bcomnes · bcomnes · Jun 2, 2026
diff --git a/README.md b/README.md
diff --git a/bin.js b/bin.js
@@ -152,10 +152,10 @@ async function run () {
 
     const tbPkgContents = await readPackage({ cwd: __dirname })
     const mineVersion = tbPkgContents?.['dependencies']?.['mine.css']
-    const uhtmlVersion = tbPkgContents?.['dependencies']?.['uhtml-isomorphic']
+    const fragtmlVersion = tbPkgContents?.['dependencies']?.['fragtml']
     const highlightVersion = tbPkgContents?.['dependencies']?.['highlight.js']
 
-    if (!mineVersion || !uhtmlVersion || !highlightVersion) {
+    if (!mineVersion || !fragtmlVersion || !highlightVersion) {
       console.error('Unable to resolve ejected dependency versions. Exiting...')
       process.exit(1)
     }
@@ -166,7 +166,7 @@ domstack eject actions:
   - Write ${join(relativeSrc, targetGlobalStylePath)}
   - Write ${join(relativeSrc, targetGlobalClientPath)}
   - Add mine.css@${mineVersion} to ${relativePkg}
-  - Add uhtml-isomorphic@${uhtmlVersion} to ${relativePkg}
+  - Add fragtml@${fragtmlVersion} to ${relativePkg}
   - Add highlight.js@${highlightVersion} to ${relativePkg}
 `)
     const answer = await askYesNo(rl, 'Continue?')
@@ -190,7 +190,7 @@ domstack eject actions:
       {
         dependencies: {
           'mine.css': mineVersion,
-          'uhtml-isomorphic': uhtmlVersion,
+          fragtml: fragtmlVersion,
           'highlight.js': highlightVersion,
         },
       })

diff --git a/docs/v11-migration.md b/docs/v11-migration.md
@@ -258,10 +258,11 @@ Previously this silently allowed both to coexist. Choose one approach:
 
 ## 12. Default Layout: uhtml-isomorphic → preact
 
-The bundled default `root.layout.js` (used when `--eject` has not been run, or when using the default layout) was rewritten from `uhtml-isomorphic` to use `preact` + `preact-render-to-string`.
+The bundled default `root.layout.js` (used when `--eject` has not been run, or when using the default layout) was rewritten from `uhtml-isomorphic` to use `htm/preact` and `preact-render-to-string`.
 
 - `uhtml-isomorphic` is **no longer a production dependency** of `@domstack/static`
-- `preact` and `preact-render-to-string` are now production dependencies
+- `preact` is now a production dependency
+- `preact-render-to-string` is now a production dependency
 
 **Action required:**
 - If your layout files import `uhtml-isomorphic` and rely on it being hoisted from domstack's `node_modules`, you must now add it explicitly to your project:

diff --git a/docs/v12-migration.md b/docs/v12-migration.md
@@ -0,0 +1,121 @@
+# Migration Guide: domstack v12
+
+This guide covers breaking and notable changes when moving from domstack v11 to v12.
+
+If you are migrating from `top-bun`, first follow the historical v11 guide at [v11-migration.md](v11-migration.md), then apply the v12 changes below.
+
+## Table of Contents
+
+1. [Default Layout Uses fragtml](#1-default-layout-uses-fragtml)
+2. [Default Dependencies Changed](#2-default-dependencies-changed)
+3. [JSX Runtime Is Opt-In](#3-jsx-runtime-is-opt-in)
+4. [Preact Examples Stay Preact](#4-preact-examples-stay-preact)
+5. [Development Server Uses @domstack/sync](#5-development-server-uses-domstacksync)
+6. [Migration Checklist](#6-migration-checklist)
+
+---
+
+## 1. Default Layout Uses fragtml
+
+The bundled default `root.layout.js` now uses [`fragtml`](https://github.com/bcomnes/fragtml#readme) for server-side HTML rendering.
+
+If you rely on the bundled default layout, no action is required. If you previously ejected the default layout and want the v12 default style, update your layout imports and rendering code from Preact/HTM to `fragtml`.
+
+```js
+// Before
+import { html } from 'htm/preact'
+import { render } from 'preact-render-to-string'
+```
+
+```js
+// After
+import { html, raw, render } from 'fragtml'
+```
+
+Use `raw(htmlString)` when intentionally inserting already-rendered HTML, such as markdown output passed to a layout as `children`.
+
+---
+
+## 2. Default Dependencies Changed
+
+The default template no longer includes Preact, HTM, or `preact-render-to-string`.
+
+When you run `domstack --eject`, domstack adds:
+
+- `mine.css`
+- `fragtml`
+- `highlight.js`
+
+It does not add:
+
+- `preact`
+- `htm`
+- `preact-render-to-string`
+
+If your project uses any of those packages directly, keep them in your own `package.json`.
+
+---
+
+## 3. JSX Runtime Is Opt-In
+
+Client `.jsx` and `.tsx` bundles are still supported through esbuild, but domstack no longer configures Preact as the default JSX runtime.
+
+If your browser client code uses JSX or TSX, install the runtime you want and configure it with `esbuild.settings`.
+
+For Preact:
+
+```sh
+npm install preact
+```
+
+```js
+// src/esbuild.settings.js
+export default async function esbuildSettingsOverride (esbuildSettings) {
+  esbuildSettings.jsx = 'automatic'
+  esbuildSettings.jsxImportSource = 'preact'
+
+  return esbuildSettings
+}
+```
+
+For React:
+
+```sh
+npm install react react-dom
+```
+
+```js
+// src/esbuild.settings.js
+export default async function esbuildSettingsOverride (esbuildSettings) {
+  esbuildSettings.jsx = 'automatic'
+  esbuildSettings.jsxImportSource = 'react'
+
+  return esbuildSettings
+}
+```
+
+---
+
+## 4. Preact Examples Stay Preact
+
+Examples that actually mount Preact in the browser still use Preact. Examples that only needed server-side HTML rendering now use `fragtml`.
+
+This means Preact remains a good opt-in client runtime, but it is no longer the default server-side layout dependency.
+
+---
+
+## 5. Development Server Uses @domstack/sync
+
+Watch/serve mode now uses [`@domstack/sync`](https://www.npmjs.com/package/@domstack/sync) for the local development server.
+
+This provides live reload, CSS injection, ghost mode, and the UI panel. If you were relying on BrowserSync-specific behavior or output, update your expectations around logs, access URLs, and reload handling.
+
+---
+
+## 6. Migration Checklist
+
+- [ ] If you use an ejected default layout, update it to `fragtml` or keep your existing layout dependencies explicitly.
+- [ ] If you use `htm/preact` or `preact-render-to-string` in server-side layouts/pages, either keep those dependencies or migrate that code to `fragtml`.
+- [ ] If you use `.jsx` or `.tsx` browser clients, add an `esbuild.settings` file that configures your JSX runtime.
+- [ ] If you use Preact browser clients, keep `preact` in your project dependencies.
+- [ ] If you rely on BrowserSync-specific dev-server behavior, test watch mode with `@domstack/sync`.
diff --git a/examples/basic/README.md b/examples/basic/README.md
@@ -86,7 +86,7 @@ Both global and page-specific CSS is demonstrated, showing how to scope styles a
 
 This is one of several examples in the DOMStack repository. For more advanced features, check out the other examples like:
 - css-modules
-- preact
+- fragtml
 - tailwind
 - and more...
 

diff --git a/examples/basic/package.json b/examples/basic/package.json
@@ -20,9 +20,7 @@
   },
   "dependencies": {
     "@domstack/static": "file:../../.",
-    "htm": "^3.1.1",
-    "preact": "^10.26.6",
-    "preact-render-to-string": "^6.5.13",
+    "fragtml": "^0.0.9",
     "mine.css": "^9.0.1",
     "highlight.js": "^11.9.0"
   }

diff --git a/examples/basic/src/js-page/loose-assets/page.ts b/examples/basic/src/js-page/loose-assets/page.ts
@@ -1,10 +1,11 @@
-import { html } from 'htm/preact'
+import { html } from 'fragtml'
+import type { HtmlResult } from 'fragtml/types.js'
 import type { PageFunction } from '@domstack/static'
 
-import sharedData from './shared-lib.js'
+import sharedData from './shared-lib.ts'
 import type { PageVars } from '../../layouts/root.layout.ts'
 
-const JSPage: PageFunction<PageVars> = async () => {
+const JSPage: PageFunction<PageVars, HtmlResult> = async () => {
   return html`
   <div>
     <p>

diff --git a/examples/basic/src/js-page/page.js b/examples/basic/src/js-page/page.js
@@ -1,11 +1,12 @@
 /**
  * @import { PageFunction } from '@domstack/static'
- * @import { PageVars } from '../layouts/root.layout.js
+ * @import { PageVars } from '../layouts/root.layout.ts'
+ * @import { HtmlResult } from 'fragtml/types.js'
  */
-import { html } from 'htm/preact'
+import { html } from 'fragtml'
 
 /**
-* @type { PageFunction <PageVars> }
+* @type { PageFunction <PageVars, HtmlResult> }
 */
 export default async function JSPage ({
   vars: {
@@ -26,7 +27,7 @@ export default async function JSPage ({
       <ul>
         <li>Access and use variables directly in your rendering logic</li>
         <li>Generate dynamic content based on data or conditions</li>
-        <li>Use component-based architecture with Preact or other libraries</li>
+        <li>Use typed HTML templates or component libraries</li>
         <li>Return either HTML strings or component objects</li>
       </ul>
     </section>
@@ -36,7 +37,7 @@ export default async function JSPage ({
       <p>
         Export a default function (async or sync) that returns a string or any
         type that your layout can handle. In this example, we're using
-        <a href="https://github.com/developit/htm"><code>htm/preact</code></a> for JSX-like syntax.
+        <a href="https://github.com/bcomnes/fragtml"><code>fragtml</code></a> for typed, safe HTML templates.
       </p>
       <div class="code-example">
         <pre><code>export default async function MyPage({ vars }) {

diff --git a/examples/basic/src/layouts/child.layout.ts b/examples/basic/src/layouts/child.layout.ts
@@ -1,11 +1,11 @@
 import type { LayoutFunction } from '@domstack/static'
-import { html } from 'htm/preact'
-import { render } from 'preact-render-to-string'
+import { html, raw, render } from 'fragtml'
+import type { HtmlResult } from 'fragtml/types.js'
 
-import defaultRootLayout from './root.layout.js'
-import type { PageVars } from './root.layout.js'
+import defaultRootLayout from './root.layout.ts'
+import type { PageVars } from './root.layout.ts'
 
-const articleLayout: LayoutFunction<PageVars> = (args) => {
+const articleLayout: LayoutFunction<PageVars, string | HtmlResult, string> = (args) => {
   const { children, ...rest } = args
   const wrappedChildren = render(html`
     <article class="bc-article h-entry" itemscope itemtype="http://schema.org/NewsArticle">
@@ -14,8 +14,8 @@ const articleLayout: LayoutFunction<PageVars> = (args) => {
 
       <section class="e-content" itemprop="articleBody">
         ${typeof children === 'string'
-          ? html`<div dangerouslySetInnerHTML=${{ __html: children }}></div>`
-          : children /* Support both preact and string children */
+          ? html`<div>${raw(children)}</div>`
+          : children
         }
       </section>
     </article>

diff --git a/examples/basic/src/layouts/root.layout.ts b/examples/basic/src/layouts/root.layout.ts
@@ -7,8 +7,8 @@
 //
 // All other variables are set on a page level basis, either by hand or by data extraction from the page type.
 
-import { html } from 'htm/preact'
-import { render } from 'preact-render-to-string'
+import { html, raw, render } from 'fragtml'
+import type { HtmlResult } from 'fragtml/types.js'
 import type { LayoutFunction } from '@domstack/static'
 
 export interface PageVars {
@@ -17,7 +17,7 @@ export interface PageVars {
   basePath?: string;
 }
 
-const RootLayout: LayoutFunction<PageVars> = async ({
+const RootLayout: LayoutFunction<PageVars, string | HtmlResult, string> = async ({
   vars: {
     title,
     siteName,
@@ -27,32 +27,25 @@ const RootLayout: LayoutFunction<PageVars> = async ({
   styles,
   children,
 }) => {
-  return /* html */`
+  return render(html`
     <!DOCTYPE html>
     <html>
-      ${render(html`
-        <head>
-          <meta charset="utf-8" />
-          <title>${siteName}${title ? ` | ${title}` : ''}</title>
-          <meta name="viewport" content="width=device-width, user-scalable=no" />
-          ${scripts
-            ? scripts.map(script => html`<script type='module' src="${script.startsWith('/') ? `${basePath ?? ''}${script}` : script}" />`)
-            : null}
-          ${styles
-            ? styles.map(style => html`<link rel="stylesheet" href="${style.startsWith('/') ? `${basePath ?? ''}${style}` : style}" />`)
-            : null}
-        </head>
-      `)}
-      ${render(html`
-        <body className="safe-area-inset">
-        ${typeof children === 'string'
-            ? html`<main className="mine-layout app-main" dangerouslySetInnerHTML="${{ __html: children }}"/>`
-            : html`<main className="mine-layout app-main">${children}</main>`
-        }
-        </body>
-      `)}
+      <head>
+        <meta charset="utf-8" />
+        <title>${siteName}${title ? ` | ${title}` : ''}</title>
+        <meta name="viewport" content="width=device-width, user-scalable=no" />
+        ${scripts
+          ? scripts.map(script => html`<script type="module" src="${script.startsWith('/') ? `${basePath ?? ''}${script}` : script}"></script>`)
+          : null}
+        ${styles
+          ? styles.map(style => html`<link rel="stylesheet" href="${style.startsWith('/') ? `${basePath ?? ''}${style}` : style}" />`)
+          : null}
+      </head>
+      <body class="safe-area-inset">
+        <main class="mine-layout app-main">${typeof children === 'string' ? raw(children) : children}</main>
+      </body>
     </html>
-  `
+  `)
 }
 
 export default RootLayout
diff --git a/examples/basic/tsconfig.json b/examples/basic/tsconfig.json
@@ -6,8 +6,7 @@
     "allowImportingTsExtensions": true,
     "rewriteRelativeImportExtensions": true,
     "verbatimModuleSyntax": true,
-    "jsx": "react-jsx",
-    "jsxImportSource": "preact"
+    "lib": ["ES2024", "DOM"]
   },
   "include": [
     "**/*",

diff --git a/examples/blog/package.json b/examples/blog/package.json
@@ -19,9 +19,7 @@
   },
   "dependencies": {
     "@domstack/static": "file:../../.",
-    "htm": "^3.1.1",
-    "mine.css": "^10.0.0",
-    "preact": "^10.26.6",
-    "preact-render-to-string": "^6.5.13"
+    "fragtml": "^0.0.9",
+    "mine.css": "^10.0.0"
   }
 }
diff --git a/examples/blog/src/about/README.md b/examples/blog/src/about/README.md
@@ -19,7 +19,7 @@ first computer programmer.
 Built with:
 
 - [domstack](https://github.com/bcomnes/domstack) — the build system
-- [preact](https://preactjs.com) — JSX rendering for layouts
+- [fragtml](https://github.com/bcomnes/fragtml) — typed HTML rendering for layouts
 - [mine.css](https://mine.css.bret.io) — baseline styles
 - [esbuild](https://esbuild.github.io) — JS/CSS bundling
 

diff --git a/examples/blog/src/blog/2024/hello-world/README.md b/examples/blog/src/blog/2024/hello-world/README.md
@@ -12,7 +12,7 @@ tags:
 
 Welcome to this blog. It's built with [domstack](https://github.com/bcomnes/domstack),
 a static site generator that lets you write pages in TypeScript, Markdown, or plain HTML
-and compose them with layouts written in JSX (via preact).
+and compose them with typed HTML layouts written with fragtml.
 
 ## What makes this interesting
 

diff --git a/examples/blog/src/blog/page.ts b/examples/blog/src/blog/page.ts
@@ -1,5 +1,4 @@
-import { html } from 'htm/preact'
-import { render } from 'preact-render-to-string'
+import { html, render } from 'fragtml'
 import type { PageFunction } from '@domstack/static'
 import type { GlobalData } from '../global.data.js'
 import type { SiteVars } from '../global.vars.js'

diff --git a/examples/blog/src/global.data.ts b/examples/blog/src/global.data.ts
@@ -1,5 +1,4 @@
-import { html } from 'htm/preact'
-import { render } from 'preact-render-to-string'
+import { html, render } from 'fragtml'
 import type { AsyncGlobalDataFunction } from '@domstack/static'
 
 export interface BlogPost {