[teamleaderleo]

What changed

Leo asked for Fast mode to be tucked into the model picker. The compact picker and full picker now use the harness-reported Fast mode config option for every harness, including Codex. The separate lightning control is gone from chat and New Tab, while the native config id, on/off values, and current default remain unchanged.

“we just want to have that toggle inside the model picker” — Leo, 2026-10-28

Scope

• Reuses the existing Fast mode checkbox row after Account in QuickModelMenu.
• Keeps the full ModelPicker Fast mode row in the same surface.
• Removes the separate speed bolt rendering and its speed prop path.
• Takes back cmux NEXT composer: capability-driven Fast and work-on New Tab #24631: Leo explicitly asked to tuck Fast mode inside the model picker and remove the separate lightning control; this replaces only that PR's adjacent Codex bolt, while keeping its capability-driven New Tab behavior.
• Scopes remembered higher Fast tiers to the active chat, harness and option, so a newly selected chat does not inherit a previous chat's speed.
• Updates the Codex gallery state and narrow layout note to assert no bolt and a menu toggle.
• The New Tab path uses the same QuickModelMenu through ComposerPickers; no separate behavior or default was introduced.

Gallery variants

The composer gallery covers Claude and Codex Fast mode states, off and on, in chat and New Tab. The Codex variant now captures the before/after behavior: the model picker contains the toggle and the composer row has no lightning control.

Before and after

Actual React gallery captures, rendered on gcp-agent-lane-1 with Chromium at the same viewport per pair. Before is feat-cmux-next c30fa03db4b0f4c3da53d7c52e7af9172a872249; after is the reviewed PR head ffb90c3e667e95209dc1150cd2e311c9892ea539. The chat pair uses agent-pane.composer-pickers#model-menu at 640 × 560 CSS px; New Tab uses agent-pane.new-tab#model-picker-open at 760 × 560 CSS px. Both are gallery fixtures, not native fleet screenshots.

Surface and theme	Before	After
Codex chat, dark
Codex chat, light
New Tab, dark
New Tab, light

Performance

No perf numbers: This changes the placement and state of a configuration control; it does not change runtime performance.

Validation

• bun test src/agent-session/acpmux/FastModeState.test.ts test/composer-fast-toggle.test.tsx src/agent-session/acpmux/QuickModelMenu.test.tsx src/agent-session/acpmux/EffortPicker.test.tsx (21 pass, 162 expectations)
• Mounted composer chat-switch regression was red before the session-scoped memory fix and green after it: chat B chooses its first Fast tier, not chat A's remembered ultrafast tier.
• CMUX_BROWSER_TESTS=1 bun test test/gallery-agent-pane-entries.test.ts --test-name-pattern="composer-pickers#fast-mode" (pass)
• Targeted gallery health: agent-pane.composer#reasoning-codex failed at the earlier head due to a static-fixture assertion and now passes. agent-pane.composer#file-not-attached fails on both this head and current base c30fa03. Five nearby model/narrow/headline states also fail identically on that base.
• vp fmt --check, vp lint, vp check --no-fmt --no-lint, python3 scripts/cmux-next/prepush-gate.py (pass)

Review (Astra independent, xhigh): SHIP at ffb90c3.

agent-identity footer
agent session

[github-actions]

cmux status _{(one comment, edited in place; each line is updated by the job that owns it)}

Review ffb90c3: HQ feed card · gallery before/after runs · checks

App of this head (app.zip, kept 1 day)

gh workflow run reload-build.yml -R manaflow-ai/cmux --ref feat-cmux-next -f tag=pr26555 -f ref=lane/nx-picker-fast-toggle -f platform=macos -f backend_mode=local

Unclear: web / react-apps-check failed: no known signature; failed step: Check webview test shards. This PR merged before its CI finished: fix forward on main.

CI failed on ffb90c3e66 (run 40649297503 attempt 1): 4 code, 1 unknown.

Job	Verdict	Why
web / react-apps-base-check (2)	code	a web test failed
web / react-apps-base-check (4)	code	a web test failed
web / react-apps-base-check (1)	code	a web test failed
web / react-apps-base-check (3)	code	a web test failed
web / react-apps-check	unknown	no known signature; failed step: Check webview test shards

Failures:

• seen on other PRs agent-pane-dock-gutters.test.ts chromium > the gutter beside every part of the stack scrolls the transcript, and the part keeps the ...: failed (job)
• seen on other PRs agent-pane-dock-gutters.test.ts webkit > the gutter beside every part of the stack scrolls the transcript, and the part keeps the po...: failed (job)
• seen on other PRs agent-pane-queue-steer.test.ts queued and steering prompts > the queue takes its own place in the stack: nothing is cut off or draw...: failed (job)
• seen on other PRs composer-edges.test.ts composer card: appearance.borders = none draws no edge: failed (job)
• seen on other PRs composer-edges.test.ts composer card: one hairline edge by default: failed (job)
• seen on other PRs composer-foot-pill-inset.test.ts the row's padding is counted from the inset, so only the pill grows, not the text's place: failed (job)
• seen on other PRs composer-foot-pill-inset.test.ts the context ring uses one compact control size in the main and quiet rows: failed (job)
• seen on other PRs composer-footer-plain.test.ts at 760 px (light): on, plain text at rest, same labels, no overlap: failed (job)
• seen on other PRs accent-glass-invariants.test.ts no orange or system accent and no opaque glass on the gallery stages: failed (job)
• seen on other PRs agent-pane-agents-pill.test.ts by default the running agents sit in the tray above the composer, not in the transcript: failed (job)
• ... 22 more in the job logs

Matched log lines

web / react-apps-base-check (2): (fail) chromium > the gutter beside every part of the stack scrolls the transcript, and the part keeps the pointer [8412.86ms]
web / react-apps-base-check (4): (fail) no orange or system accent and no opaque glass on the gallery stages [732255.34ms]
web / react-apps-base-check (1): (fail) only page.css imports the page's sheets [28.66ms]
web / react-apps-base-check (3): (fail) the summary card lists the chat's background tasks: running ones first, the finished folded [936.73ms]

Not re-run automatically: web / react-apps-base-check (2), web / react-apps-base-check (4), web / react-apps-base-check (1), web / react-apps-base-check (3), web / react-apps-check are not machine failures.

Written by scripts/ci/classify_failures.py (ci-failure-attribution.yml); signatures are its SIGNATURES table. A machine verdict is the runner's fault, not this PR's; yours means the failing file is one this PR changes, also red on main that main's latest full suite fails the same way, seen on other PRs that it failed on another pull request's run lately.

red: web / Web status; base red: the same failure on the base 59d518f; does not block
red: web / react-apps-base-check (1); no finished base run on 59d518f to compare; do not merge until green; see lane-rules
red: web / react-apps-base-check (2); no finished base run on 59d518f to compare; do not merge until green; see lane-rules
red: web / react-apps-base-check (3); no finished base run on 59d518f to compare; do not merge until green; see lane-rules
red: web / react-apps-base-check (4); no finished base run on 59d518f to compare; do not merge until green; see lane-rules
red: web / react-apps-check; base red: the same failure on the base 59d518f; does not block

Gallery before/after for ffb90c3: 16 states rendered, 16 images differ, 1157 more touched states not rendered. Images are in the run's artifact, not on this public PR.

gh run download 40649297331 -R manaflow-ai/cmux -n gallery-advisory-26555-ffb90c3e667e95209dc1150cd2e311c9892ea539 (then read gallery-review.json)

States

State	Theme	Status	Diff	Picked by
agent-pane.composer/new-chat	Apple System Colors Light	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/new-chat	Apple System Colors	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/side-session	Apple System Colors Light	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/side-session	Apple System Colors	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/new-chat-suggest-open	Apple System Colors Light	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/new-chat-suggest-open	Apple System Colors	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/new-chat-suggest-failing	Apple System Colors Light	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/new-chat-suggest-failing	Apple System Colors	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/new-chat-suggest-draft	Apple System Colors Light	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/new-chat-suggest-draft	Apple System Colors	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/new-chat-reasoning	Apple System Colors Light	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/new-chat-reasoning	Apple System Colors	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/agent-home	Apple System Colors Light	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/agent-home	Apple System Colors	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/agent-home-path	Apple System Colors Light	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer/agent-home-path	Apple System Colors	unchanged	0%	own ComposerPickers.tsx
agent-pane.composer-pickers/closed	Apple System Colors Light	changed	0.576%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/closed	Apple System Colors	changed	0.553%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/pill-rail	Apple System Colors Light	changed	0.576%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/pill-rail	Apple System Colors	changed	0.553%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/model-menu	Apple System Colors Light	changed	0.546%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/model-menu	Apple System Colors	changed	0.542%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/model-more	Apple System Colors Light	changed	0.546%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/model-more	Apple System Colors	changed	0.542%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/model-focus	Apple System Colors Light	changed	0.576%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/model-focus	Apple System Colors	changed	0.553%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/model-press-drag-release	Apple System Colors Light	changed	0.576%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/model-press-drag-release	Apple System Colors	changed	0.553%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/effort-menu	Apple System Colors Light	changed	0%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/effort-menu	Apple System Colors	changed	0%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/effort-focus	Apple System Colors Light	changed	0.576%	own ComposerPickers.gallery.tsx
agent-pane.composer-pickers/effort-focus	Apple System Colors	changed	0.553%	own ComposerPickers.gallery.tsx

_{Pick other states with a Gallery: entry.id, entry.id/variant line in the PR body.}

[teamleaderleo]

Bead cx-c5w0yd created for this PR by the cmux coordinator.

[blacksmith-sh]

Found 128 test failures on Blacksmith runners:

Failures

Test	View Logs
build_only must be a conjunctive exclusion on the helper, signing, and publication jobs , and must not gate the unsigned app build/ build_only must be a conjunctive exclusion on the helper, signing, and publication jobs , and must not gate the unsigned app build	View Logs
nightly.yml must derive the embedded key and sign every appcast through the helper/ nightly.yml must derive the embedded key and sign every appcast through the helper	View Logs
src/pages/settings/layout.test.ts/layout.test	View Logs
src/pages/settings/layout.test.ts/layout.test	View Logs
test/agent-pane-attach-huge-files.test.ts/agent-pane-attach-huge-files.test	View Logs
test/agent-pane-attach-huge-files.test.ts/agent-pane-attach-huge-files.test	View Logs
test/agent-pane-background-tasks.test.ts/agent-pane-background-tasks.test	View Logs
test/agent-pane-background-tasks.test.ts/agent-pane-background-tasks.test	View Logs
test/agent-pane-chat-unavailable.test.ts/agent-pane-chat-unavailable.test	View Logs
test/agent-pane-chat-unavailable.test.ts/agent-pane-chat-unavailable.test	View Logs

...and 118 more test failures. View all on Blacksmith: run 40649297503, run 40649297551

^{Need help on this PR? Tag @codesmith-bot with what you need.}

[teamleaderleo]

Review (codex gpt-6-astra high, next-review): BLOCK at b75ad04

• webviews/src/agent-session/acpmux/ComposerPickers.tsx:904–906: Removing the tier-cycling bolt makes Ultrafast unreachable for an option offering standard, fast, and ultrafast. Starting at standard, the replacement only toggles fast ↔ standard; the full picker uses the same logic. Remembering a previously active tier cannot select it initially. Preserve tier selection inside the picker.

[github-actions]

Shipped in:

• cmux NEXT nightly 1.0.0-nightly.4068813240101 (127a2705ef)
• cmux NEXT nightly 1.0.0-nightly.4069035197201 (2645001cde)