--- sidebar_position: 1 --- # Introduction The runtime is a library that provides utility methods for your application. There is both a Go and Javascript runtime and the aim is to try and keep them at parity where possible. The Go Runtime is available through importing `github.com/wailsapp/wails/v2/pkg/runtime`. All methods in this package take a context as the first parameter. This context should be obtained from the [OnStartup](../options.mdx#onstartup) or [OnDomReady](../options.mdx#ondomready) hooks. :::info Note Whilst the context will be provided to the [OnStartup](../options.mdx#onstartup) method, there's no guarantee the runtime will work in this method as the window is initialising in a different thread. If you wish to call runtime methods at startup, use [OnDomReady](../options.mdx#ondomready). ::: The Javascript library is available to the frontend via the `window.runtime` map. There is a runtime package generated when using `dev` mode that provides Typescript declarations for the runtime. This should be located in the `wailsjs` directory in your frontend directory. ### Quit Go Signature: `Quit(ctx context.Context)` Quits the application. ### Environment Go Signature: `Environment(ctx context.Context) EnvironmentInfo` Returns details of the current environment. #### EnvironmentInfo ```go type EnvironmentInfo struct { BuildType string // Either "production", "debug" or "dev" } ```