prerendering.md

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Edge Prerendering

Prerender pages at deploy time so the first visitor receives cached HTML.

• Markdown pages are auto-prerendered.
• Island pages with no companion loader and no dynamic params are also auto-prerendered.

Static pages (no params)

Export prerender = true from the companion .server.ts file:

// pages/about.server.ts
export const prerender = true;

Pages without dynamic params do not need getPrerenderPaths().

Dynamic pages (with params)

For pages with URL params, also export getPrerenderPaths() to specify which param combinations to prerender:

// pages/blog/[slug].server.ts
export const prerender = true;

export async function getPrerenderPaths() {
  // Return param objects matching the URL pattern
  return [{ slug: 'hello-world' }, { slug: 'getting-started' }];
}

Custom SSR

In custom SSR mode (src/main.ssr.ts), export getPrerenderPaths() at the top level. Since there's no file-based routing, return full path strings:

// src/main.ssr.ts
export const prerender = true;

export async function getPrerenderPaths() {
  return ['/', '/about', '/blog/hello-world'];
}

Relationship to revalidation

Setting routing.isr: false in void.config.ts disables ISR and this edge-prerendering behavior, including per-page exports. It does not disable build-time HTML generation with output: "static".

Prerendered pages default to a one-year revalidate TTL. Deploys clear the ISR cache.

Override the TTL per page:

// pages/about.server.ts
export const prerender = true;
export const revalidate = 3600;

If the cached page expires before your next deploy, the next request waits for a fresh render.

Behavior details

• Prerender happens once per deployment, before traffic is routed to the new version. Prerendered pages are cached at the edge.
• Only paths with a positive revalidate TTL are prerendered (TTL 0 is skipped).
• Prerender failures are logged but never block the deploy. The page will render on the first request as usual.