diff --git a/community-addon-template/src/index.js b/community-addon-template/src/index.js
index 61dc312ea..57d34e1d1 100644
--- a/community-addon-template/src/index.js
+++ b/community-addon-template/src/index.js
@@ -1,5 +1,6 @@
 import { defineAddon, defineAddonOptions } from '@sveltejs/cli-core';
 import { imports } from '@sveltejs/cli-core/js';
+import * as svelte from '@sveltejs/cli-core/svelte';
 import { parseSvelte } from '@sveltejs/cli-core/parsers';
 
 export const options = defineAddonOptions()
@@ -26,9 +27,10 @@ export default defineAddon({
 
 		sv.file('src/DemoComponent.svelte', (content) => {
 			if (!options.demo) return content;
-			const { script, generateCode } = parseSvelte(content, { typescript });
-			imports.addDefault(script.ast, { from: '../addon-template-demo.txt?raw', as: 'demo' });
-			return generateCode({ script: script.generateCode(), template: '{demo}' });
+			const { ast, generateCode } = parseSvelte(content);
+			const scriptAst = svelte.ensureScript(ast, { langTs: typescript });
+			imports.addDefault(scriptAst, { from: '../addon-template-demo.txt?raw', as: 'demo' });
+			return generateCode();
 		});
 	}
 });
diff --git a/packages/addons/_tests/mdsvex/test.ts b/packages/addons/_tests/mdsvex/test.ts
index 07c7a0ecd..ebf622898 100644
--- a/packages/addons/_tests/mdsvex/test.ts
+++ b/packages/addons/_tests/mdsvex/test.ts
@@ -3,7 +3,7 @@ import path from 'node:path';
 import { expect } from '@playwright/test';
 import { parseSvelte } from '@sveltejs/cli-core/parsers';
 import { imports } from '@sveltejs/cli-core/js';
-import * as html from '@sveltejs/cli-core/html';
+import * as svelte from '@sveltejs/cli-core/svelte';
 import { setupTest } from '../_setup/suite.ts';
 import { svxFile } from './fixtures.ts';
 import mdsvex from '../../mdsvex/index.ts';
@@ -40,19 +40,32 @@ function addFixture(cwd: string, variant: string) {
 	}
 
 	const src = fs.readFileSync(page, 'utf8');
-	const { script, template, generateCode } = parseSvelte(src);
-	imports.addDefault(script.ast, { from: './Demo.svx', as: 'Demo' });
+	const { ast, generateCode } = parseSvelte(src);
+	const scriptAst = svelte.ensureScript(ast);
+	imports.addDefault(scriptAst, { from: './Demo.svx', as: 'Demo' });
 
-	const div = html.createDiv({ class: 'mdsvex' });
-	html.appendElement(template.ast.childNodes, div);
-	const mdsvexNode = html.createElement('Demo');
-	html.appendElement(div.childNodes, mdsvexNode);
-
-	const content = generateCode({
-		script: script.generateCode(),
-		template: template.generateCode()
+	ast.fragment.nodes.push({
+		type: 'RegularElement',
+		name: 'div',
+		attributes: [
+			{
+				type: 'Attribute',
+				name: 'class',
+				value: [{ type: 'Text', data: 'mdsvex', raw: 'mdsvex', start: 0, end: 0 }],
+				start: 0,
+				end: 0
+			}
+		],
+		fragment: {
+			type: 'Fragment',
+			nodes: svelte.toFragment('<Demo />')
+		},
+		start: 0,
+		end: 0
 	});
 
+	const content = generateCode();
+
 	fs.writeFileSync(page, content, 'utf8');
 	fs.writeFileSync(svx, svxFile, 'utf8');
 }
diff --git a/packages/addons/common.ts b/packages/addons/common.ts
index 2b318a62c..f7f73c868 100644
--- a/packages/addons/common.ts
+++ b/packages/addons/common.ts
@@ -1,4 +1,5 @@
 import { imports, exports, common } from '@sveltejs/cli-core/js';
+import { toFragment, type SvelteAst, ensureScript } from '@sveltejs/cli-core/svelte';
 import { parseScript, parseSvelte } from '@sveltejs/cli-core/parsers';
 import process from 'node:process';
 
@@ -63,22 +64,34 @@ export function addEslintConfigPrettier(content: string): string {
 	return generateCode();
 }
 
-export function addToDemoPage(existingContent: string, path: string, typescript: boolean): string {
-	const { script, template, generateCode } = parseSvelte(existingContent, { typescript });
-
-	for (const node of template.ast.childNodes) {
-		// we use includes as it could be "/demo/${path}" or "resolve("demo/${path}")" or "resolve('demo/${path}')"
-		if (node.type === 'tag' && node.attribs['href'].includes(`/demo/${path}`)) {
-			return existingContent;
+export function addToDemoPage(existingContent: string, path: string, langTs: boolean): string {
+	const { ast, generateCode } = parseSvelte(existingContent);
+
+	for (const node of ast.fragment.nodes) {
+		if (node.type === 'RegularElement') {
+			const hrefAttribute = node.attributes.find(
+				(x) => x.type === 'Attribute' && x.name === 'href'
+			) as SvelteAst.Attribute;
+			if (!hrefAttribute || !hrefAttribute.value) continue;
+
+			if (!Array.isArray(hrefAttribute.value)) continue;
+
+			const hasDemo = hrefAttribute.value.some(
+				// we use includes as it could be "/demo/${path}" or "resolve("demo/${path}")" or "resolve('demo/${path}')"
+				(x) => x.type === 'Text' && x.data.includes(`/demo/${path}`)
+			);
+			if (hasDemo) {
+				return existingContent;
+			}
 		}
 	}
 
-	imports.addNamed(script.ast, { imports: ['resolve'], from: '$app/paths' });
+	imports.addNamed(ensureScript(ast, { langTs }), { imports: ['resolve'], from: '$app/paths' });
+
+	ast.fragment.nodes.unshift(...toFragment(`<a href={resolve('/demo/${path}')}>${path}</a>`));
+	ast.fragment.nodes.unshift();
 
-	return generateCode({
-		script: script.generateCode(),
-		template: `<a href={resolve('/demo/${path}')}>${path}</a>\n${template.source}`
-	});
+	return generateCode();
 }
 
 /**
diff --git a/packages/addons/paraglide/index.ts b/packages/addons/paraglide/index.ts
index b8d4d2de0..81b73dc62 100644
--- a/packages/addons/paraglide/index.ts
+++ b/packages/addons/paraglide/index.ts
@@ -1,7 +1,7 @@
-import MagicString from 'magic-string';
 import { colors, defineAddon, defineAddonOptions, log } from '@sveltejs/cli-core';
 import { common, imports, variables, exports, kit as kitJs, vite } from '@sveltejs/cli-core/js';
 import * as html from '@sveltejs/cli-core/html';
+import * as svelte from '@sveltejs/cli-core/svelte';
 import { parseHtml, parseJson, parseScript, parseSvelte } from '@sveltejs/cli-core/parsers';
 import { addToDemoPage } from '../common.ts';
 
@@ -183,35 +183,34 @@ export default defineAddon({
 
 			// add usage example
 			sv.file(`${kit.routesDirectory}/demo/paraglide/+page.svelte`, (content) => {
-				const { script, template, generateCode } = parseSvelte(content, { typescript });
-				imports.addNamed(script.ast, { from: '$lib/paraglide/messages.js', imports: ['m'] });
-				imports.addNamed(script.ast, { from: '$app/navigation', imports: ['goto'] });
-				imports.addNamed(script.ast, { from: '$app/state', imports: ['page'] });
-				imports.addNamed(script.ast, { from: '$lib/paraglide/runtime', imports: ['setLocale'] });
+				const { ast, generateCode } = parseSvelte(content);
+				const scriptAst = svelte.ensureScript(ast, { langTs: typescript });
 
-				const scriptCode = new MagicString(script.generateCode());
-
-				const templateCode = new MagicString(template.source);
+				imports.addNamed(scriptAst, { imports: { m: 'm' }, from: '$lib/paraglide/messages.js' });
+				imports.addNamed(scriptAst, {
+					imports: {
+						setLocale: 'setLocale'
+					},
+					from: '$lib/paraglide/runtime'
+				});
 
 				// add localized message
-				templateCode.append("\n\n<h1>{m.hello_world({ name: 'SvelteKit User' })}</h1>\n");
+				let templateCode = "<h1>{m.hello_world({ name: 'SvelteKit User' })}</h1>";
 
 				// add links to other localized pages, the first one is the default
 				// language, thus it does not require any localized route
 				const { validLanguageTags } = parseLanguageTagInput(options.languageTags);
 				const links = validLanguageTags
-					.map(
-						(x) =>
-							`${templateCode.getIndentString()}<button onclick={() => setLocale('${x}')}>${x}</button>`
-					)
-					.join('\n');
-				templateCode.append(`<div>\n${links}\n</div>`);
-
-				templateCode.append(
-					'<p>\nIf you use VSCode, install the <a href="https://marketplace.visualstudio.com/items?itemName=inlang.vs-code-extension" target="_blank">Sherlock i18n extension</a> for a better i18n experience.\n</p>'
-				);
+					.map((x) => `<button onclick={() => setLocale('${x}')}>${x}</button>`)
+					.join('');
+				templateCode += `<div>${links}</div>`;
+
+				templateCode +=
+					'<p>If you use VSCode, install the <a href="https://marketplace.visualstudio.com/items?itemName=inlang.vs-code-extension" target="_blank">Sherlock i18n extension</a> for a better i18n experience.</p>';
 
-				return generateCode({ script: scriptCode.toString(), template: templateCode.toString() });
+				ast.fragment.nodes.push(...svelte.toFragment(templateCode));
+
+				return generateCode();
 			});
 		}
 
diff --git a/packages/addons/tailwindcss/index.ts b/packages/addons/tailwindcss/index.ts
index 8c56eb72e..3d3540bbc 100644
--- a/packages/addons/tailwindcss/index.ts
+++ b/packages/addons/tailwindcss/index.ts
@@ -1,7 +1,7 @@
 import { defineAddon, defineAddonOptions } from '@sveltejs/cli-core';
 import { imports, vite } from '@sveltejs/cli-core/js';
+import * as svelte from '@sveltejs/cli-core/svelte';
 import { parseCss, parseJson, parseScript, parseSvelte } from '@sveltejs/cli-core/parsers';
-import { addSlot } from '@sveltejs/cli-core/html';
 
 const plugins = [
 	{
@@ -32,7 +32,7 @@ export default defineAddon({
 	shortDescription: 'css framework',
 	homepage: 'https://tailwindcss.com',
 	options,
-	run: ({ sv, options, files, typescript, kit, dependencyVersion }) => {
+	run: ({ sv, options, files, kit, dependencyVersion, typescript }) => {
 		const prettierInstalled = Boolean(dependencyVersion('prettier'));
 
 		sv.devDependency('tailwindcss', '^4.1.17');
@@ -97,30 +97,28 @@ export default defineAddon({
 			const appSvelte = 'src/App.svelte';
 			const stylesheetRelative = files.getRelative({ from: appSvelte, to: files.stylesheet });
 			sv.file(appSvelte, (content) => {
-				const { script, generateCode } = parseSvelte(content, { typescript });
-				imports.addEmpty(script.ast, { from: stylesheetRelative });
-				return generateCode({ script: script.generateCode() });
+				const { ast, generateCode } = parseSvelte(content);
+				const scriptAst = svelte.ensureScript(ast, { langTs: typescript });
+				imports.addEmpty(scriptAst, { from: stylesheetRelative });
+				return generateCode();
 			});
 		} else {
 			const layoutSvelte = `${kit?.routesDirectory}/+layout.svelte`;
 			const stylesheetRelative = files.getRelative({ from: layoutSvelte, to: files.stylesheet });
 			sv.file(layoutSvelte, (content) => {
-				const { script, template, generateCode } = parseSvelte(content, { typescript });
-				imports.addEmpty(script.ast, { from: stylesheetRelative });
+				const { ast, generateCode } = parseSvelte(content);
+				const scriptAst = svelte.ensureScript(ast, { langTs: typescript });
+				imports.addEmpty(scriptAst, { from: stylesheetRelative });
 
 				if (content.length === 0) {
 					const svelteVersion = dependencyVersion('svelte');
 					if (!svelteVersion) throw new Error('Failed to determine svelte version');
-					addSlot(script.ast, {
-						htmlAst: template.ast,
+					svelte.addSlot(ast, {
 						svelteVersion
 					});
 				}
 
-				return generateCode({
-					script: script.generateCode(),
-					template: content.length === 0 ? template.generateCode() : undefined
-				});
+				return generateCode();
 			});
 		}
 
diff --git a/packages/cli/commands/create.ts b/packages/cli/commands/create.ts
index 35addd565..616956b1d 100644
--- a/packages/cli/commands/create.ts
+++ b/packages/cli/commands/create.ts
@@ -255,11 +255,7 @@ async function createProject(cwd: ProjectPath, options: Options) {
 	});
 
 	if (options.fromPlayground) {
-		await createProjectFromPlayground(
-			options.fromPlayground,
-			projectPath,
-			language === 'typescript'
-		);
+		await createProjectFromPlayground(options.fromPlayground, projectPath);
 	}
 
 	p.log.success('Project created');
@@ -322,11 +318,7 @@ async function createProject(cwd: ProjectPath, options: Options) {
 	return { directory: projectPath, addOnNextSteps, packageManager };
 }
 
-async function createProjectFromPlayground(
-	url: string,
-	cwd: string,
-	typescript: boolean
-): Promise<void> {
+async function createProjectFromPlayground(url: string, cwd: string): Promise<void> {
 	const urlData = parsePlaygroundUrl(url);
 	const playground = await downloadPlaygroundData(urlData);
 
@@ -334,7 +326,7 @@ async function createProjectFromPlayground(
 	const dependencies = detectPlaygroundDependencies(playground.files);
 	const installDependencies = await confirmExternalDependencies(Array.from(dependencies.keys()));
 
-	setupPlaygroundProject(url, playground, cwd, installDependencies, typescript);
+	setupPlaygroundProject(url, playground, cwd, installDependencies);
 }
 
 async function confirmExternalDependencies(dependencies: string[]): Promise<boolean> {
diff --git a/packages/cli/tests/snapshots/create-with-all-addons/src/routes/+layout.svelte b/packages/cli/tests/snapshots/create-with-all-addons/src/routes/+layout.svelte
index 8b9bd05ca..0d8eb0307 100644
--- a/packages/cli/tests/snapshots/create-with-all-addons/src/routes/+layout.svelte
+++ b/packages/cli/tests/snapshots/create-with-all-addons/src/routes/+layout.svelte
@@ -1,12 +1,9 @@
 <script lang="ts">
 	import './layout.css';
 	import favicon from '$lib/assets/favicon.svg';
-	
+
 	let { children } = $props();
 </script>
 
-<svelte:head>
-	<link rel="icon" href={favicon} />
-</svelte:head>
-
+<svelte:head><link rel="icon" href={favicon} /></svelte:head>
 {@render children()}
diff --git a/packages/cli/tests/snapshots/create-with-all-addons/src/routes/demo/paraglide/+page.svelte b/packages/cli/tests/snapshots/create-with-all-addons/src/routes/demo/paraglide/+page.svelte
index 04d3480cc..671434223 100644
--- a/packages/cli/tests/snapshots/create-with-all-addons/src/routes/demo/paraglide/+page.svelte
+++ b/packages/cli/tests/snapshots/create-with-all-addons/src/routes/demo/paraglide/+page.svelte
@@ -1,16 +1,20 @@
 <script lang="ts">
 	import { setLocale } from '$lib/paraglide/runtime';
-	import { page } from '$app/state';
-	import { goto } from '$app/navigation';
 	import { m } from '$lib/paraglide/messages.js';
 </script>
 
-
-
 <h1>{m.hello_world({ name: 'SvelteKit User' })}</h1>
 <div>
 	<button onclick={() => setLocale('en')}>en</button>
 	<button onclick={() => setLocale('es')}>es</button>
-</div><p>
-If you use VSCode, install the <a href="https://marketplace.visualstudio.com/items?itemName=inlang.vs-code-extension" target="_blank">Sherlock i18n extension</a> for a better i18n experience.
+</div>
+<p>
+	If you use VSCode, install the 
+	<a
+		href="https://marketplace.visualstudio.com/items?itemName=inlang.vs-code-extension"
+		target="_blank"
+	>
+		Sherlock i18n extension
+	</a>
+	for a better i18n experience.
 </p>
diff --git a/packages/core/package.json b/packages/core/package.json
index 7019a1447..4e08e1088 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -22,6 +22,7 @@
 		"./css": "./tooling/css/index.ts",
 		"./html": "./tooling/html/index.ts",
 		"./js": "./tooling/js/index.ts",
+		"./svelte": "./tooling/svelte/index.ts",
 		"./parsers": "./tooling/parsers.ts"
 	},
 	"devDependencies": {
@@ -40,6 +41,7 @@
 		"picocolors": "^1.1.1",
 		"postcss": "^8.5.6",
 		"silver-fleece": "^1.2.1",
+		"svelte": "^5.45.0",
 		"yaml": "^2.8.1",
 		"zimmerframe": "^1.1.4"
 	},
diff --git a/packages/core/tests/js/object/property-node/input.ts b/packages/core/tests/js/object/property-node/input.ts
index 4b075890b..537cd089c 100644
--- a/packages/core/tests/js/object/property-node/input.ts
+++ b/packages/core/tests/js/object/property-node/input.ts
@@ -1,4 +1,4 @@
 const test = {
-	/** a comment */
+	// prettier-ignore
 	foo: 1
 };
diff --git a/packages/core/tests/js/object/property-node/output.ts b/packages/core/tests/js/object/property-node/output.ts
index 3719acb91..c163865df 100644
--- a/packages/core/tests/js/object/property-node/output.ts
+++ b/packages/core/tests/js/object/property-node/output.ts
@@ -1,6 +1,6 @@
 const test = {
-	/** a comment */
+	/*a comment updated*/ // prettier-ignore
 	foo: 1,
 
-	james: '007'
+	/*aka: bond, james bond*/ james: '007'
 };
diff --git a/packages/core/tests/js/object/property-node/run.ts b/packages/core/tests/js/object/property-node/run.ts
index 9db2672ea..18372acb4 100644
--- a/packages/core/tests/js/object/property-node/run.ts
+++ b/packages/core/tests/js/object/property-node/run.ts
@@ -1,18 +1,18 @@
-import { object, common, type AstTypes } from '@sveltejs/cli-core/js';
+import { object, common, type AstTypes, type Comments } from '@sveltejs/cli-core/js';
 import { getTestObjectExpression } from '../objectTestHelper.ts';
 
-export function run(ast: AstTypes.Program): void {
+export function run(ast: AstTypes.Program, comments: Comments): void {
 	const obj = getTestObjectExpression(ast);
 
 	const p1 = object.propertyNode(obj, {
 		name: 'foo',
 		fallback: object.create({})
 	});
-	p1.leadingComments = [{ type: 'Block', value: 'a comment updated' }];
+	comments.add(p1, { type: 'Block', value: 'a comment updated' });
 
 	const p2 = object.propertyNode(obj, {
 		name: 'james',
 		fallback: common.createLiteral('007')
 	});
-	p2.leadingComments = [{ type: 'Block', value: 'aka: bond, james bond' }];
+	comments.add(p2, { type: 'Block', value: 'aka: bond, james bond' });
 }
diff --git a/packages/core/tests/svelte/common/ensure-script-ts/input.svelte b/packages/core/tests/svelte/common/ensure-script-ts/input.svelte
new file mode 100644
index 000000000..175b82b52
--- /dev/null
+++ b/packages/core/tests/svelte/common/ensure-script-ts/input.svelte
@@ -0,0 +1 @@
+Nothing to see here
diff --git a/packages/core/tests/svelte/common/ensure-script-ts/output.svelte b/packages/core/tests/svelte/common/ensure-script-ts/output.svelte
new file mode 100644
index 000000000..ff42b6951
--- /dev/null
+++ b/packages/core/tests/svelte/common/ensure-script-ts/output.svelte
@@ -0,0 +1,3 @@
+<script lang="ts"></script>
+
+Nothing to see here
diff --git a/packages/core/tests/svelte/common/ensure-script-ts/run.ts b/packages/core/tests/svelte/common/ensure-script-ts/run.ts
new file mode 100644
index 000000000..2895bd1cd
--- /dev/null
+++ b/packages/core/tests/svelte/common/ensure-script-ts/run.ts
@@ -0,0 +1,5 @@
+import { type SvelteAst, ensureScript } from '@sveltejs/cli-core/svelte';
+
+export function run(ast: SvelteAst.Root): void {
+	ensureScript(ast, { langTs: true });
+}
diff --git a/packages/core/tests/svelte/common/ensure-script/input.svelte b/packages/core/tests/svelte/common/ensure-script/input.svelte
new file mode 100644
index 000000000..f7cb47851
--- /dev/null
+++ b/packages/core/tests/svelte/common/ensure-script/input.svelte
@@ -0,0 +1,3 @@
+<div>
+	<p>This is a Svelte component without script block</p>
+</div>
diff --git a/packages/core/tests/svelte/common/ensure-script/output.svelte b/packages/core/tests/svelte/common/ensure-script/output.svelte
new file mode 100644
index 000000000..c0e89bbf3
--- /dev/null
+++ b/packages/core/tests/svelte/common/ensure-script/output.svelte
@@ -0,0 +1,5 @@
+<script></script>
+
+<div>
+	<p>This is a Svelte component without script block</p>
+</div>
diff --git a/packages/core/tests/svelte/common/ensure-script/run.ts b/packages/core/tests/svelte/common/ensure-script/run.ts
new file mode 100644
index 000000000..27992909c
--- /dev/null
+++ b/packages/core/tests/svelte/common/ensure-script/run.ts
@@ -0,0 +1,5 @@
+import { type SvelteAst, ensureScript } from '@sveltejs/cli-core/svelte';
+
+export function run(ast: SvelteAst.Root): void {
+	ensureScript(ast);
+}
diff --git a/packages/core/tests/svelte/common/keep-script-ts/input.svelte b/packages/core/tests/svelte/common/keep-script-ts/input.svelte
new file mode 100644
index 000000000..3382f954b
--- /dev/null
+++ b/packages/core/tests/svelte/common/keep-script-ts/input.svelte
@@ -0,0 +1,3 @@
+<script lang="ts"></script>
+
+A script tag with ts lang attribute
diff --git a/packages/core/tests/svelte/common/keep-script-ts/output.svelte b/packages/core/tests/svelte/common/keep-script-ts/output.svelte
new file mode 100644
index 000000000..3382f954b
--- /dev/null
+++ b/packages/core/tests/svelte/common/keep-script-ts/output.svelte
@@ -0,0 +1,3 @@
+<script lang="ts"></script>
+
+A script tag with ts lang attribute
diff --git a/packages/core/tests/svelte/common/keep-script-ts/run.ts b/packages/core/tests/svelte/common/keep-script-ts/run.ts
new file mode 100644
index 000000000..27992909c
--- /dev/null
+++ b/packages/core/tests/svelte/common/keep-script-ts/run.ts
@@ -0,0 +1,5 @@
+import { type SvelteAst, ensureScript } from '@sveltejs/cli-core/svelte';
+
+export function run(ast: SvelteAst.Root): void {
+	ensureScript(ast);
+}
diff --git a/packages/core/tests/svelte/common/slot-svelte-4/output.svelte b/packages/core/tests/svelte/common/slot-svelte-4/output.svelte
new file mode 100644
index 000000000..13e0e91ed
--- /dev/null
+++ b/packages/core/tests/svelte/common/slot-svelte-4/output.svelte
@@ -0,0 +1 @@
+<slot></slot>
diff --git a/packages/core/tests/svelte/common/slot-svelte-4/run.ts b/packages/core/tests/svelte/common/slot-svelte-4/run.ts
new file mode 100644
index 000000000..11d06ce56
--- /dev/null
+++ b/packages/core/tests/svelte/common/slot-svelte-4/run.ts
@@ -0,0 +1,5 @@
+import { type SvelteAst, addSlot } from '@sveltejs/cli-core/svelte';
+
+export function run(ast: SvelteAst.Root): void {
+	addSlot(ast, { svelteVersion: '4.0.0' });
+}
diff --git a/packages/core/tests/svelte/common/slot-svelte-5/output.svelte b/packages/core/tests/svelte/common/slot-svelte-5/output.svelte
new file mode 100644
index 000000000..f82c4d3da
--- /dev/null
+++ b/packages/core/tests/svelte/common/slot-svelte-5/output.svelte
@@ -0,0 +1,5 @@
+<script>
+	const { children } = $props();
+</script>
+
+{@render children()}
diff --git a/packages/core/tests/svelte/common/slot-svelte-5/run.ts b/packages/core/tests/svelte/common/slot-svelte-5/run.ts
new file mode 100644
index 000000000..5ee31421e
--- /dev/null
+++ b/packages/core/tests/svelte/common/slot-svelte-5/run.ts
@@ -0,0 +1,5 @@
+import { type SvelteAst, addSlot } from '@sveltejs/cli-core/svelte';
+
+export function run(ast: SvelteAst.Root): void {
+	addSlot(ast, { svelteVersion: '5.0.0' });
+}
diff --git a/packages/core/tests/svelte/common/to-fragment/input.svelte b/packages/core/tests/svelte/common/to-fragment/input.svelte
new file mode 100644
index 000000000..f4f500fb8
--- /dev/null
+++ b/packages/core/tests/svelte/common/to-fragment/input.svelte
@@ -0,0 +1,5 @@
+<!-- prettier-ignore-start -->
+<div>
+	<p>This is a Svelte component.</p>
+</div>
+<!-- prettier-ignore-end -->
diff --git a/packages/core/tests/svelte/common/to-fragment/output.svelte b/packages/core/tests/svelte/common/to-fragment/output.svelte
new file mode 100644
index 000000000..ed8025189
--- /dev/null
+++ b/packages/core/tests/svelte/common/to-fragment/output.svelte
@@ -0,0 +1,3 @@
+<!-- prettier-ignore-start -->
+<div><p>This is a Svelte component.</p></div>
+<!-- prettier-ignore-end --><span>Appended Fragment</span>
diff --git a/packages/core/tests/svelte/common/to-fragment/run.ts b/packages/core/tests/svelte/common/to-fragment/run.ts
new file mode 100644
index 000000000..fad358c42
--- /dev/null
+++ b/packages/core/tests/svelte/common/to-fragment/run.ts
@@ -0,0 +1,5 @@
+import { type SvelteAst, toFragment } from '@sveltejs/cli-core/svelte';
+
+export function run(ast: SvelteAst.Root): void {
+	ast.fragment.nodes.push(...toFragment('<span>Appended Fragment</span>'));
+}
diff --git a/packages/core/tests/svelte/index.ts b/packages/core/tests/svelte/index.ts
new file mode 100644
index 000000000..08b5c238a
--- /dev/null
+++ b/packages/core/tests/svelte/index.ts
@@ -0,0 +1,38 @@
+import fs from 'node:fs';
+import { join, resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { describe, expect, test } from 'vitest';
+import { parseSvelte, serializeSvelte } from '../../tooling/index.ts';
+
+const baseDir = resolve(fileURLToPath(import.meta.url), '..');
+const categoryDirectories = getDirectoryNames(baseDir);
+
+for (const categoryDirectory of categoryDirectories) {
+	describe(categoryDirectory, () => {
+		const testNames = getDirectoryNames(join(baseDir, categoryDirectory));
+		for (const testName of testNames) {
+			test(testName, async () => {
+				const testDirectoryPath = join(baseDir, categoryDirectory, testName);
+
+				const inputFilePath = join(testDirectoryPath, 'input.svelte');
+				const input = fs.existsSync(inputFilePath) ? fs.readFileSync(inputFilePath, 'utf8') : '';
+				const ast = parseSvelte(input);
+
+				// dynamic imports always need to provide the path inline for static analysis
+				const module = await import(`./${categoryDirectory}/${testName}/run.ts`);
+				module.run(ast);
+
+				let output = serializeSvelte(ast);
+				if (!output.endsWith('\n')) output += '\n';
+				await expect(output).toMatchFileSnapshot(`${testDirectoryPath}/output.svelte`);
+			});
+		}
+	});
+}
+
+function getDirectoryNames(dir: string) {
+	return fs
+		.readdirSync(dir, { withFileTypes: true })
+		.filter((dirent) => dirent.isDirectory())
+		.map((dirent) => dirent.name);
+}
diff --git a/packages/core/tests/utils.ts b/packages/core/tests/utils.ts
index 585c6fcaa..476b78610 100644
--- a/packages/core/tests/utils.ts
+++ b/packages/core/tests/utils.ts
@@ -290,86 +290,3 @@ describe('yaml', () => {
 		`);
 	});
 });
-
-// TODO: fix https://github.com/rolldown/tsdown/issues/575 to remove the `skip`
-test.skip('tsdown escapes script tags in bundled source code', async () => {
-	const { execSync } = await import('node:child_process');
-	const fs = await import('node:fs');
-	const path = await import('node:path');
-
-	const testDir = path.join('../..', '.test-output', `tsdown-test`);
-	fs.rmSync(testDir, { recursive: true, force: true });
-	fs.mkdirSync(testDir, { recursive: true });
-
-	// Create a test file that uses dedent with script tags
-	const testFileLiteral = path.join(testDir, 'testLiteral.ts');
-	fs.writeFileSync(
-		testFileLiteral,
-		`import dedent from 'dedent';
-
-export const result = dedent\`
-	<script lang="ts">
-		console.log('Hello Literal');
-	</script>
-\`;
-`
-	);
-
-	const testFileFunction = path.join(testDir, 'testFunction.ts');
-	fs.writeFileSync(
-		testFileFunction,
-		`import dedent from 'dedent';
-
-export const result = dedent(\`
-	<script lang="ts">
-		console.log('Hello Function');
-	</script>
-\`);
-`
-	);
-
-	// Create a tsdown config
-	const configFile = path.join(testDir, 'tsdown.config.ts');
-	fs.writeFileSync(
-		configFile,
-		`import { defineConfig } from 'tsdown';
-
-export default defineConfig({
-	entry: ['testLiteral.ts', 'testFunction.ts'],
-	format: ['esm'],
-	outDir: 'dist',
-});
-`
-	);
-
-	// Create package.json with tsdown
-	const pkgJson = {
-		name: 'test',
-		type: 'module',
-		devDependencies: {
-			tsdown: '^0.15.2',
-			dedent: '^1.6.0'
-		}
-	};
-	fs.writeFileSync(path.join(testDir, 'package.json'), JSON.stringify(pkgJson, null, 2));
-
-	// Install dependencies and build
-	execSync('npm install', { cwd: testDir, stdio: 'pipe' });
-	execSync('npx tsdown', { cwd: testDir, stdio: 'pipe' });
-
-	// Read the bundled output
-	const bundledFileLiteral = path.join(testDir, 'dist', 'testLiteral.js');
-	const bundledFileFunction = path.join(testDir, 'dist', 'testFunction.js');
-	const bundledCodeLiteral = fs.readFileSync(bundledFileLiteral, 'utf-8');
-	const bundledCodeFunction = fs.readFileSync(bundledFileFunction, 'utf-8');
-
-	// Check if the bundled code contains escaped script tags
-	const hasEscapedScriptTagLiteral = bundledCodeLiteral.includes('<\\/script>');
-	const hasEscapedScriptTagFunction = bundledCodeFunction.includes('<\\/script>');
-
-	// This test demonstrates the issue: tsdown escapes </script> in the bundled source
-	// Expected: Bundled code should NOT contain escaped script tags
-	// Actual: Bundled code contains <\/script> when using dedent`...` syntax
-	expect(hasEscapedScriptTagLiteral).toBe(false);
-	expect(hasEscapedScriptTagFunction).toBe(false);
-}, 30000); // 30s timeout for npm install and build
diff --git a/packages/core/tooling/html/index.ts b/packages/core/tooling/html/index.ts
index 60b2ae078..b79c5074c 100644
--- a/packages/core/tooling/html/index.ts
+++ b/packages/core/tooling/html/index.ts
@@ -1,12 +1,10 @@
 import {
-	type AstTypes,
 	type HtmlChildNode,
 	type HtmlDocument,
 	HtmlElement,
 	HtmlElementType,
 	parseHtml
 } from '../index.ts';
-import { appendFromString } from '../js/common.ts';
 
 export { HtmlElement, HtmlElementType };
 export type { HtmlDocument };
@@ -38,23 +36,3 @@ export function addFromRawHtml(childNodes: HtmlChildNode[], html: string): void
 		childNodes.push(childNode);
 	}
 }
-
-export function addSlot(
-	jsAst: AstTypes.Program,
-	options: { htmlAst: HtmlDocument; svelteVersion: string }
-): void {
-	const slotSyntax =
-		options.svelteVersion &&
-		(options.svelteVersion.startsWith('4') || options.svelteVersion.startsWith('3'));
-
-	if (slotSyntax) {
-		const slot = createElement('slot');
-		appendElement(options.htmlAst.childNodes, slot);
-		return;
-	}
-
-	appendFromString(jsAst, {
-		code: 'let { children } = $props();'
-	});
-	addFromRawHtml(options.htmlAst.childNodes, '{@render children()}');
-}
diff --git a/packages/core/tooling/index.ts b/packages/core/tooling/index.ts
index c9fcc7074..9fb28cfa3 100644
--- a/packages/core/tooling/index.ts
+++ b/packages/core/tooling/index.ts
@@ -17,6 +17,7 @@ import { print as esrapPrint } from 'esrap';
 import ts from 'esrap/languages/ts';
 import * as acorn from 'acorn';
 import { tsPlugin } from '@sveltejs/acorn-typescript';
+import { parse as svelteParse, type AST as SvelteAst, print as sveltePrint } from 'svelte/compiler';
 import * as yaml from 'yaml';
 import type { BaseNode } from 'estree';
 
@@ -40,6 +41,7 @@ export {
 export type {
 	// html
 	ChildNode as HtmlChildNode,
+	SvelteAst,
 
 	// js
 	TsEstree as AstTypes,
@@ -291,3 +293,11 @@ interface CommentsInternal {
 function transformToInternal(comments: Comments | undefined): CommentsInternal {
 	return (comments ?? new Comments()) as unknown as CommentsInternal;
 }
+
+export function parseSvelte(content: string): SvelteAst.Root {
+	return svelteParse(content, { modern: true });
+}
+
+export function serializeSvelte(ast: SvelteAst.Root): string {
+	return sveltePrint(ast).code;
+}
diff --git a/packages/core/tooling/parsers.ts b/packages/core/tooling/parsers.ts
index 94b913fed..24fd027a3 100644
--- a/packages/core/tooling/parsers.ts
+++ b/packages/core/tooling/parsers.ts
@@ -1,5 +1,4 @@
 import * as utils from './index.ts';
-import MagicString from 'magic-string';
 
 type ParseBase = {
 	source: string;
@@ -48,136 +47,13 @@ export function parseYaml(
 	return { data, source, generateCode };
 }
 
-type SvelteGenerator = (code: {
-	script?: string;
-	module?: string;
-	css?: string;
-	template?: string;
-}) => string;
-export function parseSvelte(
-	source: string,
-	options?: { typescript?: boolean }
-): {
-	script: ReturnType<typeof parseScript>;
-	module: ReturnType<typeof parseScript>;
-	css: ReturnType<typeof parseCss>;
-	template: ReturnType<typeof parseHtml>;
-	generateCode: SvelteGenerator;
-} {
-	// `xTag` captures the whole tag block (ex: <script>...</script>)
-	// `xSource` is the contents within the tags
-	const scripts = extractScripts(source);
-	// instance block
-	const { tag: scriptTag = '', src: scriptSource = '' } =
-		scripts.find(({ attrs }) => !attrs.includes('module')) ?? {};
-	// module block
-	const { tag: moduleScriptTag = '', src: moduleSource = '' } =
-		scripts.find(({ attrs }) => attrs.includes('module')) ?? {};
-	// style block
-	const { styleTag, cssSource } = extractStyle(source);
-	// rest of the template
-	// TODO: needs more testing
-	const templateSource = source
-		.replace(moduleScriptTag, '')
-		.replace(scriptTag, '')
-		.replace(styleTag, '')
-		.trim();
-
-	const script = parseScript(scriptSource);
-	const module = parseScript(moduleSource);
-	const css = parseCss(cssSource);
-	const template = parseHtml(templateSource);
-
-	const generateCode: SvelteGenerator = (code) => {
-		const ms = new MagicString(source);
-		// TODO: this is imperfect and needs adjustments
-		if (code.script !== undefined) {
-			if (scriptSource.length === 0) {
-				const ts = options?.typescript ? ' lang="ts"' : '';
-				const indented = code.script.split('\n').join('\n\t');
-				const script = `<script${ts}>\n\t${indented}\n</script>\n\n`;
-				ms.prepend(script);
-			} else {
-				const { start, end } = locations(source, scriptSource);
-				const formatted = indent(code.script, ms.getIndentString());
-				ms.update(start, end, formatted);
-			}
-		}
-		if (code.module !== undefined) {
-			if (moduleSource.length === 0) {
-				const ts = options?.typescript ? ' lang="ts"' : '';
-				const indented = code.module.split('\n').join('\n\t');
-				// TODO: make a svelte 5 variant
-				const module = `<script${ts} context="module">\n\t${indented}\n</script>\n\n`;
-				ms.prepend(module);
-			} else {
-				const { start, end } = locations(source, moduleSource);
-				const formatted = indent(code.module, ms.getIndentString());
-				ms.update(start, end, formatted);
-			}
-		}
-		if (code.css !== undefined) {
-			if (cssSource.length === 0) {
-				const indented = code.css.split('\n').join('\n\t');
-				const style = `\n<style>\n\t${indented}\n</style>\n`;
-				ms.append(style);
-			} else {
-				const { start, end } = locations(source, cssSource);
-				const formatted = indent(code.css, ms.getIndentString());
-				ms.update(start, end, formatted);
-			}
-		}
-		if (code.template !== undefined) {
-			if (templateSource.length === 0) {
-				ms.appendLeft(0, code.template);
-			} else {
-				const { start, end } = locations(source, templateSource);
-				ms.update(start, end, code.template);
-			}
-		}
-		return ms.toString();
-	};
+export function parseSvelte(source: string): { ast: utils.SvelteAst.Root } & ParseBase {
+	const ast = utils.parseSvelte(source);
+	const generateCode = () => utils.serializeSvelte(ast);
 
 	return {
-		script: { ...script, source: scriptSource },
-		module: { ...module, source: moduleSource },
-		css: { ...css, source: cssSource },
-		template: { ...template, source: templateSource },
+		ast,
+		source,
 		generateCode
 	};
 }
-
-function locations(source: string, search: string): { start: number; end: number } {
-	const start = source.indexOf(search);
-	const end = start + search.length;
-	return { start, end };
-}
-
-function indent(content: string, indent: string): string {
-	const indented = indent + content.split('\n').join(`\n${indent}`);
-	return `\n${indented}\n`;
-}
-
-// sourced from Svelte: https://github.com/sveltejs/svelte/blob/0d3d5a2a85c0f9eccb2c8dbbecc0532ec918b157/packages/svelte/src/compiler/preprocess/index.js#L253-L256
-const regexScriptTags =
-	/<!--[^]*?-->|<script((?:\s+[^=>'"/\s]+=(?:"[^"]*"|'[^']*'|[^>\s]+)|\s+[^=>'"/\s]+)*\s*)(?:\/>|>([\S\s]*?)<\/script>)/;
-const regexStyleTags =
-	/<!--[^]*?-->|<style((?:\s+[^=>'"/\s]+=(?:"[^"]*"|'[^']*'|[^>\s]+)|\s+[^=>'"/\s]+)*\s*)(?:\/>|>([\S\s]*?)<\/style>)/;
-
-type Script = { tag: string; attrs: string; src: string };
-function extractScripts(source: string): Script[] {
-	const scripts = [];
-	const [tag = '', attrs = '', src = ''] = regexScriptTags.exec(source) ?? [];
-	if (tag) {
-		const stripped = source.replace(tag, '');
-		scripts.push({ tag, attrs, src }, ...extractScripts(stripped));
-		return scripts;
-	}
-
-	return [];
-}
-
-function extractStyle(source: string) {
-	const [styleTag = '', attributes = '', cssSource = ''] = regexStyleTags.exec(source) ?? [];
-	return { styleTag, attributes, cssSource };
-}
diff --git a/packages/core/tooling/svelte/index.ts b/packages/core/tooling/svelte/index.ts
new file mode 100644
index 000000000..ea5dcd33a
--- /dev/null
+++ b/packages/core/tooling/svelte/index.ts
@@ -0,0 +1,87 @@
+import { parseScript, type AstTypes, type SvelteAst } from '../index.ts';
+import { parseSvelte } from '../parsers.ts';
+import { appendFromString } from '../js/common.ts';
+
+export type { SvelteAst };
+
+export function ensureScript(
+	ast: SvelteAst.Root,
+	options?: { langTs?: boolean }
+): AstTypes.Program {
+	let scriptAst = ast.instance?.content;
+	if (!scriptAst) {
+		scriptAst = parseScript('').ast;
+		ast.instance = {
+			type: 'Script',
+			start: 0,
+			end: 0,
+			context: 'default',
+			attributes: options?.langTs
+				? [
+						{
+							type: 'Attribute',
+							start: 8,
+							end: 17,
+							name: 'lang',
+							value: [{ start: 14, end: 16, type: 'Text', raw: 'ts', data: 'ts' }]
+						}
+					]
+				: [],
+			content: scriptAst
+		};
+	}
+
+	return scriptAst;
+}
+
+export function addSlot(
+	ast: SvelteAst.Root,
+	options: { svelteVersion: string; langTs?: boolean }
+): void {
+	const slotSyntax =
+		options.svelteVersion &&
+		(options.svelteVersion.startsWith('4') || options.svelteVersion.startsWith('3'));
+
+	if (slotSyntax) {
+		ast.fragment.nodes.push({
+			type: 'SlotElement',
+			attributes: [],
+			fragment: {
+				type: 'Fragment',
+				nodes: []
+			},
+			name: 'slot',
+			start: 0,
+			end: 0
+		});
+
+		return;
+	}
+
+	const scriptAst = ensureScript(ast, { langTs: options.langTs });
+	appendFromString(scriptAst, {
+		code: 'const { children } = $props();'
+	});
+
+	ast.fragment.nodes.push({
+		type: 'RenderTag',
+		expression: {
+			type: 'CallExpression',
+			callee: {
+				type: 'Identifier',
+				name: 'children',
+				start: 0,
+				end: 0
+			},
+			optional: false,
+			arguments: []
+		},
+		start: 0,
+		end: 0
+	});
+}
+
+export function toFragment(content: string): SvelteAst.Fragment['nodes'] {
+	const { ast } = parseSvelte(content);
+	return ast.fragment.nodes;
+}
diff --git a/packages/create/package.json b/packages/create/package.json
index 6568e2d8e..99908763c 100644
--- a/packages/create/package.json
+++ b/packages/create/package.json
@@ -29,7 +29,8 @@
 		"@types/gitignore-parser": "^0.0.3",
 		"gitignore-parser": "^0.0.2",
 		"sucrase": "^3.35.0",
-		"tiny-glob": "^0.2.9"
+		"tiny-glob": "^0.2.9",
+		"zimmerframe": "^1.1.4"
 	},
 	"keywords": [
 		"create",
diff --git a/packages/create/playground.ts b/packages/create/playground.ts
index 0741e30d0..ff1fbf57d 100644
--- a/packages/create/playground.ts
+++ b/packages/create/playground.ts
@@ -1,9 +1,11 @@
 import fs from 'node:fs';
 import path from 'node:path';
 import * as js from '@sveltejs/cli-core/js';
+import * as svelte from '@sveltejs/cli-core/svelte';
 import { parseJson, parseScript, parseSvelte } from '@sveltejs/cli-core/parsers';
 import { isVersionUnsupportedBelow } from '@sveltejs/cli-core';
 import { getSharedFiles } from './utils.ts';
+import { walk } from 'zimmerframe';
 
 export function validatePlaygroundUrl(link: string): boolean {
 	try {
@@ -100,7 +102,8 @@ export function detectPlaygroundDependencies(files: PlaygroundData['files']): Ma
 	for (const file of files) {
 		let ast: js.AstTypes.Program | undefined;
 		if (file.name.endsWith('.svelte')) {
-			ast = parseSvelte(file.content).script.ast;
+			const { ast: svelteAst } = parseSvelte(file.content);
+			ast = svelte.ensureScript(svelteAst);
 		} else if (file.name.endsWith('.js') || file.name.endsWith('.ts')) {
 			ast = parseScript(file.content).ast;
 		}
@@ -158,8 +161,7 @@ export function setupPlaygroundProject(
 	url: string,
 	playground: PlaygroundData,
 	cwd: string,
-	installDependencies: boolean,
-	typescript: boolean
+	installDependencies: boolean
 ): void {
 	const mainFile = playground.files.find((file) => file.name === 'App.svelte');
 	if (!mainFile) throw new Error('Failed to find `App.svelte` entrypoint.');
@@ -188,19 +190,22 @@ export function setupPlaygroundProject(
 
 			if (file.name === 'src/lib/PlaygroundLayout.svelte') {
 				// getting raw content
-				const { script, template, css } = parseSvelte(file.contents);
-				// generating new content with the right language style
-				const { generateCode } = parseSvelte('', { typescript });
-				contentToWrite = generateCode({
-					script: script
-						.generateCode()
-						.replaceAll('$sv-title-$sv', playground.name)
-						.replaceAll('$sv-url-$sv', url),
-					template: template
-						.generateCode()
-						.replaceAll('onclick="{switchTheme}"', 'onclick={switchTheme}'),
-					css: css.generateCode()
+				const { ast, generateCode } = parseSvelte(file.contents);
+				// change title and url placeholders
+				const scriptAst = svelte.ensureScript(ast);
+				walk(scriptAst as js.AstTypes.Node, null, {
+					Literal(node) {
+						if (node.value === '$sv-title-$sv') {
+							node.value = playground.name;
+							node.raw = undefined;
+						} else if (node.value === '$sv-url-$sv') {
+							node.value = url;
+							node.raw = undefined;
+						}
+					}
 				});
+
+				contentToWrite = generateCode();
 			}
 
 			fs.writeFileSync(path.join(cwd, file.name), contentToWrite, 'utf-8');
@@ -210,18 +215,19 @@ export function setupPlaygroundProject(
 	// add app import to +page.svelte
 	const filePath = path.join(cwd, 'src/routes/+page.svelte');
 	const content = fs.readFileSync(filePath, 'utf-8');
-	const { script, generateCode } = parseSvelte(content, { typescript });
-	js.imports.addDefault(script.ast, { as: 'App', from: `$lib/playground/${mainFile.name}` });
-	js.imports.addDefault(script.ast, {
+	const { ast, generateCode } = parseSvelte(content);
+	const scriptAst = svelte.ensureScript(ast);
+	js.imports.addDefault(scriptAst, { as: 'App', from: `$lib/playground/${mainFile.name}` });
+	js.imports.addDefault(scriptAst, {
 		as: 'PlaygroundLayout',
 		from: `$lib/PlaygroundLayout.svelte`
 	});
-	const newContent = generateCode({
-		script: script.generateCode(),
-		template: `<PlaygroundLayout>
+	ast.fragment.nodes.push(
+		...svelte.toFragment(`<PlaygroundLayout>
 	<App />
-</PlaygroundLayout>`
-	});
+</PlaygroundLayout>`)
+	);
+	const newContent = generateCode();
 	fs.writeFileSync(filePath, newContent, 'utf-8');
 
 	// add packages as dependencies to package.json if requested
diff --git a/packages/create/test/playground.ts b/packages/create/test/playground.ts
index cb9277495..f06ad2644 100644
--- a/packages/create/test/playground.ts
+++ b/packages/create/test/playground.ts
@@ -169,7 +169,6 @@ test('real world download and convert playground async', async () => {
 		'https://svelte.dev/playground/770bbef086034b9f8e337bab57efe8d8',
 		playground,
 		directory,
-		true,
 		true
 	);
 
@@ -221,7 +220,6 @@ test('real world download and convert playground without async', async () => {
 		'https://svelte.dev/playground/770bbef086034b9f8e337bab57efe8d8',
 		playground,
 		directory,
-		true,
 		true
 	);
 
diff --git a/packages/migrate/utils.js b/packages/migrate/utils.js
index a2826bab1..bff1eda97 100644
--- a/packages/migrate/utils.js
+++ b/packages/migrate/utils.js
@@ -314,8 +314,7 @@ export function update_svelte_file(file_path, transform_script_code, transform_s
 		);
 		fs.writeFileSync(file_path, transform_svelte_code(updated, file_path), 'utf-8');
 	} catch (err) {
-		// TODO: change to import('svelte/compiler').Warning after upgrading to Svelte 5
-		const e = /** @type {any} */ (err);
+		const e = /** @type {import('svelte/compiler').Warning} */ (err);
 		console.warn(buildExtendedLogMessage(e), e.frame);
 		console.info(e.stack);
 	}
@@ -332,8 +331,7 @@ export function update_js_file(file_path, transform_code) {
 		const updated = transform_code(content, file_path.endsWith('.ts'), file_path);
 		fs.writeFileSync(file_path, updated, 'utf-8');
 	} catch (err) {
-		// TODO: change to import('svelte/compiler').Warning after upgrading to Svelte 5
-		const e = /** @type {any} */ (err);
+		const e = /** @type {import('svelte/compiler').Warning} */ (err);
 		console.warn(buildExtendedLogMessage(e), e.frame);
 		console.info(e.stack);
 	}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index aaee94169..20f7bb971 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -187,6 +187,9 @@ importers:
       silver-fleece:
         specifier: ^1.2.1
         version: 1.2.1
+      svelte:
+        specifier: ^5.45.0
+        version: 5.45.2
       yaml:
         specifier: ^2.8.1
         version: 2.8.1
@@ -211,6 +214,9 @@ importers:
       tiny-glob:
         specifier: ^0.2.9
         version: 0.2.9
+      zimmerframe:
+        specifier: ^1.1.4
+        version: 1.1.4
 
   packages/migrate:
     dependencies:
@@ -1194,6 +1200,9 @@ packages:
     resolution: {integrity: sha512-qE3Veg1YXzGHQhlA6jzebZN2qVf6NX+A7m7qlhCGG30dJixrAQhYOsJjsnBjJkCSmuOPpCk30145fr8FV0bzog==}
     engines: {node: ^12.20.0 || ^14.13.1 || >=16.0.0}
 
+  devalue@5.5.0:
+    resolution: {integrity: sha512-69sM5yrHfFLJt0AZ9QqZXGCPfJ7fQjvpln3Rq5+PS03LD32Ost1Q9N+eEnaQwGRIriKkMImXD56ocjQmfjbV3w==}
+
   diff@8.0.2:
     resolution: {integrity: sha512-sSuxWU5j5SR9QQji/o2qMvqRNYRDOcBTgsJ/DeCf4iSN4gW+gNMXM7wFIP+fdXZxoNiAnHUTGjCr+TSWXdRDKg==}
     engines: {node: '>=0.3.1'}
@@ -1347,6 +1356,9 @@ packages:
   esrap@2.1.3:
     resolution: {integrity: sha512-T/Dhhv/QH+yYmiaLz9SA3PW+YyenlnRKDNdtlYJrSOBmNsH4nvPux+mTwx7p+wAedlJrGoZtXNI0a0MjQ2QkVg==}
 
+  esrap@2.2.0:
+    resolution: {integrity: sha512-WBmtxe7R9C5mvL4n2le8nMUe4mD5V9oiK2vJpQ9I3y20ENPUomPcphBXE8D1x/Bm84oN1V+lOfgXxtqmxTp3Xg==}
+
   esrap@2.2.1:
     resolution: {integrity: sha512-GiYWG34AN/4CUyaWAgunGt0Rxvr1PTMlGC0vvEov/uOQYWne2bpN03Um+k8jT+q3op33mKouP2zeJ6OlM+qeUg==}
 
@@ -2055,6 +2067,10 @@ packages:
     resolution: {integrity: sha512-d53/xClCjHsuFXuHsn7+F/0NKkkwgRv8kLg2his5YBYqVtfIrBqkvWd+5ZjYN6ryk/jv/rJF00vexXHkK8ofXA==}
     engines: {node: '>=18'}
 
+  svelte@5.45.2:
+    resolution: {integrity: sha512-yyXdW2u3H0H/zxxWoGwJoQlRgaSJLp+Vhktv12iRw2WRDlKqUPT54Fi0K/PkXqrdkcQ98aBazpy0AH4BCBVfoA==}
+    engines: {node: '>=18'}
+
   synckit@0.11.11:
     resolution: {integrity: sha512-MeQTA1r0litLUf0Rp/iisCaL8761lKAZHaimlbGK4j0HysC4PLfqygQj9srcs0m2RdtDYnF8UuYyKpbjHYp7Jw==}
     engines: {node: ^14.18.0 || >=16.0.0}
@@ -3206,6 +3222,8 @@ snapshots:
 
   detect-newline@4.0.1: {}
 
+  devalue@5.5.0: {}
+
   diff@8.0.2: {}
 
   dir-glob@3.0.1:
@@ -3405,6 +3423,10 @@ snapshots:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.5
 
+  esrap@2.2.0:
+    dependencies:
+      '@jridgewell/sourcemap-codec': 1.5.5
+
   esrap@2.2.1:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.5
@@ -4070,6 +4092,24 @@ snapshots:
       magic-string: 0.30.21
       zimmerframe: 1.1.4
 
+  svelte@5.45.2:
+    dependencies:
+      '@jridgewell/remapping': 2.3.5
+      '@jridgewell/sourcemap-codec': 1.5.5
+      '@sveltejs/acorn-typescript': 1.0.7(acorn@8.15.0)
+      '@types/estree': 1.0.8
+      acorn: 8.15.0
+      aria-query: 5.3.2
+      axobject-query: 4.1.0
+      clsx: 2.1.1
+      devalue: 5.5.0
+      esm-env: 1.2.2
+      esrap: 2.2.0
+      is-reference: 3.0.3
+      locate-character: 3.0.0
+      magic-string: 0.30.21
+      zimmerframe: 1.1.4
+
   synckit@0.11.11:
     dependencies:
       '@pkgr/core': 0.2.9