I launched TikRapid — a free TikTok video downloader — and within the first few days the API was getting hammered. Not by real users. By bots. The problem with free download tools is obvious in hindsight. No login means no friction. No friction means bots can hit your endpoint thousands of times a minute. My API costs were climbing fast and real users were getting timeout errors because the server was busy processing junk requests. I needed bot protection that did not break the user experience. No login walls. No annoying CAPTCHAs that make people give up halfway through. Something invisible to real users but effective against automated traffic. Cloudflare Turnstile was the answer. What Turnstile actually does differently Most CAPTCHA systems make the user do something — click a checkbox, identify traffic lights, type distorted text. Turnstile runs a challenge in the background using browser signals, interaction patterns and device fingerprinting.…