Quickstart5 minutes

Your first Bretzel app

Create the project, run the server, then edit a page. At the end you will have completed the essential loop: describe the interface in Python and watch the browser follow.

Install the public alpha

Bretzel 0.1.0a2 is available on PyPI. Use Python 3.12, 3.13 or 3.14; the API may change between alpha releases.

python -m pip install bretzel

Create the project

bretzel new hello-bretzel
cd hello-bretzel
python -m venv .venv

`bretzel new` creates a minimal application in a new folder. It refuses to overwrite an existing directory.

Activate the environment

Windows PowerShell

.\.venv\Scripts\Activate.ps1

macOS or Linux

source .venv/bin/activate

Install and run

python -m pip install -e .
bretzel dev

Open `http://127.0.0.1:8000`. `bretzel dev` watches your files and restarts the application after every change.

Edit the page

Open `app/features/home.py`, change the heading, and save. The browser reloads the application.

ui.heading("My first Bretzel", level=1, size="4xl")

What the generator created

hello-bretzel/
├── app/
│   ├── main.py              # configures the application
│   └── features/
│       └── home.py          # your first page
├── pyproject.toml
└── README.md

Understand the model Read the configuration