Fleury

A retained-mode UI framework for the terminal — and the browser.
One widget tree, two surfaces.

Documentation · Get started · Widgets · Showcases

Fleury brings a Flutter-shaped authoring model to cell-based interfaces: compose widgets, keep state with StatefulWidget, rebuild with setState, and let the framework incrementally lay out and paint the result.

The same reusable widget tree can run in a native terminal or mount into a web page. Alongside the visual tree, Fleury builds a semantic graph that tests and AI agents can inspect and operate by meaning instead of terminal coordinates.

• A familiar retained UI model. Widgets, state, context, keys, constraints, focus, navigation, animation, and inherited dependencies compose the way application developers expect.
• Terminal-native rendering. Fleury paints grapheme-aware cells and sends diffed ANSI output instead of treating the terminal like a pixel canvas.
• Terminal and browser targets. Share application UI while choosing a native terminal host, a client-side web mount, or a served browser session.
• A real widget library. Forms, tables, trees, charts, document views, and agent-oriented surfaces live in fleury_widgets.
• Semantics from the start. The same semantic model supports testing, browser accessibility, inspection, and agent actions.

After installing the CLI:

fleury create my_app --dependency-source=git
cd my_app

The generated project includes a runnable counter, a widget test, and the minimal VS Code configuration needed for F5 to launch into an interactive terminal. The Git-source flag is only needed during the pre-release window; under the scaffold, the application remains ordinary Dart:

import 'package:fleury/fleury.dart';

void main() => runApp(
  const FleuryApp(
    title: 'My app',
    home: Center(child: Text('Hello, cells!')),
  ),
);

The getting-started guide covers installation, state, higher-level widgets, and running the same tree in a browser.

The launch target is a modern UTF-8, xterm-compatible terminal on POSIX. Fleury negotiates optional protocols such as Kitty keyboard and synchronized output, and retains legacy keyboard, ordinary ANSI-frame, glyph-image, and plain-link fallbacks when they are unavailable.

The Windows driver is available as a preview, but real-Windows acceptance is still pending and Windows is not part of the launch support claim. Native Sixel rendering is also experimental until cell-pixel geometry is negotiated; Kitty and iTerm2 images remain progressive enhancements, with cell art as the portable image path.

• Browse the widget catalog
• Build a multi-screen app
• Understand the architecture
• Drive an app with an agent

From a checkout, bootstrap the workspace and run the normal validation gate:

dart tool/fleury_dev.dart bootstrap
dart tool/fleury_dev.dart check --quick

Contributor notes and architecture records live under docs/; the public documentation is built from website/.