# Substack: Major incident: Delayed push notifications due to OneSignal outage

**Summary:** Substack reported major delays to Push Notifications caused by an outage at its delivery provider, OneSignal. The incident started at 2024-08-04 19:08 UTC and was resolved at 2024-08-04 20:32 UTC, lasting 1 h 23 min. _(machine-written, sol)_
- Kind: Major incident · Label: degradation (model (Jev))
- Changed: 2024-08-04 19:08 UTC · Detected: 2026-10-17 18:22 UTC
- [Source: https://stspg.io/yl1qm5nphyc2](https://stspg.io/yl1qm5nphyc2)
- [Company: Substack](https://rewindex.com/company/substack.md)
- Versions: before (none: first archived) → after incident\_version:261/rmn3jfnq4lcl@d0d73bdab96a
- Change 1 of 1 for this incident

## What changed

**1. Added: Title**

```diff
+ Delayed push notifications due to OneSignal outage
```

**2. Added: Impact**

```diff
+ major
```

**3. Added: Status**

```diff
+ resolved
```

**4. Added: Start time**

```diff
+ 2024-08-04 19:08 UTC
```

**5. Added: Resolved time**

```diff
+ 2024-08-04 20:32 UTC
```

**6. Added: Affected components**

```diff
+ Push Notifications
```

**7. Added: Update** (identified) · 2024-08-04 19:08 UTC

```diff
+ We've identified an issue with delays in push notifications due to an outage at our push notification delivery provider, OneSignal. We expect all notifications to be delivered as normal once the issue is resolved.
```

**8. Added: Update** (resolved) · 2024-08-04 20:32 UTC

```diff
+ This incident has been resolved.
```

## History of this incident

| When (UTC) | Change | Label |
| --- | --- | --- |
| 2024-08-04 19:08 UTC | Major incident: Delayed push notifications due to OneSignal outage (this change) | degradation |

All Substack changes: [timeline](https://rewindex.com/company/substack/changes.md)
_Diff excerpts are shown on normalized text: dates, counters and tokens appear as ‹date›, ‹count›, ‹tok›; noise-only edits are hidden. Rewindex shows the changed passages, not a copy of the page._


---
Canonical: https://rewindex.com/change/i533e1d0bffe9a3 · Markdown: https://rewindex.com/change/i533e1d0bffe9a3.md · JSON: https://rewindex.com/api/v1/changes/i533e1d0bffe9a3 · Generated 2026-10-18T03:28:50.579Z