Mreact Docs

Deployments

CDN Assets

Use a CDN for generated client assets when the app server should keep rendering HTML but static scripts, stylesheets, and copied public files should come from a static origin.

What moves to the CDN

Upload .mreact/client/ to the CDN origin. This directory contains hashed route scripts, shared chunks, route CSS, copied public files, and the client manifest.

import { dirname } from "node:path";
import { fileURLToPath } from "node:url";

const projectRoot = dirname(fileURLToPath(import.meta.url));

mreactRouter({
  projectRoot,
  routesDir: "src/app",
  assetBaseUrl: "https://cdn.example.com/_mreact/client/",
  publicAssetBaseUrl: "https://cdn.example.com/",
});

assetBaseUrl changes route scripts, modulepreload links, dynamic import preload helpers, navigation runtime assets, and route stylesheet assets. publicAssetBaseUrl is for router-generated public asset URLs in integrations that use the manifest. Root-relative URLs you write manually, such as <img src="/logo.svg">, remain the literal URL you wrote.

HTML routes still come from the app origin unless you use a static export workflow. The CDN asset host should not serve application routes, server actions, route handlers, or API endpoints.

Release order

Deploy CDN assets and server output in the same release transaction:

  1. Build the app.
  2. Upload .mreact/client/ to the CDN path for the release.
  3. Verify the client manifest and at least one route script exist on the CDN.
  4. Deploy server output that references that CDN path.
  5. Roll back server output before deleting CDN assets from the previous release.

This order prevents HTML from pointing at missing scripts or stylesheets. Keep old CDN assets long enough for users with open tabs, cached HTML, or slow edge propagation.

Cache headers

Hashed generated assets can use Cache-Control: public, max-age=31536000, immutable. Manifest files, non-fingerprinted public assets, and release marker files should use shorter cache or revalidation.

Do not give long immutable cache to HTML routes. Route HTML and API responses belong to Cache Policy, not the CDN asset policy.