Federated PathMNIST training with FedBN, PyTorch, and Flower


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# PathMNIST FedBN with Flower

This Flower / PyTorch app trains a compact CNN on PathMNIST with FedBN. It
follows the Flower PyTorch quickstart structure and uses the Message API
(`ServerApp`, `ClientApp`, `Message`, `ArrayRecord`, and `MetricRecord`).

The app does not write model artifacts, metric artifacts, or other local
training outputs. Running it only executes the federated training and evaluation
workflow.

## Project layout

```text
.
├── pathmnist_fedbn
│   ├── __init__.py
│   ├── client_app.py
│   ├── server_app.py
│   └── task.py
├── pyproject.toml
└── README.md
```

## Install

```bash
pip install -e .
```

With `uv`:

```bash
uv sync --python 3.12
```

## Run

```bash
flwr run . --stream
```

Override run settings with `--run-config`:

```bash
flwr run . \
  --run-config "num-server-rounds=1 train-samples-per-client=8 val-samples-per-client=8" \
  --stream
```


@chongshenng/pathmnist-fedbn

PathMNIST FedBN with Flower

Project layout

Install

Run