[Home](./index.md) > [@firebase/app-types](./app-types.md) ## app-types package ## Interfaces | Interface | Description | | --- | --- | | [FirebaseApp](./app-types.firebaseapp.md) | A FirebaseApp holds the initialization information for a collection of services.Do not call this constructor directly. Instead, use [initializeApp()](./app.initializeapp.md) to create an app. | | [FirebaseAppConfig](./app-types.firebaseappconfig.md) | | | [FirebaseOptions](./app-types.firebaseoptions.md) | |