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This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the spec changes.
A API Push torna possível que aplicações web recebam mensagens enviadas a elas de um servidor, indepententemente de aplicação estar ou não em primeiro plano, ou até mesmo carregada, em um agente de usuário. Isso permite que desenvolvedores entreguem notificações e atualizações assíncronas a usuários que optarem por elas, resultando num melhor engajamento com conteúdo novo oportuno.
Nota: Esta documentação cobre a especificação W3C da API Push; se você procura pela documentação do sistema de notificação proprietária do mecanismo push, veja Simple Push.
Conceitos e uso de Push
PushSubscription includes all the information that the application needs to send a push message: an endpoint and the encryption key needed for sending data.
The service worker will be started as necessary to handle incoming push messages, which are delivered to the
ServiceWorkerGlobalScope.onpush event handler. This allows apps to react to push messages being received, for example by displaying a notification (using
Each subscription is unique to a service worker. The endpoint for the subscription is a unique capability URL: knowledge of the endpoint is all that is necessary to send a message to your application. The endpoint URL therefore needs to be kept secret, or other applications might be able to send push messages to your application.
Activating a service worker to deliver a push message can result in increased resource usage, particularly of the battery. Different browsers have different schemes for handling this — there is currently no standard mechanism. Firefox allows a limited number (quota) of push messages to be sent to an application, although Push messages that generate notifications are exempt from this limit. The limit is refreshed each time the site is visited. In comparison, Chrome applies no limit but requires that every push message causes a notification to be displayed.
Note: As of Gecko 44, the allowed quota of push messages per application is not incremented when a new notification fires when another is still visible, for a period of three seconds. This handles cases where a burst of notifications is received, and not all generate a visible notification.
Note: Chrome currently requires you to set up a project on Google Cloud Messaging to send push messages, and use the associated project number and API key when sending push notifications. It also requires an app manifest with some special parameters to use this service. This restriction will hopefully be removed in the future.
- Represents a push action sent to the global scope of a
ServiceWorker. It contains information sent from an application to a
- Provides a way to receive notifications from third-party servers as well as request URLs for push notifications. This interface has replaced functionality offered by the obsolete
- Provides access to push data sent by a server, and includes methods to manipulate the received data.
- Provides a subcription's URL endpoint and allows unsubscription from a push service.
Service worker additions
The following additions to the Service Worker API have been specified in the Push API spec, to provide an entry point for using Push messages, and to monitor and respond to push and subscription change events.
- Returns a reference to the
PushManagerinterface for managing push subscriptions including subscribing, getting an active subscription, and accessing push permission status. This is the entry point into using Push messaging.
- An event handler fired whenever a
pushevent occurs; that is, whenever a server push message is received.
- An event handler fired whenever a
pushsubscriptionchangeevent occurs; for example, when a push subscription has been invalidated, or is about to be invalidated (e.g. when a push service sets an expiration time.)
|Push API||Working Draft||Initial definition|
|Feature||Chrome||Firefox (Gecko)||Internet Explorer||Opera||Safari (WebKit)|
|Basic support||42.0||44.0 (44.0)||Não suportado||?||?|
||Não suportado||44.0 (44.0)||Não suportado||Não suportado||Não suportado|
|Feature||Android||Android Webview||Firefox Mobile (Gecko)||Firefox OS||IE Mobile||Opera Mobile||Safari Mobile||Chrome for Android|
|Basic support||Não suportado||Não suportado||Não suportado||Não suportado||?||?||?||42.0|
||Não suportado||Não suportado||Não suportado||Não suportado||Não suportado||Não suportado||Não suportado||Não suportado|
 Currently available only on desktop versions of Firefox; also, push messages are only delivered when Firefox is running.
 This is currently not implemented. See the Microsoft Edge status information.