# AssemblyAI: Outage on US Async Endpoint

- Provider: [AssemblyAI](https://outages.cc/assemblyai.md)
- Type: Incident
- State: Resolved
- Worst impact: Major outage
- Started: 2026-09-16 20:22 UTC
- Resolved: 2026-09-16 21:37 UTC (lasted 1 h 15 min)
- Components: Asynchronous API
- Official update: https://stspg.io/tyzrb2l4mflh

## Updates from AssemblyAI

### postmortem, 2026-09-21 20:38 UTC

**Summary** On September 16, 2026, between 20:04 and 21:08 UTC, our US Async API returned elevated server errors. At peak, roughly 50% of async transcription requests on the US endpoint failed, and a portion of the requests that did succeed took longer than usual to complete. Our EU endpoint and real-time/streaming services were not affected. **Root cause** The failure originated in AWS SQS, the managed queuing service our transcription pipeline uses to distribute work. Specifically, the Fair Queues feature began rejecting valid messages with an `InvalidParameterValue` error on a parameter our services had been sending successfully for months. There was no deploy or infrastructure change on our side that triggered this; AWS confirmed it as a service-side issue and rolled back the change on their end later that evening. Because the affected queues sit in the path between our API and our transcription workers, requests that could not be queued failed outright, and a portion of the work t

### resolved, 2026-09-16 21:37 UTC

The issue, which was the result of an AWS service issue, has been resolved and we have continue to see good performance since implementing a fix so we are now closing this issue.

### monitoring, 2026-09-16 21:12 UTC

We have mitigated the issue and our Async API service is recovering.

### identified, 2026-09-16 21:10 UTC

We are seeing a reduction in the number of errors, but we are still working to fully resolve the issue.

### identified, 2026-09-16 20:57 UTC

We are continuing to investigate these elevated errors. We will provide an update as soon as possible.

### identified, 2026-09-16 20:24 UTC

The issue has been identified. This is affecting approximately 50% of all async transcriptions on the US endpoint.

### investigating, 2026-09-16 20:22 UTC

We are currently investigating an issue that is affecting all customers using our Async API on our US endpoint. Users will be receiving a server error. We will update with more information as we learn more. This began at 8pm UTC.