webui: Add a "Continue" Action for Assistant Message (#16971)

* feat: Add "Continue" action for assistant messages

* feat: Continuation logic & prompt improvements

* chore: update webui build output

* feat: Improve logic for continuing the assistant message

* chore: update webui build output

* chore: Linting

* chore: update webui build output

* fix: Remove synthetic prompt logic, use the prefill feature by sending the conversation payload ending with assistant message

* chore: update webui build output

* feat: Enable "Continue" button based on config & non-reasoning model type

* chore: update webui build output

* chore: Update packages with `npm audit fix`

* fix: Remove redundant error

* chore: update webui build output

* chore: Update `.gitignore`

* fix: Add missing change

* feat: Add auto-resizing for Edit Assistant/User Message textareas

* chore: update webui build output

tools/server/webui/.gitignore

@@ -25,3 +25,4 @@ vite.config.ts.timestamp-*
 
 *storybook.log
 storybook-static
+*.code-workspace

tools/server/webui/package-lock.json

@@ -2109,9 +2109,9 @@
 			}
 		},
 		"node_modules/@sveltejs/kit": {
-			"version": "2.48.4",
-			"resolved": "https://registry.npmjs.org/@sveltejs/kit/-/kit-2.48.4.tgz",
-			"integrity": "sha512-TGFX1pZUt9qqY20Cv5NyYvy0iLWHf2jXi8s+eCGsig7jQMdwZWKUFMR6TbvFNhfDSUpc1sH/Y5EHv20g3HHA3g==",
+			"version": "2.48.5",
+			"resolved": "https://registry.npmjs.org/@sveltejs/kit/-/kit-2.48.5.tgz",
+			"integrity": "sha512-/rnwfSWS3qwUSzvHynUTORF9xSJi7PCR9yXkxUOnRrNqyKmCmh3FPHH+E9BbgqxXfTevGXBqgnlh9kMb+9T5XA==",
 			"dev": true,
 			"license": "MIT",
 			"dependencies": {
@@ -5087,9 +5087,9 @@
 			"license": "MIT"
 		},
 		"node_modules/js-yaml": {
-			"version": "4.1.0",
-			"resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.1.0.tgz",
-			"integrity": "sha512-wpxZs9NoxZaJESJGIZTyDEaYpl0FKSA+FB9aJiyemKhMwkxQg63h4T1KJgUGHpTqPDNRcmmYLugrRjJlBtWvRA==",
+			"version": "4.1.1",
+			"resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.1.1.tgz",
+			"integrity": "sha512-qQKT4zQxXl8lLwBtHMWwaTcGfFOZviOJet3Oy/xmGk2gZH677CJM9EvtfdSkgWcATZhj/55JZ0rmy3myCT5lsA==",
 			"dev": true,
 			"license": "MIT",
 			"dependencies": {

tools/server/webui/src/lib/components/app/chat/ChatMessages/ChatMessage.svelte

@@ -10,6 +10,7 @@
 		class?: string;
 		message: DatabaseMessage;
 		onCopy?: (message: DatabaseMessage) => void;
+		onContinueAssistantMessage?: (message: DatabaseMessage) => void;
 		onDelete?: (message: DatabaseMessage) => void;
 		onEditWithBranching?: (message: DatabaseMessage, newContent: string) => void;
 		onEditWithReplacement?: (
@@ -17,6 +18,7 @@
 			newContent: string,
 			shouldBranch: boolean
 		) => void;
+		onEditUserMessagePreserveResponses?: (message: DatabaseMessage, newContent: string) => void;
 		onNavigateToSibling?: (siblingId: string) => void;
 		onRegenerateWithBranching?: (message: DatabaseMessage) => void;
 		siblingInfo?: ChatMessageSiblingInfo | null;
@@ -26,9 +28,11 @@
 		class: className = '',
 		message,
 		onCopy,
+		onContinueAssistantMessage,
 		onDelete,
 		onEditWithBranching,
 		onEditWithReplacement,
+		onEditUserMessagePreserveResponses,
 		onNavigateToSibling,
 		onRegenerateWithBranching,
 		siblingInfo = null
@@ -133,17 +137,33 @@
 		onRegenerateWithBranching?.(message);
 	}
 
+	function handleContinue() {
+		onContinueAssistantMessage?.(message);
+	}
+
 	function handleSaveEdit() {
 		if (message.role === 'user') {
+			// For user messages, trim to avoid accidental whitespace
 			onEditWithBranching?.(message, editedContent.trim());
 		} else {
-			onEditWithReplacement?.(message, editedContent.trim(), shouldBranchAfterEdit);
+			// For assistant messages, preserve exact content including trailing whitespace
+			// This is important for the Continue feature to work properly
+			onEditWithReplacement?.(message, editedContent, shouldBranchAfterEdit);
 		}
 
 		isEditing = false;
 		shouldBranchAfterEdit = false;
 	}
 
+	function handleSaveEditOnly() {
+		if (message.role === 'user') {
+			// For user messages, trim to avoid accidental whitespace
+			onEditUserMessagePreserveResponses?.(message, editedContent.trim());
+		}
+
+		isEditing = false;
+	}
+
 	function handleShowDeleteDialogChange(show: boolean) {
 		showDeleteDialog = show;
 	}
@@ -166,6 +186,7 @@
 		onEditedContentChange={handleEditedContentChange}
 		{onNavigateToSibling}
 		onSaveEdit={handleSaveEdit}
+		onSaveEditOnly={handleSaveEditOnly}
 		onShowDeleteDialogChange={handleShowDeleteDialogChange}
 		{showDeleteDialog}
 		{siblingInfo}
@@ -181,6 +202,7 @@
 		messageContent={message.content}
 		onCancelEdit={handleCancelEdit}
 		onConfirmDelete={handleConfirmDelete}
+		onContinue={handleContinue}
 		onCopy={handleCopy}
 		onDelete={handleDelete}
 		onEdit={handleEdit}

tools/server/webui/src/lib/components/app/chat/ChatMessages/ChatMessageActions.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { Edit, Copy, RefreshCw, Trash2 } from '@lucide/svelte';
+	import { Edit, Copy, RefreshCw, Trash2, ArrowRight } from '@lucide/svelte';
 	import { ActionButton, ConfirmationDialog } from '$lib/components/app';
 	import ChatMessageBranchingControls from './ChatMessageBranchingControls.svelte';
 
@@ -18,6 +18,7 @@
 		onCopy: () => void;
 		onEdit?: () => void;
 		onRegenerate?: () => void;
+		onContinue?: () => void;
 		onDelete: () => void;
 		onConfirmDelete: () => void;
 		onNavigateToSibling?: (siblingId: string) => void;
@@ -31,6 +32,7 @@
 		onCopy,
 		onEdit,
 		onConfirmDelete,
+		onContinue,
 		onDelete,
 		onNavigateToSibling,
 		onShowDeleteDialogChange,
@@ -69,6 +71,10 @@
 				<ActionButton icon={RefreshCw} tooltip="Regenerate" onclick={onRegenerate} />
 			{/if}
 
+			{#if role === 'assistant' && onContinue}
+				<ActionButton icon={ArrowRight} tooltip="Continue" onclick={onContinue} />
+			{/if}
+
 			<ActionButton icon={Trash2} tooltip="Delete" onclick={onDelete} />
 		</div>
 	</div>

tools/server/webui/src/lib/components/app/chat/ChatMessages/ChatMessageAssistant.svelte

@@ -2,6 +2,7 @@
 	import { ChatMessageThinkingBlock, MarkdownContent } from '$lib/components/app';
 	import { useProcessingState } from '$lib/hooks/use-processing-state.svelte';
 	import { isLoading } from '$lib/stores/chat.svelte';
+	import autoResizeTextarea from '$lib/utils/autoresize-textarea';
 	import { fade } from 'svelte/transition';
 	import {
 		Check,
@@ -39,6 +40,7 @@
 		onCancelEdit?: () => void;
 		onCopy: () => void;
 		onConfirmDelete: () => void;
+		onContinue?: () => void;
 		onDelete: () => void;
 		onEdit?: () => void;
 		onEditKeydown?: (event: KeyboardEvent) => void;
@@ -65,6 +67,7 @@
 		messageContent,
 		onCancelEdit,
 		onConfirmDelete,
+		onContinue,
 		onCopy,
 		onDelete,
 		onEdit,
@@ -107,6 +110,12 @@
 		void copyToClipboard(model ?? '');
 	}
 
+	$effect(() => {
+		if (isEditing && textareaElement) {
+			autoResizeTextarea(textareaElement);
+		}
+	});
+
 	function formatToolCallBadge(toolCall: ApiChatCompletionToolCall, index: number) {
 		const callNumber = index + 1;
 		const functionName = toolCall.function?.name?.trim();
@@ -190,7 +199,10 @@
 				bind:value={editedContent}
 				class="min-h-[50vh] w-full resize-y rounded-2xl px-3 py-2 text-sm {INPUT_CLASSES}"
 				onkeydown={onEditKeydown}
-				oninput={(e) => onEditedContentChange?.(e.currentTarget.value)}
+				oninput={(e) => {
+					autoResizeTextarea(e.currentTarget);
+					onEditedContentChange?.(e.currentTarget.value);
+				}}
 				placeholder="Edit assistant message..."
 			></textarea>
 
@@ -335,6 +347,9 @@
 			{onCopy}
 			{onEdit}
 			{onRegenerate}
+			onContinue={currentConfig.enableContinueGeneration && !thinkingContent
+				? onContinue
+				: undefined}
 			{onDelete}
 			{onConfirmDelete}
 			{onNavigateToSibling}

tools/server/webui/src/lib/components/app/chat/ChatMessages/ChatMessageUser.svelte

@@ -1,10 +1,11 @@
 <script lang="ts">
-	import { Check, X } from '@lucide/svelte';
+	import { Check, X, Send } from '@lucide/svelte';
 	import { Card } from '$lib/components/ui/card';
 	import { Button } from '$lib/components/ui/button';
 	import { ChatAttachmentsList, MarkdownContent } from '$lib/components/app';
 	import { INPUT_CLASSES } from '$lib/constants/input-classes';
 	import { config } from '$lib/stores/settings.svelte';
+	import autoResizeTextarea from '$lib/utils/autoresize-textarea';
 	import ChatMessageActions from './ChatMessageActions.svelte';
 
 	interface Props {
@@ -22,6 +23,7 @@
 		} | null;
 		onCancelEdit: () => void;
 		onSaveEdit: () => void;
+		onSaveEditOnly?: () => void;
 		onEditKeydown: (event: KeyboardEvent) => void;
 		onEditedContentChange: (content: string) => void;
 		onCopy: () => void;
@@ -43,6 +45,7 @@
 		deletionInfo,
 		onCancelEdit,
 		onSaveEdit,
+		onSaveEditOnly,
 		onEditKeydown,
 		onEditedContentChange,
 		onCopy,
@@ -58,6 +61,12 @@
 	let messageElement: HTMLElement | undefined = $state();
 	const currentConfig = config();
 
+	$effect(() => {
+		if (isEditing && textareaElement) {
+			autoResizeTextarea(textareaElement);
+		}
+	});
+
 	$effect(() => {
 		if (!messageElement || !message.content.trim()) return;
 
@@ -95,20 +104,34 @@
 				bind:value={editedContent}
 				class="min-h-[60px] w-full resize-none rounded-2xl px-3 py-2 text-sm {INPUT_CLASSES}"
 				onkeydown={onEditKeydown}
-				oninput={(e) => onEditedContentChange(e.currentTarget.value)}
+				oninput={(e) => {
+					autoResizeTextarea(e.currentTarget);
+					onEditedContentChange(e.currentTarget.value);
+				}}
 				placeholder="Edit your message..."
 			></textarea>
 
 			<div class="mt-2 flex justify-end gap-2">
-				<Button class="h-8 px-3" onclick={onCancelEdit} size="sm" variant="outline">
+				<Button class="h-8 px-3" onclick={onCancelEdit} size="sm" variant="ghost">
 					<X class="mr-1 h-3 w-3" />
-
 					Cancel
 				</Button>
 
-				<Button class="h-8 px-3" onclick={onSaveEdit} disabled={!editedContent.trim()} size="sm">
-					<Check class="mr-1 h-3 w-3" />
+				{#if onSaveEditOnly}
+					<Button
+						class="h-8 px-3"
+						onclick={onSaveEditOnly}
+						disabled={!editedContent.trim()}
+						size="sm"
+						variant="outline"
+					>
+						<Check class="mr-1 h-3 w-3" />
+						Save
+					</Button>
+				{/if}
 
+				<Button class="h-8 px-3" onclick={onSaveEdit} disabled={!editedContent.trim()} size="sm">
+					<Send class="mr-1 h-3 w-3" />
 					Send
 				</Button>
 			</div>

tools/server/webui/src/lib/components/app/chat/ChatMessages/ChatMessages.svelte

@@ -3,10 +3,12 @@
 	import { DatabaseStore } from '$lib/stores/database';
 	import {
 		activeConversation,
+		continueAssistantMessage,
 		deleteMessage,
-		navigateToSibling,
-		editMessageWithBranching,
 		editAssistantMessage,
+		editMessageWithBranching,
+		editUserMessagePreserveResponses,
+		navigateToSibling,
 		regenerateMessageWithBranching
 	} from '$lib/stores/chat.svelte';
 	import { getMessageSiblings } from '$lib/utils/branching';
@@ -93,6 +95,26 @@
 
 		refreshAllMessages();
 	}
+
+	async function handleContinueAssistantMessage(message: DatabaseMessage) {
+		onUserAction?.();
+
+		await continueAssistantMessage(message.id);
+
+		refreshAllMessages();
+	}
+
+	async function handleEditUserMessagePreserveResponses(
+		message: DatabaseMessage,
+		newContent: string
+	) {
+		onUserAction?.();
+
+		await editUserMessagePreserveResponses(message.id, newContent);
+
+		refreshAllMessages();
+	}
+
 	async function handleDeleteMessage(message: DatabaseMessage) {
 		await deleteMessage(message.id);
 
@@ -110,7 +132,9 @@
 			onNavigateToSibling={handleNavigateToSibling}
 			onEditWithBranching={handleEditWithBranching}
 			onEditWithReplacement={handleEditWithReplacement}
+			onEditUserMessagePreserveResponses={handleEditUserMessagePreserveResponses}
 			onRegenerateWithBranching={handleRegenerateWithBranching}
+			onContinueAssistantMessage={handleContinueAssistantMessage}
 		/>
 	{/each}
 </div>

tools/server/webui/src/lib/components/app/chat/ChatSettings/ChatSettingsDialog.svelte

@@ -52,6 +52,11 @@
 						{ value: 'dark', label: 'Dark', icon: Moon }
 					]
 				},
+				{
+					key: 'pasteLongTextToFileLen',
+					label: 'Paste long text to file length',
+					type: 'input'
+				},
 				{
 					key: 'showMessageStats',
 					label: 'Show message generation statistics',
@@ -68,14 +73,15 @@
 					type: 'checkbox'
 				},
 				{
-					key: 'askForTitleConfirmation',
-					label: 'Ask for confirmation before changing conversation title',
+					key: 'showModelInfo',
+					label: 'Show model information',
 					type: 'checkbox'
 				},
 				{
-					key: 'pasteLongTextToFileLen',
-					label: 'Paste long text to file length',
-					type: 'input'
+					key: 'enableContinueGeneration',
+					label: 'Enable "Continue" button',
+					type: 'checkbox',
+					isExperimental: true
 				},
 				{
 					key: 'pdfAsImage',
@@ -83,13 +89,13 @@
 					type: 'checkbox'
 				},
 				{
-					key: 'showModelInfo',
-					label: 'Show model information',
+					key: 'renderUserContentAsMarkdown',
+					label: 'Render user content as Markdown',
 					type: 'checkbox'
 				},
 				{
-					key: 'renderUserContentAsMarkdown',
-					label: 'Render user content as Markdown',
+					key: 'askForTitleConfirmation',
+					label: 'Ask for confirmation before changing conversation title',
 					type: 'checkbox'
 				}
 			]

tools/server/webui/src/lib/components/app/chat/ChatSettings/ChatSettingsFields.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { RotateCcw } from '@lucide/svelte';
+	import { RotateCcw, FlaskConical } from '@lucide/svelte';
 	import { Checkbox } from '$lib/components/ui/checkbox';
 	import { Input } from '$lib/components/ui/input';
 	import Label from '$lib/components/ui/label/label.svelte';
@@ -55,8 +55,12 @@
 			})()}
 
 			<div class="flex items-center gap-2">
-				<Label for={field.key} class="text-sm font-medium">
+				<Label for={field.key} class="flex items-center gap-1.5 text-sm font-medium">
 					{field.label}
+
+					{#if field.isExperimental}
+						<FlaskConical class="h-3.5 w-3.5 text-muted-foreground" />
+					{/if}
 				</Label>
 				{#if isCustomRealTime}
 					<ParameterSourceIndicator />
@@ -97,8 +101,12 @@
 				</p>
 			{/if}
 		{:else if field.type === 'textarea'}
-			<Label for={field.key} class="block text-sm font-medium">
+			<Label for={field.key} class="block flex items-center gap-1.5 text-sm font-medium">
 				{field.label}
+
+				{#if field.isExperimental}
+					<FlaskConical class="h-3.5 w-3.5 text-muted-foreground" />
+				{/if}
 			</Label>
 
 			<Textarea
@@ -129,8 +137,12 @@
 			})()}
 
 			<div class="flex items-center gap-2">
-				<Label for={field.key} class="text-sm font-medium">
+				<Label for={field.key} class="flex items-center gap-1.5 text-sm font-medium">
 					{field.label}
+
+					{#if field.isExperimental}
+						<FlaskConical class="h-3.5 w-3.5 text-muted-foreground" />
+					{/if}
 				</Label>
 				{#if isCustomRealTime}
 					<ParameterSourceIndicator />
@@ -214,9 +226,13 @@
 						for={field.key}
 						class="cursor-pointer text-sm leading-none font-medium {isDisabled
 							? 'text-muted-foreground'
-							: ''}"
+							: ''} flex items-center gap-1.5"
 					>
 						{field.label}
+
+						{#if field.isExperimental}
+							<FlaskConical class="h-3.5 w-3.5 text-muted-foreground" />
+						{/if}
 					</label>
 
 					{#if field.help || SETTING_CONFIG_INFO[field.key]}

tools/server/webui/src/lib/constants/settings-config.ts

@@ -38,7 +38,8 @@ export const SETTING_CONFIG_DEFAULT: Record<string, string | number | boolean> =
 	max_tokens: -1,
 	custom: '', // custom json-stringified object
 	// experimental features
-	pyInterpreterEnabled: false
+	pyInterpreterEnabled: false,
+	enableContinueGeneration: false
 };
 
 export const SETTING_CONFIG_INFO: Record<string, string> = {
@@ -96,5 +97,7 @@ export const SETTING_CONFIG_INFO: Record<string, string> = {
 	modelSelectorEnabled:
 		'Enable the model selector in the chat input to choose the inference model. Sends the associated model field in API requests.',
 	pyInterpreterEnabled:
-		'Enable Python interpreter using Pyodide. Allows running Python code in markdown code blocks.'
+		'Enable Python interpreter using Pyodide. Allows running Python code in markdown code blocks.',
+	enableContinueGeneration:
+		'Enable "Continue" button for assistant messages. Currently works only with non-reasoning models.'
 };

tools/server/webui/src/lib/services/chat.ts

@@ -312,7 +312,6 @@ export class ChatService {
 		let aggregatedContent = '';
 		let fullReasoningContent = '';
 		let aggregatedToolCalls: ApiChatCompletionToolCall[] = [];
-		let hasReceivedData = false;
 		let lastTimings: ChatMessageTimings | undefined;
 		let streamFinished = false;
 		let modelEmitted = false;
@@ -352,8 +351,6 @@ export class ChatService {
 				return;
 			}
 
-			hasReceivedData = true;
-
 			if (!abortSignal?.aborted) {
 				onToolCallChunk?.(serializedToolCalls);
 			}
@@ -415,7 +412,6 @@ export class ChatService {
 
 							if (content) {
 								finalizeOpenToolCallBatch();
-								hasReceivedData = true;
 								aggregatedContent += content;
 								if (!abortSignal?.aborted) {
 									onChunk?.(content);
@@ -424,7 +420,6 @@ export class ChatService {
 
 							if (reasoningContent) {
 								finalizeOpenToolCallBatch();
-								hasReceivedData = true;
 								fullReasoningContent += reasoningContent;
 								if (!abortSignal?.aborted) {
 									onReasoningChunk?.(reasoningContent);
@@ -446,15 +441,6 @@ export class ChatService {
 			if (streamFinished) {
 				finalizeOpenToolCallBatch();
 
-				if (
-					!hasReceivedData &&
-					aggregatedContent.length === 0 &&
-					aggregatedToolCalls.length === 0
-				) {
-					const noResponseError = new Error('No response received from server. Please try again.');
-					throw noResponseError;
-				}
-
 				const finalToolCalls =
 					aggregatedToolCalls.length > 0 ? JSON.stringify(aggregatedToolCalls) : undefined;
 

tools/server/webui/src/lib/stores/chat.svelte.ts

@@ -1486,6 +1486,10 @@ class ChatStore {
 					timestamp: Date.now()
 				});
 
+				// Ensure currNode points to the edited message to maintain correct path
+				await DatabaseStore.updateCurrentNode(this.activeConversation.id, messageToEdit.id);
+				this.activeConversation.currNode = messageToEdit.id;
+
 				this.updateMessageAtIndex(messageIndex, {
 					content: newContent,
 					timestamp: Date.now()
@@ -1499,6 +1503,69 @@ class ChatStore {
 		}
 	}
 
+	/**
+	 * Edits a user message and preserves all responses below
+	 * Updates the message content in-place without deleting or regenerating responses
+	 *
+	 * **Use Case**: When you want to fix a typo or rephrase a question without losing the assistant's response
+	 *
+	 * **Important Behavior:**
+	 * - Does NOT create a branch (unlike editMessageWithBranching)
+	 * - Does NOT regenerate assistant responses
+	 * - Only updates the user message content in the database
+	 * - Preserves the entire conversation tree below the edited message
+	 * - Updates conversation title if this is the first user message
+	 *
+	 * @param messageId - The ID of the user message to edit
+	 * @param newContent - The new content for the message
+	 */
+	async editUserMessagePreserveResponses(messageId: string, newContent: string): Promise<void> {
+		if (!this.activeConversation) return;
+
+		try {
+			const messageIndex = this.findMessageIndex(messageId);
+			if (messageIndex === -1) {
+				console.error('Message not found for editing');
+				return;
+			}
+
+			const messageToEdit = this.activeMessages[messageIndex];
+			if (messageToEdit.role !== 'user') {
+				console.error('Only user messages can be edited with this method');
+				return;
+			}
+
+			// Simply update the message content in-place
+			await DatabaseStore.updateMessage(messageId, {
+				content: newContent,
+				timestamp: Date.now()
+			});
+
+			this.updateMessageAtIndex(messageIndex, {
+				content: newContent,
+				timestamp: Date.now()
+			});
+
+			// Check if first user message for title update
+			const allMessages = await DatabaseStore.getConversationMessages(this.activeConversation.id);
+			const rootMessage = allMessages.find((m) => m.type === 'root' && m.parent === null);
+			const isFirstUserMessage =
+				rootMessage && messageToEdit.parent === rootMessage.id && messageToEdit.role === 'user';
+
+			if (isFirstUserMessage && newContent.trim()) {
+				await this.updateConversationTitleWithConfirmation(
+					this.activeConversation.id,
+					newContent.trim(),
+					this.titleUpdateConfirmationCallback
+				);
+			}
+
+			this.updateConversationTimestamp();
+		} catch (error) {
+			console.error('Failed to edit user message:', error);
+		}
+	}
+
 	/**
 	 * Edits a message by creating a new branch with the edited content
 	 * @param messageId - The ID of the message to edit
@@ -1696,6 +1763,200 @@ class ChatStore {
 		}
 	}
 
+	/**
+	 * Continues generation for an existing assistant message
+	 * @param messageId - The ID of the assistant message to continue
+	 */
+	async continueAssistantMessage(messageId: string): Promise<void> {
+		if (!this.activeConversation || this.isLoading) return;
+
+		try {
+			const messageIndex = this.findMessageIndex(messageId);
+			if (messageIndex === -1) {
+				console.error('Message not found for continuation');
+				return;
+			}
+
+			const messageToContinue = this.activeMessages[messageIndex];
+			if (messageToContinue.role !== 'assistant') {
+				console.error('Only assistant messages can be continued');
+				return;
+			}
+
+			// Race condition protection: Check if this specific conversation is already loading
+			// This prevents multiple rapid clicks on "Continue" from creating concurrent operations
+			if (this.isConversationLoading(this.activeConversation.id)) {
+				console.warn('Continuation already in progress for this conversation');
+				return;
+			}
+
+			this.errorDialogState = null;
+			this.setConversationLoading(this.activeConversation.id, true);
+			this.clearConversationStreaming(this.activeConversation.id);
+
+			// IMPORTANT: Fetch the latest content from the database to ensure we have
+			// the most up-to-date content, especially after a stopped generation
+			// This prevents issues where the in-memory state might be stale
+			const allMessages = await DatabaseStore.getConversationMessages(this.activeConversation.id);
+			const dbMessage = allMessages.find((m) => m.id === messageId);
+
+			if (!dbMessage) {
+				console.error('Message not found in database for continuation');
+				this.setConversationLoading(this.activeConversation.id, false);
+
+				return;
+			}
+
+			// Use content from database as the source of truth
+			const originalContent = dbMessage.content;
+			const originalThinking = dbMessage.thinking || '';
+
+			// Get conversation context up to (but not including) the message to continue
+			const conversationContext = this.activeMessages.slice(0, messageIndex);
+
+			const contextWithContinue = [
+				...conversationContext.map((msg) => {
+					if ('id' in msg && 'convId' in msg && 'timestamp' in msg) {
+						return msg as DatabaseMessage & { extra?: DatabaseMessageExtra[] };
+					}
+					return msg as ApiChatMessageData;
+				}),
+				{
+					role: 'assistant' as const,
+					content: originalContent
+				}
+			];
+
+			let appendedContent = '';
+			let appendedThinking = '';
+			let hasReceivedContent = false;
+
+			await chatService.sendMessage(
+				contextWithContinue,
+				{
+					...this.getApiOptions(),
+
+					onChunk: (chunk: string) => {
+						hasReceivedContent = true;
+						appendedContent += chunk;
+						// Preserve originalContent exactly as-is, including any trailing whitespace
+						// The concatenation naturally preserves any whitespace at the end of originalContent
+						const fullContent = originalContent + appendedContent;
+
+						this.setConversationStreaming(
+							messageToContinue.convId,
+							fullContent,
+							messageToContinue.id
+						);
+
+						this.updateMessageAtIndex(messageIndex, {
+							content: fullContent
+						});
+					},
+
+					onReasoningChunk: (reasoningChunk: string) => {
+						hasReceivedContent = true;
+						appendedThinking += reasoningChunk;
+
+						const fullThinking = originalThinking + appendedThinking;
+
+						this.updateMessageAtIndex(messageIndex, {
+							thinking: fullThinking
+						});
+					},
+
+					onComplete: async (
+						finalContent?: string,
+						reasoningContent?: string,
+						timings?: ChatMessageTimings
+					) => {
+						const fullContent = originalContent + (finalContent || appendedContent);
+						const fullThinking = originalThinking + (reasoningContent || appendedThinking);
+
+						const updateData: {
+							content: string;
+							thinking: string;
+							timestamp: number;
+							timings?: ChatMessageTimings;
+						} = {
+							content: fullContent,
+							thinking: fullThinking,
+							timestamp: Date.now(),
+							timings: timings
+						};
+
+						await DatabaseStore.updateMessage(messageToContinue.id, updateData);
+
+						this.updateMessageAtIndex(messageIndex, updateData);
+
+						this.updateConversationTimestamp();
+
+						this.setConversationLoading(messageToContinue.convId, false);
+						this.clearConversationStreaming(messageToContinue.convId);
+						slotsService.clearConversationState(messageToContinue.convId);
+					},
+
+					onError: async (error: Error) => {
+						if (this.isAbortError(error)) {
+							// User cancelled - save partial continuation if any content was received
+							if (hasReceivedContent && appendedContent) {
+								const partialContent = originalContent + appendedContent;
+								const partialThinking = originalThinking + appendedThinking;
+
+								await DatabaseStore.updateMessage(messageToContinue.id, {
+									content: partialContent,
+									thinking: partialThinking,
+									timestamp: Date.now()
+								});
+
+								this.updateMessageAtIndex(messageIndex, {
+									content: partialContent,
+									thinking: partialThinking,
+									timestamp: Date.now()
+								});
+							}
+
+							this.setConversationLoading(messageToContinue.convId, false);
+							this.clearConversationStreaming(messageToContinue.convId);
+							slotsService.clearConversationState(messageToContinue.convId);
+
+							return;
+						}
+
+						// Non-abort error - rollback to original content
+						console.error('Continue generation error:', error);
+
+						// Rollback: Restore original content in UI
+						this.updateMessageAtIndex(messageIndex, {
+							content: originalContent,
+							thinking: originalThinking
+						});
+
+						// Ensure database has original content (in case of partial writes)
+						await DatabaseStore.updateMessage(messageToContinue.id, {
+							content: originalContent,
+							thinking: originalThinking
+						});
+
+						this.setConversationLoading(messageToContinue.convId, false);
+						this.clearConversationStreaming(messageToContinue.convId);
+						slotsService.clearConversationState(messageToContinue.convId);
+
+						const dialogType = error.name === 'TimeoutError' ? 'timeout' : 'server';
+						this.showErrorDialog(dialogType, error.message);
+					}
+				},
+				messageToContinue.convId
+			);
+		} catch (error) {
+			if (this.isAbortError(error)) return;
+			console.error('Failed to continue message:', error);
+			if (this.activeConversation) {
+				this.setConversationLoading(this.activeConversation.id, false);
+			}
+		}
+	}
+
 	/**
 	 * Public methods for accessing per-conversation states
 	 */
@@ -1743,8 +2004,11 @@ export const refreshActiveMessages = chatStore.refreshActiveMessages.bind(chatSt
 export const navigateToSibling = chatStore.navigateToSibling.bind(chatStore);
 export const editAssistantMessage = chatStore.editAssistantMessage.bind(chatStore);
 export const editMessageWithBranching = chatStore.editMessageWithBranching.bind(chatStore);
+export const editUserMessagePreserveResponses =
+	chatStore.editUserMessagePreserveResponses.bind(chatStore);
 export const regenerateMessageWithBranching =
 	chatStore.regenerateMessageWithBranching.bind(chatStore);
+export const continueAssistantMessage = chatStore.continueAssistantMessage.bind(chatStore);
 export const deleteMessage = chatStore.deleteMessage.bind(chatStore);
 export const getDeletionInfo = chatStore.getDeletionInfo.bind(chatStore);
 export const updateConversationName = chatStore.updateConversationName.bind(chatStore);

tools/server/webui/src/lib/types/settings.d.ts

@@ -7,6 +7,7 @@ export interface SettingsFieldConfig {
 	key: string;
 	label: string;
 	type: 'input' | 'textarea' | 'checkbox' | 'select';
+	isExperimental?: boolean;
 	help?: string;
 	options?: Array<{ value: string; label: string; icon?: typeof import('@lucide/svelte').Icon }>;
 }