# ModelTree release updates

Recorded, source-backed changes to reviewed AI model releases: announcements, previews, availability, deprecations, and corrections.

Generated from the same records the site renders at `/updates/`. Each entry is dated by the day its **source** stated, never by the day it was checked here; both dates are given so the two are never mistaken for one another.

7 recorded changes. Every record here was last re-checked on or before 2026-09-02.

## 2026

### September 2026

- **Sep 1, 2026 — Generally available: Claude Fable 5.1** (Anthropic)
  - Anthropic launched Claude Fable 5.1 and described it as generally available, on the Claude API, Amazon Bedrock, Claude Platform on AWS, Google Cloud and Microsoft Foundry.
  - Source: [Introducing Claude Fable 5.1 and Claude Mythos 5.1](https://www.anthropic.com/claude-fable-and-mythos-5-1) (Anthropic), [API release notes](https://platform.claude.com/docs/en/release-notes/api) (Anthropic)
  - Checked 2026-09-02 · `claude-fable-5-1-general-availability`
- **Sep 1, 2026 — API available: Claude Mythos 5.1** (Anthropic)
  - Anthropic launched Claude Mythos 5.1 on the Claude API alongside Claude Fable 5.1, for Project Glasswing participants. Anthropic describes it as available only through its trusted access programs rather than generally available.
  - Source: [Introducing Claude Fable 5.1 and Claude Mythos 5.1](https://www.anthropic.com/claude-fable-and-mythos-5-1) (Anthropic), [Claude Mythos 5.1](https://platform.claude.com/docs/en/models/mythos-5-1/overview) (Anthropic), [API release notes](https://platform.claude.com/docs/en/release-notes/api) (Anthropic)
  - Checked 2026-09-02 · `claude-mythos-5-1-invitation-only-availability`

### August 2026

- **Aug 27, 2026 — API available: Qwen3.8-27B** (Alibaba Cloud)
  - Amazon announced Alibaba Cloud’s Qwen3.8-27B as available on Amazon SageMaker JumpStart. This changes where the model can be deployed and changes nothing about who created it.
  - Source: [Muse-Glimmer-30B and Qwen 3.8-27B models now available on Amazon SageMaker JumpStart](https://aws.amazon.com/about-aws/whats-new/2026/01/muse-glimmer-30b-qwen-3.8-27b-on-sagemaker-jumpstart/) (Amazon Web Services)
  - Checked 2026-08-28 · `qwen3-8-27b-on-sagemaker-jumpstart`
- **Aug 14, 2026 — Generally available: Qwen3.8-27B** (Alibaba Cloud)
  - Alibaba Cloud recorded Qwen3.8-27B as available on Hugging Face Hub and ModelScope.
  - Source: [QwenLM/Qwen3.8](https://github.com/QwenLM/Qwen3.8) (Alibaba Cloud)
  - Checked 2026-08-28 · `qwen3-8-27b-weights-published`
- **Aug 12, 2026 — Preview: MAI-Thinking-1** (Microsoft)
  - Microsoft AI announced MAI-Thinking-1 as available in public preview on Microsoft Foundry.
  - Source: [Introducing MAI-Thinking-1](https://microsoft.ai/news/introducing-mai-thinking-1/) (Microsoft)
  - Checked 2026-08-28 · `mai-thinking-1-public-preview`
- **Aug 12, 2026 — Generally available: Qwen3.8-2.4T-A95B** (Alibaba Cloud)
  - Alibaba Cloud recorded Qwen3.8-2.4T-A95B as available on Hugging Face Hub and ModelScope.
  - Source: [QwenLM/Qwen3.8](https://github.com/QwenLM/Qwen3.8) (Alibaba Cloud)
  - Checked 2026-08-28 · `qwen3-8-2-4t-a95b-weights-published`

## 2025

### December 2025

- **Dec 2, 2025 — Generally available: Amazon Nova 2 Sonic** (Amazon)
  - Amazon announced the availability of Nova 2 Sonic in Amazon Bedrock in three AWS Regions.
  - Source: [Amazon Nova 2 Sonic for real-time conversational AI](https://aws.amazon.com/about-aws/whats-new/2025/12/amazon-nova-2-sonic-real-time-conversational-ai/) (Amazon Web Services)
  - Checked 2026-08-28 · `amazon-nova-2-sonic-bedrock-availability`