DEV3 Free Webhook Tester and Inspector — Source Code (Next.js + MongoDB)

Source code of the DEV3 Webhook Tester and Inspector, a temporary webhook inbox that captures any HTTP method, with a live inspector, 256 KB body cap, 100-request cap and 48-hour expiry.

Free download: sign in to any DEV3 account and click Download ZIP. Try it live: https://dev3.tech/tools/webhook-tester-inspector 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

• Catch-all route handler with streaming body cap
• JSON and form pretty-printing, base64 for binary
• Selectable response status for retry testing
• Hourly expiry job

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.
• Polling, not SSE; sender IPs are not stored.