---
title: "AssemblyAI Legacy Summarization and Auto Chapters retire October 20: 2026-10-20 | Harbyn"
description: "AssemblyAI Legacy Summarization and Auto Chapters retire October 20, effective Oct 20, 2026; replacement: speech_understanding.request, speech_understanding.response."
canonical: "https://harbyn.com/changes/assemblyai/2026-10-06-legacy-summarization-and-auto-chapters-models-deprecated"
last-updated: 2026-10-25
---

# AssemblyAI Legacy Summarization and Auto Chapters retire October 20

Markdown version of <https://harbyn.com/changes/assemblyai/2026-10-06-legacy-summarization-and-auto-chapters-models-deprecated>.

Retirement - AssemblyAI. high severity. In effect. History: recorded after the fact.

Starting October 20, 2026, requests using the legacy Summarization model or legacy Auto Chapters model will return errors. Move the options into speech\_understanding.request and read results from speech\_understanding.response. The API key and endpoint stay the same.

The deadline passed on Oct 20, 2026.

## Facts

| Fact | Value |
| --- | --- |
| Vendor | [AssemblyAI](https://harbyn.com/vendors/assemblyai.md) |
| Kind | Retirement |
| Severity | high |
| Status | In effect |
| Announced | Oct 6, 2026 |
| Effective | Oct 20, 2026 |
| Added to Harbyn | Oct 25, 2026 |
| Lead time | Recorded after the fact: added 5 days after the deadline |
| Symbols | `summarization`, `summary_model` |
| Replacement | `speech_understanding.request`, `speech_understanding.response` |
| Review | Reviewed by a person, extracted by a model |

## Find it in your code

```sh
npx harbyn scan
```

This change names no identifier the scanner can match line by line, so the scan tells you whether your repository uses AssemblyAI, from its packages and API hosts. Nothing leaves your machine.

## Sources

Where this event comes from: the page we read, when we read it, and the hash of that snapshot.

- <https://www.assemblyai.com/changelog> (changelog, fetched 2026-10-21 14:31 UTC, sha256 `031c33b04ecfcdc53d69052d07de8b0c1942c585cf171cd8527fa5ea2ac2bdf1`)

## Related changes

### More from AssemblyAI

- [Clearer error for deleted API keys](https://harbyn.com/changes/assemblyai/2026-10-07-clearer-error-for-deleted-api-keys.md) (Behavior change, announced Oct 7, 2026)
- [Summarization chapter count scales with audio length](https://harbyn.com/changes/assemblyai/2026-09-29-summarization-chapter-count-scales-with-audio-length.md) (Behavior change, announced Sep 29, 2026)
- [Reduced hallucinations on silent multichannel audio](https://harbyn.com/changes/assemblyai/2026-10-16-reduced-hallucinations-on-silent-multichannel-audio.md) (Behavior change, announced Oct 16, 2026)
- [French transcript punctuation fix](https://harbyn.com/changes/assemblyai/2026-09-16-french-transcript-punctuation-fix.md) (Behavior change, announced Sep 16, 2026)

### Changes at other vendors

- [OpenRouter: arcee-ai/trinity-large-thinking expire 2026-10-26](https://harbyn.com/changes/openrouter/2026-10-23-arcee-ai-trinity-large-thinking-expires-2026-10-26.md) (effective Oct 26, 2026)
- [Google Cloud Run and Functions: Node.js 20 runtime decommission](https://harbyn.com/changes/google-cloud/2026-10-08-node-js-20-runtime-decommission.md) (effective Oct 30, 2026)
- [Mistral AI: Z.ai GLM 5.2 (zai-glm-5-2) retires on Mistral on October 31, 2026](https://harbyn.com/changes/mistral/2026-09-29-z-ai-glm-5-2-deprecated-and-scheduled-for-retirement.md) (effective Oct 31, 2026)
- [Fireworks AI: DeepSeek V4 Flash 0731 retires from Serverless Training November 2](https://harbyn.com/changes/fireworks/2026-10-18-upcoming-serverless-training-deprecation-deepseek-v4-flash-0731.md) (effective Nov 2, 2026)

[All upcoming deadlines](https://harbyn.com/deadlines.md)