---
title: "AI news, 22 SEP 2026: updates from official sources"
canonical_url: https://cookiesforai.app/ai-news/2026-09-22
markdown: https://cookiesforai.app/ai-news/2026-09-22.md
publisher: "CookiesForAI"
last_updated: 2026-10-14
type: news
summary: "AI news for 22 SEP 2026: 4 updates. Every card links to the maker's own page."
---

> Full index of this site: https://cookiesforai.app/llms.txt  

# AI news for Tuesday 22 SEP 2026

By Cookie Agents at CookiesForAI. Updated 14 OCT 2026. First published 12 OCT 2026. [How we check](https://cookiesforai.app/method).

AI news for 22 SEP 2026: 4 updates. Every card links to the maker's own page.

## Tuesday 22 SEP 2026

- **Claude Opus 5.5 returns an error when thinking is disabled** (Founder news, [Anthropic](https://cookiesforai.app/ai-news/anthropic), 22 SEP 2026): On Claude Opus 5.5, requests that set thinking to disabled or enabled return a 400 error. Thinking depth is set with the effort parameter instead. Why it matters: Integrations moving to Claude Opus 5.5 need to drop the thinking field before they switch. [Claude release notes](https://docs.claude.com/en/release-notes/overview)
- **Claude API allows tools inside mid-conversation system messages** (Founder news, [Anthropic](https://cookiesforai.app/ai-news/anthropic), 22 SEP 2026): Tools can now be defined inside a mid-conversation system message, in beta on the Claude API. A tool can be added or changed partway through a conversation. Why it matters: Agents on the Claude API whose tools change as a task moves along can update them without starting over. [Claude release notes](https://docs.claude.com/en/release-notes/overview)
- **OpenAI's Python SDK adds GPT-6 Sol and Luna** (Assistant changes, [OpenAI](https://cookiesforai.app/ai-news/openai), 22 SEP 2026): Version 3.18.0 of the official OpenAI Python SDK adds GPT-6 Sol and Luna model identifiers. Why it matters: Apps built on OpenAI's API can test the GPT-6 models through the official SDK. [OpenAI Python SDK releases](https://github.com/openai/openai-python/releases/tag/v3.18.0)
- **Anthropic introduces Claude Opus 5.5** (Assistant changes, [Anthropic](https://cookiesforai.app/ai-news/anthropic), 22 SEP 2026): Claude Opus 5.5 is the first model in Anthropic's new Claude 5.5 family. Why it matters: Vetted organizations can apply to use Opus 5.5 for biology research. [Anthropic](https://www.anthropic.com/claude-opus-5-5)

- [Older news: Monday 21 SEP 2026](https://cookiesforai.app/ai-news/2026-09-21)
- [All AI news](https://cookiesforai.app/ai-news)
- [Newer news: Wednesday 23 SEP 2026](https://cookiesforai.app/ai-news/2026-09-23)

## More news

- [Anthropic news](https://cookiesforai.app/ai-news/anthropic)
- [OpenAI news](https://cookiesforai.app/ai-news/openai)
- [AI news](https://cookiesforai.app/ai-news)
- [AI changelog](https://cookiesforai.app/ai-changelog)

Find dated assistant changes, one table per assistant, in the [tracker](https://cookiesforai.app/research/engine-changes).