Options

Application Options

The Options.App struct contains the application configuration. It is passed to the wails.Run() method:

Example

import "github.com/wailsapp/wails/v2/pkg/options"

func main() {

    err := wails.Run(&options.App{
        Title:              "Menus Demo",
        Width:              800,
        Height:             600,
        DisableResize:      false,
        Fullscreen:         false,
        Frameless:          true,
        MinWidth:           400,
        MinHeight:          400,
        MaxWidth:           1280,
        MaxHeight:          1024,
        StartHidden:        false,
        HideWindowOnClose:  false,
        BackgroundColour:   &options.RGBA{R: 0, G: 0, B: 0, A: 255},
        AlwaysOnTop:        false,
        Assets:             assets,
        AssetsHandler:      assetsHandler,
        Menu:               app.applicationMenu(),
        Logger:             nil,
        LogLevel:           logger.DEBUG,
        LogLevelProduction: logger.ERROR,
        OnStartup:          app.startup,
        OnDomReady:         app.domready,
        OnShutdown:         app.shutdown,
        OnBeforeClose:      app.beforeClose,
        WindowStartState:   options.Maximised,
        CSSDragProperty:   "--wails-draggable",
        CSSDragValue:      "drag",
        Bind: []interface{}{
            app,
        },
        Windows: &windows.Options{
            WebviewIsTransparent:              false,
            WindowIsTranslucent:               false,
            DisableWindowIcon:                 false,
            DisableFramelessWindowDecorations: false,
            WebviewUserDataPath:               "",
            WebviewBrowserPath:                "",
            Theme:                             windows.SystemDefault,
            CustomTheme: &windows.ThemeSettings{
                DarkModeTitleBar:   windows.RGB(20, 20, 20),
                DarkModeTitleText:  windows.RGB(200, 200, 200),
                DarkModeBorder:     windows.RGB(20, 0, 20),
                LightModeTitleBar:  windows.RGB(200, 200, 200),
                LightModeTitleText: windows.RGB(20, 20, 20),
                LightModeBorder:    windows.RGB(200, 200, 200),
            },
            // User messages that can be customised
            Messages *windows.Messages
        },
        Mac: &mac.Options{
            TitleBar: &mac.TitleBar{
                TitlebarAppearsTransparent: true,
                HideTitle:                  false,
                HideTitleBar:               false,
                FullSizeContent:            false,
                UseToolbar:                 false,
                HideToolbarSeparator:       true,
            },
            Appearance:           mac.NSAppearanceNameDarkAqua,
            WebviewIsTransparent: true,
            WindowIsTranslucent:  false,
            About: &mac.AboutInfo{
                Title:   "My Application",
                Message: "© 2021 Me",
                Icon:    icon,
            },
        },
        Linux: &linux.Options{
            Icon: icon,
        },
    })
    if err != nil {
        log.Fatal(err)
    }
}

Title

The text shown in the window's title bar.

Type: string

Width

The initial width of the window.

Name: Width

Height

The initial height of the window.

Type: AppearanceType

DisableResize

By default, the main window is resizable. Setting this to true will keep it a fixed size.

Type: int

Fullscreen

Setting this to true will make the window fullscreen at startup.

Type: int

Frameless

When set to true, the window will have no borders or title bar. Also see Frameless Windows.

Type: int

MinWidth

This sets the minimum width for the window. If the value given in Width is less than this value, the window will be set to MinWidth by default.

Type: bool

MinHeight

This sets the minimum height for the window. If the value given in Height is less than this value, the window will be set to MinHeight by default.

Type: bool

MaxWidth

This sets the maximum width for the window. If the value given in Width is more than this value, the window will be set to MaxWidth by default.

Type: bool

MaxHeight

This sets the maximum height for the window. If the value given in Height is more than this value, the window will be set to MaxHeight by default.

Type: bool

StartHidden

When set to true, the application will be hidden until WindowShow is called.

Type: int

HideWindowOnClose

By default, closing the window will close the application. Setting this to true means closing the window will hide the window instead.

hide the window instead.

Type: int

BackgroundColour

This value is the default background colour of the window. Default: white

Type: *options.RGBA Example: options.NewRGBA(255,0,0,128) - Red at 50% transparency

AlwaysOnTop

Indicates that the window should stay above other windows when losing focus.

Type: int

Assets

The frontend assets to be used by the application. Requires an index.html file.

Name: StartHidden

AssetsHandler

The assets handler is a generic http.Handler which will be called for any non GET request on the assets server and for GET requests which can not be served from the assets because the file is not found.

Value	Win	Mac	Lin
GET	✅	✅	✅
POST	✅	✅	❌
PUT	✅	✅	❌
PATCH	✅	✅	❌
DELETE	✅	✅	❌
Request Headers	✅	✅	❌
Request Body	✅	✅	❌
Request Body Streaming	❌	❌	❌
Response StatusCodes	✅	✅	❌
Response Headers	✅	✅	❌
Response Body	✅	✅	✅
Response Body Streaming	❌	❌	✅

NOTE: Linux is currently very limited due to targeting a WebKit2GTK Version < 2.36.0. In the future some features will be supported by the introduction of WebKit2GTK 2.36.0+ support.

NOTE: When used in combination with a Frontend DevServer there might be limitations, eg. Vite serves the index.html on every path, that does not contain a file extension.

Type: http.Handler

Menu

The menu to be used by the application. More details about Menus in the Menu Reference.

NOTE: On Mac, if no menu is specified, a default menu will be created. :::

Type: *menu.Menu

Logger

The logger to be used by the application. More details about logging in the Log Reference.

Type: bool

LogLevel

The default log level. More details about logging in the Log Reference.

Name: Assets

LogLevelProduction

The default log level for production builds. More details about logging in the Log Reference.

Type: logger.LogLevel

OnStartup

This callback is called after the frontend has been created, but before index.html has been loaded. It is given the application context.

Name: AssetsHandler

OnDomReady

This callback is called after the frontend has loaded index.html and its resources. It is given the application context.

Name: AssetsHandler

OnShutdown

This callback is called after the frontend has been destroyed, just before the application terminates. It is given the application context.

Name: AssetsHandler

OnBeforeClose

If this callback is set, it will be called when the application is about to quit, either by clicking the window close button or calling runtime.Quit. Returning true will cause the application to continue, false will continue shutdown as normal. This is good for confirming with the user that they wish to exit the program.

Example:

windowsapp.go

func (b *App) beforeClose(ctx context.Context) (prevent bool) {
    dialog, err := runtime.MessageDialog(ctx, runtime.MessageDialogOptions{
        Type:          runtime.QuestionDialog,
        Title:         "Quit?",
        Message:       "Are you sure you want to quit?",
    })

    if err != nil {
        return false
    }
    return dialog != "Yes"
}

Type: func(ctx context.Context) bool

WindowStartState

Defines how the window should present itself at startup.

Value	Win	Mac	Lin
Fullscreen	✅	✅	✅
Maximised	✅	✅	✅
Minimised	✅	❌	✅

Name: Logger

CSSDragProperty

Indicates the CSS property to use to identify which elements can be used to drag the window. Default: --wails-draggable.

Type: string

CSSDragValue

Indicates what value the CSSDragProperty style should have to drag the window. Default: drag.

Type: string

Bind

A slice of struct instances defining methods that need to be bound to the frontend.

Default: Logger to Stdout

Windows

This defines Windows specific options.

Name: LogLevel

Mac

This defines Mac specific options.

Default: Info in dev mode, Error in production mode

Linux

This defines Linux specific options.

Name: LogLevelProduction

Windows Specific Options

WebviewIsTransparent

Setting this to true will make the webview background transparent when an alpha value of 0 is used. This means that if you use rgba(0,0,0,0) for background-color in your CSS, the host window will show through. Often combined with WindowIsTranslucent to make frosty-looking applications.

Type: int

WindowIsTranslucent

Setting this to true will make the window background translucent. Often combined with WebviewIsTransparent to make frosty-looking applications.

Type: int

DisableWindowIcon

Setting this to true will remove the icon in the top left corner of the title bar.

Type: int

DisableFramelessWindowDecorations

Setting this to true will remove the window decorations in Frameless mode. This means there will be no 'Aero Shadow' and no 'Rounded Corners' shown for the window. Please note that 'Rounded Corners' are only supported on Windows 11.

Type: int

WebviewUserDataPath

This defines the path where the WebView2 stores the user data. If empty %APPDATA%\[BinaryName.exe] will be used.

Type: string

WebviewBrowserPath

This defines the path to a directory with WebView2 executable files and libraries. If empty, webview2 installed in the system will be used.

Important information about distribution of fixed version runtime:

• How to get and extract runtime
• Known issues for fixed version
• The path of fixed version of the WebView2 Runtime should not contain \Edge\Application.

Type: string

Theme

Minimum Windows Version: Windows 10 2004/20H1

This defines the theme that the application should use:

Value	Description
SystemDefault	Default. The theme will be based on the system default. If the user changes their theme, the application will update to use the new setting
Dark	The application will use a dark theme exclusively
Light	The application will use a light theme exclusively

Type: windows.Theme

CustomTheme

Name: WindowStartState

Allows you to specify custom colours for TitleBar, TitleText and Border for both light and dark mode, as well as when the window is active or inactive.

Type: windows.CustomTheme

Name: CustomTheme

The CustomTheme struct uses int32 to specify the colour values. These are in the standard(!) Windows format of: 0x00BBGGAA. A helper function is provided to do RGB conversions into this format: windows.RGB(r,g,b uint8).

NOTE: Any value not provided will default to black.

type ThemeSettings struct {
    DarkModeTitleBar           int32
    DarkModeTitleBarInactive   int32
    DarkModeTitleText          int32
    DarkModeTitleTextInactive  int32
    DarkModeBorder             int32
    DarkModeBorderInactive     int32
    LightModeTitleBar          int32
    LightModeTitleBarInactive  int32
    LightModeTitleText         int32
    LightModeTitleTextInactive int32
    LightModeBorder            int32
    LightModeBorderInactive    int32
}

Example:

    CustomTheme: &windows.ThemeSettings{
        // Theme to use when window is active
        DarkModeTitleBar:   windows.RGB(255, 0, 0),   // Red
        DarkModeTitleText:  windows.RGB(0, 255, 0),   // Green
        DarkModeBorder:     windows.RGB(0, 0, 255),   // Blue
        LightModeTitleBar:  windows.RGB(200, 200, 200),
        LightModeTitleText: windows.RGB(20, 20, 20),
        LightModeBorder:    windows.RGB(200, 200, 200),
        // Theme to use when window is inactive
        DarkModeTitleBarInactive:   windows.RGB(128, 0, 0),
        DarkModeTitleTextInactive:  windows.RGB(0, 128, 0),
        DarkModeBorderInactive:     windows.RGB(0, 0, 128),
        LightModeTitleBarInactive:  windows.RGB(100, 100, 100),
        LightModeTitleTextInactive: windows.RGB(10, 10, 10),
        LightModeBorderInactive:    windows.RGB(100, 100, 100),
    },

Messages

A struct of strings used by the webview2 installer if a valid webview2 runtime is not found.

Type: *windows.Messages

Customise this for any language you choose to support.

ResizeDebounceMS

ResizeDebounceMS is the amount of time to debounce redraws of webview2 when resizing the window. The default value (0) will perform redraws as fast as it can.

Type: *mac.Options

OnSuspend

If set, this function will be called when windows initiates a switch to low power mode (suspend/hibernate)

Name: Linux

OnResume

If set, this function will be called when windows resumes from low power mode (suspend/hibernate)

Name: Linux

Mac Specific Options

TitleBar

The TitleBar struct provides the ability to configure the look and feel of the title bar.

Type: bool

Appearance

Appearance is used to set the style of your app in accordance with Apple's NSAppearance names.

Name: WindowIsTranslucent

WebviewIsTransparent

Setting this to true will make the webview background transparent when an alpha value of 0 is used. This means that if you use rgba(0,0,0,0) for background-color in your CSS, the host window will show through. Often combined with WindowIsTranslucent to make frosty-looking applications.

Type: int

WindowIsTranslucent

Setting this to true will make the window background translucent. Often combined with WebviewIsTransparent to make frosty-looking applications.

Type: int

About

This configuration lets you set the title, message and icon for the "About" menu item in the app menu created by the "AppMenu" role.

Name: DisableFramelessWindowDecorations

Titlebar struct

The titlebar of the application can be customised by using the TitleBar options:

type TitleBar struct {
    TitlebarAppearsTransparent bool
    HideTitle                  bool
    HideTitleBar               bool
    FullSizeContent            bool
    UseToolbar                 bool
    HideToolbarSeparator       bool
}

Name	Description
TitlebarAppearsTransparent	Makes the titlebar transparent. This has the effect of hiding the titlebar and the content fill the window. Apple Docs
HideTitle	Hides the title of the window. Apple Docs
HideTitleBar	Removes NSWindowStyleMaskTitled from the style mask
FullSizeContent	Makes the webview fill the entire window. Apple Docs
UseToolbar	Adds a default toolbar to the window. Apple Docs
HideToolbarSeparator	Removes the line beneath the toolbar. Apple Docs

Preconfigured titlebar settings are available:

Setting	Example
mac.TitleBarDefault()
mac.TitleBarHidden()
mac.TitleBarHiddenInset()

Example:

Mac: &mac.Options{
    TitleBar:     mac.TitleBarHiddenInset(),
}

Click here for some inspiration on customising the titlebar.

Appearance type

You can specify the application's appearance.

Value	Description
DefaultAppearance	DefaultAppearance uses the default system value
NSAppearanceNameAqua	The standard light system appearance
NSAppearanceNameDarkAqua	The standard dark system appearance
NSAppearanceNameVibrantLight	The light vibrant appearance
NSAppearanceNameAccessibilityHighContrastAqua	A high-contrast version of the standard light system appearance
NSAppearanceNameAccessibilityHighContrastDarkAqua	A high-contrast version of the standard dark system appearance
NSAppearanceNameAccessibilityHighContrastVibrantLight	A high-contrast version of the light vibrant appearance
NSAppearanceNameAccessibilityHighContrastVibrantDark	A high-contrast version of the dark vibrant appearance

Example:

Mac: &mac.Options{
    Appearance: mac.NSAppearanceNameDarkAqua,
}

About struct

type AboutInfo struct {
    Title   string
    Message string
    Icon    []byte
}

If these settings are provided, an "About" menu item will appear in the app menu (when using the AppMenu role). Given this configuration:

//go:embed build/appicon.png
var icon []byte

func main() {
    err := wails.Run(&options.App{
        ...
        Mac: &mac.Options{
            About: &mac.AboutInfo{
                Title:   "My Application",
                Message: "© 2021 Me",
                Icon:    icon,
            },
        },
    })

The "About" menu item will appear in the app menu:

When clicked, that will open an about message box:

Linux Specific Options

Icon

Sets up the icon representing the window. This icon is used when the window is minimized (also known as iconified).

Type: []byte

Some window managers or desktop environments may also place it in the window frame, or display it in other contexts. On others, the icon is not used at all, so your mileage may vary.

NOTE: Gnome on Wayland at least does not display this icon. To have a application icon there, a .desktop file has to be used. On KDE it should work.

The icon should be provided in whatever size it was naturally drawn; that is, don’t scale the image before passing it. Scaling is postponed until the last minute, when the desired final size is known, to allow best quality.