goui

README

Build lightweight, modern desktop apps in Go—no GCC required

中文

GOUI is a native GUI framework written entirely in Go. Build both your interface and application logic in Go, without a browser engine or a C/C++ build toolchain.

The current version provides the foundations and controls needed for small desktop applications; public APIs are still evolving.

Related projects

Project	Purpose
goui-sourceview	Code editor extension with syntax highlighting, completion, bracket matching, and find/replace.
applesdk	Pure Go macOS SDK bindings for services including StoreKit, iCloud, and CloudKit.

Try the demo

The demo brings together controls, text editing, layouts, data views, detachable tabs, overlays, graphics, animations, and system integration. Switch between light/dark appearances, accent colors, and eight UI languages.

The current source prepares Demo 0.7.0 / build 1, adding shared commands and menu shortcut columns, independent corner radii with box shadows, selective borders, and optional Go execution tracing. See the demo guide for controls and validation steps. The downloads and screenshots below remain the published v0.6.0 artifacts until the next release is available.

Platform	Demo download
Windows x64	Download EXE
macOS Apple Silicon	Download .app ZIP
Linux x64 / X11	Download executable

The downloads above are Demo 0.6.0 / build 1. See the release notes and its BUILD-INFO.md / SHA256SUMS attachments for provenance and validation scope.

On Linux, run chmod +x goui-demo-v0.6.0-linux-amd64 before launching it. On macOS, extract and open GOUI Demo.app; the bundle is Developer ID signed and Apple-notarized.

Windows — Direct2D, dark appearance

macOS — OpenGL, light appearance

Linux / X11 — OpenGL, light appearance

To run the current source from the repository root:

CGO_ENABLED=0 go run ./example/demo

Why GOUI?

• No cgo, no GCC. Build desktop applications with CGO_ENABLED=0 using the Go toolchain, including cross-compilation for supported targets. Native APIs are bound at runtime; building your desktop application does not require a C/C++ compiler.
• One binary, one app. Embed icons and other assets with Go's embed package. Windows executables and Linux binaries can run directly; macOS can wrap the executable in an .app for application identity, icons, and signing.
• Modern appearance, native integration. A consistent Modern stylesheet with light/dark modes and accent colors, paired with native window chrome, fonts, text layout, IME, clipboard, and file dialogs.
• AI-friendly. Semantic snapshots describe the widget tree. The gui/dev adapter supports inspecting windows and popovers, dispatching input, and committing text for debugging and AI automation.

Single-binary delivery does not mean there are no system dependencies. GOUI loads native system libraries at runtime. See platforms and dependencies for requirements.

Standing on the shoulders of giants

GOUI learns from mature frameworks rather than inventing every mechanism:

GTK4 for widgets and event controllers, Flutter for constraint-based layout, Qt and Avalonia for desktop integration, and SwiftUI for declarative composition. The result remains Go-shaped, not an imitation of any one framework.

Rendering builds on native Direct2D/DirectWrite, Core Text, and Pango/Cairo, alongside the project's NanoVG Go fork. SVG support uses the project's oksvg fork. GOUI keeps these foundations behind clear platform, widget, and declarative layers.

Size and memory

GOUI is a lightweight native GUI framework. Actual executable size and runtime memory usage depend on the application and rendering backend.

Executable size

Built with Go 1.25.8, CGO_ENABLED=0, -trimpath, and -ldflags="-s -w", with -H=windowsgui also set on Windows.

Target	Minimal app	Demo
Windows amd64	4.58 MiB	8.56 MiB
macOS arm64	4.75 MiB	8.26 MiB
Linux amd64	4.46 MiB	8.43 MiB

The full demo includes its logo, SVG icons, eight-language resources, and nine feature pages. Windows includes generated icon and version resources. These figures are from development builds, not published release artifacts; .app metadata, installer/archive overhead, and system libraries are not included.

Process memory usage

Application	RSS	PSS
Minimal app	58.8 MiB	28.6 MiB
Demo	78.5 MiB	46.2 MiB

RSS includes resident shared-library pages; PSS apportions shared pages between processes. The figures are summed from Linux /proc/<pid>/smaps and are provided for reference; results on other platforms may differ.

What you can build with today

Area	Supported capabilities
Declarative UI	State and property bindings, local dependency tracking and subtree updates, composed views, common view modifiers, and custom Widgets/Views.
Controls	Buttons and connected button groups, images/icons, check/radio/toggle buttons and groups, switches, dropdowns, and linear/circular progress indicators.
Text	Formatted and selectable Labels; Unicode single-line/multiline editing, native window IME, selection, clipboard, undo/redo, placeholders, configurable obscuring, brief last-grapheme reveal, and composable input filters.
Layout	Constraint-based horizontal/vertical boxes, wrapping, baseline alignment, per-edge padding, scrolling, split views, and overlays.
Data views	Virtualized lists, trees with reusable expanders, and tables with custom editable cells, column visibility/stretching, sorting, resizing, grid lines, and alternating row colors.
Tabbed workspaces	Close requests and context menus, drag reordering, shrinking and overflow scrolling, cross-window transfer, and detaching into new windows.
Menus and overlays	Menu buttons and coordinated menu groups, shared Commands with live availability and independent shortcut-text columns, context menus, popovers, tooltips, modal input boundaries, in-window Dialogs, and Toasts.
Input	Shortcuts, Tab navigation and keyboard focus hints, event controllers, gesture competition, and drag and drop within and across applications.
Graphics and appearance	Software/OpenGL/Direct2D backends, HiDPI, transforms, clipping and path erasure, transparency, independent corner radii, selective borders with a uniform width and color, box shadows, SVG and style-aware icons, custom painting, cached DrawingArea rendering, and offscreen widget rendering.
Themes and localization	Basic fallback and Modern themes, light/dark modes, accent and semantic colors, style scopes, system settings, localization resources, and built-in text in eight languages.
Windows and system integration	Native/integrated/custom chrome, HeaderBar and window controls, transparent windows, positioning/initial centering, taskbar preferences, file dialogs and access credentials, clipboard, and opening URLs/files.
Timing and developer tools	GUI-thread timers, frame-driven animation with custom interpolation/curves, drawable checks and clipping-based paint culling, semantic snapshots and input automation, opt-in CPU-frame/resource diagnostics and FPS HUD, standard Go execution tracing, and build/package tools.

Core controls live in gui, with declarative bindings in ui. Additional controls live in widgets, with their declarative bindings in widgets/ui.

v0.7.0 highlights — release preparation

• Shared operations: menus and shortcuts can use one Command, with live enabled-state updates and aligned shortcut text. Declarative windows supply a default command group; local CommandGroup scopes, DefineCommand, and BindEnabled keep definitions and state updates explicit.
• Corners and borders: four independent corner radii and matching BoxShadow contours work across Software, OpenGL, and Direct2D. BorderSides selects single, parallel, L-shaped, or three-sided borders with one width and color; the demo shows the rounded transitions at omitted edges.
• Less offscreen work: painting skips subtrees fully outside the clip. Busy indicators and the demo's frame-driven DrawingArea stop requesting frames when fully clipped and resume when visible; business timers retain their own lifecycle.
• Frame inspection: the optional FPS HUD shows 0 when idle. Go runtime/trace records frame tasks and layout/paint phases independently of diagnostic Capture. These are CPU/runtime observations, not monitor refresh rates or GPU presentation timings.
• Stability and resource use: localization cache reads avoid repeated locking on the fast path; table trailing grid lines, row-decoration bounds, and variable-height scrolling have been corrected.
• Mobile preparation: Android/iOS foundations have reached simulator validation; complete mobile support is in development.

Build with an AI coding assistant

The GOUI application development Skill guides your AI through GOUI APIs, state, layout, styles, resources, building, and debugging. To install it, tell your AI:

Install the GOUI application development skill following https://github.com/golang-gui/goui/blob/main/skills/INSTALL.md.

The AI follows the installation instructions using its tool's native skill mechanism; no GOUI-specific Agent adapter or manual file copying is required. Tools without Skill support can read the guide directly, but this is not a native installation. Installing the Skill does not install or upgrade your application's GOUI dependency.

For code editor integration and customization, use the SourceView application development Skill, maintained in the SourceView repository with its own installation guide.

Quick start

Requires Go 1.24 or newer and a supported desktop environment. Create a module and add GOUI:

mkdir hello-goui
cd hello-goui
go mod init example.com/hello-goui
go get github.com/golang-gui/goui@latest

Save as main.go:

package main

import (
    "fmt"
    "log"

    "github.com/golang-gui/goui/theme/modern"
    "github.com/golang-gui/goui/ui"
)

func counterText(count *ui.State[int]) ui.View {
    return ui.Build(func() ui.View {
        return ui.Label(fmt.Sprintf("Clicked %d times", count.Get()))
    })
}

func main() {
    count := ui.MakeState(0)
    err := ui.Run("com.example.Hello", func(app ui.App) ui.RootView {
        return ui.Root().
            StyleSheet(modern.FromSettings(app.Settings())). // Use the Modern theme
            Windows(
                ui.Window("main").
                    Title("Hello GOUI").
                    Size(480, 240).
                    Content(
                        ui.VBox(
                            ui.Modify(counterText(&count)).MainWeight(1),
                            ui.Button("Click me").OnClick(func() {
                                // Prefer Update to count.Set(count.Get() + 1):
                                count.Update(func(old int) int {
                                    return old + 1
                                })
                            }),
                        ).Spacing(12).Padding(20),
                    ),
            )
    })
    if err != nil {
        log.Fatal(err)
    }
}

Build and run on your current platform:

CGO_ENABLED=0 go build -trimpath -ldflags="-s -w" -o hello-goui .
./hello-goui

On Windows PowerShell, use $env:CGO_ENABLED='0', then run:

go build -trimpath -ldflags="-s -w -H=windowsgui" -o hello-goui.exe ..

Views are ordinary Go values. ui.Build automatically tracks State.Get() reads during its synchronous build; changes rebuild that subtree. Keep state outside repeatedly built views, as count is here. Use ui.Modify to apply common modifiers to a function's ui.View result without adding a widget or layout boundary. Individual properties can use bindings such as BindText(&state); App.RequestUpdate explicitly rebuilds the application. System settings changes also rebuild this example, updating its Modern stylesheet.

Platforms and dependencies

The desktop application targets are:

Platform / current release target	Window system	Drawing backends	Text layout
Windows / amd64	Win32	Direct2D, OpenGL, Software	DirectWrite
macOS / arm64	AppKit	OpenGL, Software	Core Text
Linux / amd64	X11	OpenGL, Software	Pango / Cairo

On Windows and macOS, native frameworks are supplied by the operating system. On Linux, the current backend needs an X11 display server; Wayland sessions need XWayland, and window behavior still needs validation on the target desktop. Runtime libraries include X11/Xext/Xrender/Xrandr/Xcursor, GL/GLX, GLib/GIO, Fontconfig, and Pango/Cairo. Settings integration and native file dialogs use GTK. No development headers or C compiler are needed. Linux Integrated decoration additionally needs a compositor; otherwise GOUI can fall back to native decoration.

You can select a drawing backend with GOUI_PLAT_PAINTER=software or opengl; Windows also accepts direct2d. See the demo guide for platform details.

Build and package

Ordinary go build is sufficient to build an application. The optional cmd/goui tool handles platform resources and packaging from goui.toml: Windows icon/version resources, macOS Info.plist/ICNS/.app and explicit signing, and Linux desktop/icon resources. These steps do not require GCC; macOS signing uses the platform's codesign tool.

For example, build the demo and its platform resources:

CGO_ENABLED=0 go run ./cmd/goui build -config example/demo/goui.toml -ldflags="-s -w"

Mobile support

Android and iOS support is in development. Native windows, rendering, typography, and application builds have reached initial simulator validation; complete mobile UI and input support is still being developed. Desktop applications remain the current focus.

Environment variables

These are usually unnecessary. Set them before launching the application for startup configuration, debugging, or compatibility checks. Restart the application after changing them; they are not runtime switching interfaces.

Variable	Purpose and values	Default behavior
GOUI_PLAT_SCALE	Overrides the logical-unit-to-physical-pixel scale; fractional values such as 1, 1.5, and 2 are supported	Uses the platform's system scale; an unset, unparseable, or non-positive value does not override it
GOUI_PLAT_PAINTER	Selects a drawing backend: opengl, software; Windows also accepts direct2d	Uses the platform's default backend and initialization fallback policy

GOUI_PLAT_SCALE=2 means 1 DIP maps to 2 physical pixels. It does not change the operating system's display settings or replace HiDPI testing on real devices.

Backend names are lowercase. An unset or unrecognized name uses the default:

• Windows: Direct2D by default, falling back to OpenGL and then Software if initialization fails.

  Specifying direct2d follows the same sequence; explicitly selecting opengl does not fall back and returns an error if initialization fails.

• Linux / macOS: OpenGL by default, falling back to Software if initialization fails. Specifying opengl follows the same policy.

• Specifying software selects software rendering directly. These fallbacks occur during backend initialization, not automatically while the app is running.

Linux / X11 also recognizes these compatibility variables:

Variable	Purpose
GDK_SCALE	Sets a scale such as 1 or 2; precedence is GOUI_PLAT_SCALE > GDK_SCALE > desktop DPI settings
XCURSOR_THEME	Selects an installed cursor theme, overriding the desktop cursor theme setting
XCURSOR_SIZE	Sets the cursor size in positive integer pixels, such as 24 or 32, overriding the desktop cursor size setting

For example, launch the software-rendered demo at 2x from the repository root using Bash:

CGO_ENABLED=0 GOUI_PLAT_PAINTER=software GOUI_PLAT_SCALE=2 go run ./example/demo

Windows PowerShell:

$env:CGO_ENABLED = '0'
$env:GOUI_PLAT_PAINTER = 'direct2d'
$env:GOUI_PLAT_SCALE = '1.5'
go run ./example/demo

Variables in the Bash example apply only to that command; those in the PowerShell example remain set in the current terminal session. To restore automatic selection, remove the relevant variables and restart the application. For example, in PowerShell: Remove-Item Env:GOUI_PLAT_PAINTER, Env:GOUI_PLAT_SCALE -ErrorAction SilentlyContinue.

Optional development tools

GOUI_DEV_ADDR is the listening address for the gui/dev development adapter, not a platform rendering setting. First add import _ "github.com/golang-gui/goui/gui/dev" to the application, then set the variable to enable the service. It does not start unless the package is imported and the variable is set. For an application that already imports the package:

GOUI_DEV_ADDR=127.0.0.1:8888 ./your-app

The service provides semantic snapshots, input event dispatch, and text submission. Use it only for local development; enabling it in production is not recommended.

The separate gui/diagnostics package offers explicitly controlled CPU-frame and resource captures without a development server. The dev adapter also exposes /goui/dev/diagnostics for starting, reading, and stopping a capture; reading alone never enables it.

A capture can also show a click-through FPS HUD. Without a capture, standard Go runtime/trace still records goui.frame tasks and layout/paint phases when tracing is explicitly enabled. The demo provides -trace <file>; close it normally, then run go tool trace <file>. For CPU and allocation profiling, use Go's standard pprof tools. GOUI does not automatically start a profiler, HTTP server, or continuous redraw loop.

A small, layered design

ui        Declarative views and explicit update coordination
gui       Widgets, layout, painting, events, focus, signals, and snapshots
platform  Native windows, event loops, input, drawing, and typography

Use only the layers you need. animation, layout, style, icon, and mlang provide focused capabilities; gui/dev is an opt-in debugging adapter. GOUI aims to be a practical GUI toolkit, not a browser or an all-purpose platform SDK.

Roadmap

• Continue Android/iOS support and add touch input while preserving the desktop experience.
• Support more architectures, window systems, and rendering backends.
• Add more purpose-built controls and reusable application components.
• Keep optimizing performance and memory use, backed by reproducible measurements.

License and acknowledgements

GOUI is MIT licensed. Dependencies retain their own licenses.

The logo retains attribution to the Go gopher by Renee French (CC BY 4.0).