Introducing our Free Webhook Catcher for AI Agents

If you are building AI agents, connecting n8n workflows, or wiring up OpenAI function calls, you spend a lot of time staring at JSON payloads.

When your agent fires a webhook, you need to know exactly what it sent before you wire it up to your production database. For years, developers have relied on generic, ad-filled webhook testing sites that often block traffic or require annoying signups.

We got tired of this, so we built our own. Today, we’re releasing the Relayna Free Webhook Catcher.

Built for Speed and Zero Friction

The Webhook Catcher is designed to do exactly one thing perfectly: catch your HTTP requests and display them in real-time.

• No Account Required: You don’t need to sign up, give us your email, or create a Relayna account.
• Instant Unique URLs: The moment you load the page, you are assigned a secure, randomized URL (e.g., relayna.app/hook/a1b2c3d4).
• Real-Time PubSub: Built on Elixir and Phoenix LiveView, the inspector uses WebSockets to stream incoming requests to your screen in milliseconds. No refreshing required.
• Privacy First: Payloads sent to your temporary URL are streamed directly to your browser session and are never saved to our database. Once you close the tab, the data is gone forever.

How to use it

1. Go to the Webhook Catcher.
2. Copy your unique relayna.app/hook/... URL.
3. Paste it into your agent’s tool definition, Zapier, n8n, or test it with a simple cURL command:

curl -X POST https://relayna.app/hook/YOUR_UUID \
  -H "Content-Type: application/json" \
  -d '{"agent": "claude", "confidence": 0.95, "action": "refund_customer"}'

The payload, along with the HTTP method, headers, and originating IP, will instantly appear in the UI.

Why did we build this?

At Relayna, our core product is a Human-in-the-Loop (HITL) API. We help developers pause AI workflows so a human can review, approve, or reject the agent’s actions.

The foundation of our platform relies heavily on webhooks. When a human clicks “Approve” on an invoice or a code change, Relayna fires a webhook back to your server to resume the agent’s execution. We built a robust internal Webhook Inspector for our logged-in users to debug these callbacks.

We realized that the underlying real-time engine we built for our dashboard was too good to keep locked behind a login screen. By stripping out the database persistence and opening up the routing, we created a tool that the entire AI engineering community can use for free.

The Next Step: Adding Human Approval

Raw webhooks are great for moving data between systems. But what happens when that data is sensitive? What if your AI agent decides to issue a $500 refund, or send an email to your entire customer list?

If you find yourself looking at a webhook payload and thinking, “I really wish a human could approve this before it hits my database,” that’s exactly what Relayna does.

With a single API call, you can convert raw JSON payloads into secure, magic-link UI pages where your team can review the agent’s proposed actions.

Try the Free Webhook Catcher today. When you’re ready to add human oversight to your agents, grab a free Relayna API key.