goi

A declarative GUI framework for Go, rendered with WebGPU.

goi describes a window in .goi files: elements, properties, ids, if/else and for loops. Go finds elements by id, holds the state and attaches the behaviour. Edit a .goi file and the window updates without a restart: hot reload is built in.

bridge {
	Count int
	onInc func()
}

Window {
	title: "Counter"

	Column {
		padding:        24
		spacing:        16
		crossAxisAlign: center

		Text {
			text: formatf("%d", bridge.Count)
			role: displayLarge
		}

		Button {
			id:      inc
			label:   "+"
			onClick: bridge.onInc()
		}
	}
}

var count int // outside Bind: Bind runs again after every hot reload

func main() {
	app, _ := ui.NewApp()
	win, _ := app.LoadWindowFile("counter.goi", ui.WithHotReload(true))

	win.Bind(func(w *ui.Window) error {
		ui.SetData(w, "Count", count)
		return ui.SetHandler(w, "onInc", func() {
			count++
			ui.SetData(w, "Count", count)
		})
	})

	app.Run()
}

SetData feeds bridge.Count; SetHandler supplies the body a bridge call runs. The label follows the value without a manual repaint.

Start here

• .goi syntax — the language reference: declarations, imports, props, slots and literals.
• Conditionals, loops — showing an arm or repeating elements.
• Bridge — passing values and handlers from Go.
• Fragments — splitting a design across files with props, children and named slots.
• Components — every element, grouped by purpose, with a .goi example and its properties.
• Icons — every Material Symbols name the renderer can draw.
• Zed extension — highlighting, completion and diagnostics for .goi files.

Install

go get github.com/goi-gui/goi/ui

The WebGPU renderer and the SDL3 window layer live behind the ui package. Only ui is imported by an application.