Notifications & Presence

This guide covers how notifications are triggered, delivered, and configured, as well as the real-time presence and typing indicator systems.

Notification Preferences #

Each channel has a per-user notification preference with two settings:

• all — notify on every message in the channel.
• mentions — notify only on @mentions and special mentions.
• none — muted. All notifications from this channel are suppressed.

Preferences are set per channel via the channel notification settings UI or the POST /channels/{id}/notifications endpoint.

What Triggers Notifications #

A user is auto-subscribed to a thread when they post a reply. The parent message author is also auto-subscribed when the first reply is posted. Users can explicitly unsubscribe from a thread, and auto-subscribe respects that choice.

Delivery Pipeline #

When a notification is triggered, the server delivers it through a priority chain:

1. SSE (real-time) — if the user has an active connection, the notification is delivered instantly via Server-Sent Events. No further delivery is needed.
2. Push notification — if the user is offline and has registered a mobile device, a push notification is sent via FCM (Android) or APNs (iOS).
3. Email — if the user is offline, has no registered device tokens (or push is disabled), and has email enabled for the channel, a notification email is queued.

Push suppresses email: if a push notification is successfully dispatched to at least one device, email is skipped for that notification.

Push Notifications #

Push notifications deliver alerts to mobile devices when a user is offline. They are sent through a relay service (push.enzyme.im) that holds the FCM and APNs credentials for the published app.

Privacy: By default, the relay receives metadata (sender name, channel name) and a short message preview. Set include_preview: false in your push configuration to omit the preview — the relay will then receive only metadata, and the mobile app will fetch message content directly from your server when the user taps the notification.

Push notifications are enabled by the server administrator. See Push Notifications configuration for setup. No client-side configuration is needed — the mobile app handles device token registration automatically.

Token lifecycle:

• Device tokens are registered when the mobile app starts and refreshed on each launch.
• Tokens are automatically cleaned up when they become invalid (the relay reports invalid_token).
• Tokens not updated in 90 days are removed by a scheduled cleanup task.

Email Notifications #

When a user is offline, has no registered mobile devices (or push is disabled), and has email_enabled turned on for a channel, notifications are queued for email delivery.

Delivery timing:

1. A pending notification is created with a 5-minute delay.
2. The scheduler checks for ready-to-send notifications every 60 seconds.
3. Notifications are grouped by workspace into a single digest email.
4. If the user comes back online before the delay expires, the pending notification is cancelled automatically.

Email notifications require SMTP to be configured. See Email configuration for setup.

Presence #

Enzyme tracks two presence states per user per workspace:

When a user disconnects (closes the tab, loses network), the server waits 30 seconds before marking them offline. This grace period absorbs brief interruptions like page refreshes.

Presence changes are broadcast to all connected workspace members via SSE. For SSE tuning options, see SSE configuration.

Typing Indicators #

Typing indicators are real-time and ephemeral — they are never persisted.

• When a user starts typing, a typing.start event is sent (throttled to once per 2 seconds).
• If the user stops typing for 3 seconds, a typing.stop event is sent automatically.
• On the receiving side, typing indicators expire after 5 seconds without a refresh.