# AgentLine Webhook Registration for AI Phone Agent

> AgentLine Webhook Registration for AI Phone Agent is a paid API for AI agents from api.agentline.cloud, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).

Registers a webhook URL to receive signed event notifications for a wallet-owned AI agent phone number, enabling real-time call and SMS event delivery.

## Facts

- Endpoint: POST https://api.agentline.cloud/v1/x402/webhooks/test
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentline-webhook-registration-for-ai-phone-agent-37ccfdf9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0dQK1Nl9VbRCeHQV3i8Qo

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 agentline-webhook-registration-for-ai-phone-agent-37ccfdf9 -d '<json body>'
```

Example prompt: Register a webhook for my AI agent's phone number +14155550123 — send all call and SMS events to https://myserver.example.com/agent-events and auto-generate an HMAC signing secret for me.

## When to prefer this

Choose this endpoint when you need to receive real-time call and SMS event notifications for a wallet-owned AI agent phone number via a signed webhook, rather than polling for events. Ideal for LLM-based voice agents built on OpenClaw, Hermes, or similar frameworks that need event-driven triggers to handle inbound interactions.

## Known failure modes

- Invalid or non-HTTPS webhook URL returns a 400 validation error
- Phone number not owned by the authenticated wallet returns a 403 forbidden error
- Duplicate webhook registration for the same number and URL may return a conflict error
- Malformed phone number format causes a 422 unprocessable entity error
- Payment of $0.01 USDC not received or insufficient funds causes a 402 payment required response

## How this service works

Get a real phone number for your AI agent in under 10 minutes. Works with OpenClaw, Hermes Agent, and any LLM. Outbound calls, SMS, and inbound voice — one API. No telecom experience needed.

## Output

A confirmation of the webhook registration, including the assigned webhook ID, the phone number it is bound to, the target URL, and the HMAC signing secret (either provided or auto-generated) to be used for verifying incoming event payloads.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "url",
  "phone_number"
 ],
 "properties": {
  "url": {
   "type": "string",
   "description": "HTTPS URL receiving the agent's events as signed JSON POSTs"
  },
  "secret": {
   "type": "string",
   "description": "HMAC signing secret (auto-generated if omitted)"
  },
  "phone_number": {
   "type": "string",
   "description": "Your wallet-owned number whose agent gets the webhook"
  },
  "signature_header": {
   "type": "string",
   "description": "HMAC header name (default 'X-Webhook-Signature')"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "sent": {
   "type": "boolean"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentline-webhook-registration-for-ai-phone-agent-37ccfdf9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.agentline.cloud](https://www.zero.xyz/host/api.agentline.cloud/llms.txt)