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:
from products.notifications.backend.facade.api import (
create_notification,
NotificationData,
NotificationType,
Priority,
TargetType,
)Build a NotificationData and call create_notification:
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
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
- Add enum value in
products/notifications/backend/facade/enums.py - Add icon mapping in
frontend/src/lib/components/NotificationsMenu/NotificationRow.tsx(NOTIFICATION_TYPE_ICONS) - Add the same icon in the toast handler in
frontend/src/layout/navigation-3000/sidepanel/panels/activity/sidePanelNotificationsLogic.tsx(iconMap) - Add sample data in
SAMPLE_NOTIFICATIONSinproducts/notifications/backend/presentation/views.py - Run
python manage.py makemigrations notifications
Testing
Mock the feature flag in tests:
from unittest.mock import patch
with patch("posthoganalytics.feature_enabled", side_effect=lambda flag, *a, **kw: flag == "real-time-notifications"):
event = create_notification(data)