IP geolocation with zero external APIs, the Cloudflare Workers cf object

When I built whatsmy.fyi, I assumed I'd need a geolocation provider: MaxMind, ipinfo, ip-api, pick your poison. They all mean the same thing: an external dependency, an API key, a quota, added latency, and someone else's server seeing your users' IPs.

Then I found out Cloudflare Workers makes the whole category unnecessary.

The cf object

Every request that hits a Cloudflare Worker carries a request.cf object, populated at the edge before your code even runs. No lookup, no latency, no key. Here's what's inside:

{