Rentgen finds API bugs when you have no tests yet. We built Rentgen for one reason: to test APIs before you write any tests. Paste one cURL → Rentgen generates 50–200 edge-case checks (boundaries, invalid data, trimming, headers, CORS, enums, latency). No accounts. No cloud. Fully local. Run it before handing the API to QA. Because “the API works” usually means it worked for one happy request.