DEV3 Free API Request Tester — Source Code (Next.js + MongoDB)

Source code of the DEV3 API Request Tester, a small online API client that sends requests from the server with SSRF protection and shows status, timing, headers and a pretty body.

Free download: sign in to any DEV3 account and click Download ZIP. Try it live: https://dev3.tech/tools/api-request-tester shows the finished tool running.

What is in the download

• Route handlers and pages for the Next.js App Router
• The service layer, Mongoose models and the UI components, in a dev3-tools/ folder that cannot clash with your own files
• README.md (install, environment, customise), .env.example and an MIT LICENSE

What the code does

• Params, headers, JSON, form and raw bodies, bearer and basic auth
• IP-pinned requests with every redirect hop re-validated
• Response size cap, timeout and rate limit
• cURL export and local-only history without secrets

Tech stack

Next.js 15 (App Router), React 19, TypeScript, Mongoose on MongoDB, Tailwind CSS 4.

Install and customise

The How to install and How to use tabs list the steps. In short: copy the module into a Next.js app, install the listed packages, add the MongoDB connection string and run it.

Good to know

• This is server code: you need a MongoDB database and your own hosting.
• Only public hosts on ports 80, 443, 8080 and 8443 can be called.