One Cloudflare Worker, one route:

GET /avatar/<name>

<name> is anything that stands for somebody — a username, an email, an id, a Gravatar hash — and the same name always renders the same blobatar. Parameters are named as the library names them (size/s, background, hue, tone, expression, title), and Gravatar's d, f and r are accepted and ignored so that an existing Gravatar URL works by changing the host alone.

GET /avatar/ returns the full parameter list; so does any other path, with a 404.

The button clones this directory into your Git account, deploys it to yours, and hands back https://blobatar-api.<your-subdomain>.workers.dev. Every push to your clone redeploys it. To attach your own hostname, add it in the dashboard under Workers → your Worker → Domains & Routes, or as a routes entry in wrangler.jsonc.

By hand, if you would rather:

bun install
bunx wrangler deploy

Nothing, at any traffic a normal application produces. The Workers free plan allows 100,000 requests a day and 10ms of CPU per request; rendering a blobatar measures 12µs and the response is 357 bytes gzipped. There is no database, no bucket and no bound resource of any kind — the avatar is a pure function of the URL, which is what lets Cache-Control push most of the traffic off this Worker and into caches nobody pays for.

Run from the repository root, so the library is built first:

bun api      # wrangler dev → localhost:8787/avatar/alain

Then the tests, which need that same build:

bun --filter blobatar build
bun --filter blobatar-api test

Unlike apps/site and apps/demo, this app has no blobatar/* tsconfig aliases to the library source. It resolves the package the way a fresh clone does — through exports, at the version in package.json — because that is what anyone pressing the button will run.

avatar.ts and params.ts here are the endpoint, and apps/site imports them rather than holding a copy: blobatar.dev serves this Worker with the landing page attached, and run_worker_first scopes it to /avatar/* there. The two deployments differ only in what happens off that path — the site, or the help text above. See ADR-0005.