createCloudflarePrerenderSource

createCloudflarePrerenderSource({ binding, directory }) is the Workers PrerenderSource: when a request asks for a page with render: "prerender", the application queries it by pathname and the source reads the HTML, CSRF meta insertion offset, ETag, navigation payload and, since 1.3 and 1.4, script and style hashes from the assets binding. The index (manifest.json) and each page are read once per isolate.

Pages live in assets/_meeko/prerender/ but are never served as files: the application returns them as documents, with the session's CSRF meta, CSP and page headers.

Usage#

import { createCloudflareAssetReader, createCloudflarePrerenderSource, createWorker } from "@meekojs/meeko/cloudflare";

export default createWorker(({ env, platform }) => createApp({
  production: true,
  platform,
  assets: createCloudflareAssetReader({ binding: env.ASSETS, assets: manifest.assets ?? {} }),
  prerender: createCloudflarePrerenderSource({ binding: env.ASSETS }),
}));

Type#

function createCloudflarePrerenderSource(
  options: CloudflarePrerenderSourceOptions,
): PrerenderSource

interface CloudflarePrerenderSourceOptions {
	readonly binding: CloudflareAssetsBinding
	readonly directory?: string
}

interface PrerenderSource {
	get(pathname: string): Promise<PrerenderedPage | undefined>
}

Parameters#

Return value#

A PrerenderSource with get(pathname), which resolves to:

• undefined if the index does not list the route (or there is no index: an application without prerendered pages);
• { html, headOffset, etag, payload?, scriptHashes?, styleHashes? } if it does.

A failed read is not cached: the next request retries it.

Examples#

A prerendered page in Workers#

// app/pages/precios.route.ts
import { definePage } from "@meekojs/meeko/framework";

export const route = definePage({ render: "prerender", head: () => ({ title: "Precios" }) });

meeko build --adapter cloudflare renders it in Node and writes it to assets/_meeko/prerender/. In production:

GET /precios (without a session) → build HTML, ETag, cache-control: public, max-age=0, must-revalidate
GET /precios (with a session) → the same HTML with <meta name="meeko-csrf-token">, cache-control: private, no-store

CSP with hashes (since 1.7)#

// meeko.config.ts
import { defineMeekoConfig } from "@meekojs/meeko/framework";

export default defineMeekoConfig({
  server: { adapter: "cloudflare", contentSecurityPolicy: { "default-src": ["'self'"], "script-src": ["'self'"], "object-src": ["'none'"] } },
});

The /precios response carries the policy with the index's scriptHashes and styleHashes, without a nonce, and still responds with 304 to an If-None-Match.

Common mistakes#

A folder without a trailing /#

createCloudflarePrerenderSource({ binding: env.ASSETS, directory: "/_meeko/prerender" });

TypeError: Prerender directory must start and end with /, when creating the application.

createCloudflarePrerenderSource({ binding: env.ASSETS, directory: "/_meeko/prerender/" });

An index listing a page that was not uploaded#

assets/_meeko/prerender/manifest.json deployed without assets/_meeko/prerender/precios/index.html

The /precios request responds with 500 and onError receives Error: Missing prerendered file /_meeko/prerender/…. Deploy the complete output.

npx wrangler deploy --config .meeko/output/cloudflare/wrangler.jsonc

Notes#

• Once per isolate. The index and each page are stored in isolate memory after the first read; a new deployment creates new isolates.
• No TCP or disk. Everything is read through the ASSETS binding.
• Security. Paths are only looked up in the index; the filename comes from the index, never the request.
• Session. The prerendered HTML is the same for everyone: Meeko inserts each session's CSRF meta at headOffset and marks the response as private, no-store.

Related#

• createWorkerServes a Meeko application from a Cloudflare module Worker, created once per isolate with its bindings, forwarding Socket upgrades to their room's Durable Object.
• createCloudflareAssetReaderServes only build files listed in the manifest from Cloudflare's Static Assets binding, with the ETag, HEAD, 304 and caching behavior of the other adapters.
• definePageDeclares a page's route options (params and search schemas, rendering mode, loader, head, layout, middleware, cache and sitemap) with types flowing between them.
• Cloudflare WorkersMeeko as a full-stack framework
• Rendering modesMeeko as a full-stack framework