--- 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" 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, 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. Type: `int`
Default: 1024. ### Height The initial height of the window. Type: `int`
Default: 768 ### DisableResize By default, the main window is resizable. Setting this to `true` will keep it a fixed size. Type: `bool` ### Fullscreen Setting this to `true` will make the window fullscreen at startup. Type: `bool` ### Frameless When set to `true`, the window will have no borders or title bar. Also see [Frameless Windows](../guides/frameless.mdx). 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. 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. 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. 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. Type: `int` ### StartHidden When set to `true`, the application will be hidden until [WindowShow](../reference/runtime/window.mdx#windowshow) is called. 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. Type: `bool` ### BackgroundColour This value is the default background colour of the window. Example: options.NewRGBA(255,0,0,128) - Red at 50% transparency Type: `*options.RGBA`
Default: white ### AlwaysOnTop Indicates that the window should stay above other windows when losing focus. Type: `bool` ### Assets The frontend assets to be used by the application. Requires an `index.html` file. Type: `embed.FS` ### 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](../reference/runtime/menu.mdx). :::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](../reference/runtime/log.mdx). Type: `logger.Logger`
Default: Logs to Stdout ### LogLevel The default log level. More details about logging in the [Log Reference](../reference/runtime/log.mdx). 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). 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. 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. 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. 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{ Title: "Quit?", Message: "Are you sure you want to quit?", Type: ` runtime`.QuestionDialog, }) 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 | ✅ | ❌ | ✅ | Type: `options.WindowStartState` ### Bind A slice of struct instances defining methods that need to be bound to the frontend. Type: `[]interface{}` ### Windows This defines [Windows specific options](#windows-specific-options). Type: `*windows.Options` ### Mac This defines [Mac specific options](#mac-specific-options). Type: `*mac.Options` ### Linux This defines [Linux specific options](#linux-specific-options). Type: `*linux.Options` ## 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](#WindowIsTranslucent) to make frosty-looking applications. Type: `bool` ### WindowIsTranslucent Setting this to `true` will make the window background translucent. Often combined with [WebviewIsTransparent](#WebviewIsTransparent) to make frosty-looking applications. Type: `bool` ### DisableWindowIcon Setting this to `true` will remove the icon in the top left corner of the title bar. 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. Type: `bool` ### 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](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) 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 :::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. 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. 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: `uint16` ### OnSuspend If set, this function will be called when windows initiates a switch to low power mode (suspend/hibernate) Type: `func()` ### OnResume If set, this function will be called when windows resumes from low power mode (suspend/hibernate) Type: `func()` ## Mac Specific Options ### TitleBar The TitleBar struct provides the ability to configure the look and feel of the title bar. Type: [`*mac.TitleBar`](#titlebar-struct) ### 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. Type: [`AppearanceType`](#appearance-type) ### 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. Type: `bool` ### WindowIsTranslucent Setting this to `true` will make the window background translucent. Often combined with [WebviewIsTransparent](#WebviewIsTransparent) to make frosty-looking applications. 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. Type: [`About`](#about-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 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, } ``` #### 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:

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.