Step 2 of 6

Origins & routing

Pick the canonical host, name the two origins, and decide which paths go where. First match wins — order matters.

Name your hosts

Canonical host: the one your users and Google see. e.g. www.example.com.
Primary origin: serves most traffic. e.g. brand.webflow.io.
Secondary origin: serves a subset, usually by path prefix. e.g. legacy.example.com.

Routing rules

A rule is just { prefix, to }. The Worker walks the list in order and uses the first one whose prefix matches the request path. Put the most specific rules first; end with a catch-all "/" to the primary.

const RULES = [
  { prefix: '/blog',  to: 'secondary' }, // legacy WordPress blog
  { prefix: '/shop',  to: 'secondary' }, // legacy storefront
  { prefix: '/',      to: 'primary'   }, // everything else → Webflow
];

Try it: which origin handles this request?

Edit the config, then enter a request URL to see what the Worker would do. Nothing is sent over the network — this is a faithful reimplementation of the same rules in the browser.

Canonical host

Primary origin

Secondary origin

Path rules (first match wins)

Rewrite canonical / og:url / hreflang back to canonical host Strip Content-Security-Policy from response Force HTTPS on incoming requests

Request URL

The Worker so far

// src/index.js
const PRIMARY   = 'brand.webflow.io';
const SECONDARY = 'legacy.example.com';

const RULES = [
  { prefix: '/blog', to: SECONDARY },
  { prefix: '/shop', to: SECONDARY },
  { prefix: '/',     to: PRIMARY   },
];

export default {
  async fetch(request) {
    const url = new URL(request.url);
    const rule = RULES.find(r => url.pathname.startsWith(r.prefix));
    if (!rule) return new Response('Not Found', { status: 404 });

    const upstream = `https://${rule.to}${url.pathname}${url.search}`;
    return fetch(upstream, request);
  },
};

This works — but the response still references the upstream host. Open the legacy page and you'll find <link rel="canonical" href="https://legacy.example.com/blog/x">. Google will index that URL, not yours. Fix it in the next step.