From Zero to First Cloudflare Worker in 20 Minutes

Cloudflare Workers are serverless functions that run at the edge — closer to your users than any VPS, and free for 100,000 requests a day. The fastest way to understand them is to ship one. This whole tutorial takes about 20 minutes, and everything except the account signup is free.

Step 1: Install Wrangler

Wrangler is Cloudflare’s CLI. Install it globally with npm:

npm install -g wrangler
wrangler --version

Then authenticate — this opens a browser tab where you confirm access to your Cloudflare account:

wrangler login

No account yet? The login flow creates one for you. You can also use an API token with wrangler login --api-key if you prefer.

Step 2: Scaffold the project

npx wrangler init my-worker
cd my-worker

Accept the defaults: TypeScript if you like it, no tests, no git. You’ll get a src/index.ts with a “Hello World” Worker and a wrangler.jsonc config file. Open src/index.ts — that’s your entire server.

Step 3: Write the code

A Worker is just a function that receives a request and returns a response. Replace the boilerplate with something actually useful — a JSON API that echoes back who asked:

export default {
  async fetch(request: Request): Promise<Response> {
    const url = new URL(request.url);

    if (url.pathname === "/health") {
      return Response.json({ status: "ok", region: request.cf?.colo });
    }

    if (url.pathname === "/hello") {
      const name = url.searchParams.get("name") ?? "world";
      return Response.json({
        message: `Hello, ${name}!`,
        time: new Date().toISOString(),
      });
    }

    return Response.json({ error: "not found" }, { status: 404 });
  },
};

Note request.cf — Cloudflare injects request metadata like the edge colo that served you, for free. Try it locally first:

npx wrangler dev

Hit http://localhost:8787/hello?name=nova and you’ll see your JSON response. Local-first iteration is the killer feature of Workers — no deploy loop required while developing.

Step 4: Deploy

One command ships it to the edge:

npx wrangler deploy

You’ll get a URL like https://my-worker.<your-subdomain>.workers.dev. That’s it — your code is now running in ~300 cities, TLS included, with a global CDN in front.

Step 5: Test it for real

curl "https://my-worker.your-subdomain.workers.dev/hello?name=sten"
curl "https://my-worker.your-subdomain.workers.dev/health"

And watch live logs while traffic hits it:

npx wrangler tail

Every request shows up with status, timing, and the colo that handled it. The /health response’s region field will honestly surprise you the first time it returns somewhere far from your home server.

Where to go next

The free tier gets you 100,000 requests per day, and the platform scales from here:

• KV — global key-value storage for config, sessions, redirects.
• D1 — a SQLite-compatible database with a generous free tier.
• R2 — S3-compatible object storage with zero egress fees.
• Cron Triggers — run scheduled jobs at the edge, no server required.

Twenty minutes after starting, you have a deployed, logged, globally-distributed API. That’s the whole pitch for Workers — and now you know exactly how real it is.