# Push notifications

Your Action can push notifications to users whenever relevant, such as sending a reminder when the due date for a task is near.

This guide describes how to set up push notifications for your Action.

## Supported surfaces

Push notifications are available on Android and iOS devices (iOS devices must have the Assistant app installed to receive push notifications). They are not currently supported on voice-activated speakers, smart displays, or other surfaces.

## Prerequisites

Your project must contain at least one [global intent](https://developers.google.com/assistant/conversational/intents#custom_intents), which is invoked when the user taps a push notification received from Assistant.

## Get started

The following sections describe how to set up push notifications in your Action.

### Create an intent for triggering

The intent you create in this section triggers the notifications flow. To create
this intent, follow these steps:

1. Go to the [Actions console](https://console.actions.google.com/) and click **Develop** in the top menu.
2. Click **Intents** in the left menu to expand the section.
3. Click the at the bottom of the list and enter a name for the new intent.
4. Press `Enter/Return` to create the new intent.
5. Add training phrases for triggering the notifications flow. Some examples are:

   - `Notify me`
   - `Send notifications`
   - `Subscribe to notifications`
6. Click **Save**.

![](https://developers.google.com/static/assistant/engagement/images/training-phrases.png)

### Transition to system intent

To set up the transition to the `Notifications` system scene, follow these steps:

1. Under **Scenes** in the left menu, click the scene you want to add the notifications subscription flow to.
2. Under the **User intent handling** section of the scene, click **+** to add a new intent handler.
3. Under **Intent**, select the intent you created in the previous section.
4. Under **Transition** , select the **Notifications** system scene.

5. Click **Save**.

![](https://developers.google.com/static/assistant/engagement/images/transition.png)

### Configure system scene

To configures the `Notifications` system scene, follow these steps:

1. Under **Scenes** in the left menu, select the new **Notifications** system scene.
2. Under the **Configure intent** section, click **Select intent**.
3. Under the **Select intent** section, select the intent you want to be matched when a user taps a push notification.

   > [!NOTE]
   > **Note:** The intent you choose for this step needs to be a global intent.

4. For **Customize opt-in prompt**, enter a prompt that is displayed to users when they're asked to subscribe to push notifications. The prompt is in the form of "Is it ok if I send push notifications for $prompt".

5. Click **Save**.

![](https://developers.google.com/static/assistant/engagement/images/configure-scene.png)

### Configure opt-in

To configure opting in to push notifications, follow these steps:

1. Under **Scenes** , select the **Notifications** system scene.
2. Under **Conditions** , select **If the user says "yes"**.
3. Enable **Call your webhook** and provide an event handler name, such as `subscribe_to_notifications`.
4. Enable **Send prompts** and provide a simple prompt to let the user know they'll be sent notifications:

       candidates:
       - first simple:
         variants:
         - speech: 'Great, I'll send you notifications.'

5. Under **Transition** , select **End conversation** to end the conversation after a user subscribes to notifications.

![](https://developers.google.com/static/assistant/engagement/images/configure-yes.png)

### Configure opt-out

To configure opting out of push notifications, follow these steps:

1. Under **Conditions** , select **If the user says "no"**.
2. Enable **Send prompts** and provide a simple prompt to let the user know they won't be sent notifications:

       candidates:
       - first simple:
         variants:
         - speech: Okay, I won't send you notifications.

3. Under **Transition** , select **End conversation** to end the conversation after a user opts out of notifications.

![](https://developers.google.com/static/assistant/engagement/images/configure-no.png)

### Configure webhook

To configure your webhook, follow these steps:

1. In your webhook, add an intent handler for storing the `updatesUserId`:

       app.handle('subscribe_to_notifications', conv => {
         const intentName = '<name_of_intent_to_trigger>';
         const notificationsSlot = conv.session.params['NotificationSlot_${intentName}'];
         if(notificationsSlot.permissionStatus == 'PERMISSION_GRANTED') {
           const updateUserId = notificationsSlot.additionalUserData.updateUserId;
           // Store the user ID and the notification's target intent for later use.
           // (Use a database, like Firestore, for best practice.)
         }
       });

## Send notifications

Push notifications are sent to users using the Actions API. To use this API, you need to activate the API in your Google Cloud project and set up and download a JSON service account key.

You can then use the Google OAuth2 client library to exchange the service account key for an access token and use the token to authenticate your requests to the Actions API.

### Get a service account key

1. Go to the [Google API console](https://console.developers.google.com/apis/api/actions.googleapis.com/overview) and select your project from the **Select a project** dropdown.
2. Click **Enable** to enable the Actions API for your project.
3. Go to the [Google Cloud console credentials page](https://console.developers.google.com/apis/credentials) and select your project from the **Select a project** dropdown.
4. Click **Create credentials \> Service account**.
5. Enter a service account name and click **Create**.
6. From the **Select a role** dropdown, select **Project \> Owner**.
7. Click **Continue**.
8. Click **Create key** to download the service account JSON file.

### Exchange the key for an access token and send a notification

To send push notifications through the Actions API, you need to exchange the service account key for an access token. We recommend using a Google API client library for this. In the series of code snippets that follow, we use the Google API Node.js client library.

1. Install the Google API client library and request:

   `npm install googleapis request --save`
2. Use the following code to get an access token from the service account key and send a push notification:

       // Use the Actions API to send a Google Assistant push notification.
       let client = auth.fromJSON(require('./service-account.json'));
       client.scopes = ['https://www.googleapis.com/auth/actions.fulfillment.conversation'];
       let notification = {
         userNotification: {
           title: 'Example notification title',
         },
         target: {
           userId: '<UPDATES_USER_ID>',
           intent: 'Notifications Intent',
         },
       };
       client.authorize((err, tokens) => {
         if (err) {
           throw new Error('Auth error: ${err}');
         }
         request.post('https://actions.googleapis.com/v2/conversations:send', {
           'auth': {
             'bearer': tokens.access_token,
           },
           'json': true,
           'body': {'customPushMessage': notification, 'isInSandbox': true},
         }, (err, httpResponse, body) => {
           if (err) {
             throw new Error('API request error: ${err}');
           }
           console.log('${httpResponse.statusCode}: ' + '${httpResponse.statusMessage}');
           console.log(JSON.stringify(body));
         });
       });