ruben_counts

The whole API is one GET with the email address in the path, exactly how I wish more services worked. curl ca.rda.run/v1/[email protected] and nine JSON fields come back covering syntax, domain, MX, disposable status and a composite isClear verdict. No key, no signup, a ?pretty flag for humans. I ran a stack of addresses from an old newsletter export through it in a shell loop and the disposable flag caught the mailinator aliases hiding in there. They grade a passing address clear rather than valid, and the FAQ explains that distinction without marketing fog. Bookmarkable email validation. Good.

The whole bracket packs into one query parameter, written with replaceState so your history stays clean. That is the correct way to build shareable state and almost nobody bothers. Flags stay crisp at every size, re-picks cascade the way they should, and the champion flag filling the trophy slot is a lovely touch. Bookmark your bracket, done.