[teamleaderleo]

Leo, 2026-11-03:

also, darn, i guess i realize why there was previously some sort of weird rectangle background behind buttons before. but surely we can do a nice and unobtrusive apple glass type thing that's super subtle until there's text or something beneath right ... if u just look at how chatgpt ios does things...

In a one-tab pane (#33142) the transcript runs up under the tab row, so text scrolled right under the header tools and collided with them. Now the tools sit in one glass capsule, as ChatGPT iOS floats its buttons:

• At rest (first message below the row): no capsule. The tools stay plain glyphs, so the "no fill at rest" rule (Agent pane header: no background behind the top-right icons at rest #32687, Agent chat: header buttons draw no plate, pressed included (takes back #27546's fill) #28962) holds.
• Text underneath (the scroller's existing data-fade-top): one rounded pill fades in behind the whole group in 160 ms. It uses the shared glass tint (--ds-glass-plain-tint of the theme surface), --ds-glass-popover-blur, the --glass-edge hairline and --elevation-1. Words under the tools go soft and dim, and the glyphs stay legible.
• No hard rectangle. The old rectangle was the chat's page color painted behind the tools in the tab row. Agent chat: no opaque rectangle behind the header buttons in the tab row #32944 removed it, and the per-button resting plates went in PR3: remove top-right header icon plates #26499, Agent chat: header buttons draw no plate, pressed included (takes back #27546's fill) #28962 and Agent pane header: no background behind the top-right icons at rest #32687. This change brings back neither: the capsule is clear at rest and is frosted glass over text, not a fill.
• No layout shift. The capsule is a ::before behind the group, and no box moves; the test checks this. It adds no JS and no scroll work: the selector reuses the transcript's existing data-fade-top through :has(). No observer or timer.
• Hover and pressed still light only their own button, drawn over the capsule.
• Reduce Transparency: the capsule is the opaque surface, with no blur. Reduce Motion: no fade.
• Two or more tabs keep the plain row, so nothing scrolls under it and there is no capsule.

Gallery agent-pane.header:

• glass-pill-rest and glass-pill-over-text: chosen.
• glass-none-over-text: before.
• glass-faint-rest and glass-faint-over-text: always faint. Rejected: it puts a shape back behind the tools at rest.
• glass-circles-rest and glass-circles-over-text: a disc per button. Rejected: four touching discs on a 26px pitch, the ⋮ becomes an oval, and it is busier than ChatGPT's one pill.

Design references: cmux/live/panels-subagent-glass-buttons-no-close, cmux/live/transcript-subagent-pill-no-close-button (the ChatGPT iOS reference), cmux/live/toolbar-session-info-button-background-2, cmux/live/toolbar-session-info-button-background (the plates Leo disliked).

Design spec: design/chat-header.md (leo-workspace).

Tests: webviews/test/chat-header-glass.test.ts (Chromium and WebKit) checks:

• no capsule at rest;
• the capsule is round and frosted over text, and lifts the pixels under the tools;
• no tool moves;
• two tabs never get it.

Captures: webviews/scripts/agent-pane/capture-header-glass.mjs.

Agent session: agent session

🤖 Generated with Claude Code

---

^{Open in [code]smith · Need help on this PR? Tag @codesmith-bot with what you need.}

---

Summary by cubic

Makes the agent chat header tools float in a single frosted-glass capsule when transcript text scrolls under them, so rows no longer collide with the buttons in a one-tab pane.

The capsule stays invisible at rest (tools remain plain glyphs), fades in via the motion scale's micro token once text passes beneath, and sits on a ::before behind the buttons so nothing moves. It's pure CSS built on the transcript's existing data-fade-top — no JS or scroll work. Reduce Transparency turns the capsule opaque without blur; Reduce Motion skips the fade. Multi-tab panes keep the plain row. Gallery agent-pane.header covers the chosen pill over text plus always-faint and per-button circles alternatives; tests verify the capsule appears only over scrolled text and that the pill is a backing surface, not a control, on the no-capsules allowlist.

^{Written for commit f63c77a. Summary will update on new commits.}

[github-actions]

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

Review f63c77a: 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=pr34325 -f ref=leo/header-tools-glass -f platform=macos -f backend_mode=local

Gallery before/after for f63c77a: 16 states rendered, 14 images differ, 1299 more touched states not rendered. Images are in the run's artifact, not on this public PR; the independent review of this head reads them on its own, so the PR needs no hand-made screenshots of these states.

gh run download 41754870936 -R manaflow-ai/cmux -n gallery-advisory-34325-f63c77a8576049fb65c6b922aa9eddedd7fde2b5 (then read gallery-review.json)

States

State	Theme	Status	Diff	Picked by
agent-pane.header/glass-pill-rest	Apple System Colors Light	new	0%	own header.gallery.ts
agent-pane.header/glass-pill-rest	Apple System Colors	new	0%	own header.gallery.ts
agent-pane.header/glass-pill-over-text	Apple System Colors Light	new	0%	own header.gallery.ts
agent-pane.header/glass-pill-over-text	Apple System Colors	new	0%	own header.gallery.ts
agent-pane.header/glass-none-over-text	Apple System Colors Light	new	0%	own header.gallery.ts
agent-pane.header/glass-none-over-text	Apple System Colors	new	0%	own header.gallery.ts
agent-pane.header/glass-faint-rest	Apple System Colors Light	new	0%	own header.gallery.ts
agent-pane.header/glass-faint-rest	Apple System Colors	new	0%	own header.gallery.ts
agent-pane.header/glass-faint-over-text	Apple System Colors Light	new	0%	own header.gallery.ts
agent-pane.header/glass-faint-over-text	Apple System Colors	new	0%	own header.gallery.ts
agent-pane.header/glass-circles-rest	Apple System Colors Light	new	0%	own header.gallery.ts
agent-pane.header/glass-circles-rest	Apple System Colors	new	0%	own header.gallery.ts
agent-pane.header/glass-circles-over-text	Apple System Colors Light	new	0%	own header.gallery.ts
agent-pane.header/glass-circles-over-text	Apple System Colors	new	0%	own header.gallery.ts
agent-pane.header/standalone-compact	Apple System Colors Light	unchanged	0%	own header.gallery.ts
agent-pane.header/standalone-compact	Apple System Colors	unchanged	0%	own header.gallery.ts
agent-pane.header-action-stability/idle	Apple System Colors Light	unchanged	0%	own header.css
agent-pane.header-action-stability/idle	Apple System Colors	unchanged	0%	own header.css
agent-pane.header-action-stability/busy	Apple System Colors Light	unchanged	0%	own header.css
agent-pane.header-action-stability/busy	Apple System Colors	unchanged	0%	own header.css
agent-pane.header-tools/native-row-off	Apple System Colors Light	unchanged	0%	own header.css
agent-pane.header-tools/native-row-off	Apple System Colors	unchanged	0%	own header.css
agent-pane.header-tools/native-row-tools	Apple System Colors Light	unchanged	0%	own header.css
agent-pane.header-tools/native-row-tools	Apple System Colors	unchanged	0%	own header.css
agent-pane.header-tools/unified-compact	Apple System Colors Light	unchanged	0%	own header.css
agent-pane.header-tools/unified-compact	Apple System Colors	unchanged	0%	own header.css
agent-pane.header-tools/unified-roomy	Apple System Colors Light	unchanged	0%	own header.css
agent-pane.header-tools/unified-roomy	Apple System Colors	unchanged	0%	own header.css
agent-pane.header-tools/unified-tight	Apple System Colors Light	unchanged	0%	own header.css
agent-pane.header-tools/unified-tight	Apple System Colors	unchanged	0%	own header.css
agent-pane.header-tools/more-even-box	Apple System Colors Light	unchanged	0%	own header.css
agent-pane.header-tools/more-even-box	Apple System Colors	unchanged	0%	own header.css

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

Pending: CI is running on f63c77a857; the result below was for 78ed9407d4 and no longer applies.

Last result: Unclear: web / react-apps-check failed: no known signature; failed step: Check webview test shards.

Written by scripts/ci/classify_failures.py (ci-failure-attribution.yml); it is rewritten when this head's CI completes.

web and size checks: green

[teamleaderleo]

Owned by an agent session · session

[teamleaderleo]

Review (codex gpt-6.1-sol xhigh, router-review): BLOCK at 68599ee

BLOCK at 68599ee

Visual verdict: no images; Leo tries the build

1. [P1] [blocking] webviews/test/chat-header-glass.test.ts:95 — The two-tab fixture removes data-solo-tab, so the capsule rules no longer match. Its nonexistent ::before has content: none but computed opacity "1", making this assertion fail in both browser engines. Assert that content is "none" instead; the test already captures it.

Follow-ups:

2. [P2] [follow-up] webviews/src/agent-session/acpmux/header/header.css:189 — Provide rest and over-text captures in light and dark themes; this head has no images for visual review.

[blacksmith-sh]

Found 53 test failures on Blacksmith runners:

Failures

Test	View Logs
/tmp/tmpjkskx4wp/summary-missing.json (live):/summary-missing.json (live):	View Logs
/tmp/tmpy5uv21dz/summary-fail.json (live):/summary-fail.json (live):	View Logs
[new_workspaces] debug.new_workspace timed 0 of 50 new workspace rows/ [new_workspaces] debug.new_workspace timed 0 of 50 new workspace rows	View Logs
[new_workspaces] the window draws no frames/[new_workspaces] the window draws no frames	View Logs
[tabs] debug.tab_switch timed 0 of 40 switches/ [tabs] debug.tab_switch timed 0 of 40 switches	View Logs
[tabs] the window draws no frames/[tabs] the window draws no frames	View Logs
main.DeveloperIdAppTests.test_download_prints_the_active_profile_only/ test_download_prints_the_active_profile_only	View Logs
convention violations found (ERROR lines above)./ convention violations found (ERROR lines above).	View Logs
stubs: /System/Library/Frameworks/Security.framework/Versions/A/Security has no stub/ Security has no stub	View Logs
stubs: CoreFoundation.tbd: install-name /System/Library/Frameworks/ CoreFoundation.framework/Versions/A/CoreFoundation, missing 1: ['_CFRetain']/ CoreFoundation, missing 1: ['_CFRetain']	View Logs

...and 43 more test failures. View all on Blacksmith: run 41744562261, run 41744562094

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

[teamleaderleo]

Review (codex gpt-6.1-sol xhigh, next-review, since=20261103T233735Z): BLOCK at 02083b9

BLOCK at 02083b9
Visual verdict: no images; Leo tries the build

1. [P1] [blocking] webviews/src/agent-session/acpmux/header/header.css:189 and header.gallery.ts:67: The new raw z-index:-1 values and gallery backdrop filters produce three layer-check violations. The checker passes before this diff and exits 1 at head. Existing webviews/test/check-layers.test.ts:88 asserts exit 0, so tests fail despite the branch’s advisory style checks. Use var(--layer-backdrop) in both files and add reduced-transparency handling for the gallery circles.

2. [P2] [follow-up] webviews/scripts/agent-pane/capture-header-glass.mjs:1: Publish usable light/dark captures at rest and over text; none were available for visual review.

[teamleaderleo]

Review (codex, router-review): SHIP at 78ed940

Reviewer: codex gpt-6.1-sol xhigh, fast tier.

SHIP at 78ed940

Visual verdict: SHIP — reviewed all supplied images; the capsule fits ChatGPT/Claude’s restrained floating controls. Existing before/after pairs are unchanged.

No actionable correctness findings. Script syntax, layer, and motion checks passed; browser tests could not run because Bun is unavailable.

Follow-ups: none

[cmux-bot]

cmux-bot approves 78ed940: an independent review passed this exact head (router-review receipt by teamleaderleo). A push needs a new review; a later BLOCK at this head dismisses this approval.

A newer verdict blocks 47668e5 (no independent SHIP at the head).

[teamleaderleo]

Closing without merging. The surface this styled is gone from the base. #34327 shows a pane's tab strip at every tab count, so the transcript always starts below the tab row. #34392 then removed the lone-tab solo row (data-solo-tab, the scroller pulled up under the row), and that is where text ran under the header tools in the reported screenshot. On the base nothing scrolls beneath the tools now, so there's no "text beneath" case for the capsule. Putting it on the always-shown row would draw a shape behind the tools with nothing under it, which goes against both the ask ("super subtle until there's text or something beneath") and the header's no-fill-at-rest rule.

The branch leo/header-tools-glass keeps the work (CSS, gallery variants agent-pane.header/glass-*, test/chat-header-glass.test.ts, the capture script) in case controls float over the transcript again. It had an exact-head SHIP at 78ed940.