Modern API development has become slightly absurd. A developer sends one request from inside VS Code, gets a beautiful green 200 OK , leans back in the chair like a Formula 1 engineer after a flawless pit stop, and declares: “Yep. Works.” Except… no. It doesn’t. It means one request worked once. And this is exactly where Thunder Client and Rentgen stop being competitors and start becoming two completely different tools living in different parts of the API lifecycle. Thunder Client is excellent at what it was built for. It keeps API requests inside the editor, close to the code, without forcing developers to open another giant platform with seventeen tabs, sync popups, team workspaces, cloud agents, and whatever else modern software companies now consider “essential productivity”. You change an endpoint. You send a request. You inspect the response. You tweak headers. You debug quickly. Perfectly reasonable workflow. But then reality arrives.…