Apps (Compute)

An app is code, a static site, or both on one address. Code runs in lightweight isolates (the same workerd runtime as Cloudflare Workers) on every edge node, so the nearest node answers each visitor. Apps start in milliseconds and you pay for what they use.

Create an app

• Editor: create an app under Apps and write code in the browser.
• Build with AI: describe it and let Studio write it.
• GitHub: connect a repository; every push builds and deploys, and pull requests get preview addresses.
• CLI: rr deploy from your computer, see rrangler.

Write a handler

export default {
  async fetch(request, env, ctx) {
    const url = new URL(request.url);
    if (url.pathname === "/api/hello") {
      return Response.json({ hello: env.GREETING ?? "world" });
    }
    return new Response("Not found", { status: 404 });
  },

  // Optional: runs on the schedule set under Triggers
  async scheduled(event, env, ctx) {
    ctx.waitUntil(cleanUp(env));
  },
};