Model Releases
Claude Opus 5.5 will be the first Opus meant to fall back to a less capable model for 'a small set of capabilities related to the developmen…
Claude Opus 5.5 is the first Opus variant that can automatically fall back from its main model to a reduced‑capability version when executing a small set of specialized tasks associated with frontier
Claude Opus 5.5 is the first Opus variant that can automatically fall back from its main model to a reduced‑capability version when executing a small set of specialized tasks associated with frontier LLM development, such as kernel engineering. The feature was announced by “M1Astra” on September 22, 2026.
Source: Clem Delangue (X) | 2026-09-22