Adopt macOS 26 Liquid Glass design

[rodchristiansen]

Summary

• NavigationSplitView with native glass sidebar and system titlebar on macOS 26
• SwiftUI .toolbar for bell and new-tab buttons with .accessoryBarAction style
• 8pt external padding around terminal detail content for Liquid Glass spacing
• 6pt internal terminal content inset keeps text within safe zone
• Leading corners (top-left, bottom-left) rounded at AppKit portal level when sidebar visible
• Bonsplit tab bar hidden for single-tab panes on macOS 26
• Old titlebar accessory controllers and custom titlebar overlay skipped on macOS 26
• App icon auto-set skipped on macOS 26 (system handles dark variants)

Known limitations

• Terminal corner rounding (right side): CAMetalLayer ignores Core Animation clipping (cornerRadius, masksToBounds, layer.mask on parent views). Left corners work because the sidebar glass provides contrast. Full corner rounding deferred to follow-up.
• Light mode sidebar tint: NavigationSplitView's glass material adds a subtle gray tint in light mode. This matches native apps (Finder, Mail) and is the expected system behavior.

Test plan

• Verify glass sidebar renders correctly in light and dark mode
• Verify toolbar buttons (bell, +) appear and function
• Verify 8pt padding around terminal on all sides
• Verify terminal text has internal padding (doesn't touch edges)
• Verify left corners are rounded when sidebar is visible
• Toggle sidebar visibility — padding and corners adapt
• Test fullscreen transitions
• Test split panes and workspace switching
• Test drag/drop reordering in sidebar

🤖 Generated with Claude Code

---

Summary by cubic

Adopts macOS 26 Liquid Glass and updates cmux’s current app and CLI baseline. On macOS 26, custom AppKit titlebar/sidebar handling is replaced with native NavigationSplitView, system titlebar behavior, and SwiftUI toolbar actions; older macOS versions keep the legacy path.

App changes

• Restores the right sidebar, persists its width, and uses the system sidebar toggle when visible with a custom leading toggle when hidden.
• Adds window-scoped notification popovers, pane actions, new-tab controls, updated shortcut ⌃⌘S, and native window dragging.
• Adds Liquid Glass spacing, hover states, terminal insets, sidebar-aware corner rounding, single-tab bar hiding, scrollbar fixes, and terminal/browser focus and selection regressions fixes.
• Updates app icon assets for light and dark variants; macOS 26 uses the system icon handling.
• The terminal’s right corners remain unclipped because CAMetalLayer does not honor parent view clipping.

CLI, integrations, and delivery

• Replaces cmuxterm with the Swift cmux CLI and adds cmux omx/cmux omc integrations.
• Adds generic setup-hooks and uninstall-hooks support for Codex, Cursor, Gemini, Copilot, CodeBuddy, Factory, and Qoder.
• Adds the system-wide hotkey, shared shortcut matching, zsh TERM handoff, user zshenv opt-outs, and printable shifted-punctuation input fixes.
• Adds macOS 15/26 compatibility CI, GhosttyKit builds and checksum guards, nightly/release workflows, and post-release Homebrew updates.

^{Written for commit ef0ed32. Summary will update on new commits.}

Summary by CodeRabbit

• New Features

  • Added toolbar items for sidebar, notifications, and creating a new workspace.
  • Notifications can appear in a dedicated popover and via system notification on newer macOS.

• Improvements

  • Modern split-view navigation with constrained sidebar widths and hidden dividers on newer macOS.
  • Updated titlebar/window appearance and enabled window movability on newer macOS.
  • Reduced terminal top padding, refined corner rounding and scroll insets, removed sidebar scrim.
  • Subtle glass hover effects for tabs and footer buttons.

• Other

  • Default sidebar shortcut changed; app icon resource explicitly included.

---

Note

Medium Risk
Medium risk because it changes core window/layout behavior and notification popover handling with macOS-version branching (including some AppKit toolbar/view hierarchy manipulation) that could regress multi-window UI interactions.

Overview
On macOS 26+, the main window layout switches to NavigationSplitView to get native Liquid Glass sidebar/titlebar behavior, adds an 8pt padded detail area, disables custom titlebar overlays/accessories, and relies on system safe areas/window dragging instead of the previous "immovable window" approach.

Notifications UI is reworked for macOS 26: the bell button becomes a SwiftUI toolbar item with a per-window SwiftUI popover, plus new AppDelegate notification broadcasts/state tracking so menu/command invocations toggle/dismiss the correct window’s popover.

Additional macOS 26 polish includes Liquid Glass hover/active effects in the sidebar, hiding bonsplit’s single-tab tab bar, insetting terminal scroll content for rounded-corner safe zones, rounding terminal leading corners based on actual split-view sidebar visibility, and avoiding manual WindowGlassEffect insertion so it doesn’t fight system glass. Separately, the default Toggle Sidebar shortcut changes and project wiring/resources are updated (including bundling AppIcon.icon and updating the vendor/bonsplit submodule URL).

^{Reviewed by Cursor Bugbot for commit cdf6eb0. Bugbot is set up for automated code reviews on this repo. Configure here.}

[rodchristiansen]

Rebased onto current manaflow-ai/main (tip 03a0c14b) and squashed to a single commit to keep the diff clean against the "Split AppDelegate support code" refactor.

Reconciliation notes:

• Sources/cmuxApp.swift: kept the mainWindowContent extraction; merged in upstream's new .environmentObject(fileExplorerState) and appDelegate.fileExplorerState = fileExplorerState. applyIcon keeps both upstream's isApplicationFinishedLaunching guard and the macOS 26 early return.
• Sources/ContentView.swift: upstream moved SidebarBackdrop into a helper layer, so the old conditional .background modifier is no longer needed on this path.
• Sources/Workspace.swift: combined upstream's new tabTitleFontSize parameter with tabBarHeight/showSplitButtons (argument order fixed).
• project.pbxproj: re-applied the AppIcon.icon wiring (PBXBuildFile entry, folder.iconcomposer.icon type, Resources phase) on top of upstream's current state.
• vendor/bonsplit: pinned at upstream SHA. The single-tab tab-bar hiding needs the matching bonsplit-side change (PaneContainerView conditional on tabBarHeight > 0 || tabs.count > 1). Happy to open that as a separate bonsplit PR — without it, the tab bar just renders at 0 height on macOS 26 rather than being truly hidden.

Local compile (xcodebuild … Debug) passes on macOS 26. Net diff +605 / -134 across 10 files, unchanged in scope vs the prior tip.

[cubic-dev-ai]

6 issues found across 10 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="Sources/GhosttyTerminalView.swift">

<violation number="1" location="Sources/GhosttyTerminalView.swift:9599">
P2: Fixed 6pt inset is not clamped to current bounds, so transient tiny host sizes can produce zero/negative scroll/surface dimensions.</violation>
</file>

<file name="Sources/AppDelegate.swift">

<violation number="1" location="Sources/AppDelegate.swift:8645">
P2: macOS 26 notification toggle can still broadcast globally when no target window is resolved, causing multiple windows to toggle instead of only the intended one.</violation>

<violation number="2" location="Sources/AppDelegate.swift:8651">
P2: macOS 26 notifications popover toggle is SwiftUI-notification driven, but dismiss/isShown still query only the legacy titlebar accessory controller, causing stale state and potential no-op dismiss behavior.</violation>
</file>

<file name="Sources/ContentView.swift">

<violation number="1" location="Sources/ContentView.swift:14750">
P2: Sidebar-toggle stripping depends on hardcoded English toolbar labels, which can fail on localized macOS and leave duplicate sidebar controls.</violation>

<violation number="2" location="Sources/ContentView.swift:14825">
P2: Divider-hiding logic patches every NSSplitView in the window, not just NavigationSplitView, risking unintended UI regressions in unrelated split-based views.</violation>
</file>

<file name="Sources/TerminalWindowPortal.swift">

<violation number="1" location="Sources/TerminalWindowPortal.swift:1507">
P2: Sidebar detection via `targetFrame.origin.x > 20` is not specific to sidebar visibility and can incorrectly round split panes when sidebar is hidden.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit c89a423. Configure here.}

[cursor]

Bonsplit submodule URL changed to personal fork

Medium Severity

The bonsplit submodule URL was changed from the organization repo (manaflow-ai/bonsplit.git) to a personal fork (rodchristiansen/bonsplit.git). Merging this to main would make the project depend on a personal fork rather than the canonical organization repository, creating a bus-factor risk and potential access issues for other contributors.

 

^{Reviewed by Cursor Bugbot for commit c89a423. Configure here.}

[cubic-dev-ai]

2 issues found across 7 files (changes from recent commits).

_{You’re at about 92% of the monthly review limit. You may want to disable incremental reviews to conserve quota. Reviews will continue until that limit is exceeded. If you need help avoiding interruptions, please contact contact@cubic.dev.}

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="Sources/Workspace.swift">

<violation number="1" location="Sources/Workspace.swift:6756">
P2: Removing the `surfaceTabBarFontSize` plumbing makes the tab-title font-size setting a no-op for new workspaces and config/theme refreshes.</violation>
</file>

<file name=".gitmodules">

<violation number="1" location=".gitmodules:10">
P2: Point this submodule back to the organization-owned bonsplit repository to avoid relying on a personal fork that can disappear or drift unexpectedly.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P2: Removing the surfaceTabBarFontSize plumbing makes the tab-title font-size setting a no-op for new workspaces and config/theme refreshes.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At Sources/Workspace.swift, line 6756:

<comment>Removing the `surfaceTabBarFontSize` plumbing makes the tab-title font-size setting a no-op for new workspaces and config/theme refreshes.</comment>

<file context>
@@ -6752,8 +6752,7 @@ final class Workspace: Identifiable, ObservableObject {
-            backgroundOpacity: config.backgroundOpacity,
-            tabTitleFontSize: config.surfaceTabBarFontSize
+            backgroundOpacity: config.backgroundOpacity
         )
     }
 
</file context>

[cubic-dev-ai]

P2: Point this submodule back to the organization-owned bonsplit repository to avoid relying on a personal fork that can disappear or drift unexpectedly.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At .gitmodules, line 10:

<comment>Point this submodule back to the organization-owned bonsplit repository to avoid relying on a personal fork that can disappear or drift unexpectedly.</comment>

<file context>
@@ -7,4 +7,4 @@
 [submodule "vendor/bonsplit"]
 	path = vendor/bonsplit
-	url = https://github.com/manaflow-ai/bonsplit.git
+	url = https://github.com/rodchristiansen/bonsplit.git
</file context>

Suggested change

	url = https://github.com/rodchristiansen/bonsplit.git
	url = https://github.com/manaflow-ai/bonsplit.git

[greptile-apps]

Too many files changed for review (1265 files, 100 file limit).