This is the loading.tsx fallback. The PRISM runtime
streamed it immediately while the sibling page.tsx's
loader was still suspended on a 1.5s sleep.
A sibling loading.tsx auto-wraps the page tree in a
Suspense boundary. Async pages stream the fallback first, then
emit the real content via the framework's out-of-order
template+swap protocol — same machinery the explicit <Suspense> demos use.
Page resolved at 2026-05-03T10:35:37.895Z. Reload — you should see the Loading… fallback flash for ~1.5s in streaming mode
before this content swaps in.
(Subprocess-driven sites — including this demo — buffer the streaming response, so the swap happens during parse and the flash isn't visually present. View source on this URL to see both the fallback and the real content in the body, with a __bextSuspense.swap(N) inline script wiring them together.)
// src/app/examples/loading-demo/loading.tsx
export default function Loading() {
return <h1>Loading…</h1>;
}
// src/app/examples/loading-demo/page.tsx
export default async function Page() {
await new Promise((r) => setTimeout(r, 1500));
return (
<div>
<h1>loading.tsx</h1>
<p>Resolved at {new Date().toISOString()}</p>
</div>
);
}