A Cloudflare worker that allows you to make your domains or email addresses aliases to your Fediverse account

webfinger-cf-worker.js

// add your domain to CF and assign this worker to a route: example.com/.well-known/webfinger*

export default {
  async fetch(request, env) {
    return await handleRequest(request);
  },
};

const lookupmap = {
  "acct:me@example.com": {
    self: "https://mastodon.social/users/me_example",
    profile: "https://mastodon.social/@me_example",
  },
};

async function handleRequest(request) {
  const u = new URL(request.url);
  const resource = (u.searchParams.get("resource") ?? "").toLowerCase().trim();
  const result = lookupmap[resource];
  if (!result) {
    return new Response("resource not found", {
      headers: { "Content-Type": "text/plain" },
      status: 404,
    });
  }
  return new Response(
    JSON.stringify({
      subject: resource,
      aliases: [
        result.profile,
        result.self,
      ],
      links: [
        {
          rel: "http://webfinger.net/rel/profile-page",
          type: "text/html",
          href: result.profile,
        },
        {
          rel: "self",
          type: "application/activity+json",
          href: result.self,
        },
        {
          rel: "http://ostatus.org/schema/1.0/subscribe",
          // replace "mastodon.social" below with your Mastodon instance
          template: `https://mastodon.social/authorize_interaction?uri={uri}`,
        },
      ],
    })
  );
}