cmux NEXT composer: capability-driven Fast and work-on New Tab

Merged
TE
14d ago
+538-117

The composer’s Fast affordance follows model capability instead of a harness-name guess. Models marked as a free, easy inline toggle show a lightning bolt directly beside the model name in the picker; paid or otherwise non-toggleable Fast stays tucked inside the model menu. Claude therefore has no bolt while Codex can show one. The New Tab Minimal default is the composer alone: no greeting or heading is shown until the user opts into the work-on question and other widgets.

Leo’s direction: “the bolt sits beside the model name only for harnesses where fast is a free, easy toggle (Codex). For Claude (paid fast), and any harness where fast isn't freely toggleable, keep fast tucked inside the model menu; show no bolt on the button.” He later clarified: “Default new tab: no heading text at all ... Add opt-in widgets above the composer, each its own toggle, all off by default.”

The new-tab customize menu and Settings expose independent toggles for the work-on heading, clock, stopwatch, original warm time-of-day lines, and a bundled public-domain quote. Gallery variants cover all widgets off and all on, plus Codex-above, Claude-below, and current-fixed layout comparisons.

Coordination

  • Lucas’s #24194 is teammate-owned and untouched. This changes only trigger content/capability plumbing and preserves provider-tab menu behavior; the shared QuickModelMenu file may need the small merge of his spacer after his PR lands.
  • Lucas’s #21244 is teammate-owned and untouched. Project icon restoration is in #24623.

Validation

  • git diff --check
  • Capability fixtures cover Codex inline Fast and Claude menu-only Fast.
  • New-tab tests cover all widgets off, independent opt-ins, Settings defaults, and all-on/all-off gallery entries.
  • Browser/unit execution is pending the checkout’s missing @base-ui/utils/useIsoLayoutEffect dependency.

Changelog

Made Fast placement capability-driven and added opt-in New Tab widgets with a quiet composer-only default.

agent-identity footer
Agent session: big-red

Gallery: agent-pane.new-tab/widgets-all-off, agent-pane.new-tab/widgets-all-on, agent-pane.new-tab/layout-codex-tabs-above, agent-pane.composer/reasoning-codex