KerasNLP: Modular NLP Workflows for Keras

KerasNLP is a natural language processing library that works natively with TensorFlow, JAX, or PyTorch. Built on Keras 3, these models, layers, metrics, and tokenizers can be trained and serialized in any framework and re-used in another without costly migrations.

KerasNLP supports users through their entire development cycle. Our workflows are built from modular components that have state-of-the-art preset weights and architectures when used out-of-the-box and are easily customizable when more control is needed.

This library is an extension of the core Keras API; all high-level modules are Layers or Models that receive that same level of polish as core Keras. If you are familiar with Keras, congratulations! You already understand most of KerasNLP.

See our Getting Started guide for example usage of our modular API starting with evaluating pretrained models and building up to designing a novel transformer architecture and training a tokenizer from scratch.

We are a new and growing project and welcome contributions.

Quick Links

For everyone

• Home Page
• Developer Guides
• API Reference
• Getting Started guide

For contributors

• Contributing Guide
• Roadmap
• Style Guide
• API Design Guide
• Call for Contributions

Installation

KerasNLP supports both Keras 2 and Keras 3. We recommend Keras 3 for all new users, as it enables using KerasNLP models and layers with JAX, TensorFlow and PyTorch.

Keras 2 Installation

To install the latest KerasNLP release with Keras 2, simply run:

pip install --upgrade keras-nlp

Keras 3 Installation

There are currently two ways to install Keras 3 with KerasNLP. To install the stable versions of KerasNLP and Keras 3, you should install Keras 3 after installing KerasNLP. This is a temporary step while TensorFlow is pinned to Keras 2, and will no longer be necessary after TensorFlow 2.16.

pip install --upgrade keras-nlp
pip install --upgrade keras>=3

Using KerasNLP with Keras Core

As of version 0.6.0, KerasNLP supports multiple backends with Keras Core out of the box. There are two ways to configure KerasNLP to run with multi-backend support:

1. Via the KERAS_BACKEND environment variable. If set, then KerasNLP will be using Keras Core with the backend specified (e.g., KERAS_BACKEND=jax).
2. Via the .keras/keras.json and .keras/keras_nlp.json config files (which are automatically created the first time you import KerasNLP):
   • Set your backend of choice in .keras/keras.json; e.g., "backend": "jax".
   • Set "multi_backend": True in .keras/keras_nlp.json.

Once that configuration step is done, you can just import KerasNLP and start using it on top of your backend of choice:

import keras_nlp

gpt2_lm = keras_nlp.models.GPT2CausalLM.from_preset("gpt2_base_en")
gpt2_lm.generate("My trip to Yosemite was", max_length=200)

Until Keras Core is officially released as Keras 3.0, KerasNLP will use tf.keras as the default backend. To restore this default behavior, simply unset KERAS_BACKEND and ensure that "multi_backend": False or is unset in .keras/keras_nlp.json. You will need to restart the Python runtime for changes to take effect.

To install the latest nightly changes for both KerasNLP and Keras, you can use our nightly package.

pip install --upgrade keras-nlp-nightly

[!IMPORTANT] Keras 3 will not function with TensorFlow 2.14 or earlier.

Read Getting started with Keras for more information on installing Keras 3 and compatibility with different frameworks.

Quickstart

Fine-tune BERT on a small sentiment analysis task using the keras_nlp.models API:

import os
os.environ["KERAS_BACKEND"] = "tensorflow"  # Or "jax" or "torch"!

import keras_nlp
import tensorflow_datasets as tfds

imdb_train, imdb_test = tfds.load(
    "imdb_reviews",
    split=["train", "test"],
    as_supervised=True,
    batch_size=16,
)
# Load a BERT model.
classifier = keras_nlp.models.BertClassifier.from_preset(
    "bert_base_en_uncased", 
    num_classes=2,
)
# Fine-tune on IMDb movie reviews.
classifier.fit(imdb_train, validation_data=imdb_test)
# Predict two new examples.
classifier.predict(["What an amazing movie!", "A total waste of my time."])

For more in depth guides and examples, visit https://keras.io/keras_nlp/.

Configuring your backend

If you have Keras 3 installed in your environment (see installation above), you can use KerasNLP with any of JAX, TensorFlow and PyTorch. To do so, set the KERAS_BACKEND environment variable. For example:

export KERAS_BACKEND=jax

Or in Colab, with:

import os
os.environ["KERAS_BACKEND"] = "jax"

import keras_nlp

[!IMPORTANT] Make sure to set the KERAS_BACKEND before import any Keras libraries, it will be used to set up Keras when it is first imported.

Compatibility

We follow Semantic Versioning, and plan to provide backwards compatibility guarantees both for code and saved models built with our components. While we continue with pre-release 0.y.z development, we may break compatibility at any time and APIs should not be consider stable.

Disclaimer

KerasNLP provides access to pre-trained models via the keras_nlp.models API. These pre-trained models are provided on an "as is" basis, without warranties or conditions of any kind. The following underlying models are provided by third parties, and subject to separate licenses: BART, DeBERTa, DistilBERT, GPT-2, OPT, RoBERTa, Whisper, and XLM-RoBERTa.

Citing KerasNLP

If KerasNLP helps your research, we appreciate your citations. Here is the BibTeX entry:

@misc{kerasnlp2022,
  title={KerasNLP},
  author={Watson, Matthew, and Qian, Chen, and Bischof, Jonathan and Chollet, 
  Fran\c{c}ois and others},
  year={2022},
  howpublished={\url{https://github.com/keras-team/keras-nlp}},
}

Acknowledgements

Thank you to all of our wonderful contributors!