RyUI documentation

RyUI makes native iOS and Android apps in Go. An app's interface is Go functions that return views; RyUI shows them with each platform's own widgets (UIKit on iOS, Android Views and Material 3 on Android), and updates only the views that read a signal when it changes.

func Counter() ui.Node {
	count := signal.New(0)
	label := signal.Func(func() string {
		return fmt.Sprintf("Count: %d", count.Get())
	})
	return ui.SafeArea(ui.Style{Align: ui.AlignCenter, Justify: ui.JustifyCenter},
		ui.Text(label),
		ui.Button(ui.ButtonProps{
			Title:   ui.Val("Add"),
			Variant: ui.ButtonFilled,
			OnPress: func() { count.Set(count.Peek() + 1) },
		}),
	)
}

func main() { app.Run(Counter) }

How it works

Your app is Go: its components, its state and the rest of its code, in one library built into the app. RyUI's core runs the components, lays the views out (flexbox, in Go), and sends the platform what changed, in a batch for each frame; the app's host, in Swift on iOS and Kotlin on Android, makes and updates the platform's own views. A text field is a UITextField or an EditText, a list a UICollectionView or a RecyclerView, a stack of screens a UINavigationController or Material's app bar with its back gesture. So an app that sets no style looks as the platform's apps do, and gets their accessibility, text input and scrolling as they have them.

Signals hold the state. A component runs once; when a signal changes, only the props that read it are sent again, without diffing a tree.

RyUI needs Go 1.26 or later, and runs on iOS 16 and Android 8 (API 26) and later. ryui dev runs your Go code on your Mac while you work, and reloads it as you save, on the simulator, an emulator or a phone.

Guides

Reference