diff --git a/src/lib/components/chat/FileNav/FilePreview.svelte b/src/lib/components/chat/FileNav/FilePreview.svelte
index 0d3a98d3fc..9015f456d3 100644
--- a/src/lib/components/chat/FileNav/FilePreview.svelte
+++ b/src/lib/components/chat/FileNav/FilePreview.svelte
@@ -423,6 +423,8 @@
 			{#key selectedFile}
 				<MarkdownDocument
 					content={fileContent}
+					onSave={readOnly ? null : onSave}
+					bind:saving
 					id={`file-${selectedFile}`}
 					path={selectedFile ?? ''}
 					{baseUrl}
diff --git a/src/lib/components/chat/FileNav/MarkdownDocument.svelte b/src/lib/components/chat/FileNav/MarkdownDocument.svelte
index 213a64bb1e..b6f0b273d6 100644
--- a/src/lib/components/chat/FileNav/MarkdownDocument.svelte
+++ b/src/lib/components/chat/FileNav/MarkdownDocument.svelte
@@ -17,13 +17,17 @@
 
 <script lang="ts">
 	import { getAllContexts, mount, unmount, setContext, onDestroy } from 'svelte';
+	import { writable } from 'svelte/store';
 	import DOMPurify from 'dompurify';
 	import { v4 as uuidv4 } from 'uuid';
 	import { downloadFileBlob } from '$lib/apis/terminal';
 	import MarkdownTokens from '../Messages/Markdown/MarkdownTokens.svelte';
-	import type { Token } from 'marked';
+	import type { Token, Tokens } from 'marked';
+	import { toast } from 'svelte-sonner';
 
 	export let content: string;
+	export let onSave: ((content: string) => Promise<void>) | null = null;
+	export let saving = false;
 	export let id: string;
 	export let path = '';
 	export let baseUrl = '';
@@ -95,8 +99,69 @@
 		release();
 	}
 
+	function markdownTasks(tokens: Token[]) {
+		const tasks: Tokens.ListItem[] = [];
+		documentMarkdown.walkTokens(tokens, (token) => {
+			if (token.type === 'list_item' && token.task) tasks.push(token as Tokens.ListItem);
+		});
+		return tasks;
+	}
+
+	function toggleMarkdownTask(content: string, index: number, checked: boolean) {
+		const tasks = markdownTasks(documentMarkdown.lexer(content));
+		if (!tasks[index]) throw new Error('Task no longer exists. Reload the file and try again.');
+		if (tasks[index].checked === checked) return content;
+
+		// Confirm the marker with the renderer's parser, so duplicates and code examples stay untouched.
+		for (const match of content.matchAll(/\[[ xX]\]/g)) {
+			const offset = match.index! + 1;
+			if ((content[offset].toLowerCase() === 'x') === checked) continue;
+			const updated = content.slice(0, offset) + (checked ? 'x' : ' ') + content.slice(offset + 1);
+			const next = markdownTasks(documentMarkdown.lexer(updated));
+			if (
+				next.length === tasks.length &&
+				next.every((task, i) => task.checked === (i === index ? checked : tasks[i].checked))
+			) {
+				return updated;
+			}
+		}
+		throw new Error('Could not locate the task in the file. Reload the file and try again.');
+	}
+
+	const taskEnabled = writable(false);
+	$: taskEnabled.set(!!onSave);
 	setContext('markdown', {
 		document: true,
+		taskEnabled,
+		onTaskClick: async ({
+			item,
+			checked,
+			input
+		}: {
+			item: Tokens.ListItem;
+			checked: boolean;
+			input: HTMLInputElement;
+		}) => {
+			input.checked = !!item.checked;
+			if (!onSave || saving) return;
+			const previous = content;
+			const wasChecked = !!item.checked;
+			saving = true;
+			try {
+				const index = markdownTasks(tokens).indexOf(item);
+				const updated = toggleMarkdownTask(content, index, checked);
+				// Keep the rendered document in place while saving this single marker.
+				parsedContent = content = updated;
+				item.checked = input.checked = checked;
+				await onSave(updated);
+			} catch (error) {
+				parsedContent = content = previous;
+				item.checked = input.checked = wasChecked;
+				toast.error(String(error));
+			} finally {
+				saving = false;
+			}
+		},
 		allowRemoteContent: true,
 		lexer: (source: string) => documentMarkdown.lexer(source),
 		parseInline: (tokens: Token[]) =>
@@ -142,7 +207,12 @@
 		update(props);
 		return { update, destroy };
 	}
-	$: tokens = documentMarkdown.lexer(content);
+	let parsedContent: string | undefined;
+	let tokens: Token[] = [];
+	$: if (content !== parsedContent) {
+		tokens = documentMarkdown.lexer(content);
+		parsedContent = content;
+	}
 	const resolveHtmlImages = (node: HTMLElement) => {
 		let alive = true;
 		const update = () => {
@@ -261,7 +331,7 @@
 	.document-markdown :global(.codespan) {
 		font-size: 0.95em;
 	}
-	.document-markdown :global(input[type='checkbox']) {
+	.document-markdown :global(input[type='checkbox']:disabled) {
 		cursor: default;
 	}
 	.document-markdown :global(.document-code-block) {
diff --git a/src/lib/components/chat/Messages/Markdown/MarkdownTokens.svelte b/src/lib/components/chat/Messages/Markdown/MarkdownTokens.svelte
index cf9fef79e3..72f9075ae0 100644
--- a/src/lib/components/chat/Messages/Markdown/MarkdownTokens.svelte
+++ b/src/lib/components/chat/Messages/Markdown/MarkdownTokens.svelte
@@ -1,21 +1,30 @@
 <script lang="ts">
 	import { decode } from 'html-entities';
 	import { onMount, getContext } from 'svelte';
+	import type { Readable } from 'svelte/store';
 	import type { Action } from 'svelte/action';
 	const i18n = getContext('i18n');
 	const markdown = getContext<
 		| {
 				document?: boolean;
+				taskEnabled?: Readable<boolean>;
+				onTaskClick?: (event: {
+					item: Tokens.ListItem;
+					checked: boolean;
+					input: HTMLInputElement;
+				}) => void;
 				lexer?: (source: string) => Token[];
 				renderHtml?: Action<HTMLElement, { id: string; tokens: Token[]; top: boolean }>;
 		  }
 		| undefined
 	>('markdown');
 
+	const taskEnabled = markdown?.taskEnabled;
+
 	import fileSaver from 'file-saver';
 	const { saveAs } = fileSaver;
 
-	import { type Token } from 'marked';
+	import { type Token, type Tokens } from 'marked';
 	import { copyToClipboard, unescapeHtml } from '$lib/utils';
 	import { resolveChatMessageToolCall } from '$lib/apis/chats';
 
@@ -340,18 +349,19 @@
 					<li dir="auto" class="text-start">
 						{#if item?.task}
 							<input
-								class=" translate-y-[1px] -translate-x-1 [&:dir(rtl)]:translate-x-1 flex-shrink-0"
+								class="task-checkbox translate-y-[1px] -translate-x-1 [&:dir(rtl)]:translate-x-1 flex-shrink-0"
 								type="checkbox"
-								disabled={markdown?.document ?? false}
+								disabled={markdown?.document && !$taskEnabled}
 								checked={item.checked}
 								on:change={(e) => {
-									onTaskClick({
+									(markdown?.onTaskClick ?? onTaskClick)({
 										id: id,
 										token: token,
 										tokenIdx: tokenIdx,
 										item: item,
 										itemIdx: itemIdx,
-										checked: e.target.checked
+										input: e.currentTarget,
+										checked: e.currentTarget.checked
 									});
 								}}
 							/>
@@ -379,31 +389,27 @@
 		{:else}
 			<ul dir="auto" class="">
 				{#each token.items as item, itemIdx}
-					<li
-						dir="auto"
-						class="text-start {item?.task
-							? 'flex -translate-x-6.5 [&:dir(rtl)]:translate-x-6.5 gap-3 '
-							: ''}"
-					>
+					<li dir="auto" class="text-start {item?.task ? 'relative list-none' : ''}">
 						{#if item?.task}
 							<input
-								class="flex-shrink-0"
+								class="task-checkbox"
 								type="checkbox"
-								disabled={markdown?.document ?? false}
+								disabled={markdown?.document && !$taskEnabled}
 								checked={item.checked}
 								on:change={(e) => {
-									onTaskClick({
+									(markdown?.onTaskClick ?? onTaskClick)({
 										id: id,
 										token: token,
 										tokenIdx: tokenIdx,
 										item: item,
 										itemIdx: itemIdx,
-										checked: e.target.checked
+										input: e.currentTarget,
+										checked: e.currentTarget.checked
 									});
 								}}
 							/>
 
-							<div>
+							<div class="task-content">
 								<svelte:self
 									id={`${id}-${tokenIdx}-${itemIdx}`}
 									{chatId}
@@ -673,4 +679,22 @@
 	li {
 		margin-inline-start: 1.5em;
 	}
+
+	ul > li > input.task-checkbox {
+		position: absolute;
+		inset-inline-start: -1.5em;
+		top: calc((1lh - 0.875rem) / 2);
+		margin: 0;
+	}
+
+	input.task-checkbox::after {
+		inset: 0;
+		width: auto;
+		height: auto;
+		background-size: 100% 100%;
+	}
+
+	.task-content > :global(p:first-child) {
+		margin-top: 0;
+	}
 </style>