Flower: A Friendly Federated AI Framework

Build

Flower (flwr) is a framework for building federated AI systems. The design of Flower is based on a few guiding principles:

Customizable: Federated learning systems vary wildly from one use case to another. Flower allows for a wide range of different configurations depending on the needs of each individual use case.
Extendable: Flower originated from a research project at the University of Oxford, so it was built with AI research in mind. Many components can be extended and overridden to build new state-of-the-art systems.
Framework-agnostic: Different machine learning frameworks have different strengths. Flower can be used with any machine learning framework, for example, PyTorch, TensorFlow, Hugging Face Transformers, PyTorch Lightning, scikit-learn, JAX, TFLite, MONAI, fastai, MLX, XGBoost, LeRobot for federated robots, Pandas for federated analytics, or even raw NumPy for users who enjoy computing gradients by hand.
Understandable: Flower is written with maintainability in mind. The community is encouraged to both read and contribute to the codebase.

Meet the Flower community on flower.ai!

Federated Learning Tutorial

Flower's goal is to make federated learning accessible to everyone. This series of tutorials introduces the fundamentals of federated learning and how to implement them in Flower.

What is Federated Learning?
Get started with Flower
Write your first Flower App
Write your first Flower App with PyTorch
Use a federated learning strategy
Customize a Flower Strategy
Communicate Custom Messages

Stay tuned, more tutorials are coming soon. Topics include Privacy and Security in Federated Learning, and Scaling Federated Learning.

Documentation

Flower Docs:

Flower Baselines

Flower Baselines is a collection of community-contributed projects that reproduce the experiments performed in popular federated learning publications. Researchers can build on Flower Baselines to quickly evaluate new ideas. The Flower community loves contributions! Make your work more visible and enable others to build on it by contributing it as a baseline!

Please refer to the Flower Baselines Documentation for a detailed categorization of baselines and for additional info including:

Flower Usage Examples

Several code examples show different usage scenarios of Flower (in combination with popular machine learning frameworks such as PyTorch or TensorFlow).

Quickstart examples:

Other examples:

Community

Flower is built by a wonderful community of researchers and engineers. Join Slack to meet them, contributions are welcome.

Citation

If you publish work that uses Flower, please cite Flower as follows:

@article{beutel2020flower,
  title={Flower: A Friendly Federated Learning Research Framework},
  author={Beutel, Daniel J and Topal, Taner and Mathur, Akhil and Qiu, Xinchi and Fernandez-Marques, Javier and Gao, Yan and Sani, Lorenzo and Kwing, Hei Li and Parcollet, Titouan and Gusmão, Pedro PB de and Lane, Nicholas D},
  journal={arXiv preprint arXiv:2007.14390},
  year={2020}
}

Please also consider adding your publication to the list of Flower-based publications in the docs, just open a Pull Request.

Contributing to Flower

We welcome contributions. Please see CONTRIBUTING.md to get started!

Release files for flwr-nightly 1.38.0.dev20260918

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for flwr-nightly 1.38.0.dev20260918
File	Size	Uploaded
flwr_nightly-1.38.0.dev20260918.tar.gz	672.1 kB	Sep 18, 2026	Details

Built distribution (wheel)

Table of built distributions (wheels) for flwr-nightly 1.38.0.dev20260918
File	Interpreter	ABI	Platform	Reset
flwr_nightly-1.38.0.dev20260918-py3-none-any.whl 1.2 MB Sep 18, 2026	Python 3	none	any	Details

Total release size: 1.8 MB

Release files / flwr_nightly-1.38.0.dev20260918.tar.gz

Download URL	flwr_nightly-1.38.0.dev20260918.tar.gz
Size	672.1 kB
Tags	Source
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Upload date	Sep 18, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`uv/0.10.7 {"installer":{"name":"uv","version":"0.10.7","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"Ubuntu","version":"24.04","id":"noble","libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":true}`

Release files / flwr_nightly-1.38.0.dev20260918-py3-none-any.whl

Download URL	flwr_nightly-1.38.0.dev20260918-py3-none-any.whl
Size	1.2 MB
Tags	Python 3
SHA-256 checksum How to use checksums	`568160c2d33a8fbfd1b8f6df6675f166392366cd921dea5eb802757e4618b31c`
BLAKE2b-256 checksum How to use checksums	`87c6cecec268b23f8a8390ff53ffda78217ff989eb3a493ae724be8bba3dbc77`
Upload date	Sep 18, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`uv/0.10.7 {"installer":{"name":"uv","version":"0.10.7","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"Ubuntu","version":"24.04","id":"noble","libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":true}`