To get started, install the canary version of react & react-dom:
# Any package manager can be usedbun add react@canary react-dom@canaryTo render a React component to an HTML stream server-side (SSR):
import { renderToReadableStream } from "react-dom/server";
function Component(props: { message: string }) {
return (
<body>
<h1>{props.message}</h1>
</body>
);
}
const stream = await renderToReadableStream(
<Component message="Hello from server!" />,
);
Combining this with Bun.serve(), we get a simple SSR HTTP server:
Bun.serve({
async fetch() {
const stream = await renderToReadableStream(
<Component message="Hello from server!" />,
);
return new Response(stream, {
headers: { "Content-Type": "text/html" },
});
},
});
React 19 and later includes an SSR optimization that takes advantage of Bun's "direct" ReadableStream implementation. If you run into an error like export named 'renderToReadableStream' not found, please make sure to install the canary version of react & react-dom, or import from react-dom/server.browser instead of react-dom/server. See facebook/react#28941 for more information.