Version 2.1.68

Typing "ultrathink" in a message now sets reasoning effort to "high" for that turn. In the previous version, ultrathink was deprecated and showed a dismissive message — it now has real functionality again.

ultrathink about the architecture of this codebase and suggest improvements

• When "ultrathink" appears anywhere in your message, effort is automatically set to high for that turn
• A notification briefly displays: "Effort set to high for this turn"
• The word "ultrathink" is rendered with a rainbow color shimmer effect in the terminal (cycling through red, orange, yellow, green, blue, indigo, and violet)
• Controlled by the tengu_turtle_carbon feature flag (defaults to enabled)
• Replaces the old "Ultrathink no longer does anything. Thinking budget is now max by default." deprecation message

Ultrathink effort injection (search for "ultrathink_effort") — rqY() at line ~290076 checks jd() ("tengu_turtle_carbon") and Vf7() (/\bultrathink\b/i)

Users who were automatically migrated from legacy Opus models to Opus 4.6 can now opt out by setting an environment variable.

export CLAUDE_CODE_DISABLE_LEGACY_MODEL_REMAP=1

• When your model is auto-remapped to Opus 4.6, the notification now reads: "Model updated to Opus 4.6 · Set CLAUDE_CODE_DISABLE_LEGACY_MODEL_REMAP=1 to opt out"
• The notification displays for 8 seconds (up from 3) when the opt-out message is shown, giving you time to read the instructions
• Setting the environment variable to 1 disables the automatic model remapping entirely
• The remap behavior is also gated by the tengu_grey_wool feature flag (defaults to enabled)

Model remap opt-out (search for "CLAUDE_CODE_DISABLE_LEGACY_MODEL_REMAP") — gy1() at line ~535228

The effort callout dialog for Opus 4.6 users has been redesigned with server-configurable content and a simplified option set.

• Dialog title and description are now fetched from the server (via tengu_grey_step2 feature flag) instead of being hardcoded
• Options are simplified to three clear choices:
• "Use medium effort (recommended)"
• "Use high effort"
• "Use low effort" (new — previously only medium and high were offered)
• Removed verbose per-option descriptions and the "(current)" suffix labeling
• Uses a separate dismiss state (effortCalloutV2Dismissed) so users who dismissed the old dialog may see the new one

Server-controlled effort dialog (search for "tengu_grey_step2") — zb6() at line ~162660, dialog at ohq() line ~588325

The automatic migration that silently set Opus 4.6 effort to "medium" has been removed.

• Previously, on startup, the app would set opus46EffortMediumMigrationTimestamp and briefly flash "Opus 4.6 effort updated to medium"
• This silent migration has been completely removed — effort is no longer changed behind the scenes
• Default effort for Opus 4.6 is now determined by feature flags (tengu_quartz_falcon, tengu_grey_step2) rather than a one-time migration

Removed migration function (search for "opus46EffortMediumMigrationTimestamp" — present in v2.1.67, absent in v2.1.68)

The redesigned effort dialog described above is gated behind the tengu_grey_step2 feature flag, which defaults to { enabled: false }.

Feature-flagged (disabled by default, server-controlled rollout)

• The tengu_grey_step2 flag controls whether the dialog appears and provides its title and description text
• A separate tengu_quartz_falcon flag also influences the default effort level for Opus 4.6
• First-party users who previously dismissed the old effort dialog won't see the new one until tengu_grey_step2 is enabled server-side
• API users (By() or wb6()) can also be enrolled via the same flag

Dialog visibility (search for "effortCalloutV2Dismissed") — zIq() at line ~588370 checks zb6().enabled