roshabbhandari/API-Tester ? reverse-engineered prompt

Build me a simple web app for testing API requests.

I want a clean page where I can enter an endpoint, choose a method like GET or POST, add headers and a JSON body, then send the request and see the response clearly on the page. It should show the status code, response headers, and formatted response body so it’s easy to read. If the request fails, show a helpful error message instead of breaking.

Make it feel lightweight and easy to use, with a basic home page and a neat interface. Use the existing app, templates, static, and tests structure, and add a few tests for the main request handling and response display. If you need anything current from the ecosystem, look up the latest docs online.