# Ably: Major incident: Elevated API Errors

**Summary:** Ably reported a major DDoS incident causing token-request errors across all Ably Realtime regions (503 responses) and intermittent ably.com unavailability. Recorded start: 2026-10-01 15:36 UTC; duration: 26 min, with token errors lasting approximately six minutes. Ably restored token-request service by increasing capacity and added targeted traffic-blocking and rate-limiting rules. _(machine-written, sol)_
- Kind: Major incident · Label: security (model (Jev))
- Changed: 2026-10-01 15:36 UTC · Detected: 2026-10-17 18:22 UTC
- [Source: https://stspg.io/v5stt2xyrp3f](https://stspg.io/v5stt2xyrp3f)
- [Company: Ably](https://rewindex.com/company/ably.md)
- Versions: before (none: first archived) → after incident\_version:173/nx8s78gq143r@4d2e05fde178
- Change 1 of 1 for this incident

## What changed

**1. Added: Title**

```diff
+ Elevated API Errors
```

**2. Added: Impact**

```diff
+ major
```

**3. Added: Status**

```diff
+ postmortem
```

**4. Added: Start time**

```diff
+ 2026-10-01 15:36 UTC
```

**5. Added: Resolved time**

```diff
+ 2026-10-01 16:03 UTC
```

**6. Added: Update** (investigating) · 2026-10-01 15:36 UTC

```diff
+ We're experiencing an elevated level of API errors and are currently looking into the issue.
```

**7. Added: Update** (resolved) · 2026-10-01 16:03 UTC

```diff
+ Between 15:30 UTC to 15:36 UTC there were elevated errors affecting token requests in all regions resulting in 503 error responses.
```

**8. Added: Update** (postmortem) · 2026-10-01 17:20 UTC

```diff
+ On October 1, a distributed denial-of-service \(DDoS\) attack caused elevated token-request errors across all Ably Realtime regions for approximately six minutes and intermittent unavailability of [ably.com](http://ably.com). We restored token-request service by increasing capacity and added targeted traffic-blocking and rate-limiting rules to mitigate the attack. We are strengthening endpoint protection and reviewing our firewall controls to reduce the risk of recurrence.
```

## History of this incident

| When (UTC) | Change | Label |
| --- | --- | --- |
| 2026-10-01 15:36 UTC | Major incident: Elevated API Errors (this change) | security |

All Ably changes: [timeline](https://rewindex.com/company/ably/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._


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Canonical: https://rewindex.com/change/ib78eaacf25bae6 · Markdown: https://rewindex.com/change/ib78eaacf25bae6.md · JSON: https://rewindex.com/api/v1/changes/ib78eaacf25bae6 · Generated 2026-10-18T02:28:08.937Z