--- description: Learn about Ultralytics transformer encoder, layer, MLP block, LayerNorm2d and the deformable transformer decoder layer. Expand your understanding of these crucial AI modules. keywords: Ultralytics, Ultralytics documentation, TransformerEncoderLayer, TransformerLayer, MLPBlock, LayerNorm2d, DeformableTransformerDecoderLayer --- # Reference for `ultralytics/nn/modules/transformer.py` !!! Note This file is available at [https://github.com/ultralytics/ultralytics/blob/main/ultralytics/nn/modules/transformer.py](https://github.com/ultralytics/ultralytics/blob/main/ultralytics/nn/modules/transformer.py). If you spot a problem please help fix it by [contributing](https://docs.ultralytics.com/help/contributing/) a [Pull Request](https://github.com/ultralytics/ultralytics/edit/main/ultralytics/nn/modules/transformer.py) 🛠️. Thank you 🙏!

## ::: ultralytics.nn.modules.transformer.TransformerEncoderLayer

## ::: ultralytics.nn.modules.transformer.AIFI

## ::: ultralytics.nn.modules.transformer.TransformerLayer

## ::: ultralytics.nn.modules.transformer.TransformerBlock

## ::: ultralytics.nn.modules.transformer.MLPBlock

## ::: ultralytics.nn.modules.transformer.MLP

## ::: ultralytics.nn.modules.transformer.LayerNorm2d

## ::: ultralytics.nn.modules.transformer.MSDeformAttn

## ::: ultralytics.nn.modules.transformer.DeformableTransformerDecoderLayer

## ::: ultralytics.nn.modules.transformer.DeformableTransformerDecoder