Tech reporter Alex Heath posted that Anthropic plans to release a public version of Mythos tomorrow, renaming and making minor adjustments to ship it as Fable 5. The build will include strict safety protections, will be less permissive for web operations than the version available to Project Glasswing partners, and will substantially improve performance on long‑horizon, multi‑turn tasks.

2026-06-09

Tech reporter Alex Heath posted that Anthropic plans to release a public version of Mythos tomorrow, renaming and making minor adjustments to ship it as Fable 5. The build will include strict safety protections, will be less permissive for web operations than the version available to Project Glasswing partners, and will substantially improve performance on long‑horizon, multi‑turn tasks.