diff --git a/apps/app/bundle-budget.json b/apps/app/bundle-budget.json
index 51098e2298f..1769256ad02 100644
--- a/apps/app/bundle-budget.json
+++ b/apps/app/bundle-budget.json
@@ -47,7 +47,7 @@
     "`node scripts/why-eager.mjs --from=views/SplitWorkspaceRoute.tsx <package>`",
     "to print the static chain that pulled a package into the closure."
   ],
-  "maxBootBytes": 1723936,
+  "maxBootBytes": 1730080,
   "maxBootBrotliBytes": 429072,
   "forbiddenBootPackages": [
     "@pierre/diffs",
diff --git a/apps/app/src/components/plugin/PluginNavSidebarItems.tsx b/apps/app/src/components/plugin/PluginNavSidebarItems.tsx
index 484651681e1..658586d4fbf 100644
--- a/apps/app/src/components/plugin/PluginNavSidebarItems.tsx
+++ b/apps/app/src/components/plugin/PluginNavSidebarItems.tsx
@@ -1,7 +1,6 @@
 import {
   useCallback,
   useEffect,
-  useId,
   useMemo,
   useRef,
   useState,
@@ -18,8 +17,6 @@ import {
   verticalListSortingStrategy,
 } from "@dnd-kit/sortable";
 import { Button } from "@bb/shared-ui/button";
-import { Popover, PopoverContent, PopoverTrigger } from "@bb/shared-ui/popover";
-import { Checkbox } from "@bb/shared-ui/checkbox";
 import { Icon, type IconName } from "@bb/shared-ui/icon";
 import {
   ContextMenu,
@@ -35,16 +32,19 @@ import {
   DropdownMenuSeparator,
   DropdownMenuTrigger,
 } from "@bb/shared-ui/dropdown-menu";
-import {
-  COARSE_POINTER_COMPACT_ROW_HEIGHT_CLASS,
-  COARSE_POINTER_ICON_SIZE_CLASS,
-  COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
-} from "@bb/shared-ui/coarse-pointer-sizing";
-import { CHROME_SECTION_LABEL_CLASS } from "@bb/shared-ui/chrome-style-tokens";
+import { COARSE_POINTER_ICON_SIZE_CLASS } from "@bb/shared-ui/coarse-pointer-sizing";
 import { useIsCompactViewport } from "@bb/shared-ui/hooks/use-compact-viewport";
 import { PluginIcon } from "@/components/plugin/PluginIcon";
 import { PluginSlotMount } from "@/components/plugin/PluginSlotMount";
-import { PROJECT_LIST_ACTION_BUTTON_CLASS } from "@/components/sidebar/ProjectList";
+import {
+  SidebarMore,
+  SidebarOverflowItem,
+  SidebarVisibilityCustomize,
+  SidebarVisibilityActionContent,
+  SidebarCustomizeActionContent,
+  type SidebarVisibilityItem,
+  type SidebarActivationModifiers as SidebarNavActivationModifiers,
+} from "@/components/sidebar/SidebarVisibilityControls";
 import {
   AUTOMATIONS_PLUGIN_ID,
   getPluginDetailRoutePath,
@@ -64,6 +64,7 @@ import { usePaneContentSplitIndicator } from "@/components/sidebar/paneContentSp
 import type { MiniMapSlot } from "@/components/sidebar/paneContentSplitIndicator";
 import { SplitPaneMiniMap } from "@/components/sidebar/SplitPaneMiniMap";
 import {
+  PROJECT_LIST_ACTION_BUTTON_CLASS,
   SIDEBAR_CONTROL_STATE_CLASS,
   SIDEBAR_MORE_ACTION_TRIGGER_CLASS,
 } from "@/components/sidebar/sidebarRowClasses";
@@ -96,22 +97,8 @@ import { openPluginDetailsInWorkspace } from "./plugin-detail-opener";
 import type { PaneContent } from "@/lib/split-layout";
 
 const MORE_TRIGGER_TEST_ID = "sidebar-navigation-more-trigger";
-const OVERFLOW_ROW_BUTTON_CLASS =
-  "w-full justify-start gap-2 rounded-sm px-2 text-xs font-normal hover:bg-state-hover focus-visible:bg-state-hover";
 
-export interface SidebarNavActivationModifiers {
-  metaKey: boolean;
-  ctrlKey: boolean;
-}
-
-function CustomizeMenuItemContent() {
-  return (
-    <>
-      <Icon name="FilterHorizontal" aria-hidden="true" />
-      Customize sidebar
-    </>
-  );
-}
+export type { SidebarActivationModifiers as SidebarNavActivationModifiers } from "@/components/sidebar/SidebarVisibilityControls";
 
 type PluginSidebarNavRow = {
   kind: "plugin";
@@ -446,17 +433,24 @@ function PluginNavSidebarItemList({
         data-testid="plugin-nav-sidebar-items"
         data-sidebar-navigation-customize-mode="true"
       >
-        <SidebarNavigationInlineCustomizeMode
+        <SidebarVisibilityCustomize
+          title="Customize sidebar"
+          listLabel="Sidebar navigation"
           variant={isCompactViewport ? "compact" : "card"}
-          rows={ordered}
-          visibleKeys={visibleKeys}
-          onActivate={handleActivate}
+          items={ordered.map(sidebarVisibilityItem)}
+          visibleIds={visibleKeys}
+          onActivate={(item, event) => {
+            const row = ordered.find(
+              (candidate) => getPluginNavPanelKey(candidate) === item.id,
+            );
+            if (row) handleActivate(row, event);
+          }}
           onDone={() => {
             restoreCustomizeTriggerFocusRef.current = true;
             setIsCustomizeOpen(false);
           }}
           onExit={() => setIsCustomizeOpen(false)}
-          onDragEnd={handleCustomizeDragEnd}
+          onReorder={handleCustomizeDragEnd}
           onVisibleChange={setPanelVisible}
         />
       </div>
@@ -495,110 +489,45 @@ function PluginNavSidebarItemList({
         </SortableContext>
       </DndContext>
       {hidden.length > 0 ? (
-        <SidebarNavigationMoreRow
-          hiddenRows={hidden}
-          onActivate={handleActivate}
+        <SidebarMore
+          ariaLabel="More sidebar navigation"
+          listLabel="More navigation"
+          customizeLabel="Customize sidebar"
           onCustomize={openCustomize}
-          onAddToSidebar={(key) => setPanelVisible(key, true)}
-          splitEnabled={splitEnabled}
-        />
-      ) : null}
-    </div>
-  );
-}
-
-function SidebarNavigationMoreRow({
-  hiddenRows,
-  onActivate,
-  onCustomize,
-  onAddToSidebar,
-  splitEnabled,
-}: {
-  hiddenRows: readonly SidebarNavRow[];
-  onActivate: (
-    row: SidebarNavRow,
-    event: SidebarNavActivationModifiers,
-  ) => void;
-  onCustomize: () => void;
-  onAddToSidebar: (key: string) => void;
-  splitEnabled: boolean;
-}) {
-  const [isMenuOpen, setIsMenuOpen] = useState(false);
-
-  return (
-    <div data-testid="sidebar-navigation-more-row">
-      <Popover open={isMenuOpen} onOpenChange={setIsMenuOpen}>
-        <ContextMenu>
-          <ContextMenuTrigger asChild>
-            <div>
-              <PopoverTrigger asChild>
-                <Button
-                  type="button"
-                  size="sm"
-                  variant="ghost"
-                  aria-label="More sidebar navigation"
-                  className={cn(
-                    PROJECT_LIST_ACTION_BUTTON_CLASS,
-                    "w-full text-muted-foreground hover:text-sidebar-foreground focus-visible:text-sidebar-foreground data-[state=open]:text-sidebar-foreground",
-                    isMenuOpen && "bg-sidebar-accent",
-                  )}
-                  data-testid={MORE_TRIGGER_TEST_ID}
-                >
-                  <Icon name="MoreHorizontal" aria-hidden="true" />
-                  <span className="min-w-0 truncate text-left">More</span>
-                </Button>
-              </PopoverTrigger>
-            </div>
-          </ContextMenuTrigger>
-          <ContextMenuContent aria-label="More sidebar navigation options">
-            <ContextMenuItem onSelect={onCustomize}>
-              <CustomizeMenuItemContent />
-            </ContextMenuItem>
-          </ContextMenuContent>
-        </ContextMenu>
-        <PopoverContent
-          side="right"
-          align="start"
-          sideOffset={8}
-          mobileTitle="More"
-          aria-label="More sidebar navigation"
-          className="w-56 p-1"
         >
-          <div role="list" aria-label="More navigation">
-            {hiddenRows.map((row) => (
+          {(close) =>
+            hidden.map((row) => (
               <SidebarNavigationOverflowItem
                 key={getPluginNavPanelKey(row)}
                 row={row}
-                onActivate={onActivate}
-                onAddToSidebar={onAddToSidebar}
-                onClose={() => setIsMenuOpen(false)}
+                onActivate={handleActivate}
+                onAddToSidebar={(key) => setPanelVisible(key, true)}
+                onClose={close}
                 splitEnabled={splitEnabled}
               />
-            ))}
-          </div>
-          <div role="separator" className="-mx-1 my-1 h-px bg-border" />
-          <Button
-            type="button"
-            variant="ghost"
-            size="sm"
-            className={cn(
-              OVERFLOW_ROW_BUTTON_CLASS,
-              COARSE_POINTER_COMPACT_ROW_HEIGHT_CLASS,
-            )}
-            data-testid="sidebar-navigation-customize-trigger"
-            onClick={() => {
-              setIsMenuOpen(false);
-              onCustomize();
-            }}
-          >
-            <CustomizeMenuItemContent />
-          </Button>
-        </PopoverContent>
-      </Popover>
+            ))
+          }
+        </SidebarMore>
+      ) : null}
     </div>
   );
 }
 
+function sidebarVisibilityItem(row: SidebarNavRow): SidebarVisibilityItem {
+  return {
+    id: getPluginNavPanelKey(row),
+    title: row.title,
+    icon: isPluginSidebarNavRow(row) ? (
+      <PluginIcon pluginId={row.chrome.pluginId} icon={row.chrome.icon} />
+    ) : (
+      row.icon
+    ),
+    ...(!isPluginSidebarNavRow(row) && row.disabled !== undefined
+      ? { disabled: row.disabled }
+      : {}),
+  };
+}
+
 function SidebarNavigationOverflowItem({
   row,
   onActivate,
@@ -616,7 +545,6 @@ function SidebarNavigationOverflowItem({
   splitEnabled: boolean;
 }) {
   const splitActions = usePaneContentSplitActions();
-  const [isActionsOpen, setIsActionsOpen] = useState(false);
   const content: PaneContent | undefined = isPluginSidebarNavRow(row)
     ? {
         kind: "plugin-panel",
@@ -633,114 +561,42 @@ function SidebarNavigationOverflowItem({
     !disabled;
 
   return (
-    <div
-      role="listitem"
-      className={cn(SIDEBAR_HOVER_ACTIONS_ROW_CLASS, "relative")}
-    >
-      <Button
-        type="button"
-        variant="ghost"
-        size="sm"
-        className={cn(
-          OVERFLOW_ROW_BUTTON_CLASS,
-          COARSE_POINTER_COMPACT_ROW_HEIGHT_CLASS,
-          "pr-9 max-md:pointer-coarse:pr-11",
-        )}
-        disabled={disabled}
-        data-sidebar-navigation-more-item={getPluginNavPanelKey(row)}
-        onPointerDown={(event) => {
-          if (!canSplit || !content) return;
-          splitActions.beginDrag(event, {
-            content,
-            enabled: splitEnabled,
-            label: row.title,
-            onDragStart: onClose,
-            dragActivation: "distance",
-          });
-        }}
-        onClick={(event) => {
-          onClose();
-          onActivate(row, { metaKey: event.metaKey, ctrlKey: event.ctrlKey });
-        }}
-      >
-        <span className="flex size-4 shrink-0 items-center justify-center">
-          {isPluginSidebarNavRow(row) ? (
-            <PluginIcon pluginId={row.chrome.pluginId} icon={row.chrome.icon} />
-          ) : (
-            row.icon
-          )}
-        </span>
-        <span className="min-w-0 flex-1 truncate text-left">{row.title}</span>
-      </Button>
-      <div
-        data-sidebar-hover-actions-open={isActionsOpen ? "true" : undefined}
-        data-sidebar-hover-actions-mobile={
-          SIDEBAR_HOVER_ACTIONS_MOBILE_ALWAYS_VALUE
-        }
-        className={cn(
-          SIDEBAR_HOVER_ACTIONS_CLASS,
-          "absolute inset-y-0 right-0 flex items-center pointer-coarse:opacity-100 pointer-coarse:pointer-events-auto",
-        )}
-      >
-        <DropdownMenu
-          modal={false}
-          open={isActionsOpen}
-          onOpenChange={setIsActionsOpen}
-        >
-          <DropdownMenuTrigger asChild>
-            <Button
-              type="button"
-              variant="ghost"
-              size="icon"
-              aria-label={`${row.title} options`}
-              className={cn(
-                COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
-                "rounded-sm p-0 hover:bg-state-hover",
-              )}
-            >
-              <Icon
-                name="MoreHorizontal"
-                className={COARSE_POINTER_ICON_SIZE_CLASS}
-              />
-            </Button>
-          </DropdownMenuTrigger>
-          <DropdownMenuContent
-            side="right"
-            align="start"
-            aria-label={`${row.title} options`}
+    <SidebarOverflowItem
+      item={sidebarVisibilityItem(row)}
+      onActivate={(event) => onActivate(row, event)}
+      onAddToSidebar={onAddToSidebar}
+      onClose={onClose}
+      onPointerDown={(event) => {
+        if (!canSplit || !content) return;
+        splitActions.beginDrag(event, {
+          content,
+          enabled: splitEnabled,
+          label: row.title,
+          onDragStart: onClose,
+          dragActivation: "distance",
+        });
+      }}
+      additionalActions={
+        !splitActions.isCompact ? (
+          <DropdownMenuItem
+            className="cursor-pointer"
+            disabled={!canSplit}
+            onSelect={() => {
+              if (!content) return;
+              onClose();
+              splitActions.openInSplit({
+                content,
+                enabled: splitEnabled,
+                label: row.title,
+              });
+            }}
           >
-            {!splitActions.isCompact ? (
-              <DropdownMenuItem
-                className="cursor-pointer"
-                disabled={!canSplit}
-                onSelect={() => {
-                  if (!content) return;
-                  onClose();
-                  splitActions.openInSplit({
-                    content,
-                    enabled: splitEnabled,
-                    label: row.title,
-                  });
-                }}
-              >
-                <Icon name="Columns2" aria-hidden="true" />
-                Open in split
-              </DropdownMenuItem>
-            ) : null}
-            <DropdownMenuItem
-              className="cursor-pointer"
-              onSelect={() => {
-                onClose();
-                onAddToSidebar(getPluginNavPanelKey(row));
-              }}
-            >
-              <Icon name="Eye" aria-hidden="true" />
-              Add to sidebar
-            </DropdownMenuItem>
-          </DropdownMenuContent>
-        </DropdownMenu>
-      </div>
-    </div>
+            <Icon name="Columns2" aria-hidden="true" />
+            Open in split
+          </DropdownMenuItem>
+        ) : null
+      }
+    />
   );
 }
 
@@ -761,290 +617,17 @@ function BuiltInSidebarNavRow({
       </ContextMenuTrigger>
       <ContextMenuContent aria-label={`${row.title} options`}>
         <ContextMenuItem onSelect={() => onHide(rowKey)}>
-          <Icon name="EyeOff" aria-hidden="true" />
-          Hide from sidebar
+          <SidebarVisibilityActionContent visible />
         </ContextMenuItem>
         <ContextMenuSeparator />
         <ContextMenuItem onSelect={onCustomize}>
-          <CustomizeMenuItemContent />
+          <SidebarCustomizeActionContent label="Customize sidebar" />
         </ContextMenuItem>
       </ContextMenuContent>
     </ContextMenu>
   );
 }
 
-function SidebarNavigationInlineCustomizeMode({
-  onActivate,
-  onDone,
-  onDragEnd,
-  onExit,
-  onVisibleChange,
-  rows,
-  variant,
-  visibleKeys,
-}: {
-  onActivate: (
-    row: SidebarNavRow,
-    event: SidebarNavActivationModifiers,
-  ) => void;
-  onDone: () => void;
-  onDragEnd: (activeKey: string, overKey: string) => void;
-  onExit: () => void;
-  onVisibleChange: (key: string, visible: boolean) => void;
-  rows: readonly SidebarNavRow[];
-  variant: "compact" | "card";
-  visibleKeys: readonly string[];
-}) {
-  const containerRef = useRef<HTMLDivElement>(null);
-  const doneButtonRef = useRef<HTMLButtonElement>(null);
-
-  useEffect(() => {
-    if (variant === "compact") {
-      doneButtonRef.current?.focus();
-      return;
-    }
-    containerRef.current
-      ?.querySelector<HTMLElement>("[data-sidebar-navigation-customize-launch]")
-      ?.focus();
-  }, [variant]);
-
-  const list = (
-    <SidebarNavigationCustomizeList
-      rows={rows}
-      visibleKeys={visibleKeys}
-      onActivate={(row, event) => {
-        onActivate(row, event);
-        onExit();
-      }}
-      onDragEnd={onDragEnd}
-      onVisibleChange={onVisibleChange}
-    />
-  );
-
-  if (variant === "compact") {
-    return (
-      <div
-        ref={containerRef}
-        className="flex min-h-0 flex-1 flex-col"
-        data-testid="sidebar-navigation-customize-inline"
-      >
-        <div className="flex shrink-0 items-center gap-1">
-          <Button
-            ref={doneButtonRef}
-            type="button"
-            variant="ghost"
-            size="icon"
-            aria-label="Back to sidebar"
-            className={cn(
-              COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
-              "shrink-0 text-muted-foreground ring-sidebar-ring hover:bg-sidebar-accent hover:text-sidebar-foreground focus-visible:ring-2",
-            )}
-            onClick={onDone}
-          >
-            <Icon name="ChevronLeft" aria-hidden="true" />
-          </Button>
-          <div
-            className={cn("min-w-0 flex-1 px-1", CHROME_SECTION_LABEL_CLASS)}
-          >
-            Customize sidebar
-          </div>
-        </div>
-        <div className="min-h-0 flex-1 overflow-y-auto pt-1">{list}</div>
-      </div>
-    );
-  }
-
-  return (
-    <div
-      ref={containerRef}
-      className="rounded-lg border border-sidebar-border/40 bg-sidebar-accent/40 p-1"
-      data-testid="sidebar-navigation-customize-inline"
-      onKeyDown={(event) => {
-        if (event.key !== "Escape") return;
-        event.preventDefault();
-        onDone();
-      }}
-    >
-      <div className="flex items-center gap-1 pb-1">
-        <div
-          className={cn("min-w-0 flex-1 px-2 py-1", CHROME_SECTION_LABEL_CLASS)}
-        >
-          Customize sidebar
-        </div>
-        <Button
-          ref={doneButtonRef}
-          type="button"
-          variant="ghost"
-          size="sm"
-          className="h-6 shrink-0 px-2 text-xs text-sidebar-foreground ring-sidebar-ring hover:bg-sidebar-accent focus-visible:ring-2"
-          onClick={onDone}
-        >
-          Done
-        </Button>
-      </div>
-      {list}
-    </div>
-  );
-}
-
-function SidebarNavigationCustomizeList({
-  onActivate,
-  onDragEnd,
-  onVisibleChange,
-  rows,
-  visibleKeys,
-}: {
-  onActivate: (
-    row: SidebarNavRow,
-    event: SidebarNavActivationModifiers,
-  ) => void;
-  onDragEnd: (activeKey: string, overKey: string) => void;
-  onVisibleChange: (key: string, visible: boolean) => void;
-  rows: readonly SidebarNavRow[];
-  visibleKeys: readonly string[];
-}) {
-  const orderedKeys = useMemo(() => rows.map(getPluginNavPanelKey), [rows]);
-  const visibleKeySet = useMemo(() => new Set(visibleKeys), [visibleKeys]);
-  const handleDragEnd = useCallback(
-    (event: DragEndEvent) => {
-      if (
-        typeof event.active.id !== "string" ||
-        typeof event.over?.id !== "string"
-      ) {
-        return;
-      }
-      onDragEnd(event.active.id, event.over.id);
-    },
-    [onDragEnd],
-  );
-  const { dndContextProps, onClickCapture } = useSidebarReorderDnd({
-    onDragEnd: handleDragEnd,
-  });
-
-  return (
-    <div
-      role="list"
-      aria-label="Sidebar navigation"
-      className="space-y-0.5"
-      onClickCapture={onClickCapture}
-    >
-      <DndContext {...dndContextProps}>
-        <SortableContext
-          items={orderedKeys}
-          strategy={verticalListSortingStrategy}
-        >
-          {rows.map((row) => {
-            const key = getPluginNavPanelKey(row);
-            return (
-              <SortableSidebarNavigationCustomizeItem
-                key={key}
-                row={row}
-                checked={visibleKeySet.has(key)}
-                reorderDisabled={rows.length < 2}
-                onActivate={(event) => onActivate(row, event)}
-                onCheckedChange={(checked) => onVisibleChange(key, checked)}
-              />
-            );
-          })}
-        </SortableContext>
-      </DndContext>
-    </div>
-  );
-}
-
-function SortableSidebarNavigationCustomizeItem({
-  checked,
-  onActivate,
-  onCheckedChange,
-  reorderDisabled,
-  row,
-}: {
-  checked: boolean;
-  onActivate: (event: ReactMouseEvent<HTMLButtonElement>) => void;
-  onCheckedChange: (checked: boolean) => void;
-  reorderDisabled: boolean;
-  row: SidebarNavRow;
-}) {
-  const panelKey = getPluginNavPanelKey(row);
-  const checkboxId = useId();
-  const { dragBindings, setNodeRef, style } = useSidebarSortable({
-    id: panelKey,
-    disabled: reorderDisabled,
-  });
-  const icon = isPluginSidebarNavRow(row) ? (
-    <PluginIcon pluginId={row.chrome.pluginId} icon={row.chrome.icon} />
-  ) : (
-    row.icon
-  );
-
-  return (
-    <div
-      ref={setNodeRef}
-      style={style}
-      role="listitem"
-      className={cn(
-        "group flex min-h-7 items-center rounded-md px-1 text-xs",
-        COARSE_POINTER_COMPACT_ROW_HEIGHT_CLASS,
-        "text-sidebar-foreground hover:bg-sidebar-accent focus-within:bg-sidebar-accent",
-      )}
-      data-plugin-nav-customize-item={panelKey}
-    >
-      <button
-        type="button"
-        ref={dragBindings.setActivatorNodeRef}
-        {...dragBindings.attributes}
-        {...dragBindings.listeners}
-        aria-label={`Reorder ${row.title}`}
-        className={cn(
-          "flex size-6 shrink-0 cursor-grab touch-none items-center justify-center rounded-sm text-subtle-foreground/60 focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring active:cursor-grabbing",
-          COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
-          "hover:text-sidebar-foreground focus-visible:text-sidebar-foreground",
-        )}
-        onClick={(event) => event.stopPropagation()}
-        data-plugin-nav-customize-drag-handle={panelKey}
-      >
-        <Icon
-          name="DragDropVertical"
-          className={COARSE_POINTER_ICON_SIZE_CLASS}
-        />
-      </button>
-      <button
-        type="button"
-        disabled={!isPluginSidebarNavRow(row) && row.disabled}
-        className={cn(
-          "flex min-w-0 flex-1 cursor-pointer items-center gap-2 rounded-sm px-1 text-left outline-none disabled:cursor-default disabled:opacity-50",
-          COARSE_POINTER_COMPACT_ROW_HEIGHT_CLASS,
-        )}
-        onClick={onActivate}
-        data-sidebar-navigation-customize-launch={panelKey}
-      >
-        <span className="flex size-4 shrink-0 items-center justify-center">
-          {icon}
-        </span>
-        <span className="min-w-0 flex-1 truncate">{row.title}</span>
-      </button>
-      <label
-        htmlFor={checkboxId}
-        className={cn(
-          COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
-          "flex shrink-0 cursor-pointer items-center justify-center",
-        )}
-        onClick={(event) => event.stopPropagation()}
-      >
-        <Checkbox
-          id={checkboxId}
-          checked={checked}
-          aria-label={`Show ${row.title} in sidebar`}
-          onCheckedChange={(nextChecked) =>
-            onCheckedChange(nextChecked === true)
-          }
-          data-plugin-nav-customize-checkbox={panelKey}
-        />
-      </label>
-    </div>
-  );
-}
-
 const SortableSidebarNavRow = function SortableSidebarNavRow({
   row,
   reorderDisabled,
@@ -1111,8 +694,7 @@ function PluginNavRowMenuItems({
         View details
       </Item>
       <Item onSelect={onHide}>
-        <Icon name="EyeOff" aria-hidden="true" />
-        Hide from sidebar
+        <SidebarVisibilityActionContent visible />
       </Item>
       <Separator />
       <Item disabled={disablePending} onSelect={onDisable}>
diff --git a/apps/app/src/components/project/ProjectActionsMenu.tsx b/apps/app/src/components/project/ProjectActionsMenu.tsx
index a78cd841b11..4ab6310f643 100644
--- a/apps/app/src/components/project/ProjectActionsMenu.tsx
+++ b/apps/app/src/components/project/ProjectActionsMenu.tsx
@@ -29,6 +29,7 @@ import { useProjectActions } from "./ProjectActionsProvider";
 
 interface ProjectActionsMenuBaseProps {
   project: ProjectResponse;
+  extraActions?: (surface: ProjectActionsMenuSurface) => ReactNode;
 }
 
 interface ProjectActionsMenuProps extends ProjectActionsMenuBaseProps {
@@ -53,6 +54,7 @@ function stopProjectActionsMenuClickPropagation(event: MouseEvent) {
 export function ProjectActionsMenuItems({
   project,
   surface,
+  extraActions,
 }: ProjectActionsMenuItemsProps) {
   const navigate = useNavigate();
   const { hostId: pickerHostId } = usePathPickerHost();
@@ -93,6 +95,7 @@ export function ProjectActionsMenuItems({
           Add local path
         </ActionMenuItem>
       ) : null}
+      {extraActions?.(surface)}
       <ActionMenuSeparator surface={surface} />
       <ActionMenuItem
         surface={surface}
@@ -111,6 +114,7 @@ export function ProjectActionsMenuItems({
 export function ProjectActionsMenu({
   project,
   triggerClassName,
+  extraActions,
 }: ProjectActionsMenuProps) {
   return (
     <DropdownMenu>
@@ -139,7 +143,11 @@ export function ProjectActionsMenu({
         align="end"
         onClick={stopProjectActionsMenuClickPropagation}
       >
-        <ProjectActionsMenuItems project={project} surface="dropdown" />
+        <ProjectActionsMenuItems
+          project={project}
+          surface="dropdown"
+          extraActions={extraActions}
+        />
       </DropdownMenuContent>
     </DropdownMenu>
   );
@@ -159,12 +167,19 @@ function ProjectActionsCompactLongPressMenu({
   children,
   project,
   onOpenChange,
+  extraActions,
 }: ProjectActionsContextMenuProps) {
   return (
     <CompactLongPressMenu
       label={`${project.name} actions`}
       onOpenChange={onOpenChange}
-      items={<ProjectActionsMenuItems project={project} surface="dropdown" />}
+      items={
+        <ProjectActionsMenuItems
+          project={project}
+          surface="dropdown"
+          extraActions={extraActions}
+        />
+      }
     >
       {children}
     </CompactLongPressMenu>
@@ -175,6 +190,7 @@ function ProjectActionsDesktopContextMenu({
   children,
   project,
   onOpenChange,
+  extraActions,
 }: ProjectActionsContextMenuProps) {
   return (
     <ContextMenu onOpenChange={onOpenChange}>
@@ -183,7 +199,11 @@ function ProjectActionsDesktopContextMenu({
         aria-label={`${project.name} actions`}
         onClick={stopProjectActionsMenuClickPropagation}
       >
-        <ProjectActionsMenuItems project={project} surface="context" />
+        <ProjectActionsMenuItems
+          project={project}
+          surface="context"
+          extraActions={extraActions}
+        />
       </ContextMenuContent>
     </ContextMenu>
   );
diff --git a/apps/app/src/components/sidebar/ProjectList.modes.test.tsx b/apps/app/src/components/sidebar/ProjectList.modes.test.tsx
index 48db4f6d65e..bd2b21008f7 100644
--- a/apps/app/src/components/sidebar/ProjectList.modes.test.tsx
+++ b/apps/app/src/components/sidebar/ProjectList.modes.test.tsx
@@ -9,7 +9,10 @@ import {
   render,
   screen,
   waitFor,
+  within,
 } from "@testing-library/react";
+import { MemoryRouter } from "react-router-dom";
+import { TooltipProvider } from "@bb/shared-ui/tooltip";
 import {
   createStore,
   Provider as JotaiProvider,
@@ -23,6 +26,7 @@ import { buildMachineThreadGroups } from "@bb/client-core";
 import {
   collapsedSidebarSectionIdsAtom,
   sidebarCollapsedMachinesAtom,
+  sidebarHiddenGroupsAtom,
   sidebarManualSectionOrderAtom,
   sidebarMachineSectionOrderAtom,
   sidebarOrganizationModeAtom,
@@ -45,6 +49,18 @@ vi.mock("@/hooks/queries/system-queries", () => ({
   useSystemConfig: () => ({ data: undefined }),
 }));
 
+vi.mock("@/components/thread/ThreadActionsProvider", () => ({
+  useThreadActions: () => ({
+    renameThread: vi.fn(),
+    requestRename: vi.fn(),
+    requestDelete: vi.fn(),
+    archiveThreadAndChildren: vi.fn(),
+    unarchiveThread: vi.fn(),
+    togglePin: vi.fn(),
+    toggleRead: vi.fn(),
+  }),
+}));
+
 const queryClient = new QueryClient();
 
 vi.mock("@bb/client-core", async (importOriginal) => {
@@ -156,30 +172,34 @@ function MachineModeProbe({ threads = [] }: { threads?: ThreadListEntry[] }) {
   };
 
   return (
-    <QueryClientProvider client={queryClient}>
-      <MachineModeSections
-        threads={threads}
-        draftThreadIds={new Set()}
-        effectivePinnedThreadIds={new Set()}
-        status="ready"
-        showPinnedSection={false}
-        pinnedSection={{ label: "Pinned", content: null }}
-        pinnedReorderPending={false}
-        pinnedRootNodes={[]}
-        pinnedThreads={[]}
-        onReorderPinnedThread={vi.fn()}
-        threadsSection={{ label: "Threads" }}
-        collapsedSectionIds={collapsedSectionIdSet}
-        collapsedThreadIds={new Set()}
-        collapsedEnvironmentIds={new Set()}
-        compareThreads={() => 0}
-        renderSectionDisplayOptions={() => null}
-        isSectionDisplayOptionsOpen={() => false}
-        onToggleCollapsed={handleToggleCollapsed}
-        onToggleThreadCollapsed={vi.fn()}
-        onToggleEnvironmentCollapsed={vi.fn()}
-      />
-    </QueryClientProvider>
+    <TooltipProvider>
+      <QueryClientProvider client={queryClient}>
+        <MemoryRouter>
+          <MachineModeSections
+            threads={threads}
+            draftThreadIds={new Set()}
+            effectivePinnedThreadIds={new Set()}
+            status="ready"
+            showPinnedSection={false}
+            pinnedSection={{ label: "Pinned", content: null }}
+            pinnedReorderPending={false}
+            pinnedRootNodes={[]}
+            pinnedThreads={[]}
+            onReorderPinnedThread={vi.fn()}
+            threadsSection={{ label: "Threads" }}
+            collapsedSectionIds={collapsedSectionIdSet}
+            collapsedThreadIds={new Set()}
+            collapsedEnvironmentIds={new Set()}
+            compareThreads={() => 0}
+            renderSectionDisplayOptions={() => null}
+            isSectionDisplayOptionsOpen={() => false}
+            onToggleCollapsed={handleToggleCollapsed}
+            onToggleThreadCollapsed={vi.fn()}
+            onToggleEnvironmentCollapsed={vi.fn()}
+          />
+        </MemoryRouter>
+      </QueryClientProvider>
+    </TooltipProvider>
   );
 }
 
@@ -293,4 +313,71 @@ describe("sidebar organization mode sections", () => {
     expect(screen.getByLabelText("Plan mode active")).not.toBeNull();
     expect(screen.queryByLabelText("Thread working")).toBeNull();
   });
+
+  it("keeps hidden machine activity in More and restores the saved collapse state", async () => {
+    const store = createStore();
+    const savedOrder = ["machine:no-machine", "pinned"];
+    store.set(sidebarMachineSectionOrderAtom, savedOrder);
+    store.set(sidebarHiddenGroupsAtom, ["machine:no-machine"]);
+    store.set(sidebarCollapsedMachinesAtom, ["no-machine"]);
+
+    render(
+      <JotaiProvider store={store}>
+        <MachineModeProbe threads={[makeThread()]} />
+      </JotaiProvider>,
+    );
+
+    const more = screen.getByRole("button", { name: "More machines" });
+    expect(within(more).getByLabelText("Plan mode active")).not.toBeNull();
+    expect(screen.queryByText("No machine")).toBeNull();
+    expect(screen.queryByText("Machine activity")).toBeNull();
+
+    fireEvent.click(more);
+    const hiddenMachines = await screen.findByRole("list", {
+      name: "Hidden machines",
+    });
+    expect(within(hiddenMachines).getByText("Machine activity")).not.toBeNull();
+    fireEvent.click(
+      within(hiddenMachines).getByRole("button", {
+        name: "Collapse No machine section",
+      }),
+    );
+    expect(within(hiddenMachines).queryByText("Machine activity")).toBeNull();
+    fireEvent.click(
+      within(hiddenMachines).getByRole("button", {
+        name: "Expand No machine section",
+      }),
+    );
+    expect(within(hiddenMachines).getByText("Machine activity")).not.toBeNull();
+    expect(within(more).getByLabelText("Plan mode active")).not.toBeNull();
+    fireEvent.keyDown(
+      within(hiddenMachines).getByRole("button", {
+        name: "No machine options",
+      }),
+      { key: "Enter" },
+    );
+    const restore = await screen.findByRole("menuitem", {
+      name: "Add to sidebar",
+    });
+    expect(
+      screen.getByRole("list", { name: "Hidden machines" }),
+    ).not.toBeNull();
+    expect(
+      screen.getByRole("button", { name: "Customize list" }),
+    ).not.toBeNull();
+    fireEvent.click(restore);
+
+    await waitFor(() =>
+      expect(
+        screen.queryByRole("button", { name: "More machines" }),
+      ).toBeNull(),
+    );
+    expect(
+      screen.getByRole("button", { name: "Expand No machine section" }),
+    ).not.toBeNull();
+    expect(screen.queryByText("Machine activity")).toBeNull();
+    expect(store.get(sidebarHiddenGroupsAtom)).toEqual([]);
+    expect(store.get(sidebarCollapsedMachinesAtom)).toEqual(["no-machine"]);
+    expect(store.get(sidebarMachineSectionOrderAtom)).toEqual(savedOrder);
+  });
 });
diff --git a/apps/app/src/components/sidebar/ProjectList.tsx b/apps/app/src/components/sidebar/ProjectList.tsx
index 9f8f7e6e466..8f356d2a0ad 100644
--- a/apps/app/src/components/sidebar/ProjectList.tsx
+++ b/apps/app/src/components/sidebar/ProjectList.tsx
@@ -1,3 +1,9 @@
+import {
+  ThreadListVisibility,
+  ThreadListMore,
+  ThreadListVisibilityGroupScope,
+  type ThreadListVisibilityGroup,
+} from "./ThreadListVisibility";
 import {
   memo,
   useCallback,
@@ -69,13 +75,11 @@ import {
   ConfirmDeleteDialogContent,
 } from "@/components/dialogs/ConfirmDeleteDialog";
 import { Icon } from "@bb/shared-ui/icon";
-import { LIST_HOVER_TRANSITION } from "@bb/shared-ui/motion";
 import { Skeleton } from "@bb/shared-ui/skeleton";
 import {
   SidebarGroupContent,
   SidebarStickyStack,
 } from "@/components/ui/sidebar.js";
-import { COARSE_POINTER_ROW_HEIGHT_CLASS } from "@bb/shared-ui/coarse-pointer-sizing";
 import {
   ChronologicalSectionThreadSections,
   ProjectThreadTree,
@@ -119,11 +123,7 @@ import {
   type SidebarSectionId,
 } from "./sidebarCollapsedAtoms";
 import { useUiPreferencesReady } from "@/lib/ui-preferences/UiPreferencesSync";
-import {
-  SIDEBAR_ROW_BASE_CLASS,
-  SIDEBAR_ROW_INTERACTIVE_STATE_CLASS,
-  SIDEBAR_STANDARD_ROW_PADDING_CLASS,
-} from "./sidebarRowClasses";
+import { PROJECT_LIST_ACTION_BUTTON_CLASS } from "./sidebarRowClasses";
 import {
   SidebarHeaderActionsProvider,
   SidebarHeaderControls,
@@ -180,14 +180,7 @@ interface LocalSourcePathTarget {
   projectId: string;
 }
 
-export const PROJECT_LIST_ACTION_BUTTON_CLASS = cn(
-  SIDEBAR_ROW_BASE_CLASS,
-  LIST_HOVER_TRANSITION,
-  SIDEBAR_STANDARD_ROW_PADDING_CLASS,
-  SIDEBAR_ROW_INTERACTIVE_STATE_CLASS,
-  COARSE_POINTER_ROW_HEIGHT_CLASS,
-  "min-w-0 cursor-pointer justify-start overflow-hidden font-normal ring-sidebar-ring focus-visible:ring-2 disabled:cursor-default disabled:opacity-70 max-md:pointer-coarse:[&_[data-icon-root]]:size-5",
-);
+export { PROJECT_LIST_ACTION_BUTTON_CLASS } from "./sidebarRowClasses";
 
 interface ProjectThreadListStateArgs {
   status: ConnectionAwareQueryStatus | undefined;
@@ -846,7 +839,7 @@ function ProjectModeSections({
     compareThreads,
     draftThreadIds,
     onToggleThreadCollapsed,
-    order: persistedOrder,
+    order,
     onOrderChange,
     pinned: {
       pinnedReorderPending,
@@ -886,47 +879,87 @@ function ProjectModeSections({
     },
   };
 
-  return (
-    <ReorderableSidebarSectionOrderList order={order} threadDnd={threadDnd}>
-      {(sectionId, consumeClickSuppression) => {
-        const builtInSection = renderBuiltInSidebarSection({
-          sectionId,
-          sections: builtInSections,
-          disabled: reorderDisabled,
-          collapsedSectionIds,
-          onToggleCollapsed,
-          consumeClickSuppression,
-          showPinnedSection,
-        });
-        if (builtInSection !== undefined) return builtInSection;
-        const row = projectRowsBySectionId.get(sectionId);
-        if (!row) return null;
-        return (
-          <SortableProjectRow
-            key={sectionId}
-            sortableId={sectionId}
-            project={row.project}
-            rootItems={projectItemsByProjectId.get(row.project.id)}
+  const visibilityGroups: ThreadListVisibilityGroup[] = projectRows.map(
+    (row) => {
+      const id = buildSidebarEntitySectionId("project", row.project.id);
+      const items = projectItemsByProjectId.get(row.project.id) ?? [];
+      return {
+        id,
+        title: row.project.name,
+        threads: getProjectThreadItemDescendants(items),
+        renderContent: (close) => (
+          <ProjectThreadTree
+            projectId={row.project.id}
+            rootItems={items}
             threadListState={row.threadListState}
             progressiveDisclosureEnabled={progressiveDisclosureEnabled}
             selectedThreadId={selectedThreadId}
-            isActive={row.isActive}
-            isCollapsed={collapsedProjectIds.has(row.project.id)}
             collapsedThreadIds={collapsedThreadIds}
             collapsedEnvironmentIds={collapsedEnvironmentIds}
             compareThreads={compareThreads}
-            isLocalPathInvalid={row.isLocalPathInvalid}
-            onProjectSelect={onProjectSelect}
-            onCreateProjectThread={onCreateProjectThread}
-            onToggleProjectCollapsed={toggleProjectCollapsed}
+            variant="section"
+            onProjectSelect={() => {
+              close();
+              onProjectSelect?.();
+            }}
             onToggleThreadCollapsed={onToggleThreadCollapsed}
             onToggleEnvironmentCollapsed={onToggleEnvironmentCollapsed}
-            reorderDisabled={reorderDisabled}
-            consumeProjectClickSuppression={consumeClickSuppression}
           />
-        );
-      }}
-    </ReorderableSidebarSectionOrderList>
+        ),
+      };
+    },
+  );
+
+  return (
+    <ThreadListVisibility
+      groups={visibilityGroups}
+      order={persistedOrder}
+      onOrderChange={onOrderChange}
+      label="Projects"
+    >
+      <ReorderableSidebarSectionOrderList order={order} threadDnd={threadDnd}>
+        {(sectionId, consumeClickSuppression) => {
+          const builtInSection = renderBuiltInSidebarSection({
+            sectionId,
+            sections: builtInSections,
+            disabled: reorderDisabled,
+            collapsedSectionIds,
+            onToggleCollapsed,
+            consumeClickSuppression,
+            showPinnedSection,
+          });
+          if (builtInSection !== undefined) return builtInSection;
+          const row = projectRowsBySectionId.get(sectionId);
+          if (!row) return null;
+          return (
+            <ThreadListVisibilityGroupScope key={sectionId} id={sectionId}>
+              <SortableProjectRow
+                sortableId={sectionId}
+                project={row.project}
+                rootItems={projectItemsByProjectId.get(row.project.id)}
+                threadListState={row.threadListState}
+                progressiveDisclosureEnabled={progressiveDisclosureEnabled}
+                selectedThreadId={selectedThreadId}
+                isActive={row.isActive}
+                isCollapsed={collapsedProjectIds.has(row.project.id)}
+                collapsedThreadIds={collapsedThreadIds}
+                collapsedEnvironmentIds={collapsedEnvironmentIds}
+                compareThreads={compareThreads}
+                isLocalPathInvalid={row.isLocalPathInvalid}
+                onProjectSelect={onProjectSelect}
+                onCreateProjectThread={onCreateProjectThread}
+                onToggleProjectCollapsed={toggleProjectCollapsed}
+                onToggleThreadCollapsed={onToggleThreadCollapsed}
+                onToggleEnvironmentCollapsed={onToggleEnvironmentCollapsed}
+                reorderDisabled={reorderDisabled}
+                consumeProjectClickSuppression={consumeClickSuppression}
+              />
+            </ThreadListVisibilityGroupScope>
+          );
+        }}
+      </ReorderableSidebarSectionOrderList>
+      <ThreadListMore />
+    </ThreadListVisibility>
   );
 }
 
@@ -995,7 +1028,7 @@ function SectionModeSections({
       ),
     [sections],
   );
-  const { onOrderChange, order } = useSidebarModeSectionOrder({
+  const { onOrderChange, order, persistedOrder } = useSidebarModeSectionOrder({
     mode: "chronological",
     entitySectionIds: threadSectionIds,
     showPinnedSection,
@@ -1015,6 +1048,7 @@ function SectionModeSections({
       onRemoveSection={onRemoveSection}
       onToggleThreadCollapsed={onToggleThreadCollapsed}
       onToggleEnvironmentCollapsed={onToggleEnvironmentCollapsed}
+      fullSectionOrder={persistedOrder}
       topLevelSectionOrder={order}
       onTopLevelSectionOrderChange={onOrderChange}
       pinnedReorderPending={pinnedReorderPending}
@@ -1201,7 +1235,7 @@ export function MachineModeSections({
     compareThreads,
     draftThreadIds,
     onToggleThreadCollapsed,
-    order: persistedOrder,
+    order,
     onOrderChange,
     pinned: {
       pinnedReorderPending,
@@ -1237,56 +1271,95 @@ export function MachineModeSections({
     },
   };
 
-  return (
-    <ReorderableSidebarSectionOrderList order={order} threadDnd={threadDnd}>
-      {(sectionId, consumeClickSuppression) => {
-        const builtInSection = renderBuiltInSidebarSection({
-          sectionId,
-          sections: builtInSections,
-          disabled: reorderDisabled,
-          collapsedSectionIds,
-          onToggleCollapsed,
-          consumeClickSuppression,
-          showPinnedSection,
-        });
-        if (builtInSection !== undefined) return builtInSection;
-        const section = machineSectionsById.get(sectionId);
-        if (!section) return null;
-        return (
-          <SortableSidebarSection
-            key={sectionId}
-            id={sectionId}
-            label={section.label}
-            disabled={reorderDisabled}
-            actions={renderSectionDisplayOptions(sectionId, section.label)}
-            actionsOpen={isSectionDisplayOptionsOpen(sectionId)}
-            actionsMobileAlways
-            collapsedActivity={section.activity}
-            collapsedThreads={section.threadListState.threads}
-            collapseControl={{
-              isCollapsed: collapsedMachineKeys.has(section.key),
-              onToggleCollapsed: () => toggleMachineCollapsed(section.key),
+  const visibilityGroups: ThreadListVisibilityGroup[] = machineSections.map(
+    (section) => {
+      const id = buildSidebarEntitySectionId("machine", section.key);
+      const items = machineItemsBySectionId.get(id) ?? [];
+      return {
+        id,
+        title: section.label,
+        threads: getProjectThreadItemDescendants(items),
+        renderContent: (close) => (
+          <ProjectThreadTree
+            rootItems={items}
+            threadListState={section.threadListState}
+            progressiveDisclosureEnabled={progressiveDisclosureEnabled}
+            selectedThreadId={selectedThreadId}
+            collapsedThreadIds={collapsedThreadIds}
+            collapsedEnvironmentIds={collapsedEnvironmentIds}
+            compareThreads={compareThreads}
+            variant="section"
+            onProjectSelect={() => {
+              close();
+              onProjectSelect?.();
             }}
-            consumeClickSuppression={consumeClickSuppression}
-          >
-            <ProjectThreadTree
-              dndParentKey={sectionId}
-              rootItems={machineItemsBySectionId.get(sectionId)}
-              threadListState={section.threadListState}
-              progressiveDisclosureEnabled={progressiveDisclosureEnabled}
-              compareThreads={compareThreads}
-              variant="section"
-              selectedThreadId={selectedThreadId}
-              collapsedThreadIds={collapsedThreadIds}
-              collapsedEnvironmentIds={collapsedEnvironmentIds}
-              onProjectSelect={onProjectSelect}
-              onToggleThreadCollapsed={onToggleThreadCollapsed}
-              onToggleEnvironmentCollapsed={onToggleEnvironmentCollapsed}
-            />
-          </SortableSidebarSection>
-        );
-      }}
-    </ReorderableSidebarSectionOrderList>
+            onToggleThreadCollapsed={onToggleThreadCollapsed}
+            onToggleEnvironmentCollapsed={onToggleEnvironmentCollapsed}
+          />
+        ),
+      };
+    },
+  );
+
+  return (
+    <ThreadListVisibility
+      groups={visibilityGroups}
+      order={persistedOrder}
+      onOrderChange={onOrderChange}
+      label="Machines"
+    >
+      <ReorderableSidebarSectionOrderList order={order} threadDnd={threadDnd}>
+        {(sectionId, consumeClickSuppression) => {
+          const builtInSection = renderBuiltInSidebarSection({
+            sectionId,
+            sections: builtInSections,
+            disabled: reorderDisabled,
+            collapsedSectionIds,
+            onToggleCollapsed,
+            consumeClickSuppression,
+            showPinnedSection,
+          });
+          if (builtInSection !== undefined) return builtInSection;
+          const section = machineSectionsById.get(sectionId);
+          if (!section) return null;
+          return (
+            <ThreadListVisibilityGroupScope key={sectionId} id={sectionId}>
+              <SortableSidebarSection
+                id={sectionId}
+                label={section.label}
+                disabled={reorderDisabled}
+                actions={renderSectionDisplayOptions(sectionId, section.label)}
+                actionsOpen={isSectionDisplayOptionsOpen(sectionId)}
+                actionsMobileAlways
+                collapsedActivity={section.activity}
+                collapsedThreads={section.threadListState.threads}
+                collapseControl={{
+                  isCollapsed: collapsedMachineKeys.has(section.key),
+                  onToggleCollapsed: () => toggleMachineCollapsed(section.key),
+                }}
+                consumeClickSuppression={consumeClickSuppression}
+              >
+                <ProjectThreadTree
+                  dndParentKey={sectionId}
+                  rootItems={machineItemsBySectionId.get(sectionId)}
+                  threadListState={section.threadListState}
+                  progressiveDisclosureEnabled={progressiveDisclosureEnabled}
+                  compareThreads={compareThreads}
+                  variant="section"
+                  selectedThreadId={selectedThreadId}
+                  collapsedThreadIds={collapsedThreadIds}
+                  collapsedEnvironmentIds={collapsedEnvironmentIds}
+                  onProjectSelect={onProjectSelect}
+                  onToggleThreadCollapsed={onToggleThreadCollapsed}
+                  onToggleEnvironmentCollapsed={onToggleEnvironmentCollapsed}
+                />
+              </SortableSidebarSection>
+            </ThreadListVisibilityGroupScope>
+          );
+        }}
+      </ReorderableSidebarSectionOrderList>
+      <ThreadListMore />
+    </ThreadListVisibility>
   );
 }
 
diff --git a/apps/app/src/components/sidebar/ProjectRow.interactions.test.tsx b/apps/app/src/components/sidebar/ProjectRow.interactions.test.tsx
index c91095aeb06..f158d51b7ee 100644
--- a/apps/app/src/components/sidebar/ProjectRow.interactions.test.tsx
+++ b/apps/app/src/components/sidebar/ProjectRow.interactions.test.tsx
@@ -6,6 +6,7 @@ import {
   render,
   screen,
   waitFor,
+  within,
 } from "@testing-library/react";
 import type { ThreadListEntry } from "@bb/domain";
 import { afterEach, describe, expect, it, vi } from "vitest";
@@ -23,7 +24,12 @@ import {
 import { buildSidebarEntitySectionId } from "@bb/client-core";
 import { makeThreadListEntry } from "@bb/test-helpers/domain-fixtures";
 import { makeProjectResponse } from "@/test/fixtures/projects";
-import { sidebarOrganizationModeAtom } from "./sidebarCollapsedAtoms";
+import {
+  sidebarHiddenGroupsAtom,
+  sidebarManualSectionOrderAtom,
+  sidebarOrganizationModeAtom,
+} from "./sidebarCollapsedAtoms";
+import { useSidebarModeSectionOrder } from "./useSidebarModeSectionOrder";
 
 const mockUpdateEnvironment = vi.hoisted(() => ({
   mutate: vi.fn(),
@@ -142,6 +148,48 @@ function expectCollapsedActivityAtSidebarEdge(label: string) {
   expect(edgeSlot).toBeInstanceOf(HTMLElement);
 }
 
+function CustomSectionsVisibilityProbe({
+  threads,
+  onProjectSelect,
+}: {
+  threads: ThreadListEntry[];
+  onProjectSelect: () => void;
+}) {
+  const { order, persistedOrder, onOrderChange } = useSidebarModeSectionOrder({
+    mode: "chronological",
+    entitySectionIds: ["section:sec_building", "section:sec_review"],
+    showPinnedSection: false,
+  });
+
+  return (
+    <ChronologicalSectionThreadSections
+      threadListState={{ status: "ready", threads }}
+      compareThreads={() => 0}
+      sections={[
+        { id: "sec_building", name: "Building" },
+        { id: "sec_review", name: "Review" },
+      ]}
+      collapsedThreadIds={new Set()}
+      collapsedEnvironmentIds={new Set()}
+      onProjectSelect={onProjectSelect}
+      onToggleThreadCollapsed={vi.fn()}
+      onToggleEnvironmentCollapsed={vi.fn()}
+      topLevelSectionOrder={order}
+      fullSectionOrder={persistedOrder}
+      onTopLevelSectionOrderChange={onOrderChange}
+      pinnedReorderPending={false}
+      pinnedThreads={[]}
+      onReorderPinnedThread={vi.fn()}
+      builtInSections={{
+        collapsedSectionIds: new Set(),
+        onToggleCollapsed: vi.fn(),
+        pinned: { label: "Pinned", content: null },
+        threads: { label: "Threads" },
+      }}
+    />
+  );
+}
+
 describe("ProjectRow interactions", () => {
   it("renders the destination gap as a muted copy of the dragged row", () => {
     render(<DropPreviewRow depth={0} thread={makeThread()} />);
@@ -359,6 +407,9 @@ describe("ProjectRow interactions", () => {
                 topLevelSectionOrder={[
                   buildSidebarEntitySectionId("section", sectionId),
                 ]}
+                fullSectionOrder={[
+                  buildSidebarEntitySectionId("section", sectionId),
+                ]}
                 onTopLevelSectionOrderChange={vi.fn()}
                 pinnedReorderPending={false}
                 pinnedThreads={[]}
@@ -427,6 +478,9 @@ describe("ProjectRow interactions", () => {
                 topLevelSectionOrder={[
                   buildSidebarEntitySectionId("section", sectionId),
                 ]}
+                fullSectionOrder={[
+                  buildSidebarEntitySectionId("section", sectionId),
+                ]}
                 onTopLevelSectionOrderChange={vi.fn()}
                 pinnedReorderPending={false}
                 pinnedThreads={[]}
@@ -454,6 +508,110 @@ describe("ProjectRow interactions", () => {
     expect(screen.queryByLabelText("Plan mode active")).toBeNull();
   });
 
+  it("hides a section with inherited descendants and restores its saved position", async () => {
+    const store = createStore();
+    const savedOrder = [
+      "section:sec_review",
+      "section:sec_building",
+      "pinned",
+      "threads",
+    ];
+    store.set(sidebarOrganizationModeAtom, "chronological");
+    store.set(sidebarManualSectionOrderAtom, savedOrder);
+    const onProjectSelect = vi.fn();
+    const threads = [
+      makeThread({
+        id: "thr_review_parent",
+        title: "Review parent",
+        titleFallback: "Review parent",
+        sectionId: "sec_review",
+      }),
+      makeThread({
+        id: "thr_inherited_child",
+        title: "Inherited child",
+        titleFallback: "Inherited child",
+        parentThreadId: "thr_review_parent",
+        sectionId: null,
+      }),
+    ];
+    const { container } = render(
+      <TooltipProvider>
+        <Provider store={store}>
+          <QueryClientProvider client={new QueryClient()}>
+            <MemoryRouter>
+              <CustomSectionsVisibilityProbe
+                threads={threads}
+                onProjectSelect={onProjectSelect}
+              />
+            </MemoryRouter>
+          </QueryClientProvider>
+        </Provider>
+      </TooltipProvider>,
+    );
+
+    expect(screen.getByText("Review parent")).not.toBeNull();
+    expect(screen.getByText("Inherited child")).not.toBeNull();
+    expect(screen.queryByRole("button", { name: "More sections" })).toBeNull();
+    fireEvent.pointerDown(
+      screen.getByRole("button", { name: "Review section actions" }),
+      { button: 0 },
+    );
+    fireEvent.click(
+      await screen.findByRole("menuitem", { name: "Hide from list" }),
+    );
+
+    expect(screen.queryByText("Review parent")).toBeNull();
+    expect(screen.queryByText("Inherited child")).toBeNull();
+    expect(store.get(sidebarHiddenGroupsAtom)).toEqual(["section:sec_review"]);
+    expect(store.get(sidebarManualSectionOrderAtom)).toEqual(savedOrder);
+    fireEvent.click(screen.getByRole("button", { name: "More sections" }));
+    const hiddenSections = await screen.findByRole("list", {
+      name: "Hidden sections",
+    });
+    expect(within(hiddenSections).getByText("Review parent")).not.toBeNull();
+    fireEvent.click(
+      within(hiddenSections).getByRole("link", {
+        name: "Open Inherited child",
+      }),
+    );
+    await waitFor(() =>
+      expect(
+        screen.queryByRole("list", { name: "Hidden sections" }),
+      ).toBeNull(),
+    );
+    expect(onProjectSelect).toHaveBeenCalledOnce();
+    expect(store.get(sidebarHiddenGroupsAtom)).toEqual(["section:sec_review"]);
+
+    fireEvent.click(screen.getByRole("button", { name: "More sections" }));
+    const reopenedSections = await screen.findByRole("list", {
+      name: "Hidden sections",
+    });
+    fireEvent.pointerDown(
+      within(reopenedSections).getByRole("button", { name: "Review options" }),
+      { button: 0 },
+    );
+    fireEvent.click(
+      await screen.findByRole("menuitem", { name: "Add to sidebar" }),
+    );
+
+    await waitFor(() =>
+      expect(
+        screen.queryByRole("button", { name: "More sections" }),
+      ).toBeNull(),
+    );
+    expect(screen.getByText("Inherited child")).not.toBeNull();
+    expect(store.get(sidebarHiddenGroupsAtom)).toEqual([]);
+    expect(store.get(sidebarManualSectionOrderAtom)).toEqual(savedOrder);
+    expect(
+      Array.from(
+        container.querySelectorAll<HTMLElement>(
+          "[data-sidebar-visibility-group]",
+        ),
+        (element) => element.dataset.sidebarVisibilityGroup,
+      ),
+    ).toEqual(["section:sec_review", "section:sec_building"]);
+  });
+
   it("surfaces named activity when the project is collapsed", () => {
     renderProjectRow(
       vi.fn(),
diff --git a/apps/app/src/components/sidebar/ProjectRow.tsx b/apps/app/src/components/sidebar/ProjectRow.tsx
index f2409148977..0d3f2a4204a 100644
--- a/apps/app/src/components/sidebar/ProjectRow.tsx
+++ b/apps/app/src/components/sidebar/ProjectRow.tsx
@@ -1,3 +1,10 @@
+import {
+  ThreadListVisibility,
+  ThreadListMore,
+  ThreadListVisibilityGroupScope,
+  ThreadListVisibilityMenuItems,
+  type ThreadListVisibilityGroup,
+} from "./ThreadListVisibility";
 import {
   SidebarHeaderControls,
   SidebarSectionMenuItems,
@@ -248,6 +255,7 @@ interface ChronologicalBuiltInSidebarSections {
 interface ChronologicalSectionThreadSectionsProps extends SectionThreadTreeProps {
   builtInSections: ChronologicalBuiltInSidebarSections;
   topLevelSectionOrder: readonly SidebarSectionId[];
+  fullSectionOrder: readonly SidebarSectionId[];
   onTopLevelSectionOrderChange: (order: SidebarSectionId[]) => void;
   pinnedReorderPending: boolean;
   pinnedRootNodes?: readonly ProjectThreadNode[];
@@ -2143,6 +2151,7 @@ export const ChronologicalSectionThreadSections = memo(
     onToggleEnvironmentCollapsed,
     builtInSections,
     topLevelSectionOrder,
+    fullSectionOrder,
     onTopLevelSectionOrderChange,
     pinnedReorderPending,
     pinnedRootNodes = EMPTY_PINNED_ROOT_NODES,
@@ -2322,6 +2331,35 @@ export const ChronologicalSectionThreadSections = memo(
         content: threadsContent,
       },
     };
+
+    const visibilityGroups: ThreadListVisibilityGroup[] = sectionItems.map(
+      (item) => ({
+        id: buildSidebarEntitySectionId("section", item.group.id),
+        title: item.group.name,
+        threads: getProjectThreadItemDescendants(item.group.items),
+        renderContent: (close) => (
+          <ProjectThreadTree
+            rootItems={item.group.items}
+            progressiveDisclosureEnabled={false}
+            threadListState={{
+              status: "ready",
+              threads: getProjectThreadItemDescendants(item.group.items),
+            }}
+            compareThreads={compareThreads}
+            variant="section"
+            selectedThreadId={selectedThreadId}
+            collapsedThreadIds={collapsedThreadIds}
+            collapsedEnvironmentIds={collapsedEnvironmentIds}
+            onProjectSelect={() => {
+              close();
+              onProjectSelect?.();
+            }}
+            onToggleThreadCollapsed={onToggleThreadCollapsed}
+            onToggleEnvironmentCollapsed={onToggleEnvironmentCollapsed}
+          />
+        ),
+      }),
+    );
     const orderedSections = (
       <SidebarSectionOrderList order={topLevelSectionOrder}>
         {(sectionId) => {
@@ -2339,23 +2377,35 @@ export const ChronologicalSectionThreadSections = memo(
           }
           const sectionItem = sectionItemsBySectionId.get(sectionId);
           return sectionItem ? (
-            <div key={sectionId}>{renderItems([sectionItem])}</div>
+            <ThreadListVisibilityGroupScope key={sectionId} id={sectionId}>
+              {renderItems([sectionItem])}
+            </ThreadListVisibilityGroupScope>
           ) : null;
         }}
       </SidebarSectionOrderList>
     );
 
-    return sectionDnd ? (
-      <DndContext {...sectionDnd.dndContextProps}>
-        <SectionThreadDndProvider value={renderedSectionDnd}>
-          {orderedSections}
-          <SectionThreadDragOverlayPortal
-            activeThread={sectionDnd.activeThread}
-          />
-        </SectionThreadDndProvider>
-      </DndContext>
-    ) : (
-      orderedSections
+    return (
+      <ThreadListVisibility
+        groups={visibilityGroups}
+        order={fullSectionOrder}
+        onOrderChange={onTopLevelSectionOrderChange}
+        label="Sections"
+      >
+        {sectionDnd ? (
+          <DndContext {...sectionDnd.dndContextProps}>
+            <SectionThreadDndProvider value={renderedSectionDnd}>
+              {orderedSections}
+              <SectionThreadDragOverlayPortal
+                activeThread={sectionDnd.activeThread}
+              />
+            </SectionThreadDndProvider>
+          </DndContext>
+        ) : (
+          orderedSections
+        )}
+        <ThreadListMore />
+      </ThreadListVisibility>
     );
   },
 );
@@ -2427,12 +2477,21 @@ function ProjectRowComponent({
       onNewThread={onCreateProjectThread ? handleCreateThread : undefined}
       onOpenChange={setIsDropdownActionsOpen}
     >
-      <ProjectActionsMenuItems project={project} surface="dropdown" />
+      <ProjectActionsMenuItems
+        project={project}
+        surface="dropdown"
+        extraActions={(surface) => (
+          <ThreadListVisibilityMenuItems surface={surface} />
+        )}
+      />
     </SidebarHeaderControls>
   );
 
   return (
     <ProjectActionsContextMenu
+      extraActions={(surface) => (
+        <ThreadListVisibilityMenuItems surface={surface} />
+      )}
       project={project}
       onOpenChange={setIsContextActionsOpen}
     >
diff --git a/apps/app/src/components/sidebar/SectionGrouping.stories.tsx b/apps/app/src/components/sidebar/SectionGrouping.stories.tsx
index 0fad9e63c17..f6a52ed5e71 100644
--- a/apps/app/src/components/sidebar/SectionGrouping.stories.tsx
+++ b/apps/app/src/components/sidebar/SectionGrouping.stories.tsx
@@ -182,6 +182,12 @@ export function ChronologicalSections() {
             threadListState={projectTree(sectionThreads)}
             compareThreads={compareStandardThreads}
             sections={STORY_SECTIONS}
+            fullSectionOrder={[
+              ...STORY_SECTIONS.map((section) =>
+                buildSidebarEntitySectionId("section", section.id),
+              ),
+              "threads",
+            ]}
             collapsedThreadIds={new Set()}
             collapsedEnvironmentIds={new Set()}
             onToggleThreadCollapsed={noop}
@@ -226,6 +232,12 @@ function WorktreeGroupingStage({
           threadListState={projectTree(worktreeSectionThreads)}
           compareThreads={compareStandardThreads}
           sections={WORKTREE_SECTIONS}
+          fullSectionOrder={[
+            ...WORKTREE_SECTIONS.map((section) =>
+              buildSidebarEntitySectionId("section", section.id),
+            ),
+            "threads",
+          ]}
           collapsedThreadIds={new Set()}
           collapsedEnvironmentIds={new Set()}
           onToggleThreadCollapsed={noop}
diff --git a/apps/app/src/components/sidebar/SidebarHeaderControls.tsx b/apps/app/src/components/sidebar/SidebarHeaderControls.tsx
index d8d7c82b940..08a1f1162aa 100644
--- a/apps/app/src/components/sidebar/SidebarHeaderControls.tsx
+++ b/apps/app/src/components/sidebar/SidebarHeaderControls.tsx
@@ -26,6 +26,7 @@ import {
 } from "./sidebarCollapsedAtoms";
 import { SidebarControlButton, SidebarRowControls } from "./SidebarRowControls";
 import { SIDEBAR_CONTROL_BUTTON_CLASS } from "./sidebarRowClasses";
+import { ThreadListVisibilityMenuItems } from "./ThreadListVisibility";
 
 interface HeaderCreationActions {
   onNewProject?: () => void;
@@ -271,11 +272,13 @@ export function SidebarHeaderControls({
                   </DropdownMenuSub>
                 ),
               )}
-              {children && (
+              {children ? (
                 <>
                   <DropdownMenuSeparator />
                   {children}
                 </>
+              ) : (
+                <ThreadListVisibilityMenuItems />
               )}
             </>
           )}
@@ -300,6 +303,7 @@ export function SidebarSectionMenuItems({
           Rename
         </DropdownMenuItem>
       )}
+      <ThreadListVisibilityMenuItems />
       {onRemove && (
         <>
           <DropdownMenuSeparator />
diff --git a/apps/app/src/components/sidebar/SidebarOverview.stories.tsx b/apps/app/src/components/sidebar/SidebarOverview.stories.tsx
index 5eaec28fd5b..84d52e67ceb 100644
--- a/apps/app/src/components/sidebar/SidebarOverview.stories.tsx
+++ b/apps/app/src/components/sidebar/SidebarOverview.stories.tsx
@@ -59,6 +59,7 @@ import {
 import { splitLayoutAtom } from "@/lib/split-layout/atoms";
 import {
   sidebarOrganizationModeAtom,
+  sidebarHiddenGroupsAtom,
   type SidebarOrganizationMode,
 } from "./sidebarCollapsedAtoms";
 import { makePluginRegistrationSet } from "@/test/fixtures/plugins";
@@ -94,6 +95,11 @@ const personalProject = makeProject({
 });
 
 const loadedSidebarNavigation = makeSidebarBootstrapResponse({
+  sections: [
+    { id: "sec_story_build", name: "In progress", createdAt: 0, updatedAt: 0 },
+    { id: "sec_story_review", name: "Review", createdAt: 0, updatedAt: 0 },
+    { id: "sec_story_later", name: "Later", createdAt: 0, updatedAt: 0 },
+  ],
   personalProject: makeProjectWithThreadsResponse({
     ...personalProject,
     threads: [
@@ -154,6 +160,7 @@ const loadedSidebarNavigation = makeSidebarBootstrapResponse({
         }),
         makeThreadListEntry({
           id: "thr_story_active",
+          sectionId: "sec_story_build",
           projectId: bbProject.id,
           title: "Ship realtime sidebar updates",
           titleFallback: "Ship realtime sidebar updates",
@@ -201,6 +208,7 @@ const loadedSidebarNavigation = makeSidebarBootstrapResponse({
         }),
         makeThreadListEntry({
           id: "thr_story_worktree_b",
+          sectionId: "sec_story_review",
           projectId: bbProject.id,
           environmentId: "env_story_sidebar",
           environmentName: "Sidebar polish",
@@ -221,6 +229,7 @@ const loadedSidebarNavigation = makeSidebarBootstrapResponse({
       threads: [
         makeThreadListEntry({
           id: "thr_story_docs",
+          sectionId: "sec_story_review",
           projectId: docsProject.id,
           title: "Refresh onboarding docs",
           titleFallback: "Refresh onboarding docs",
@@ -228,6 +237,27 @@ const loadedSidebarNavigation = makeSidebarBootstrapResponse({
           createdAt: 120,
           updatedAt: 120,
         }),
+        ...Array.from({ length: 40 }, (_, index) => {
+          const title = [
+            "Review keyboard navigation",
+            "Clarify the onboarding checklist",
+            "Update screenshots for the release guide",
+            "Verify nested thread actions",
+          ][index % 4];
+          return makeThreadListEntry({
+            id: `thr_story_docs_${index}`,
+            projectId: docsProject.id,
+            sectionId: "sec_story_review",
+            title: `${title} ${index + 1}`,
+            titleFallback: `${title} ${index + 1}`,
+            parentThreadId:
+              index % 8 === 1 ? `thr_story_docs_${index - 1}` : null,
+            latestAttentionAt: 110 - index,
+            createdAt: 110 - index,
+            updatedAt: 110 - index,
+            lastReadAt: index % 3 === 0 ? 0 : 120,
+          });
+        }),
       ],
     }),
   ],
@@ -459,21 +489,30 @@ function OrganizationSidebar({
 }) {
   const [store] = useState(() => createStore());
   const [isModeSeeded, setIsModeSeeded] = useState(false);
-  const [queryClient] = useState(
-    () =>
-      new QueryClient({
-        defaultOptions: {
-          queries: {
-            retry: false,
-          },
+  const [queryClient] = useState(() => {
+    const client = new QueryClient({
+      defaultOptions: {
+        queries: {
+          retry: false,
+          refetchOnMount: false,
+          refetchOnWindowFocus: false,
+          refetchOnReconnect: false,
         },
-      }),
-  );
+      },
+    });
+    client.setQueryData(hostsQueryKey(), hosts ?? machineStoryHosts);
+    return client;
+  });
 
   useLayoutEffect(() => {
     setIsModeSeeded(false);
     const unsubscribe = store.sub(sidebarOrganizationModeAtom, noop);
     store.set(sidebarOrganizationModeAtom, mode);
+    store.set(sidebarHiddenGroupsAtom, [
+      `project:${docsProject.id}`,
+      "section:sec_story_review",
+      `machine:${HOST_IDS.remote}`,
+    ]);
 
     setIsModeSeeded(true);
 
@@ -539,7 +578,7 @@ export function OrganizationModes() {
           navigation={emptySidebarNavigation}
         />
       </StoryRow>
-      <StoryRow label="Manually">
+      <StoryRow label="Custom">
         <OrganizationSidebar
           mode="chronological"
           navigation={loadedSidebarNavigation}
diff --git a/apps/app/src/components/sidebar/SidebarVisibilityControls.test.tsx b/apps/app/src/components/sidebar/SidebarVisibilityControls.test.tsx
new file mode 100644
index 00000000000..c0988a0b53d
--- /dev/null
+++ b/apps/app/src/components/sidebar/SidebarVisibilityControls.test.tsx
@@ -0,0 +1,37 @@
+// @vitest-environment jsdom
+import { cleanup, fireEvent, render, screen } from "@testing-library/react";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { CompactViewportOverrideProvider } from "@bb/shared-ui/hooks/use-compact-viewport";
+import { SidebarVisibilityCustomize } from "./SidebarVisibilityControls";
+
+afterEach(cleanup);
+
+describe("shared sidebar visibility controls", () => {
+  it("lets group customization toggle visibility without navigating away", () => {
+    const onVisibleChange = vi.fn();
+    const onDone = vi.fn();
+    render(
+      <CompactViewportOverrideProvider isCompactViewport={false}>
+        <SidebarVisibilityCustomize
+          items={[{ id: "section:review", title: "Review" }]}
+          visibleIds={[]}
+          title="Customize list"
+          listLabel="Sections"
+          testIdPrefix="sidebar-thread-list"
+          variant="card"
+          onVisibleChange={onVisibleChange}
+          onReorder={() => {}}
+          onDone={onDone}
+        />
+      </CompactViewportOverrideProvider>,
+    );
+
+    fireEvent.click(screen.getByRole("button", { name: "Review" }));
+    expect(onVisibleChange).toHaveBeenCalledWith("section:review", true);
+    expect(onDone).not.toHaveBeenCalled();
+    fireEvent.keyDown(screen.getByRole("button", { name: "Review" }), {
+      key: "Escape",
+    });
+    expect(onDone).toHaveBeenCalledOnce();
+  });
+});
diff --git a/apps/app/src/components/sidebar/SidebarVisibilityControls.tsx b/apps/app/src/components/sidebar/SidebarVisibilityControls.tsx
new file mode 100644
index 00000000000..9cb27802dc7
--- /dev/null
+++ b/apps/app/src/components/sidebar/SidebarVisibilityControls.tsx
@@ -0,0 +1,593 @@
+import {
+  useCallback,
+  useEffect,
+  useId,
+  useMemo,
+  useRef,
+  useState,
+  type PointerEventHandler,
+  type ReactNode,
+} from "react";
+import { DndContext, type DragEndEvent } from "@dnd-kit/core";
+import {
+  SortableContext,
+  verticalListSortingStrategy,
+} from "@dnd-kit/sortable";
+import { Button } from "@bb/shared-ui/button";
+import { Checkbox } from "@bb/shared-ui/checkbox";
+import { Icon } from "@bb/shared-ui/icon";
+import { Popover, PopoverContent, PopoverTrigger } from "@bb/shared-ui/popover";
+import {
+  ContextMenu,
+  ContextMenuContent,
+  ContextMenuItem,
+  ContextMenuTrigger,
+} from "@bb/shared-ui/context-menu";
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuTrigger,
+} from "@bb/shared-ui/dropdown-menu";
+import {
+  COARSE_POINTER_COMPACT_ROW_HEIGHT_CLASS,
+  COARSE_POINTER_ICON_SIZE_CLASS,
+  COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
+} from "@bb/shared-ui/coarse-pointer-sizing";
+import { CHROME_SECTION_LABEL_CLASS } from "@bb/shared-ui/chrome-style-tokens";
+import { cn } from "@bb/shared-ui/lib/utils";
+import {
+  SIDEBAR_HOVER_ACTIONS_CLASS,
+  SIDEBAR_HOVER_ACTIONS_MOBILE_ALWAYS_VALUE,
+  SIDEBAR_HOVER_ACTIONS_ROW_CLASS,
+} from "@/components/ui/sidebar-hover-actions";
+import {
+  PROJECT_LIST_ACTION_BUTTON_CLASS,
+  SIDEBAR_CONTROL_BUTTON_CLASS,
+} from "./sidebarRowClasses";
+import { TopLevelSidebarSection } from "./TopLevelSidebarSection";
+import { useSidebarSortable } from "./sortableMotion";
+import { useSidebarReorderDnd } from "./useSidebarReorderDnd";
+
+const OVERFLOW_ROW_BUTTON_CLASS =
+  "w-full justify-start gap-2 rounded-sm px-2 text-xs font-normal hover:bg-state-hover focus-visible:bg-state-hover";
+
+export interface SidebarVisibilityItem {
+  id: string;
+  title: string;
+  icon?: ReactNode;
+  disabled?: boolean;
+}
+
+export interface SidebarActivationModifiers {
+  metaKey: boolean;
+  ctrlKey: boolean;
+}
+
+export function SidebarCustomizeActionContent({ label }: { label: string }) {
+  return (
+    <>
+      <Icon name="FilterHorizontal" aria-hidden="true" />
+      {label}
+    </>
+  );
+}
+
+export function SidebarVisibilityActionContent({
+  visible,
+  label,
+}: {
+  visible: boolean;
+  label?: string;
+}) {
+  return (
+    <>
+      <Icon name={visible ? "EyeOff" : "Eye"} aria-hidden="true" />
+      {label ?? (visible ? "Hide from sidebar" : "Add to sidebar")}
+    </>
+  );
+}
+
+export function SidebarMore({
+  activity,
+  ariaLabel,
+  children,
+  customizeLabel,
+  listLabel,
+  onCustomize,
+  testIdPrefix = "sidebar-navigation",
+}: {
+  activity?: ReactNode;
+  ariaLabel: string;
+  children: (close: () => void) => ReactNode;
+  customizeLabel: string;
+  listLabel: string;
+  onCustomize: () => void;
+  testIdPrefix?: string;
+}) {
+  const [isMenuOpen, setIsMenuOpen] = useState(false);
+  const close = useCallback(() => setIsMenuOpen(false), []);
+
+  return (
+    <div data-testid={`${testIdPrefix}-more-row`}>
+      <Popover open={isMenuOpen} onOpenChange={setIsMenuOpen}>
+        <ContextMenu>
+          <ContextMenuTrigger asChild>
+            <div>
+              <PopoverTrigger asChild>
+                <Button
+                  type="button"
+                  size="sm"
+                  variant="ghost"
+                  aria-label={ariaLabel}
+                  className={cn(
+                    PROJECT_LIST_ACTION_BUTTON_CLASS,
+                    "w-full text-muted-foreground hover:text-sidebar-foreground focus-visible:text-sidebar-foreground data-[state=open]:text-sidebar-foreground",
+                    isMenuOpen && "bg-sidebar-accent",
+                  )}
+                  data-testid={`${testIdPrefix}-more-trigger`}
+                >
+                  <Icon name="MoreHorizontal" aria-hidden="true" />
+                  <span className="min-w-0 truncate text-left">More</span>
+                  {activity ? (
+                    <span className="ml-auto flex shrink-0">{activity}</span>
+                  ) : null}
+                </Button>
+              </PopoverTrigger>
+            </div>
+          </ContextMenuTrigger>
+          <ContextMenuContent aria-label={`${ariaLabel} options`}>
+            <ContextMenuItem onSelect={onCustomize}>
+              <SidebarCustomizeActionContent label={customizeLabel} />
+            </ContextMenuItem>
+          </ContextMenuContent>
+        </ContextMenu>
+        <PopoverContent
+          side="right"
+          align="start"
+          sideOffset={8}
+          mobileTitle="More"
+          aria-label={ariaLabel}
+          className="flex max-h-[min(var(--radix-popover-content-available-height),calc(100dvh-0.5rem))] w-56 flex-col overflow-hidden p-1 max-md:min-h-0 max-md:flex-1"
+        >
+          <div
+            role="list"
+            aria-label={listLabel}
+            className="min-h-0 flex-1 overflow-y-auto overscroll-contain"
+          >
+            {children(close)}
+          </div>
+          <div
+            role="separator"
+            className="-mx-1 my-1 h-px shrink-0 bg-border"
+          />
+          <Button
+            type="button"
+            variant="ghost"
+            size="sm"
+            className={cn(
+              OVERFLOW_ROW_BUTTON_CLASS,
+              COARSE_POINTER_COMPACT_ROW_HEIGHT_CLASS,
+              "shrink-0",
+            )}
+            data-testid={`${testIdPrefix}-customize-trigger`}
+            onClick={() => {
+              close();
+              onCustomize();
+            }}
+          >
+            <SidebarCustomizeActionContent label={customizeLabel} />
+          </Button>
+        </PopoverContent>
+      </Popover>
+    </div>
+  );
+}
+
+export function SidebarOverflowItem({
+  activity,
+  additionalActions,
+  children,
+  expanded,
+  item,
+  onActivate,
+  onAddToSidebar,
+  onClose,
+  onExpandedChange,
+  onPointerDown,
+  testIdPrefix = "sidebar-navigation",
+}: {
+  activity?: ReactNode;
+  additionalActions?: ReactNode;
+  children?: ReactNode;
+  expanded?: boolean;
+  item: SidebarVisibilityItem;
+  onActivate?: (event: SidebarActivationModifiers) => void;
+  onAddToSidebar: (id: string) => void;
+  onClose: () => void;
+  onExpandedChange?: (expanded: boolean) => void;
+  onPointerDown?: PointerEventHandler<HTMLButtonElement>;
+  testIdPrefix?: string;
+}) {
+  const [isActionsOpen, setIsActionsOpen] = useState(false);
+
+  const actions = (
+    <DropdownMenu
+      modal={false}
+      open={isActionsOpen}
+      onOpenChange={setIsActionsOpen}
+    >
+      <DropdownMenuTrigger asChild>
+        <Button
+          type="button"
+          variant="ghost"
+          size="icon"
+          aria-label={`${item.title} options`}
+          className={
+            onExpandedChange
+              ? SIDEBAR_CONTROL_BUTTON_CLASS
+              : cn(
+                  COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
+                  "rounded-sm p-0 hover:bg-state-hover",
+                )
+          }
+        >
+          <Icon
+            name="MoreHorizontal"
+            className={COARSE_POINTER_ICON_SIZE_CLASS}
+          />
+        </Button>
+      </DropdownMenuTrigger>
+      <DropdownMenuContent
+        side="right"
+        align="start"
+        sideOffset={4}
+        aria-label={`${item.title} options`}
+      >
+        {additionalActions}
+        <DropdownMenuItem
+          className="cursor-pointer"
+          onSelect={() => {
+            onClose();
+            onAddToSidebar(item.id);
+          }}
+        >
+          <SidebarVisibilityActionContent visible={false} />
+        </DropdownMenuItem>
+      </DropdownMenuContent>
+    </DropdownMenu>
+  );
+
+  if (onExpandedChange) {
+    return (
+      <div role="listitem" data-sidebar-overflow-item={item.id}>
+        <TopLevelSidebarSection
+          label={item.title}
+          stickyHeader={false}
+          collapseControl={{
+            isCollapsed: !expanded,
+            onToggleCollapsed: () => onExpandedChange(!expanded),
+          }}
+          status={!expanded ? activity : undefined}
+          actions={actions}
+          actionsOpen={isActionsOpen}
+          actionsMobileAlways
+        >
+          {children}
+        </TopLevelSidebarSection>
+      </div>
+    );
+  }
+
+  return (
+    <div role="listitem">
+      <div className={cn(SIDEBAR_HOVER_ACTIONS_ROW_CLASS, "relative")}>
+        <Button
+          type="button"
+          variant="ghost"
+          size="sm"
+          className={cn(
+            OVERFLOW_ROW_BUTTON_CLASS,
+            COARSE_POINTER_COMPACT_ROW_HEIGHT_CLASS,
+            "pr-9 max-md:pointer-coarse:pr-11",
+          )}
+          disabled={item.disabled}
+          data-sidebar-overflow-item={item.id}
+          data-sidebar-navigation-more-item={
+            testIdPrefix === "sidebar-navigation" ? item.id : undefined
+          }
+          onPointerDown={onPointerDown}
+          onClick={(event) => {
+            if (!onActivate) return;
+            onClose();
+            onActivate({ metaKey: event.metaKey, ctrlKey: event.ctrlKey });
+          }}
+        >
+          {item.icon ? (
+            <span className="flex size-4 shrink-0 items-center justify-center">
+              {item.icon}
+            </span>
+          ) : null}
+          <span className="min-w-0 flex-1 truncate text-left">
+            {item.title}
+          </span>
+          {activity}
+        </Button>
+        <div
+          data-sidebar-hover-actions-open={isActionsOpen ? "true" : undefined}
+          data-sidebar-hover-actions-mobile={
+            SIDEBAR_HOVER_ACTIONS_MOBILE_ALWAYS_VALUE
+          }
+          className={cn(
+            SIDEBAR_HOVER_ACTIONS_CLASS,
+            "absolute inset-y-0 right-0 flex items-center pointer-coarse:opacity-100 pointer-coarse:pointer-events-auto",
+          )}
+        >
+          {actions}
+        </div>
+      </div>
+    </div>
+  );
+}
+
+export function SidebarVisibilityCustomize({
+  items,
+  listLabel,
+  onActivate,
+  onDone,
+  onExit,
+  onReorder,
+  onVisibleChange,
+  testIdPrefix = "sidebar-navigation",
+  title,
+  variant,
+  visibleIds,
+}: {
+  items: readonly SidebarVisibilityItem[];
+  listLabel: string;
+  onActivate?: (
+    item: SidebarVisibilityItem,
+    event: SidebarActivationModifiers,
+  ) => void;
+  onDone: () => void;
+  onExit?: () => void;
+  onReorder: (activeId: string, overId: string) => void;
+  onVisibleChange: (id: string, visible: boolean) => void;
+  testIdPrefix?: string;
+  title: string;
+  variant: "compact" | "card";
+  visibleIds: readonly string[];
+}) {
+  const containerRef = useRef<HTMLDivElement>(null);
+  const doneButtonRef = useRef<HTMLButtonElement>(null);
+  const orderedIds = useMemo(() => items.map((item) => item.id), [items]);
+  const visibleIdSet = useMemo(() => new Set(visibleIds), [visibleIds]);
+  const handleDragEnd = useCallback(
+    (event: DragEndEvent) => {
+      if (
+        typeof event.active.id !== "string" ||
+        typeof event.over?.id !== "string"
+      )
+        return;
+      onReorder(event.active.id, event.over.id);
+    },
+    [onReorder],
+  );
+  const { dndContextProps, onClickCapture } = useSidebarReorderDnd({
+    onDragEnd: handleDragEnd,
+  });
+
+  useEffect(() => {
+    if (variant === "compact") {
+      doneButtonRef.current?.focus();
+      return;
+    }
+    containerRef.current
+      ?.querySelector<HTMLElement>("[data-sidebar-customize-launch]")
+      ?.focus();
+  }, [variant]);
+
+  const list = (
+    <div
+      role="list"
+      aria-label={listLabel}
+      className="space-y-0.5"
+      onClickCapture={onClickCapture}
+    >
+      <DndContext {...dndContextProps}>
+        <SortableContext
+          items={orderedIds}
+          strategy={verticalListSortingStrategy}
+        >
+          {items.map((item) => (
+            <SidebarCustomizeItem
+              key={item.id}
+              item={item}
+              checked={visibleIdSet.has(item.id)}
+              reorderDisabled={items.length < 2}
+              onActivate={
+                onActivate
+                  ? (event) => {
+                      onActivate(item, event);
+                      onExit?.();
+                    }
+                  : undefined
+              }
+              onCheckedChange={(checked) => onVisibleChange(item.id, checked)}
+              testIdPrefix={testIdPrefix}
+            />
+          ))}
+        </SortableContext>
+      </DndContext>
+    </div>
+  );
+
+  if (variant === "compact") {
+    return (
+      <div
+        ref={containerRef}
+        className="flex min-h-0 flex-1 flex-col"
+        data-testid={`${testIdPrefix}-customize-inline`}
+      >
+        <div className="flex shrink-0 items-center gap-1">
+          <Button
+            ref={doneButtonRef}
+            type="button"
+            variant="ghost"
+            size="icon"
+            aria-label="Back to sidebar"
+            className={cn(
+              COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
+              "shrink-0 text-muted-foreground ring-sidebar-ring hover:bg-sidebar-accent hover:text-sidebar-foreground focus-visible:ring-2",
+            )}
+            onClick={onDone}
+          >
+            <Icon name="ChevronLeft" aria-hidden="true" />
+          </Button>
+          <div
+            className={cn("min-w-0 flex-1 px-1", CHROME_SECTION_LABEL_CLASS)}
+          >
+            {title}
+          </div>
+        </div>
+        <div className="min-h-0 flex-1 overflow-y-auto pt-1">{list}</div>
+      </div>
+    );
+  }
+
+  return (
+    <div
+      ref={containerRef}
+      className="rounded-lg border border-sidebar-border/40 bg-sidebar-accent/40 p-1"
+      data-testid={`${testIdPrefix}-customize-inline`}
+      onKeyDown={(event) => {
+        if (event.key !== "Escape") return;
+        event.preventDefault();
+        onDone();
+      }}
+    >
+      <div className="flex items-center gap-1 pb-1">
+        <div
+          className={cn("min-w-0 flex-1 px-2 py-1", CHROME_SECTION_LABEL_CLASS)}
+        >
+          {title}
+        </div>
+        <Button
+          ref={doneButtonRef}
+          type="button"
+          variant="ghost"
+          size="sm"
+          className="h-6 shrink-0 px-2 text-xs text-sidebar-foreground ring-sidebar-ring hover:bg-sidebar-accent focus-visible:ring-2"
+          onClick={onDone}
+        >
+          Done
+        </Button>
+      </div>
+      {list}
+    </div>
+  );
+}
+
+function SidebarCustomizeItem({
+  checked,
+  item,
+  onActivate,
+  onCheckedChange,
+  reorderDisabled,
+  testIdPrefix,
+}: {
+  checked: boolean;
+  item: SidebarVisibilityItem;
+  onActivate?: ((event: SidebarActivationModifiers) => void) | undefined;
+  onCheckedChange: (checked: boolean) => void;
+  reorderDisabled: boolean;
+  testIdPrefix: string;
+}) {
+  const checkboxId = useId();
+  const { dragBindings, setNodeRef, style } = useSidebarSortable({
+    id: item.id,
+    disabled: reorderDisabled,
+  });
+  const isNavigation = testIdPrefix === "sidebar-navigation";
+
+  return (
+    <div
+      ref={setNodeRef}
+      style={style}
+      role="listitem"
+      className={cn(
+        "group flex min-h-7 items-center rounded-md px-1 text-xs",
+        COARSE_POINTER_COMPACT_ROW_HEIGHT_CLASS,
+        "text-sidebar-foreground hover:bg-sidebar-accent focus-within:bg-sidebar-accent",
+      )}
+      data-sidebar-customize-item={item.id}
+      data-plugin-nav-customize-item={isNavigation ? item.id : undefined}
+    >
+      <button
+        type="button"
+        ref={dragBindings.setActivatorNodeRef}
+        {...dragBindings.attributes}
+        {...dragBindings.listeners}
+        aria-label={`Reorder ${item.title}`}
+        className={cn(
+          "flex size-6 shrink-0 cursor-grab touch-none items-center justify-center rounded-sm text-subtle-foreground/60 focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring active:cursor-grabbing",
+          COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
+          "hover:text-sidebar-foreground focus-visible:text-sidebar-foreground",
+        )}
+        onClick={(event) => event.stopPropagation()}
+        data-plugin-nav-customize-drag-handle={
+          isNavigation ? item.id : undefined
+        }
+      >
+        <Icon
+          name="DragDropVertical"
+          className={COARSE_POINTER_ICON_SIZE_CLASS}
+        />
+      </button>
+      <button
+        type="button"
+        disabled={item.disabled}
+        className={cn(
+          "flex min-w-0 flex-1 cursor-pointer items-center gap-2 rounded-sm px-1 text-left outline-none disabled:cursor-default disabled:opacity-50",
+          COARSE_POINTER_COMPACT_ROW_HEIGHT_CLASS,
+        )}
+        onClick={(event) => {
+          if (onActivate)
+            onActivate({ metaKey: event.metaKey, ctrlKey: event.ctrlKey });
+          else onCheckedChange(!checked);
+        }}
+        data-sidebar-customize-launch={item.id}
+        data-sidebar-navigation-customize-launch={
+          isNavigation ? item.id : undefined
+        }
+      >
+        {item.icon ? (
+          <span className="flex size-4 shrink-0 items-center justify-center">
+            {item.icon}
+          </span>
+        ) : null}
+        <span className="min-w-0 flex-1 truncate">{item.title}</span>
+      </button>
+      <label
+        htmlFor={checkboxId}
+        className={cn(
+          COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
+          "flex shrink-0 cursor-pointer items-center justify-center",
+        )}
+        onClick={(event) => event.stopPropagation()}
+      >
+        <Checkbox
+          id={checkboxId}
+          checked={checked}
+          aria-label={`Show ${item.title} in sidebar`}
+          onCheckedChange={(nextChecked) =>
+            onCheckedChange(nextChecked === true)
+          }
+          data-plugin-nav-customize-checkbox={
+            isNavigation ? item.id : undefined
+          }
+        />
+      </label>
+    </div>
+  );
+}
diff --git a/apps/app/src/components/sidebar/SidebarWindowedItems.test.tsx b/apps/app/src/components/sidebar/SidebarWindowedItems.test.tsx
index cd3a973f00d..c245abede1a 100644
--- a/apps/app/src/components/sidebar/SidebarWindowedItems.test.tsx
+++ b/apps/app/src/components/sidebar/SidebarWindowedItems.test.tsx
@@ -2,6 +2,7 @@
 
 import { cleanup, render, screen } from "@testing-library/react";
 import { createRef } from "react";
+import { createPortal } from "react-dom";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 const sidebarMocks = vi.hoisted(() => ({
@@ -23,6 +24,7 @@ vi.mock("@/components/ui/sidebar.js", async (importOriginal) => {
 import {
   SIDEBAR_CONTENT_SELECTOR,
   SidebarContent,
+  SidebarContentElementContext,
 } from "@/components/ui/sidebar.js";
 import { SidebarWindowedItems } from "./SidebarWindowedItems";
 
@@ -214,6 +216,33 @@ describe("SidebarWindowedItems", () => {
     ).toHaveLength(0);
   });
 
+  it("keeps all overflow rows mounted when a portal opts out of sidebar windowing", () => {
+    sidebarMocks.scrollElementRef = null;
+    render(
+      <SidebarContent>
+        {createPortal(
+          <SidebarContentElementContext.Provider value={null}>
+            <SidebarWindowedItems
+              itemKeys={Array.from({ length: 40 }, (_, index) => `${index}`)}
+              estimateRows={() => 1}
+              renderItem={(index) => (
+                <span data-testid={`overflow-item-${index}`}>
+                  Thread {index}
+                </span>
+              )}
+            />
+          </SidebarContentElementContext.Provider>,
+          document.body,
+        )}
+      </SidebarContent>,
+    );
+
+    expect(screen.getAllByTestId(/^overflow-item-/)).toHaveLength(40);
+    expect(
+      document.querySelectorAll("[data-sidebar-windowed-item]:empty"),
+    ).toHaveLength(0);
+  });
+
   it("keeps promote-all for a zero-height container", () => {
     sidebarMocks.scrollElementRef = { current: null };
     const container = mountSidebarContentContainer(0);
diff --git a/apps/app/src/components/sidebar/ThreadListVisibility.tsx b/apps/app/src/components/sidebar/ThreadListVisibility.tsx
new file mode 100644
index 00000000000..f34ff7b2a99
--- /dev/null
+++ b/apps/app/src/components/sidebar/ThreadListVisibility.tsx
@@ -0,0 +1,271 @@
+import { SidebarContentElementContext } from "@/components/ui/sidebar";
+import {
+  createContext,
+  useContext,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+  type ReactNode,
+} from "react";
+import { useAtom } from "jotai";
+import type { ThreadListEntry } from "@bb/domain";
+import { getCollapsedChildActivity } from "@bb/client-core";
+import { DropdownMenuItem } from "@bb/shared-ui/dropdown-menu";
+import { ContextMenuItem } from "@bb/shared-ui/context-menu";
+import { ActionMenuSeparator } from "@/components/ui/action-menu-items";
+import { useIsCompactViewport } from "@bb/shared-ui/hooks/use-compact-viewport";
+import { usePromptDraftInputThreadIds } from "@/hooks/usePromptDraftStorage";
+import { usePluginThreadRowStatusForThreads } from "@/lib/plugin-thread-row-status";
+import { reorderStoredOrder } from "@/lib/stored-order";
+import {
+  sidebarHiddenGroupsAtom,
+  type SidebarSectionId,
+} from "./sidebarCollapsedAtoms";
+import { CollapsedThreadStatusGlyph } from "./ThreadRow";
+import {
+  SidebarMore,
+  SidebarOverflowItem,
+  SidebarVisibilityCustomize,
+  SidebarVisibilityActionContent,
+  SidebarCustomizeActionContent,
+  type SidebarVisibilityItem,
+} from "./SidebarVisibilityControls";
+
+export interface ThreadListVisibilityGroup extends SidebarVisibilityItem {
+  id: SidebarSectionId;
+  threads: readonly ThreadListEntry[];
+  renderContent: (close: () => void) => ReactNode;
+}
+
+interface ThreadListVisibilityState {
+  hiddenGroups: readonly ThreadListVisibilityGroup[];
+  hide: (id: string) => void;
+  restore: (id: string) => void;
+  customize: () => void;
+  label: string;
+}
+
+const VisibilityContext = createContext<ThreadListVisibilityState | null>(null);
+const GroupContext = createContext<string | null>(null);
+
+export function ThreadListVisibility({
+  groups,
+  order,
+  onOrderChange,
+  label,
+  children,
+}: {
+  groups: readonly ThreadListVisibilityGroup[];
+  order: readonly SidebarSectionId[];
+  onOrderChange: (order: SidebarSectionId[]) => void;
+  label: string;
+  children: ReactNode;
+}) {
+  const [hidden, setHidden] = useAtom(sidebarHiddenGroupsAtom);
+  const [customizing, setCustomizing] = useState(false);
+  const compact = useIsCompactViewport();
+  const container = useRef<HTMLDivElement>(null);
+  const focusTarget = useRef<string | null>(null);
+  const hiddenIds = useMemo(() => new Set(hidden), [hidden]);
+  const groupsById = new Map(groups.map((group) => [group.id, group]));
+  const orderedGroups = order.flatMap((id) => {
+    const group = groupsById.get(id);
+    return group ? [group] : [];
+  });
+  const setVisible = (id: string, visible: boolean) => {
+    setHidden((current) =>
+      visible
+        ? current.filter((key) => key !== id)
+        : current.includes(id)
+          ? current
+          : [...current, id],
+    );
+  };
+  useEffect(() => {
+    if (focusTarget.current === null || customizing) return;
+    const id = focusTarget.current;
+    focusTarget.current = null;
+    const frame = requestAnimationFrame(() => {
+      const root = container.current;
+      const target =
+        id === "more"
+          ? root?.querySelector<HTMLElement>(
+              '[data-testid="sidebar-thread-list-more-trigger"]',
+            )
+          : Array.from(
+              root?.querySelectorAll<HTMLElement>(
+                "[data-sidebar-visibility-group]",
+              ) ?? [],
+            )
+              .find((element) => element.dataset.sidebarVisibilityGroup === id)
+              ?.querySelector<HTMLElement>(
+                'button[aria-label$=" actions"], button',
+              );
+      (target ?? root)?.focus();
+    });
+    return () => cancelAnimationFrame(frame);
+  }, [hidden, customizing]);
+  const value: ThreadListVisibilityState = {
+    hiddenGroups: orderedGroups.filter((group) => hiddenIds.has(group.id)),
+    label,
+    customize: () => setCustomizing(true),
+    hide: (id) => {
+      focusTarget.current = "more";
+      setVisible(id, false);
+    },
+    restore: (id) => {
+      focusTarget.current = id;
+      setVisible(id, true);
+    },
+  };
+  return (
+    <VisibilityContext.Provider value={value}>
+      <div ref={container} tabIndex={-1} className="min-w-0 outline-none">
+        {customizing ? (
+          <SidebarVisibilityCustomize
+            items={orderedGroups}
+            visibleIds={orderedGroups
+              .filter((group) => !hiddenIds.has(group.id))
+              .map((group) => group.id)}
+            onVisibleChange={setVisible}
+            onReorder={(activeId, overId) => {
+              const groupIds = orderedGroups.map((group) => group.id);
+              const next = reorderStoredOrder({
+                activeId,
+                overId,
+                order: groupIds,
+                visibleIds: groupIds,
+              });
+              if (next) onOrderChange(next);
+            }}
+            onDone={() => {
+              focusTarget.current = "more";
+              setCustomizing(false);
+            }}
+            title="Customize list"
+            listLabel={label}
+            variant={compact ? "compact" : "card"}
+            testIdPrefix="sidebar-thread-list"
+          />
+        ) : (
+          children
+        )}
+      </div>
+    </VisibilityContext.Provider>
+  );
+}
+
+export function ThreadListVisibilityGroupScope({
+  id,
+  children,
+}: {
+  id: string;
+  children: ReactNode;
+}) {
+  return (
+    <GroupContext.Provider value={id}>
+      <div data-sidebar-visibility-group={id}>{children}</div>
+    </GroupContext.Provider>
+  );
+}
+
+export function ThreadListVisibilityMenuItems({
+  surface = "dropdown",
+}: {
+  surface?: "dropdown" | "context";
+}) {
+  const state = useContext(VisibilityContext);
+  const id = useContext(GroupContext);
+  if (!state) return null;
+  const Item = surface === "context" ? ContextMenuItem : DropdownMenuItem;
+  return (
+    <>
+      <ActionMenuSeparator surface={surface} />
+      {id !== null && (
+        <Item onSelect={() => state.hide(id)}>
+          <SidebarVisibilityActionContent visible label="Hide from list" />
+        </Item>
+      )}
+      <Item onSelect={state.customize}>
+        <SidebarCustomizeActionContent label="Customize list" />
+      </Item>
+    </>
+  );
+}
+
+function GroupActivity({ threads }: { threads: readonly ThreadListEntry[] }) {
+  const drafts = usePromptDraftInputThreadIds(threads);
+  const pluginStatus = usePluginThreadRowStatusForThreads(threads);
+  return (
+    <CollapsedThreadStatusGlyph
+      activity={getCollapsedChildActivity(threads, drafts)}
+      pluginStatus={pluginStatus}
+    />
+  );
+}
+
+function HiddenGroup({
+  group,
+  close,
+  restore,
+}: {
+  group: ThreadListVisibilityGroup;
+  close: () => void;
+  restore: (id: string) => void;
+}) {
+  const [expanded, setExpanded] = useState(true);
+  return (
+    <SidebarOverflowItem
+      item={group}
+      onClose={close}
+      onAddToSidebar={restore}
+      expanded={expanded}
+      onExpandedChange={setExpanded}
+      activity={<GroupActivity threads={group.threads} />}
+      testIdPrefix="sidebar-thread-list"
+    >
+      {group.renderContent(close)}
+    </SidebarOverflowItem>
+  );
+}
+
+export function ThreadListMore() {
+  const state = useContext(VisibilityContext);
+  if (!state || state.hiddenGroups.length === 0) return null;
+  const groups = state.hiddenGroups;
+  const threads = [
+    ...new Map(
+      groups
+        .flatMap((group) => group.threads)
+        .map((thread) => [thread.id, thread]),
+    ).values(),
+  ];
+  return (
+    <div className="mt-4">
+      <SidebarMore
+        ariaLabel={`More ${state.label.toLowerCase()}`}
+        listLabel={`Hidden ${state.label.toLowerCase()}`}
+        customizeLabel="Customize list"
+        onCustomize={state.customize}
+        activity={<GroupActivity threads={threads} />}
+        testIdPrefix="sidebar-thread-list"
+      >
+        {(close) => (
+          <SidebarContentElementContext.Provider value={null}>
+            <div data-sidebar-overflow="true">
+              {groups.map((group) => (
+                <HiddenGroup
+                  key={group.id}
+                  group={group}
+                  close={close}
+                  restore={state.restore}
+                />
+              ))}
+            </div>
+          </SidebarContentElementContext.Provider>
+        )}
+      </SidebarMore>
+    </div>
+  );
+}
diff --git a/apps/app/src/components/sidebar/ThreadRow.tsx b/apps/app/src/components/sidebar/ThreadRow.tsx
index b5d5f7c23ab..d8c677e04dd 100644
--- a/apps/app/src/components/sidebar/ThreadRow.tsx
+++ b/apps/app/src/components/sidebar/ThreadRow.tsx
@@ -389,7 +389,7 @@ function ThreadRowComponent({
   );
   const rowClassName = cn(
     SIDEBAR_HOVER_ACTIONS_ROW_CLASS,
-    "group/thread-row",
+    "group/thread-row cursor-pointer",
     SIDEBAR_ROW_BASE_CLASS,
     LIST_HOVER_TRANSITION,
     parentOptions?.stickyLevel === undefined && "relative",
diff --git a/apps/app/src/components/sidebar/sidebarCollapsedAtoms.ts b/apps/app/src/components/sidebar/sidebarCollapsedAtoms.ts
index 4cebed98a60..59d07b1a7c0 100644
--- a/apps/app/src/components/sidebar/sidebarCollapsedAtoms.ts
+++ b/apps/app/src/components/sidebar/sidebarCollapsedAtoms.ts
@@ -40,6 +40,10 @@ export const sidebarMachineSectionOrderAtom = createSyncedPreferenceAtom(
   "sidebar.machineSectionOrder",
 );
 
+export const sidebarHiddenGroupsAtom = createSyncedPreferenceAtom(
+  "sidebar.hiddenGroups",
+);
+
 export const sidebarOrganizationModeAtom = createSyncedPreferenceAtom(
   "sidebar.organizationMode",
 );
diff --git a/apps/app/src/components/sidebar/sidebarRowClasses.ts b/apps/app/src/components/sidebar/sidebarRowClasses.ts
index ff5027158d1..68bf4dd0b06 100644
--- a/apps/app/src/components/sidebar/sidebarRowClasses.ts
+++ b/apps/app/src/components/sidebar/sidebarRowClasses.ts
@@ -1,4 +1,6 @@
+import { LIST_HOVER_TRANSITION } from "@bb/shared-ui/motion";
 import {
+  COARSE_POINTER_ROW_HEIGHT_CLASS,
   COARSE_POINTER_CHILD_ICON_BUTTON_CLASS,
   COARSE_POINTER_DOT_SIZE_CLASS,
   COARSE_POINTER_ROW_ACTION_SIZE_CLASS,
@@ -74,6 +76,7 @@ export const SIDEBAR_ROW_OPEN_IN_SPLIT_STATE_CLASS =
   "bb-sidebar-open-in-split-row";
 
 export const SIDEBAR_FOOTER_ACTION_CLASS = cn(
+  COARSE_POINTER_ROW_HEIGHT_CLASS,
   COARSE_POINTER_CHILD_ICON_BUTTON_CLASS,
   "text-muted-foreground hover:text-sidebar-foreground [&>[data-icon-root]]:opacity-80",
 );
@@ -83,3 +86,12 @@ export const SIDEBAR_MORE_ACTION_TRIGGER_CLASS =
 
 export const SIDEBAR_PROJECT_GROUP_LINE_CLASS =
   "before:pointer-events-none before:absolute before:bottom-0 before:left-4 before:top-0 before:z-[45] before:w-px before:bg-border-hairline before:opacity-70 before:content-[''] max-md:pointer-coarse:before:left-5";
+
+export const PROJECT_LIST_ACTION_BUTTON_CLASS = cn(
+  SIDEBAR_ROW_BASE_CLASS,
+  LIST_HOVER_TRANSITION,
+  SIDEBAR_STANDARD_ROW_PADDING_CLASS,
+  SIDEBAR_ROW_INTERACTIVE_STATE_CLASS,
+  COARSE_POINTER_ROW_HEIGHT_CLASS,
+  "min-w-0 cursor-pointer justify-start overflow-hidden font-normal ring-sidebar-ring focus-visible:ring-2 disabled:cursor-default disabled:opacity-70 max-md:pointer-coarse:[&_[data-icon-root]]:size-5",
+);
diff --git a/apps/app/src/components/sidebar/sidebarThreadShortcuts.test.ts b/apps/app/src/components/sidebar/sidebarThreadShortcuts.test.ts
index ead212f1a9b..c15aa5d0678 100644
--- a/apps/app/src/components/sidebar/sidebarThreadShortcuts.test.ts
+++ b/apps/app/src/components/sidebar/sidebarThreadShortcuts.test.ts
@@ -68,4 +68,32 @@ describe("sidebar thread shortcuts", () => {
       getSidebarThreadShortcutTargets(root).map((target) => target.threadId),
     ).toEqual(["thr_a", "thr_d"]);
   });
+
+  it("excludes More menu rows and placeholders from both shortcut orders", () => {
+    const root = document.createElement("aside");
+    appendShortcutTarget(root, "thr_a");
+    const overflow = document.createElement("div");
+    overflow.dataset.sidebarOverflow = "true";
+    root.append(overflow);
+    const nestedGroup = document.createElement("div");
+    overflow.append(nestedGroup);
+    appendShortcutTarget(nestedGroup, "thr_hidden");
+    const placeholder = document.createElement("div");
+    placeholder.setAttribute(
+      "data-sidebar-windowed-nav",
+      "thr_hidden_windowed:proj_1",
+    );
+    nestedGroup.append(placeholder);
+    appendShortcutTarget(root, "thr_b");
+
+    for (const targets of [
+      getSidebarThreadShortcutTargets(root),
+      getSidebarThreadNavigationTargets(root),
+    ]) {
+      expect(targets.map(({ threadId, key }) => ({ threadId, key }))).toEqual([
+        { threadId: "thr_a", key: "1" },
+        { threadId: "thr_b", key: "2" },
+      ]);
+    }
+  });
 });
diff --git a/apps/app/src/components/sidebar/sidebarThreadShortcuts.ts b/apps/app/src/components/sidebar/sidebarThreadShortcuts.ts
index 6ce8380ae5a..7af399a3e87 100644
--- a/apps/app/src/components/sidebar/sidebarThreadShortcuts.ts
+++ b/apps/app/src/components/sidebar/sidebarThreadShortcuts.ts
@@ -55,6 +55,9 @@ function collectSidebarThreadTargets(
   const targets: SidebarThreadShortcutTarget[] = [];
 
   for (const element of elements) {
+    if (element.closest("[data-sidebar-overflow='true']")) {
+      continue;
+    }
     if (element instanceof HTMLAnchorElement) {
       const threadId = element.dataset.sidebarThreadId;
       if (!threadId) {
diff --git a/apps/app/src/components/sidebar/useSidebarModeSectionOrder.test.tsx b/apps/app/src/components/sidebar/useSidebarModeSectionOrder.test.tsx
new file mode 100644
index 00000000000..8ce04fbe5bf
--- /dev/null
+++ b/apps/app/src/components/sidebar/useSidebarModeSectionOrder.test.tsx
@@ -0,0 +1,112 @@
+// @vitest-environment jsdom
+
+import type { ReactNode } from "react";
+import { act, cleanup, renderHook } from "@testing-library/react";
+import { createStore, Provider } from "jotai";
+import { afterEach, describe, expect, it } from "vitest";
+import {
+  sidebarHiddenGroupsAtom,
+  sidebarManualSectionOrderAtom,
+  sidebarSectionOrderAtom,
+  type SidebarSectionId,
+} from "./sidebarCollapsedAtoms";
+import { useSidebarModeSectionOrder } from "./useSidebarModeSectionOrder";
+
+afterEach(cleanup);
+
+describe("sidebar group visibility and ordering", () => {
+  it("retains hidden, pinned, and disconnected slots when visible groups move", () => {
+    const store = createStore();
+    store.set(sidebarSectionOrderAtom, [
+      "pinned",
+      "project:a",
+      "project:b",
+      "project:offline",
+      "project:c",
+      "threads",
+    ]);
+    store.set(sidebarHiddenGroupsAtom, ["project:b"]);
+    const { result, rerender } = renderHook(
+      ({ entitySectionIds }: { entitySectionIds: SidebarSectionId[] }) =>
+        useSidebarModeSectionOrder({
+          mode: "project",
+          entitySectionIds,
+          showPinnedSection: false,
+        }),
+      {
+        initialProps: {
+          entitySectionIds: ["project:a", "project:b", "project:c"],
+        },
+        wrapper: ({ children }: { children: ReactNode }) => (
+          <Provider store={store}>{children}</Provider>
+        ),
+      },
+    );
+
+    expect(result.current.order).toEqual(["project:a", "project:c", "threads"]);
+
+    act(() =>
+      result.current.onOrderChange(["project:c", "project:a", "threads"]),
+    );
+    expect(store.get(sidebarSectionOrderAtom)).toEqual([
+      "pinned",
+      "project:c",
+      "project:b",
+      "project:offline",
+      "project:a",
+      "threads",
+    ]);
+    act(() => store.set(sidebarHiddenGroupsAtom, []));
+    rerender({
+      entitySectionIds: [
+        "project:a",
+        "project:b",
+        "project:c",
+        "project:offline",
+      ],
+    });
+    expect(result.current.order).toEqual([
+      "project:c",
+      "project:b",
+      "project:offline",
+      "project:a",
+      "threads",
+    ]);
+  });
+
+  it("lets customization move hidden groups without making them visible", () => {
+    const store = createStore();
+    store.set(sidebarManualSectionOrderAtom, [
+      "pinned",
+      "section:a",
+      "section:b",
+      "threads",
+    ]);
+    store.set(sidebarHiddenGroupsAtom, ["section:b"]);
+    const { result } = renderHook(
+      () =>
+        useSidebarModeSectionOrder({
+          mode: "chronological",
+          entitySectionIds: ["section:a", "section:b"],
+          showPinnedSection: false,
+        }),
+      {
+        wrapper: ({ children }: { children: ReactNode }) => (
+          <Provider store={store}>{children}</Provider>
+        ),
+      },
+    );
+
+    act(() => result.current.onOrderChange(["section:b", "section:a"]));
+    expect(store.get(sidebarManualSectionOrderAtom)).toEqual([
+      "pinned",
+      "section:b",
+      "section:a",
+      "threads",
+    ]);
+    expect(result.current.order).toEqual(["section:a", "threads"]);
+    expect(store.get(sidebarHiddenGroupsAtom)).toEqual(["section:b"]);
+    act(() => store.set(sidebarHiddenGroupsAtom, []));
+    expect(result.current.order).toEqual(["section:b", "section:a", "threads"]);
+  });
+});
diff --git a/apps/app/src/components/sidebar/useSidebarModeSectionOrder.ts b/apps/app/src/components/sidebar/useSidebarModeSectionOrder.ts
index 77a0507a360..1dad9c24e91 100644
--- a/apps/app/src/components/sidebar/useSidebarModeSectionOrder.ts
+++ b/apps/app/src/components/sidebar/useSidebarModeSectionOrder.ts
@@ -1,6 +1,8 @@
 import { useCallback, useMemo } from "react";
-import { useAtom } from "jotai";
+import { useAtom, useAtomValue } from "jotai";
+import { reorderStoredOrder } from "@/lib/stored-order";
 import {
+  sidebarHiddenGroupsAtom,
   sidebarManualSectionOrderAtom,
   sidebarMachineSectionOrderAtom,
   sidebarSectionOrderAtom,
@@ -8,6 +10,7 @@ import {
   type SidebarSectionId,
 } from "./sidebarCollapsedAtoms";
 import {
+  buildSidebarEntitySectionId,
   normalizeSidebarSectionOrder,
   type LegacySidebarEntityAnchor,
 } from "@bb/client-core";
@@ -16,19 +19,23 @@ const MODE_SECTION_ORDER_CONFIG: Record<
   SidebarOrganizationMode,
   {
     atom: typeof sidebarSectionOrderAtom;
+    entityKind: "project" | "section" | "machine";
     legacyEntityAnchor: LegacySidebarEntityAnchor;
   }
 > = {
   project: {
     atom: sidebarSectionOrderAtom,
+    entityKind: "project",
     legacyEntityAnchor: "projects",
   },
   chronological: {
     atom: sidebarManualSectionOrderAtom,
+    entityKind: "section",
     legacyEntityAnchor: "sections",
   },
   machine: {
     atom: sidebarMachineSectionOrderAtom,
+    entityKind: "machine",
     legacyEntityAnchor: "machines",
   },
 };
@@ -54,6 +61,11 @@ export function useSidebarModeSectionOrder({
 }: UseSidebarModeSectionOrderArgs): UseSidebarModeSectionOrderResult {
   const config = MODE_SECTION_ORDER_CONFIG[mode];
   const [storedOrder, setStoredOrder] = useAtom(config.atom);
+  const hiddenGroups = useAtomValue(sidebarHiddenGroupsAtom);
+  const hiddenGroupIds = useMemo(
+    () => new Set<string>(hiddenGroups),
+    [hiddenGroups],
+  );
   const persistedOrder = useMemo(
     () =>
       normalizeSidebarSectionOrder({
@@ -73,14 +85,42 @@ export function useSidebarModeSectionOrder({
   const order = useMemo(
     () =>
       persistedOrder.filter(
-        (sectionId) => sectionId !== "pinned" || showPinnedSection,
+        (sectionId) =>
+          (sectionId !== "pinned" || showPinnedSection) &&
+          !hiddenGroupIds.has(sectionId),
       ),
-    [persistedOrder, showPinnedSection],
+    [hiddenGroupIds, persistedOrder, showPinnedSection],
   );
   const onOrderChange = useCallback(
-    (nextOrder: SidebarSectionId[]) => setStoredOrder(nextOrder),
-    [setStoredOrder],
+    (nextOrder: SidebarSectionId[]) => {
+      const nextIds = new Set(nextOrder);
+      setStoredOrder((current) => {
+        const storedEntityIds = current
+          .filter((id) => id.startsWith(`${config.entityKind}:`))
+          .map((id) =>
+            buildSidebarEntitySectionId(
+              config.entityKind,
+              id.slice(config.entityKind.length + 1),
+            ),
+          );
+        const fullOrder = normalizeSidebarSectionOrder({
+          storedOrder: current,
+          entitySectionIds: [...entitySectionIds, ...storedEntityIds],
+          legacyEntityAnchor: config.legacyEntityAnchor,
+          hasPinnedSection: true,
+          hasThreadsSection:
+            hasThreadsSection !== false || current.includes("threads"),
+        });
+        return (
+          reorderStoredOrder({
+            order: fullOrder,
+            visibleIds: fullOrder.filter((id) => nextIds.has(id)),
+            nextVisibleIds: nextOrder,
+          }) ?? current
+        );
+      });
+    },
+    [config, entitySectionIds, hasThreadsSection, setStoredOrder],
   );
-
   return { onOrderChange, order, persistedOrder };
 }
diff --git a/apps/app/src/components/thread/ThreadActionsMenu.test.tsx b/apps/app/src/components/thread/ThreadActionsMenu.test.tsx
index 61a89024053..2636a2dbddc 100644
--- a/apps/app/src/components/thread/ThreadActionsMenu.test.tsx
+++ b/apps/app/src/components/thread/ThreadActionsMenu.test.tsx
@@ -3,13 +3,22 @@
 import { cleanup, fireEvent, render, screen } from "@testing-library/react";
 import { CompactViewportOverrideProvider } from "@bb/shared-ui/hooks/use-compact-viewport";
 import type { ReactNode } from "react";
+import { createStore, Provider } from "jotai";
 import { afterEach, describe, expect, it, vi } from "vitest";
+import {
+  sidebarHiddenGroupsAtom,
+  sidebarManualSectionOrderAtom,
+  sidebarOrganizationModeAtom,
+} from "@/components/sidebar/sidebarCollapsedAtoms";
 import { makeThreadListEntry } from "../../../.ladle/story-fixtures";
 import {
   ThreadActionsContextMenu,
   ThreadActionsMenu,
 } from "./ThreadActionsMenu";
-import { ThreadSectionMoveProvider } from "./ThreadSectionMoveProvider";
+import {
+  AppThreadSectionMoveProvider,
+  ThreadSectionMoveProvider,
+} from "./ThreadSectionMoveProvider";
 
 const moveThreadToSection = vi.hoisted(() => vi.fn());
 const copyToClipboardWithToast = vi.hoisted(() => vi.fn());
@@ -112,6 +121,53 @@ describe("ThreadActionsMenu", () => {
 });
 
 describe("ThreadActionsMenu section moves", () => {
+  it("keeps hidden sections selectable without restoring them to the list", async () => {
+    const store = createStore();
+    const hidden = ["section:sec_planning", "section:sec_building"];
+    const order = [
+      "section:sec_building",
+      "pinned",
+      "threads",
+      "section:sec_planning",
+    ];
+    store.set(sidebarOrganizationModeAtom, "chronological");
+    store.set(sidebarHiddenGroupsAtom, hidden);
+    store.set(sidebarManualSectionOrderAtom, order);
+    const unfiledThread = makeThreadListEntry({
+      ...thread,
+      parentThreadId: null,
+      sectionId: null,
+    });
+    renderWide(
+      <Provider store={store}>
+        <AppThreadSectionMoveProvider
+          sections={[
+            { id: "sec_planning", name: "Planning" },
+            { id: "sec_building", name: "Building" },
+          ]}
+        >
+          <ThreadActionsMenu thread={unfiledThread} />
+        </AppThreadSectionMoveProvider>
+      </Provider>,
+      false,
+    );
+
+    fireEvent.pointerDown(
+      screen.getByRole("button", { name: "Thread actions" }),
+      { button: 0 },
+    );
+    const building = await openMoveSubmenu();
+    expect(screen.getByRole("menuitem", { name: "Planning" })).not.toBeNull();
+    fireEvent.click(building);
+
+    expect(moveThreadToSection).toHaveBeenCalledWith({
+      thread: unfiledThread,
+      sectionId: "sec_building",
+    });
+    expect(store.get(sidebarHiddenGroupsAtom)).toEqual(hidden);
+    expect(store.get(sidebarManualSectionOrderAtom)).toEqual(order);
+  });
+
   it("moves from the overflow menu and indicates the current section", async () => {
     renderWide(<ThreadActionsMenu thread={thread} />);
 
diff --git a/apps/app/src/components/thread/ThreadSectionMoveProvider.tsx b/apps/app/src/components/thread/ThreadSectionMoveProvider.tsx
index b4f3b079162..6b97c7ee624 100644
--- a/apps/app/src/components/thread/ThreadSectionMoveProvider.tsx
+++ b/apps/app/src/components/thread/ThreadSectionMoveProvider.tsx
@@ -68,7 +68,7 @@ export function AppThreadSectionMoveProvider({
       ),
     [sections],
   );
-  const { order } = useSidebarModeSectionOrder({
+  const { persistedOrder: order } = useSidebarModeSectionOrder({
     mode: "chronological",
     entitySectionIds,
     showPinnedSection: false,
diff --git a/apps/app/src/components/ui/sidebar.tsx b/apps/app/src/components/ui/sidebar.tsx
index 89a301a2d62..107240993c9 100644
--- a/apps/app/src/components/ui/sidebar.tsx
+++ b/apps/app/src/components/ui/sidebar.tsx
@@ -1816,4 +1816,5 @@ export {
   useOptionalIsSidebarShowing,
   useSidebar,
   useSidebarContentElementRef,
+  SidebarContentElementContext,
 };
diff --git a/apps/app/src/components/ui/theme.css b/apps/app/src/components/ui/theme.css
index b44ea1dea83..2426b2a9436 100644
--- a/apps/app/src/components/ui/theme.css
+++ b/apps/app/src/components/ui/theme.css
@@ -200,6 +200,10 @@
     --bb-sidebar-sticky-stack-padding-top: 0.5rem;
   }
 
+  [data-sidebar-sticky-tier] {
+    position: relative;
+  }
+
   [data-sidebar-sticky-stack] [data-sidebar-sticky-tier] {
     position: sticky;
     top: var(--bb-sidebar-sticky-tier-top);
diff --git a/apps/app/src/lib/stored-order.test.ts b/apps/app/src/lib/stored-order.test.ts
index 385dcabda51..ddbce15d029 100644
--- a/apps/app/src/lib/stored-order.test.ts
+++ b/apps/app/src/lib/stored-order.test.ts
@@ -75,6 +75,33 @@ describe("reorderStoredOrder", () => {
     ).toEqual(["side-chat", "quickstart", "browser"]);
   });
 
+  it("applies a full visible order while retaining hidden and absent slots", () => {
+    expect(
+      reorderStoredOrder({
+        order: ["pinned", "browser", "quickstart", "terminal", "side-chat"],
+        visibleIds: ["browser", "terminal", "side-chat"],
+        nextVisibleIds: ["side-chat", "browser", "terminal"],
+      }),
+    ).toEqual(["pinned", "side-chat", "quickstart", "browser", "terminal"]);
+  });
+
+  it.each([
+    { nextVisibleIds: ["browser"] },
+    { nextVisibleIds: ["browser", "browser"] },
+    { nextVisibleIds: ["browser", "unknown"] },
+  ])(
+    "rejects a replacement order with changed membership: $nextVisibleIds",
+    ({ nextVisibleIds }) => {
+      expect(
+        reorderStoredOrder({
+          order: ["browser", "quickstart", "terminal"],
+          visibleIds: ["browser", "terminal"],
+          nextVisibleIds,
+        }),
+      ).toBeNull();
+    },
+  );
+
   it("declines a drag that ends where it started or outside the list", () => {
     expect(
       reorderStoredOrder({
diff --git a/apps/app/src/lib/stored-order.ts b/apps/app/src/lib/stored-order.ts
index 759f5837f22..b0a43312658 100644
--- a/apps/app/src/lib/stored-order.ts
+++ b/apps/app/src/lib/stored-order.ts
@@ -38,25 +38,36 @@ export function arrangeByStoredOrder<TItem>({
   return { ordered, normalizedOrder };
 }
 
-interface ReorderStoredOrderArgs {
-  activeId: string;
-  overId: string;
-  order: readonly string[];
-  visibleIds: readonly string[];
-}
-
-export function reorderStoredOrder({
-  activeId,
-  overId,
-  order,
-  visibleIds,
-}: ReorderStoredOrderArgs): string[] | null {
-  const from = visibleIds.indexOf(activeId);
-  const to = visibleIds.indexOf(overId);
-  if (from === -1 || to === -1 || from === to) return null;
+type ReorderStoredOrderArgs<TId extends string> = {
+  order: readonly TId[];
+  visibleIds: readonly TId[];
+} & (
+  | { activeId: string; overId: string }
+  | { nextVisibleIds: readonly TId[] }
+);
 
-  const nextVisible = arrayMove(visibleIds, from, to);
+export function reorderStoredOrder<TId extends string>(
+  args: ReorderStoredOrderArgs<TId>,
+): TId[] | null {
+  const { order, visibleIds } = args;
   const visibleSet = new Set(visibleIds);
+  let nextVisible: readonly TId[];
+  if ("nextVisibleIds" in args) {
+    nextVisible = args.nextVisibleIds;
+    if (
+      nextVisible.length !== visibleIds.length ||
+      new Set(nextVisible).size !== visibleSet.size ||
+      nextVisible.some((id) => !visibleSet.has(id)) ||
+      haveSameOrder(nextVisible, visibleIds)
+    ) {
+      return null;
+    }
+  } else {
+    const from = visibleIds.findIndex((id) => id === args.activeId);
+    const to = visibleIds.findIndex((id) => id === args.overId);
+    if (from === -1 || to === -1 || from === to) return null;
+    nextVisible = arrayMove(visibleIds, from, to);
+  }
   let cursor = 0;
   return order.map((id) => (visibleSet.has(id) ? nextVisible[cursor++] : id));
 }
diff --git a/apps/server/test/public/public-ui-preferences.test.ts b/apps/server/test/public/public-ui-preferences.test.ts
index f1a52b13beb..e3b7808ea0d 100644
--- a/apps/server/test/public/public-ui-preferences.test.ts
+++ b/apps/server/test/public/public-ui-preferences.test.ts
@@ -29,6 +29,90 @@ async function resetPreference(
 }
 
 describe("public ui preferences", () => {
+  it("persists hidden groups across organizations without changing saved order", async () => {
+    await withTestHarness(async (harness) => {
+      const key = "sidebar.hiddenGroups";
+      const order = ["project:proj_active", "project:proj_hidden", "threads"];
+      expect(await readJson(await listPreferences(harness))).toMatchObject({
+        preferences: { [key]: { revision: 0, value: [] } },
+      });
+      expect(
+        (
+          await putPreference(harness, "sidebar.sectionOrder", {
+            expectedRevision: 0,
+            value: order,
+          })
+        ).status,
+      ).toBe(200);
+      const hidden = [
+        "project:proj_hidden",
+        "section:section_review",
+        "machine:host_offline",
+        "project:proj_deleted",
+      ];
+      const saved = await putPreference(harness, key, {
+        expectedRevision: 0,
+        value: [...hidden, hidden[0]],
+      });
+      expect(saved.status).toBe(200);
+      expect(await readJson(saved)).toMatchObject({
+        revision: 1,
+        value: hidden,
+      });
+      expect(await readJson(await listPreferences(harness))).toMatchObject({
+        preferences: { [key]: { revision: 1, value: hidden } },
+      });
+      const replaced = await putPreference(harness, key, {
+        expectedRevision: 1,
+        value: ["section:section_review"],
+      });
+      expect(replaced.status).toBe(200);
+      expect(await readJson(replaced)).toMatchObject({
+        revision: 2,
+        value: ["section:section_review"],
+      });
+      expect(await readJson(await resetPreference(harness, key))).toMatchObject({
+        revision: 3,
+        value: [],
+      });
+      expect(await readJson(await listPreferences(harness))).toMatchObject({
+        preferences: {
+          [key]: { revision: 3, value: [] },
+          "sidebar.sectionOrder": { revision: 1, value: order },
+        },
+      });
+    });
+  });
+
+  it("rejects built-in, malformed, and oversized hidden-group lists", async () => {
+    await withTestHarness(async (harness) => {
+      const key = "sidebar.hiddenGroups";
+      const invalidValues = [
+        null,
+        "project:proj_hidden",
+        [12],
+        ["pinned"],
+        ["threads"],
+        ["environment:env_1"],
+        ["project:"],
+        ["section:"],
+        ["machine:"],
+        ["project: "],
+        [`project:${"x".repeat(1_024)}`],
+        Array.from({ length: 10_001 }, () => "project:proj_hidden"),
+      ];
+      for (const value of invalidValues) {
+        expect(
+          (await putPreference(harness, key, { expectedRevision: 0, value }))
+            .status,
+        ).toBe(400);
+      }
+      expect(await readJson(await listPreferences(harness))).toMatchObject({
+        preferences: { [key]: { revision: 0, value: [] } },
+      });
+    });
+  });
+
   it("retains unavailable footer IDs and rejects malformed footer preferences", async () => {
     await withTestHarness(async (harness) => {
       for (const key of ["sidebar.footerOrder", "sidebar.hiddenFooterItems"]) {
diff --git a/docs/configuration.md b/docs/configuration.md
index 2c7d83de432..5673e0162f9 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -686,6 +686,7 @@ client wrote first, so a stale window cannot silently clobber a newer value.
 | `sidebar.sectionOrder`            | Section id list for **By project**                  |
 | `sidebar.manualSectionOrder`      | Section id list for **Manually**                    |
 | `sidebar.machineSectionOrder`     | Section id list for **By machine**                  |
+| `sidebar.hiddenGroups`            | Project, custom section, and machine ids moved into More |
 | `sidebar.collapsedSections`       | Collapsed built-in sections (`pinned`, `threads`)   |
 | `sidebar.collapsedProjects`       | Collapsed project ids                               |
 | `sidebar.collapsedThreads`        | Thread ids whose children are collapsed             |
@@ -744,6 +745,35 @@ value. A change on one device reaches every other connected window through the
 Sidebar width and open state stay in the browser because they depend on the
 window size.
 
+### Thread-list visibility
+
+Choose **Hide from list** in a project, custom section, or machine's menu to
+move it into **More**. Its menu in More offers **Add to sidebar** to restore it.
+**Customize list** manages visibility and order for the current
+organization. Hiding a group preserves its threads, saved order, and collapse
+state; pinned threads stay in Pinned. Hidden work remains reachable through More,
+search, and direct links. More shows activity without automatically restoring
+hidden groups.
+
+`sidebar.hiddenGroups` defaults to `[]` and accepts `project:<projectId>`,
+`section:<sectionId>`, and `machine:<hostId>` keys (`machine:no-machine` for the
+unassigned machine group). Each organization uses only its matching keys.
+Built-in Pinned and Threads sections cannot be hidden. Duplicate keys are
+deduplicated; unavailable IDs are retained without creating sidebar rows, and
+new groups default to visible.
+
+```sh
+bb settings ui get sidebar.hiddenGroups
+bb settings ui set sidebar.hiddenGroups '["project:proj_example","section:sec_example"]'
+bb settings ui reset sidebar.hiddenGroups
+```
+
+`set` replaces the complete list across organizations, so include any existing
+keys you want to keep hidden. `reset` restores the default empty list and shows
+every group. SDK callers use `sdk.system.uiPreferences.list()` for the current
+value and revision, `.set({ key: "sidebar.hiddenGroups", value, expectedRevision })`
+to replace the list, and `.reset({ key: "sidebar.hiddenGroups" })` to show all.
+
 ### Sidebar footer
 
 Settings → Appearance → Sidebar footer lets users reorder and hide built-in and
diff --git a/packages/domain/src/plugin-sdk-version.ts b/packages/domain/src/plugin-sdk-version.ts
index e6dc0e7cdde..3d1be9edfb6 100644
--- a/packages/domain/src/plugin-sdk-version.ts
+++ b/packages/domain/src/plugin-sdk-version.ts
@@ -1,3 +1,3 @@
-export const PLUGIN_SDK_VERSION = "0.4.107";
+export const PLUGIN_SDK_VERSION = "0.4.108";
 
 export const PLUGIN_SDK_MAJOR = Number(PLUGIN_SDK_VERSION.split(".", 1)[0]);
diff --git a/packages/domain/src/ui-preferences.ts b/packages/domain/src/ui-preferences.ts
index 5ec43f9aff4..fe6077bfa43 100644
--- a/packages/domain/src/ui-preferences.ts
+++ b/packages/domain/src/ui-preferences.ts
@@ -34,6 +34,10 @@ const uiPreferenceStringSchema = z
 const uiPreferenceStringListSchema = z
   .array(uiPreferenceStringSchema)
   .max(UI_PREFERENCE_LIST_MAX_LENGTH);
+const sidebarHiddenGroupsSchema = z
+  .array(uiPreferenceStringSchema.regex(/^(project|section|machine):\S+$/))
+  .max(UI_PREFERENCE_LIST_MAX_LENGTH)
+  .transform((value) => [...new Set(value)]);
 
 export const UI_PREFERENCE_KEYS = [
   "sidebar.organizationMode",
@@ -43,6 +47,7 @@ export const UI_PREFERENCE_KEYS = [
   "sidebar.sectionOrder",
   "sidebar.manualSectionOrder",
   "sidebar.machineSectionOrder",
+  "sidebar.hiddenGroups",
   "sidebar.collapsedSections",
   "sidebar.collapsedProjects",
   "sidebar.collapsedThreads",
@@ -113,6 +118,11 @@ export const uiPreferenceDefinitions = {
     ["pinned", "machines", "threads"],
     "Top-level section order when the sidebar is organized by machine.",
   ),
+  "sidebar.hiddenGroups": defineUiPreference(
+    sidebarHiddenGroupsSchema,
+    [],
+    "Project, custom section, and machine groups moved into More, using project:<id>, section:<id>, or machine:<id>. Setting this list replaces the hidden groups across all sidebar organizations; reset shows every group.",
+  ),
   "sidebar.collapsedSections": defineUiPreference(
     z
       .array(collapsibleSidebarSectionIdSchema)
diff --git a/packages/plugin-sdk/package.json b/packages/plugin-sdk/package.json
index 28fd6a30e58..4899b3afe66 100644
--- a/packages/plugin-sdk/package.json
+++ b/packages/plugin-sdk/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@get-bb/plugin-sdk",
-  "version": "0.4.107",
+  "version": "0.4.108",
   "homepage": "https://github.com/get-bb/bb#readme",
   "bugs": {
     "url": "https://github.com/get-bb/bb/issues"
diff --git a/packages/templates/src/templates/bb-guide-customization.md b/packages/templates/src/templates/bb-guide-customization.md
index 800584f7c3a..8b3d4355454 100644
--- a/packages/templates/src/templates/bb-guide-customization.md
+++ b/packages/templates/src/templates/bb-guide-customization.md
@@ -265,9 +265,9 @@ Server-backed sidebar preferences
 Sidebar layout lives on the server in a keyed, revisioned registry so every
 window, device, and the CLI share it: organization mode, chronological sort,
 section orders, collapsed rows and sections, navigation entry order and
-visibility, and the navigation and thread-list provider pickers. The sidebar
-waits for them alongside the project list, and an upgrade uploads the old
-browser-stored layout once.
+visibility, hidden thread-list groups, and the navigation and thread-list
+provider pickers. The sidebar waits for them alongside the project list, and
+an upgrade uploads the old browser-stored layout once.
 
   bb settings ui list [--json]
   bb settings ui get <key> [--json]
@@ -295,6 +295,29 @@ Sort by selects a field, and selecting it again reverses its arrow/direction.
 The default preserves each field's original order (newest first for dates,
 A–Z for titles). For example: `bb settings ui set sidebar.sortDirection ascending`.
 
+Thread-list visibility
+
+A project, custom section, or machine's menu offers Hide from list; its menu
+inside More offers Add to sidebar. Customize list manages visibility and
+order for the current organization. Hiding preserves the group's threads, order,
+and collapse state. Pinned threads remain in Pinned; More carries hidden activity.
+
+`sidebar.hiddenGroups` defaults to `[]`. Its keys are `project:<projectId>`,
+`section:<sectionId>`, and `machine:<hostId>` (`machine:no-machine` for the
+unassigned group). Each organization uses its own keys. Pinned and Threads cannot
+be hidden. Duplicate keys are deduplicated, and unavailable IDs remain saved
+without producing rows. New groups default visible.
+
+  bb settings ui get sidebar.hiddenGroups
+  bb settings ui set sidebar.hiddenGroups '["project:proj_example","section:sec_example"]'
+  bb settings ui reset sidebar.hiddenGroups
+
+`set` replaces the entire list across organizations; include existing keys you
+want to keep hidden. `reset` shows all groups. SDK callers use
+`sdk.system.uiPreferences.list()` to read the current revision, then
+`.set({ key: "sidebar.hiddenGroups", value, expectedRevision })` or
+`.reset({ key: "sidebar.hiddenGroups" })`.
+
 Sidebar footer actions
 
 Settings → Appearance → Sidebar footer supports drag ordering and visibility.
diff --git a/plugins/bb-guide/skills/bb-cli/references/app-settings.md b/plugins/bb-guide/skills/bb-cli/references/app-settings.md
index 4d7eb501389..0dbb5faa312 100644
--- a/plugins/bb-guide/skills/bb-cli/references/app-settings.md
+++ b/plugins/bb-guide/skills/bb-cli/references/app-settings.md
@@ -16,8 +16,8 @@ every window and client sees the same value.
 - The server keeps a keyed, revisioned registry of sidebar layout preferences
   (`sidebar.organizationMode`, `sidebar.threadGrouping.environment`,
   `sidebar.chronologicalSort`, the section
-  orders, the collapsed-id lists, `sidebar.pluginPanelOrder`,
-  `sidebar.visiblePluginPanels`, `sidebar.navigationProvider`,
+  orders, the collapsed-id lists, `sidebar.hiddenGroups`,
+  `sidebar.pluginPanelOrder`, `sidebar.visiblePluginPanels`, `sidebar.navigationProvider`,
   `sidebar.threadListProvider`).
 - `sidebar.organizationMode` defaults to Custom (`chronological`) when unset;
   existing server and legacy browser choices are preserved.
@@ -36,6 +36,26 @@ every window and client sees the same value.
 - `bb settings ui reset <key> [--json]` writes the default and advances the
   revision.
 
+### Thread-list visibility
+
+- A project, custom section, or machine's menu offers **Hide from list**;
+  its menu inside **More** offers **Add to sidebar**. **Customize list**
+  manages visibility and order for the current organization. Hidden groups keep
+  their threads, saved order, and collapse state; pinned threads remain in Pinned.
+  More carries hidden activity without automatically restoring groups.
+- `sidebar.hiddenGroups` defaults to `[]`. Use `project:<projectId>`,
+  `section:<sectionId>`, or `machine:<hostId>` keys (`machine:no-machine` for the
+  unassigned group). Each organization applies only its matching keys. Built-in
+  Pinned and Threads cannot be hidden. Duplicate keys are deduplicated;
+  unavailable IDs are retained without creating rows, and new groups are visible.
+- `bb settings ui get sidebar.hiddenGroups` reads the current list.
+  `bb settings ui set sidebar.hiddenGroups '["project:proj_example"]'` replaces
+  the complete list across organizations; include existing keys you want to keep
+  hidden. `bb settings ui reset sidebar.hiddenGroups` shows every group again.
+- SDK callers use `sdk.system.uiPreferences.list()` for the value and revision,
+  `.set({ key: "sidebar.hiddenGroups", value, expectedRevision })` to replace it,
+  and `.reset({ key: "sidebar.hiddenGroups" })` to show all groups.
+
 ## Keyboard shortcuts
 
 - `showKeyboardHints` defaults to true. Set it with