diff --git a/tools/ui/src/lib/components/app/models/ModelsSelectorDropdown.svelte b/tools/ui/src/lib/components/app/models/ModelsSelectorDropdown.svelte
index 1e1798e2fa..30dedcbae9 100644
--- a/tools/ui/src/lib/components/app/models/ModelsSelectorDropdown.svelte
+++ b/tools/ui/src/lib/components/app/models/ModelsSelectorDropdown.svelte
@@ -1,8 +1,9 @@
 <script lang="ts">
 	import ModelLoadHighlight from './ModelLoadHighlight.svelte';
 	import type { ModelItem } from './utils';
-	import { ChevronDown, Loader2 } from '@lucide/svelte';
+	import { ChevronDown, Lightbulb, Loader2 } from '@lucide/svelte';
 	import {
+		ChatFormActionAddReasoningSubmenu,
 		DialogModelInformation,
 		DropdownMenuSearchable,
 		ModelId,
@@ -11,10 +12,11 @@
 	} from '$lib/components/app';
 	import * as DropdownMenu from '$lib/components/ui/dropdown-menu';
 	import * as Tooltip from '$lib/components/ui/tooltip';
-	import { MODEL_SELECTOR_ICON } from '$lib/constants';
+	import { MODEL_SELECTOR_ICON, SETTINGS_KEYS } from '$lib/constants';
 	import { KeyboardKey, ServerModelStatus } from '$lib/enums';
 	import { useModelsSelector } from '$lib/hooks/use-models-selector.svelte';
-	import { modelsStore } from '$lib/stores';
+	import { useReasoningMenu } from '$lib/hooks/use-reasoning-menu.svelte';
+	import { modelsStore, settingsStore } from '$lib/stores';
 	import { modelLoadFraction } from '$lib/utils';
 
 	interface Props {
@@ -37,6 +39,9 @@
 
 	let isOpen = $state(false);
 	let highlightedId = $state<string | null>(null);
+	// The model submenu opens together with the menu so the list and its search
+	// box are immediately available, as before the submenu was introduced
+	let modelSubOpen = $state(false);
 
 	const ms = useModelsSelector({
 		currentModel: () => currentModel,
@@ -44,24 +49,41 @@
 		onOpenChange: (open) => {
 			isOpen = open;
 			highlightedId = null;
+
+			if (open) {
+				// Defer submenu open so the Sub component is mounted first;
+				// setting bind:open synchronously can be lost if the Sub hasn't
+				// rendered yet.
+				queueMicrotask(() => {
+					if (isOpen) modelSubOpen = true;
+				});
+			} else {
+				modelSubOpen = false;
+			}
 		},
 		useGlobalSelection: () => useGlobalSelection
 	});
 
+	const reasoning = useReasoningMenu();
+
+	const showOrgNameInTrigger = $derived(
+		settingsStore.config[SETTINGS_KEYS.SHOW_MODEL_ORG_NAME_IN_TRIGGER] ?? false
+	);
+
 	$effect(() => {
 		void ms.searchTerm;
 		highlightedId = null;
 	});
 
-	// Focus the dropdown's search box without scrolling the page. bits-ui
+	// Focus the model submenu's search box without scrolling the page. bits-ui
 	// auto-focuses the opened content by default, which can yank the page
 	// scroll; we prevent that on the Content and refocus the search here.
 	$effect(() => {
-		if (!isOpen) return;
+		if (!isOpen || !modelSubOpen) return;
 
 		requestAnimationFrame(() => {
 			const search = document.querySelector<HTMLElement>(
-				'[data-slot="dropdown-menu-content"] input'
+				'[data-slot="dropdown-menu-sub-content"] input'
 			);
 
 			search?.focus({ preventScroll: true });
@@ -188,7 +210,7 @@
 							<DropdownMenu.Trigger
 								{...props}
 								class={[
-									`relative inline-grid cursor-pointer grid-cols-[1fr_auto_1fr] items-center gap-1.5 rounded-sm bg-background px-1.5 py-1 text-xs shadow-sm transition hover:bg-muted-foreground/20 focus:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:cursor-not-allowed disabled:opacity-60 dark:bg-muted-foreground/15 dark:text-secondary-foreground`,
+									`relative inline-grid cursor-pointer grid-cols-[1fr_auto_1fr] items-center gap-1 rounded-sm bg-background px-1.5 py-1 text-xs shadow-sm transition hover:bg-muted-foreground/20 focus:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:cursor-not-allowed disabled:opacity-60 dark:bg-muted-foreground/15 dark:text-secondary-foreground`,
 									!ms.isCurrentModelInCache
 										? 'bg-red-400/10 !text-red-400 hover:bg-red-400/20 hover:text-red-400'
 										: forceForegroundText
@@ -203,16 +225,22 @@
 							>
 								<MODEL_SELECTOR_ICON class="h-3.5 w-3.5 shrink-0" />
 
-								{#if selectedOption}
-									<ModelId
-										class="min-w-0 overflow-hidden"
-										hideOrgName={false}
-										hideQuantization
-										modelId={selectedOption.model}
-									/>
-								{:else}
-									<span class="min-w-0 font-medium">Select model</span>
-								{/if}
+								<span class="flex min-w-0 items-center gap-1">
+									{#if selectedOption}
+										<ModelId
+											class="min-w-0 overflow-hidden"
+											hideOrgName={!showOrgNameInTrigger}
+											hideQuantization
+											modelId={selectedOption.model}
+										/>
+									{:else}
+										<span class="min-w-0 font-medium">Select model</span>
+									{/if}
+
+									{#if reasoning.isReasoningActive}
+										<Lightbulb class="h-3.5 w-3.5 shrink-0 text-amber-400" />
+									{/if}
+								</span>
 
 								{#if ms.updating || ms.isLoadingModel}
 									<Loader2 class="h-3 w-3.5 shrink-0 animate-spin" />
@@ -236,73 +264,94 @@
 
 				<DropdownMenu.Content
 					align="end"
-					class="w-full max-w-[100vw] pt-0 sm:w-max sm:max-w-[calc(100vw-2rem)]"
+					class="w-full md:min-w-64 md:max-w-80 max-w-[calc(100vw-2rem)]"
 					onOpenAutoFocus={(event) => event.preventDefault()}
 				>
-					<DropdownMenuSearchable
-						emptyMessage="No models found."
-						isEmpty={ms.filteredOptions.length === 0 && ms.isCurrentModelInCache}
-						onSearchChange={(v) => ms.setSearchTerm(v)}
-						onSearchKeyDown={handleSearchKeyDown}
-						placeholder="Search models..."
-						searchValue={ms.searchTerm}
-					>
-						<div class="models-list">
-							{#if !ms.isCurrentModelInCache && currentModel}
-								<!-- Show unavailable model as first option (disabled) -->
-								<button
-									aria-disabled="true"
-									aria-selected="true"
-									class="flex w-full cursor-not-allowed items-center bg-red-400/10 p-2 text-left text-sm text-red-400"
-									disabled
-									role="option"
-									type="button"
-								>
-									<ModelId class="flex-1" hideQuantization modelId={currentModel} />
+					<DropdownMenu.Sub bind:open={modelSubOpen}>
+						<DropdownMenu.SubTrigger class="flex cursor-pointer items-center gap-2">
+							<MODEL_SELECTOR_ICON class="h-4 w-4" />
 
-									<span class="ml-2 text-xs whitespace-nowrap opacity-70">(not available)</span>
-								</button>
-							{/if}
-
-							{#if ms.filteredOptions.length === 0}
-								<p class="px-4 py-3 text-sm text-muted-foreground">No models found.</p>
-							{/if}
-
-							{#snippet modelOption(item: ModelItem, hideOrgName: boolean)}
-								{@const { option } = item}
-								{@const isSelected = currentModel === option.model || ms.activeId === option.id}
-								{@const isHighlighted = option.id === highlightedId}
-								{@const isFav = ms.isFavorite(option.model)}
-
-								<ModelsSelectorOption
-									{hideOrgName}
-									{isFav}
-									{isHighlighted}
-									{isSelected}
-									onInfoClick={ms.handleInfoClick}
-									onKeyDown={(event) => {
-										if (event.key === KeyboardKey.ENTER || event.key === KeyboardKey.SPACE) {
-											event.preventDefault();
-											void handleModelKeyAction(option.id, event.altKey);
-										}
-									}}
-									onMouseEnter={() => (highlightedId = option.id)}
-									onSelect={ms.handleSelect}
-									{option}
+							{#if selectedOption}
+								<ModelId
+									class="min-w-0 flex-1 overflow-hidden"
+									hideOrgName={!showOrgNameInTrigger}
+									hideQuantization
+									modelId={selectedOption.model}
 								/>
-							{/snippet}
+							{:else}
+								<span class="min-w-0 flex-1 truncate text-muted-foreground">No model</span>
+							{/if}
+						</DropdownMenu.SubTrigger>
 
-							<ModelsSelectorList
-								activeId={ms.activeId}
-								{currentModel}
-								groups={ms.groupedFilteredOptions}
-								onInfoClick={ms.handleInfoClick}
-								onSelect={ms.handleSelect}
-								renderOption={modelOption}
-								sectionHeaderClass="my-1.5 px-2 py-2 text-[13px] font-semibold text-muted-foreground/70 select-none"
-							/>
-						</div>
-					</DropdownMenuSearchable>
+						<DropdownMenu.SubContent class="w-100 max-w-[calc(100vw-2rem)] pt-0">
+							<DropdownMenuSearchable
+								emptyMessage="No models found."
+								isEmpty={ms.filteredOptions.length === 0 && ms.isCurrentModelInCache}
+								onSearchChange={(v) => ms.setSearchTerm(v)}
+								onSearchKeyDown={handleSearchKeyDown}
+								placeholder="Search models..."
+								searchValue={ms.searchTerm}
+							>
+								<div class="models-list">
+									{#if !ms.isCurrentModelInCache && currentModel}
+										<!-- Show unavailable model as first option (disabled) -->
+										<button
+											aria-disabled="true"
+											aria-selected="true"
+											class="flex w-full cursor-not-allowed items-center bg-red-400/10 p-2 text-left text-sm text-red-400"
+											disabled
+											role="option"
+											type="button"
+										>
+											<ModelId class="flex-1" hideQuantization modelId={currentModel} />
+
+											<span class="ml-2 text-xs whitespace-nowrap opacity-70">(not available)</span>
+										</button>
+									{/if}
+
+									{#if ms.filteredOptions.length === 0}
+										<p class="px-4 py-3 text-sm text-muted-foreground">No models found.</p>
+									{/if}
+
+									{#snippet modelOption(item: ModelItem, hideOrgName: boolean)}
+										{@const { option } = item}
+										{@const isSelected = currentModel === option.model || ms.activeId === option.id}
+										{@const isHighlighted = option.id === highlightedId}
+										{@const isFav = ms.isFavorite(option.model)}
+
+										<ModelsSelectorOption
+											{hideOrgName}
+											{isFav}
+											{isHighlighted}
+											{isSelected}
+											onInfoClick={ms.handleInfoClick}
+											onKeyDown={(event) => {
+												if (event.key === KeyboardKey.ENTER || event.key === KeyboardKey.SPACE) {
+													event.preventDefault();
+													void handleModelKeyAction(option.id, event.altKey);
+												}
+											}}
+											onMouseEnter={() => (highlightedId = option.id)}
+											onSelect={ms.handleSelect}
+											{option}
+										/>
+									{/snippet}
+
+									<ModelsSelectorList
+										activeId={ms.activeId}
+										{currentModel}
+										groups={ms.groupedFilteredOptions}
+										onInfoClick={ms.handleInfoClick}
+										onSelect={ms.handleSelect}
+										renderOption={modelOption}
+										sectionHeaderClass="my-1.5 px-2 py-2 text-[13px] font-semibold text-muted-foreground/70 select-none"
+									/>
+								</div>
+							</DropdownMenuSearchable>
+						</DropdownMenu.SubContent>
+					</DropdownMenu.Sub>
+
+					<ChatFormActionAddReasoningSubmenu />
 				</DropdownMenu.Content>
 			</DropdownMenu.Root>
 		{:else}
@@ -332,12 +381,16 @@
 							{#if selectedOption}
 								<ModelId
 									class="min-w-0 overflow-hidden"
-									hideOrgName={false}
+									hideOrgName={!showOrgNameInTrigger}
 									hideQuantization
 									modelId={selectedOption.model}
 								/>
 							{/if}
 
+							{#if reasoning.isReasoningActive}
+								<Lightbulb class="h-3.5 w-3.5 shrink-0 text-amber-400" />
+							{/if}
+
 							{#if ms.updating}
 								<Loader2 class="h-3 w-3.5 shrink-0 animate-spin" />
 							{/if}