAutoModel

[[autodoc]] FlaxAutoModel

## FlaxAutoModelForCausalLM

[[autodoc]] FlaxAutoModelForCausalLM

## FlaxAutoModelForPreTraining

[[autodoc]] FlaxAutoModelForPreTraining

## FlaxAutoModelForMaskedLM

[[autodoc]] FlaxAutoModelForMaskedLM

## FlaxAutoModelForSeq2SeqLM

[[autodoc]] FlaxAutoModelForSeq2SeqLM

## FlaxAutoModelForSequenceClassification

[[autodoc]] FlaxAutoModelForSequenceClassification

## FlaxAutoModelForQuestionAnswering

[[autodoc]] FlaxAutoModelForQuestionAnswering

## FlaxAutoModelForTokenClassification

[[autodoc]] FlaxAutoModelForTokenClassification

## FlaxAutoModelForMultipleChoice

[[autodoc]] FlaxAutoModelForMultipleChoice

## FlaxAutoModelForNextSentencePrediction

[[autodoc]] FlaxAutoModelForNextSentencePrediction

## FlaxAutoModelForImageClassification

[[autodoc]] FlaxAutoModelForImageClassification

## FlaxAutoModelForVision2Seq

[[autodoc]] FlaxAutoModelForVision2Seq