Claude Code 2.1.280 sets Opus 5.5 as the default Opus model, with a 1M-token window
2026-09-27 · that day's edition · one of the five
The changelog lists Opus 5.5 at 4 dollars per million input tokens and 20 dollars per million output tokens.
The Claude Code changelog from Anthropic lists 114 entries under version 2.1.280, dated September 22, 2026. It fixes writes through a symlinked path being judged by their in-tree spelling: the permission prompt now names where the write actually lands, and acceptEdits, allow rules and auto mode no longer approve a write that lands outside the project tree. The same release adds Claude Opus 5.5 as the default Opus model, with a 1M-token context window priced at 4 dollars/20 dollars per million input/output tokens and 20 cents per million tokens for cache reads.