Rendering: SSG & Streaming

Krate is SSG-first: every page is pre-rendered to static HTML at build time. On top of that base, pages can opt into Streaming SSR — including per-request data via runtime components.

SSG (default)

export default function Page() {
  return <h1>Hello, World!</h1>;
}

The page is rendered once at build time. The output is a static HTML file plus a hydration bundle. This is the fastest and most portable mode — it works on any static host.

Server components (// @server) are evaluated at build time and their output is baked into the static HTML, so build-time data needs no special page-level function. See Data Fetching.

Streaming SSR

Streaming uses Suspense-based two-phase rendering for pages that import runtime components, or when ssr.streaming forces all pages into streaming mode:

1. Phase 1 (fallback) — renders the page with fallback content.
2. Phase 2 (resolved) — streams resolved content via <!--suspense-resolved:N--> markers with chunked transfer encoding.

This is the recommended path for per-request data, which lives in runtime components (// @runtime):

// @runtime
export default function PriceTag({ price }) {
  return <span>{price}</span>;
}

// Force ALL pages to streaming SSR
export default defineConfig({
  ssr: { streaming: true },
});

Or opt in per page:

export const config = { streaming: true };

How streaming works

• Pages are built to static HTML where possible.
• Pages with runtime components are compiled into server bundles and rendered at request time by the Node renderer server.
• The renderer resolves runtime component props and streams resolved content through Suspense boundaries.
• manifest.json records each page's mode and metadata.

Choosing an approach

Need	Approach
Static content, fastest	SSG (default)
Data at build time	Server component (@server)
Per-request data	Runtime component (@runtime) + Streaming SSR
Static + dynamic route URLs	generateStaticParams

See Component Tiers for how server and runtime components work, and Data Fetching for the full data model.