{"version":"2.1.196","anchor":"fast-mode-model-scope-narrowed","canonical_anchor":"fast-mode-model-scope-narrowed","heading":"Fast Mode Model Scope Narrowed","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.196\/e\/fast-mode-model-scope-narrowed","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.196","markdown":"### Fast Mode Model Scope Narrowed\n\nFast mode (Opus with faster output, toggled with `\/fast`) is now documented as available on Opus 4.8 and 4.7 only \u2014 Opus 4.6 has been removed from the list. Opus 4.7 fast mode is additionally flagged as deprecated with a removal date.\n\n**Details**\n\n- Fast-mode eligibility (`ig()`) passes if the catalog `fast_mode` capability is set on the resolved model, or if the lowercase model ID contains `opus-4-7` or `opus-4-8`; the previous `opus-4-6` string match has been removed.\n- Fast mode is restricted to the first-party Anthropic API (`uc()` returns false for Bedrock, Vertex, and other providers); toggling on any other provider returns `\"Fast mode is only available when using the Anthropic API directly\"`.\n- When toggled ON, the active fast-mode model resolves via alias `\"opus\"` (or `\"opus[1m]\"` for 1M context); `iW()` returns the display name `\"Opus 4.8\"` for the confirmation message.\n- The Opus 4.7 deprecation notice fires only when the currently active model resolves to `claude-opus-4-7`. The removal date is read from the `tengu_sunset_penguin_opus47` GrowthBook flag (default `\"2026-07-25\"`); if the date has already passed or is unparseable, no notice is shown.\n- The deprecation notice (`SGo()`) carries `priority: \"immediate\"` and `color: \"warning\"`, surfacing immediately on the next fast-mode toggle rather than as a background notification.\n\n**Evidence**\n\nUpdated fast mode tip (search for `\"available on Opus 4.8\/4.7.\"`) and deprecation logic (search for `\"opus47-fast-mode-deprecation\"` and `\"tengu_sunset_penguin_opus47\"`)\n\n- Flag `tengu_sunset_penguin_opus47`: Not enough to say (read for one account on one subscription tier against v2.1.196; this account: no value returned, anonymous baseline: no value returned, compiled default: 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."}