A new warning notice says that fast mode for Opus 4.8 is deprecated, meaning it is being phased out, and will be removed on a given date. The date comes from a setting sent by the server. If the server sends none, the date is 30 November 2026. The notice appears only until that date.
If you use Opus 4.8 fast mode, you are warned before it is removed and have time to switch to something else.
tengu_sunset_penguin_opus48 Not enough to sayNothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.
This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.314: not a boolean we can read
These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.
Read once, for one account on one subscription tier, against v2.1.314. It isn't a statement about your account. What a flag value here can and cannot tell you
New in this build: tengu_sunset_penguin_opus48