Claude Fable 5.1 is generally available in GitHub Copilot
Tech · Releases · Tue, September 1, 2026
Claude Fable 5.1 from Anthropic is now available in GitHub Copilot. The latest model in Anthropic’s Mythos class, Claude Fable 5.1 is designed for long-horizon, autonomous coding and knowledge-work tasks.
Every year
Also on Sep 1, 2026
| Date | Event | When |
|---|---|---|
| Tue, Sep 1, 2026 | Bear season opens (MN) | Now |
Source, method and history
- Source
- github
- How we know
- From the Releases API (releases.fru.dev), which reads each vendor's changelog.
- Who
- github
- Recurs
- one-off
- More on fru.dev
- releases.fru.dev
- Feed
- Subscribe to Releases
- Changes
- 2026-09-25: added to 2026-09-01