--- sidebar_position: 3 --- # Options ## Application Options The `Options.App` struct contains the application configuration. It is passed to the `wails.Run()` method: ```go title="Example" import ( "github.com/wailsapp/wails/v2/pkg/options" "github.com/wailsapp/wails/v2/pkg/options/assetserver" "github.com/wailsapp/wails/v2/pkg/options/linux" "github.com/wailsapp/wails/v2/pkg/options/mac" "github.com/wailsapp/wails/v2/pkg/options/windows" ) func main() { err := wails.Run(&options.App{ Title: "Menus Demo", Width: 800, Height: 600, DisableResize: false, Fullscreen: false, WindowStartState: options.Maximised, 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, AssetServer: &assetserver.Options{ Assets: assets, Handler: assetsHandler, Middleware: assetsMidldeware, }, Menu: app.applicationMenu(), Logger: nil, LogLevel: logger.DEBUG, LogLevelProduction: logger.ERROR, OnStartup: app.startup, OnDomReady: app.domready, OnShutdown: app.shutdown, OnBeforeClose: app.beforeClose, CSSDragProperty: "--wails-draggable", CSSDragValue: "drag", ZoomFactor: 1.0, IsZoomControlEnabled: false, Bind: []interface{}{ app, }, Windows: &windows.Options{ WebviewIsTransparent: false, WindowIsTranslucent: false, BackdropType: windows.Mica, 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 // OnSuspend is called when Windows enters low power mode OnSuspend func() // OnResume is called when Windows resumes from low power mode OnResume func() }, 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, WindowIsTranslucent: false, }, Debug: options.Debug{ OpenInspectorOnStartup: false, }, }) if err != nil { log.Fatal(err) } } ``` ### Title The text shown in the window's title bar. Name: Title
Type: `string` ### Width The initial width of the window. Name: Width
Type: `int`
Default: 1024. ### Height The initial height of the window. Name: Height
Type: `int`
Default: 768 ### DisableResize By default, the main window is resizable. Setting this to `true` will keep it a fixed size. Name: DisableResize
Type: `bool` ### Fullscreen Deprecated: Please use [WindowStartState](#windowstartstate). ### WindowStartState Defines how the window should present itself at startup. | Value | Win | Mac | Lin | | ---------- | --- | --- | --- | | Fullscreen | ✅ | ✅ | ✅ | | Maximised | ✅ | ✅ | ✅ | | Minimised | ✅ | ❌ | ✅ | Name: WindowStartState
Type: `options.WindowStartState` ### Frameless When set to `true`, the window will have no borders or title bar. Also see [Frameless Windows](../guides/frameless.mdx). Name: Frameless
Type: `bool` ### 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. Name: MinWidth
Type: `int` ### 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. Name: MinHeight
Type: `int` ### 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. Name: MaxWidth
Type: `int` ### 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. Name: MaxHeight
Type: `int` ### StartHidden When set to `true`, the application will be hidden until [WindowShow](../reference/runtime/window.mdx#windowshow) is called. Name: StartHidden
Type: `bool` ### HideWindowOnClose By default, closing the window will close the application. Setting this to `true` means closing the window will hide the window instead. Name: HideWindowOnClose
Type: `bool` ### BackgroundColour This value is the default background colour of the window. Example: options.NewRGBA(255,0,0,128) - Red at 50% transparency Name: BackgroundColour
Type: `*options.RGBA`
Default: white ### AlwaysOnTop Indicates that the window should stay above other windows when losing focus. Name: AlwaysOnTop
Type: `bool` ### Assets Deprecated: Please use Assets on [AssetServer specific options](#assetserver). ### AssetsHandler Deprecated: Please use AssetsHandler on [AssetServer specific options](#assetserver). ### AssetServer This defines AssetServer specific options. It allows to customize the AssetServer with static assets, serving assets dynamically with an `http.Handler` or hook into the request chain with an `assetserver.Middleware`. Not all features of an `http.Request` are currently supported, please see the following feature matrix: | Feature | Win | Mac | Lin | | ----------------------- | --- | --- | ------ | | GET | ✅ | ✅ | ✅ | | POST | ✅ | ✅ | ✅ [^1] | | PUT | ✅ | ✅ | ✅ [^1] | | PATCH | ✅ | ✅ | ✅ [^1] | | DELETE | ✅ | ✅ | ✅ [^1] | | Request Headers | ✅ | ✅ | ✅ [^1] | | Request Body | ✅ | ✅ | ❌ | | Request Body Streaming | ❌ | ❌ | ❌ | | Response StatusCodes | ✅ | ✅ | ✅ [^1] | | Response Headers | ✅ | ✅ | ✅ [^1] | | Response Body | ✅ | ✅ | ✅ | | Response Body Streaming | ❌ | ❌ | ✅ | | WebSockets | ❌ | ❌ | ❌ | | HTTP Redirects 30x | ✅ | ❌ | ❌ | Name: AssetServer
Type: `*assetserver.Options` #### Assets The static frontend assets to be used by the application. A GET request is first tried to be served from this `fs.FS`. If the `fs.FS` returns `os.ErrNotExist` for that file, the request handling will fallback to the [Handler](#handler) and tries to serve the GET request from it. If set to nil, all GET requests will be forwarded to [Handler](#handler). Name: Assets
Type: `fs.FS` #### Handler The assets handler is a generic `http.Handler` for fallback handling of assets that can't be found. The handler will be called for every GET request that can't be served from [Assets](#assets), due to `os.ErrNotExist`. Furthermore all non GET requests will always be served from this Handler. If not defined, the result is the following in cases where the Handler would have been called: - GET request: `http.StatusNotFound` - Other request: `http.StatusMethodNotAllowed` 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. Name: AssetsHandler
Type: `http.Handler` #### Middleware Middleware is a HTTP Middleware which allows to hook into the AssetServer request chain. It allows to skip the default request handler dynamically, e.g. implement specialized Routing etc. The Middleware is called to build a new `http.Handler` used by the AssetSever and it also receives the default handler used by the AssetServer as an argument. If not defined, the default AssetServer request chain is executed. Name: Middleware
Type: `assetserver.Middleware` ### Menu The menu to be used by the application. More details about Menus in the [Menu Reference](../reference/runtime/menu.mdx). :::note On Mac, if no menu is specified, a default menu will be created. ::: Name: Menu
Type: `*menu.Menu` ### Logger The logger to be used by the application. More details about logging in the [Log Reference](../reference/runtime/log.mdx). Name: Logger
Type: `logger.Logger`
Default: Logs to Stdout ### LogLevel The default log level. More details about logging in the [Log Reference](../reference/runtime/log.mdx). Name: LogLevel
Type: `logger.LogLevel`
Default: `Info` in dev mode, `Error` in production mode ### LogLevelProduction The default log level for production builds. More details about logging in the [Log Reference](../reference/runtime/log.mdx). Name: LogLevelProduction
Type: `logger.LogLevel`
Default: `Error` ### 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: OnStartup
Type: `func(ctx context.Context)` ### OnDomReady This callback is called after the frontend has loaded `index.html` and its resources. It is given the application context. Name: OnDomReady
Type: `func(ctx context.Context)` ### OnShutdown This callback is called after the frontend has been destroyed, just before the application terminates. It is given the application context. Name: OnShutdown
Type: `func(ctx context.Context)` ### 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: ```go title=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" } ``` Name: OnBeforeClose
Type: `func(ctx context.Context) bool` ### CSSDragProperty Indicates the CSS property to use to identify which elements can be used to drag the window. Default: `--wails-draggable`. Name: CSSDragProperty
Type: `string` ### CSSDragValue Indicates what value the `CSSDragProperty` style should have to drag the window. Default: `drag`. Name: CSSDragValue
Type: `string` ### ZoomFactor Name: ZoomFactor
Type: `float64` This defines the zoom factor for the WebView2. This is the option matching the Edge user activated zoom in or out. ### IsZoomControlEnabled Name: IsZoomControlEnabled
Type: `bool` This enables the zoom factor to be changed by the user. Please note that the zoom factor can be set in the options while disallowing the user to change it at runtime (f.e. for a kiosk application or similar). ### Bind A slice of struct instances defining methods that need to be bound to the frontend. Name: Bind
Type: `[]interface{}` ### Windows This defines [Windows specific options](#windows). Name: Windows
Type: `*windows.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](#WindowIsTranslucent) to make frosty-looking applications. Name: WebviewIsTransparent
Type: `bool` #### WindowIsTranslucent Setting this to `true` will make the window background translucent. Often combined with [WebviewIsTransparent](#WebviewIsTransparent). For Windows 11 versions before build 22621, this will use the [BlurBehind](https://learn.microsoft.com/en-us/windows/win32/dwm/blur-ovw) method for translucency, which can be slow. For Windows 11 versions after build 22621, this will enable the newer translucency types that are much faster. By default, the type of translucency used will be determined by Windows. To configure this, use the [BackdropType](#BackdropType) option. Name: WindowIsTranslucent
Type: `bool` #### BackdropType :::note Requires Windows 11 build 22621 or later. ::: Sets the translucency type of the window. This is only applicable if [WindowIsTranslucent](#WindowIsTranslucent) is set to `true`. Name: BackdropType
Type `windows.BackdropType` The value can be one of the following: | Value | Description | | ------- | ----------------------------------------------------------------------------------------- | | Auto | Let Windows decide which backdrop to use | | None | Do not use translucency | | Acrylic | Use [Acrylic](https://learn.microsoft.com/en-us/windows/apps/design/style/acrylic) effect | | Mica | Use [Mica](https://learn.microsoft.com/en-us/windows/apps/design/style/mica) effect | | Tabbed | Use Tabbed. This is a backdrop that is similar to Mica. | #### DisableWindowIcon Setting this to `true` will remove the icon in the top left corner of the title bar. Name: DisableWindowIcon
Type: `bool` #### DisableFramelessWindowDecorations Setting this to `true` will remove the window decorations in [Frameless](#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. Name: DisableFramelessWindowDecorations
Type: `bool` #### WebviewUserDataPath This defines the path where the WebView2 stores the user data. If empty `%APPDATA%\[BinaryName.exe]` will be used. Name: WebviewUserDataPath
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](https://docs.microsoft.com/en-us/microsoft-edge/webview2/concepts/distribution#details-about-the-fixed-version-runtime-distribution-mode) - [Known issues for fixed version](https://docs.microsoft.com/en-us/microsoft-edge/webview2/concepts/distribution#known-issues-for-fixed-version) - [The path of fixed version of the WebView2 Runtime should not contain \Edge\Application\.](https://docs.microsoft.com/en-us/microsoft-edge/webview2/reference/win32/webview2-idl?view=webview2-1.0.1245.22#createcorewebview2environmentwithoptions) Name: WebviewBrowserPath
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 | Name: Theme
Type: `windows.Theme` #### CustomTheme :::note Minimum Windows Version: Windows 10/11 2009/21H2 Build 22000 ::: 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. Name: CustomTheme
Type: `windows.CustomTheme` ##### CustomTheme type 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. ```go 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: ```go 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. Name: Messages
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. Name: ResizeDebounceMS
Type: `uint16` #### OnSuspend If set, this function will be called when Windows initiates a switch to low power mode (suspend/hibernate) Name: OnSuspend
Type: `func()` #### OnResume If set, this function will be called when Windows resumes from low power mode (suspend/hibernate) Name: OnResume
Type: `func()` ### Mac This defines [Mac specific options](#mac). Name: Mac
Type: `*mac.Options` #### TitleBar The TitleBar struct provides the ability to configure the look and feel of the title bar. Name: TitleBar
Type: [`*mac.TitleBar`](#titlebar-struct) ##### Titlebar struct The titlebar of the application can be customised by using the TitleBar options: ```go 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](https://developer.apple.com/documentation/appkit/nswindow/1419167-titlebarappearstransparent?language=objc) | | HideTitle | Hides the title of the window. [Apple Docs](https://developer.apple.com/documentation/appkit/nswindowtitlevisibility?language=objc) | | HideTitleBar | Removes [NSWindowStyleMaskTitled](https://developer.apple.com/documentation/appkit/nswindowstylemask/nswindowstylemasktitled/) from the style mask | | FullSizeContent | Makes the webview fill the entire window. [Apple Docs](https://developer.apple.com/documentation/appkit/nswindowstylemask/nswindowstylemaskfullsizecontentview) | | UseToolbar | Adds a default toolbar to the window. [Apple Docs](https://developer.apple.com/documentation/appkit/nstoolbar?language=objc) | | HideToolbarSeparator | Removes the line beneath the toolbar. [Apple Docs](https://developer.apple.com/documentation/appkit/nstoolbar/1516954-showsbaselineseparator?language=objc) | Preconfigured titlebar settings are available: | Setting | Example | | --------------------------- | ---------------------------------------------- | | `mac.TitleBarDefault()` | ![](/img/reference/titlebar-default.webp) | | `mac.TitleBarHidden()` | ![](/img/reference/titlebar-hidden.webp) | | `mac.TitleBarHiddenInset()` | ![](/img/reference/titlebar-hidden-inset.webp) | Example: ```go Mac: &mac.Options{ TitleBar: mac.TitleBarHiddenInset(), } ``` Click [here](https://github.com/lukakerr/NSWindowStyles) for some inspiration on customising the titlebar. #### Appearance Appearance is used to set the style of your app in accordance with Apple's [NSAppearance](https://developer.apple.com/documentation/appkit/nsappearancename?language=objc) names. Name: Appearance
Type: [`mac.AppearanceType`](#appearance-type) ##### Appearance type You can specify the application's [appearance](https://developer.apple.com/documentation/appkit/nsappearance?language=objc). | 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: ```go Mac: &mac.Options{ Appearance: mac.NSAppearanceNameDarkAqua, } ``` #### 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](#WindowIsTranslucent) to make frosty-looking applications. Name: WebviewIsTransparent
Type: `bool` #### WindowIsTranslucent Setting this to `true` will make the window background translucent. Often combined with [WebviewIsTransparent](#WebviewIsTransparent) to make frosty-looking applications. Name: WindowIsTranslucent
Type: `bool` #### 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: About
Type: [`*mac.AboutInfo`](#about-struct) ##### About struct ```go 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 //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: ```mdx-code-block

``` When clicked, that will open an about message box: ```mdx-code-block

``` ### Linux This defines [Linux specific options](#linux). Name: Linux
Type: `*linux.Options` #### Icon Sets up the icon representing the window. This icon is used when the window is minimized (also known as iconified). Name: Icon
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. #### WindowIsTranslucent Setting this to `true` will make the window background translucent. Some window managers may ignore it, or result in a black window. Name: WindowIsTranslucent
Type: `bool` ### Debug This defines [Debug specific options](#Debug) that apply to debug builds. Name: Debug
Type: `options.Debug` #### OpenInspectorOnStartup Setting this to `true` will open the WebInspector on startup of the application. Name: OpenInspectorOnStartup
Type: `bool` [^1]: This requires WebKit2GTK 2.36+ support and your app needs to be build with the build tag `webkit2_36` to activate support for this feature. This also bumps the minimum requirement of WebKit2GTK to 2.36 for your app.