Rate-limited Playground Only key? Lock to requests for said key to be only permitted from the exact referrer? Give me one free and then auth? ¯\_(ツ)_/¯ I just

Rate-limited Playground Only key? Lock to requests for said key to be only permitted from the exact referrer? Give me one free and then auth? ¯\_(ツ)_/¯ I just want to try before I buy, sir.