--- name: sending-notifications description: 'How to send real-time in-app notifications from PostHog backend code. Use when integrating notifications into a new feature, wiring up a notification source (alerts, comments, approvals, pipelines, issues), or choosing the right target type and priority for a notification.' --- # Sending real-time notifications ## When to use this You're adding notification support to a PostHog feature — for example, notifying a user when they're mentioned in a comment, when an alert fires, or when an approval is requested. ## The facade API All notification creation goes through a single function. Import from the facade, not from internal modules: ```python from products.notifications.backend.facade.api import ( create_notification, NotificationData, NotificationType, Priority, TargetType, ) ``` Build a `NotificationData` and call `create_notification`: ```python event = create_notification( NotificationData( team_id=team.id, notification_type=NotificationType.ALERT_FIRING, priority=Priority.CRITICAL, title="Event ingestion latency > 30s", body="Events are queuing up. Ingestion pipeline is degraded.", target_type=TargetType.USER, target_id=str(user.id), resource_type="dashboard", resource_id="42", source_url="/dashboard/42", ) ) ``` Returns a `NotificationEvent` on success, or `None` if the feature flag is disabled, no recipients were resolved, or the team doesn't exist. Safe to call in any context. ## NotificationData fields **Required:** | Field | Type | Description | | ------------------- | ------------------ | -------------------------------------------------------------------------- | | `team_id` | `int` | Team context — used to look up the organization and check the feature flag | | `notification_type` | `NotificationType` | Determines the icon in the UI | | `title` | `str` | Notification headline (~100 chars recommended) | | `body` | `str` | Longer description shown on expand. Can be empty string | | `target_type` | `TargetType` | Who receives this: `user`, `team`, `organization`, or `role` | | `target_id` | `str` | ID of the target (user ID, team ID, org UUID, or role UUID as string) | **Optional:** | Field | Type | Default | Description | | --------------- | ---------------------------------- | -------- | ----------------------------------------------------------------------------------------- | | `resource_type` | `NotificationResourceType \| None` | `None` | Access-controlled types (e.g. `"dashboard"`) auto-filter recipients without viewer access | | `resource_id` | `str` | `""` | ID of the resource for linking | | `source_url` | `str` | `""` | Relative URL path (e.g. `/dashboard/42`), shown as link icon in UI | | `priority` | `Priority` | `NORMAL` | `normal` = popover only; `critical` = popover + persistent toast | | `resolver` | `RecipientsResolver \| None` | `None` | Custom recipient resolver. Default handles user/team/org/role targeting | ## Choosing parameters ### Notification type | Type | When to use | | -------------------- | ------------------------------------------------ | | `comment_mention` | User was @mentioned in a comment or discussion | | `alert_firing` | A monitoring alert threshold was breached | | `approval_requested` | A change requires the user's approval | | `approval_resolved` | An approval the user requested has been resolved | | `pipeline_failure` | A data pipeline or batch export failed | | `issue_assigned` | An error tracking issue was assigned to the user | ### Priority **Be very careful with `critical`.** It triggers a persistent toast popup that overlays the user's screen and must be manually dismissed. This is intentionally intrusive — reserve it for genuine emergencies like outages, security alerts, or SLA breaches. Overusing `critical` will train users to ignore notifications entirely. When in doubt, use `normal`. ### Target type | Target | `target_id` value | Recipients | | -------------- | ----------------- | -------------------------------------- | | `user` | User ID | Just that user | | `team` | Team ID | All members of the team's organization | | `organization` | Organization ID | All organization members | | `role` | Role ID | All users with that RBAC role | ### Resource type and access control When `resource_type` matches an access-controlled resource (dashboard, feature_flag, experiment, etc.), recipients without `viewer` access are automatically excluded. For notification-only types (`pipeline`, `approval`, `comment`), no AC filtering is applied. ## Delivery pipeline ```text Django (create_notification) → Postgres (NotificationEvent row) → Kafka (notification_events topic, on transaction commit) → Go livestream service (Kafka consumer) → Redis SPUBLISH (sharded pub/sub, keyed by org ID) → SSE (/notifications endpoint) → Browser (popover + optional toast) ``` Kafka publish happens on `transaction.on_commit` — won't fire if the transaction rolls back. ## Adding a new notification type 1. Add enum value in `products/notifications/backend/facade/enums.py` 2. Add icon mapping in `frontend/src/lib/components/NotificationsMenu/NotificationRow.tsx` (`NOTIFICATION_TYPE_ICONS`) 3. Add the same icon in the toast handler in `frontend/src/layout/navigation-3000/sidepanel/panels/activity/sidePanelNotificationsLogic.tsx` (`iconMap`) 4. Add sample data in `SAMPLE_NOTIFICATIONS` in `products/notifications/backend/presentation/views.py` 5. Run `python manage.py makemigrations notifications` ## Testing Mock the feature flag in tests: ```python from unittest.mock import patch with patch("posthoganalytics.feature_enabled", side_effect=lambda flag, *a, **kw: flag == "real-time-notifications"): event = create_notification(data) ```