Introducing WebhookSpy: A Free Webhook Testing Tool Built with AI

At work, we've been using a self-hosted version of Webhook.site. It hasn't been a great experience. I won't go into the details, but let's just say it left me wondering: how hard could it be to build a simple webhook tester that covers 95% of use cases?

Turns out, not very hard at all—especially with AI assistance.

From Idea to Working Prototype

I spun up OpenAI Codex and gave it a simple prompt describing the tech stack I wanted and the core functionality. It built me a solid proof of concept in no time.

From there, I moved to Claude Code to iterate on features and refine the UI/UX. After just a few hours, I had something fully functional and deployed to production.

What is WebhookSpy?

WebhookSpy is a free tool for testing webhooks. It generates a unique URL that you can use as a webhook endpoint. When a request hits that URL, you can see all the details—headers, body, query parameters, and more—in real time.

It's simple, fast, and does exactly what you need without any fuss.

Discovering Elysia

One unexpected bonus from this project was discovering Elysia—a web framework built on Bun. It's incredibly fast and has one of the cleanest APIs I've worked with. Best of all, it automatically generates beautiful API documentation with minimal configuration.

If you're looking for a modern, performant alternative to Express or Fastify, Elysia is worth checking out.

Open Source and Self-Hostable

WebhookSpy is completely open source. The codebase is well-documented, so you can:

• Contribute: Found a bug or have a feature idea? PRs are welcome.
• Self-host: Need to keep your webhook data on your own infrastructure? Spin up your own instance.

Check out the GitHub repository for documentation and setup instructions.

AI-Assisted Development

This project is a perfect example of how AI can accelerate the development process. What might have taken days or weeks to build from scratch took just a few hours with the right AI tools. Codex handled the initial scaffolding, and Claude helped me polish the experience.

I'm not saying AI wrote perfect code—there was plenty of back-and-forth and manual tweaking involved. But the speed at which you can go from idea to deployed product is remarkable.

Try It Out

Do you have a webhook to test? Give it a spin at WebhookSpy.com. It's free to use and requires no sign-up. Or grab the source and host it yourself.