Push Notifications — Guide40

Node Configuration

{
  "nodeType": "SendPushNotification",
  "name": "pushApprovalAlert",
  "config": {
    "credentialId": 22,
    "provider": "fcm",
    "deviceToken": "$output.fetchUserDevice.fcmToken",
    "title": "Approval Required",
    "body": "Invoice $output.createInvoice.invoiceNumber needs your sign-off",
    "data": {
      "executionId": "$context.executionId",
      "invoiceId": "$output.createInvoice.invoiceId",
      "deepLink": "acme://approvals/$output.createInvoice.invoiceId"
    },
    "badge": 1,
    "sound": "default",
    "priority": "high",
    "ttlSeconds": 86400
  }
}

Configuration Fields

Field	Type	Required	Description
`credentialId`	int	Yes	FCM service account key JSON or APNs p8 key, stored via `ICredentialResolver`
`provider`	fcm \| apns	Yes	Push provider. Determines adapter used.
`deviceToken`	string / expr	Yes	FCM registration token or APNs device token for the target device.
`title`	string / expr	Yes	Notification title shown in device notification tray.
`body`	string / expr	Yes	Notification body text.
`data`	object	No	Custom key-value data payload delivered to the app (not shown in tray). Values are evaluated expressions.
`badge`	int / expr	No	iOS badge count. Ignored by FCM on Android.
`sound`	string	No	Notification sound. Use `"default"` or a custom sound file name bundled in the app.
`priority`	high \| normal	No	FCM message priority. `high` wakes the device immediately.
`ttlSeconds`	int	No	Time-to-live in seconds. If device is offline longer than TTL, message is dropped.

FCM vs APNs

Aspect	FCM (Firebase Cloud Messaging)	APNs (Apple Push)
Platform	Android (also iOS via FCM bridge)	iOS, macOS, watchOS
Credential type	Service account JSON key	p8 key file + Team ID + Key ID + Bundle ID
Token format	FCM registration token (long string)	64-char hex device token
Priority	`high` / `normal`	10 (immediate) / 5 (power-save)
Data-only message	Omit `notification` key — data only	Set `content-available: 1`

PushChannelAdapter — FCM

public class PushChannelAdapter : IMessagingChannelAdapter
{
    public string ChannelType => "Push";

    public async Task<MessagingResult> SendAsync(
        MessagingMessage message,
        MessagingConfig config,
        CancellationToken ct)
    {
        if (config.Provider == "apns")
            return await SendViaApns(message, config, ct);

        // FCM path
        var serviceAccountJson = await _credentials.GetPasswordAsync(config.CredentialId, ct);
        var credential = GoogleCredential
            .FromJson(serviceAccountJson)
            .CreateScoped("https://www.googleapis.com/auth/firebase.messaging");

        var fcmMessage = new Message
        {
            Token = message.To,
            Notification = new Notification { Title = message.Title, Body = message.Body },
            Data = message.Data?.ToDictionary(k => k.Key, k => k.Value?.ToString() ?? ""),
            Android = new AndroidConfig
            {
                Priority = config.Priority == "high"
                    ? Priority.High : Priority.Normal,
                Ttl = TimeSpan.FromSeconds(config.TtlSeconds ?? 86400)
            }
        };

        var app = FirebaseApp.Create(new AppOptions { Credential = credential });
        var messageId = await FirebaseMessaging.DefaultInstance.SendAsync(fcmMessage, ct);

        return new MessagingResult
        {
            MessageId = messageId,
            Channel = "push",
            Recipient = message.To,
            SentAt = DateTimeOffset.UtcNow,
            Status = "sent"
        };
    }
}

Data-only notifications: To send a silent background push (no UI notification) for in-app processing, omit title and body and include only a data payload. On FCM Android, this is a "data message". On APNs, combine with content-available: 1.

Token staleness: Device tokens expire when a user reinstalls the app or resets their device. Store tokens in your entity system and listen for FCM's NotRegistered error to clean up stale tokens automatically.

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