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Server rendering

Ness renders HTML with React streaming SSR. Route loaders run on the server, the shell can be flushed before slower <Suspense> content, and the browser hydrates the same route tree.

app/root.tsx owns the document. It is one default-exported component that renders the whole document with <Outlet /> inside it — there is no Layout export, and no root ErrorBoundary:

import { Links, Outlet, Scripts, ScrollRestoration } from 'react-router';

export default function App() {
  return (
    <html lang="en">
      <head>
        <meta charSet="utf-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1" />
        <Links />
      </head>
      <body>
        <Outlet />
        <ScrollRestoration />
        <Scripts />
      </body>
    </html>
  );
}

<Links /> stays, because stylesheets are the framework's to inject. There is no <Meta />: a page declares its own metadata with the components from @nessframework/components, which React hoists into <head> from anywhere in the tree. See Components.

Keep <title> out of the root. React does not deduplicate it, and the browser takes the first one in the document, so a root title would silently win over every page's own.

Errors are caught by the route-level error.tsx that every starter ships, which renders inside the <Outlet /> and therefore inside the document. That boundary covers its own segment: app/routes/error.tsx catches what the routes in app/routes throw, and a nested directory needs its own error.tsx, or an app/routes/layout.tsx above it, to be covered as well. Anything that escapes every boundary falls to React Router's built-in error page, which renders a document of its own.

The default entry handles abort signals, bots, stream errors, serialized loader data, CSP-aware scripts, and hydration. Use ness reveal entry.server when you need a custom nonce, stream timeout, or renderer.

In production, ness start serves immutable assets, public files, SSR or RSC responses, page caching, image optimization, and /_ness/health.

It also negotiates Accept-Encoding on the way out, serving the .br or .gz twin sitting next to a static asset when the client will take it and compressing the rendered response otherwise. With server.trustProxy on, X-Forwarded-Proto and X-Forwarded-Host are applied to request.url before the request is handled, so loaders and redirects see the address the visitor used. On SIGTERM the health route starts reporting 503 and in-flight requests are drained before the process exits.