# Webhook Relay Inbox Registration

> Webhook Relay Inbox Registration is a paid API for AI agents from predator-ubuntu.taild9a745.ts.net, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-28).

Registers a named webhook relay inbox that accepts inbound HTTP callbacks for 30 days and lets you poll for received payloads

## Facts

- Endpoint: POST https://predator-ubuntu.taild9a745.ts.net/v1/hook/register?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/webhook-relay-inbox-registration-9fa677fd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-bYKf6X1yN2haU4qmFeLg

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability webhook-relay-inbox-registration-9fa677fd -d '<json body>'
```

Example prompt: Set up a webhook relay inbox called 'stripe-events' so I can give Stripe a URL to send payment webhooks to, and then poll it later to see what came in.

## When to prefer this

Choose this endpoint when an AI agent or automation needs a temporary, hosted inbound webhook URL without standing up its own server. Ideal for capturing async callbacks from third-party services (Stripe, GitHub, Zapier, etc.) during a bounded 30-day period. Prefer over manual ngrok tunnels or custom server setups when you need a quick, pay-per-use relay that can be polled programmatically. Not suitable if you need webhooks to be forwarded in real-time via push to another server, or if you need retention beyond 30 days.

## Known failure modes

- Name exceeds 128 characters — validation error returned
- Payment of $0.02 USDC not settled — 402 response blocking registration
- Duplicate inbox name may overwrite or conflict with existing inbox
- Inbox expires after 30 days — polling after expiry returns no data
- Network unreachability of the Tailscale host returns connection errors

## How this service works

Webhook relay inbox for 30 days: get a unique inbound URL, point external services at it, poll for received webhooks

## Output

Returns a unique inbound URL that external services can POST to, along with an inbox identifier and expiry information. The agent can subsequently poll the inbox to retrieve any webhook payloads received within the 30-day window.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "name": {
   "type": "string",
   "maxLength": 128
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/webhook-relay-inbox-registration-9fa677fd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from predator-ubuntu.taild9a745.ts.net](https://www.zero.xyz/host/predator-ubuntu.taild9a745.ts.net/llms.txt)