# x402.shizu.me Webhook Inbox (Async Callback Bucket)

> x402.shizu.me Webhook Inbox (Async Callback Bucket) is a paid API for AI agents from x402.shizu.me, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Mints a durable public capture URL for receiving async callbacks, form posts, or service results, then drains queued deliveries on demand — no server required.

## Facts

- Endpoint: GET https://x402.shizu.me/webhook
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-shizu-me-webhook-inbox-async-callback-bucket-520b584c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_p9DL6C0OqchH8ThdgPjMC

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 x402-shizu-me-webhook-inbox-async-callback-bucket-520b584c
```

Example prompt: Create a temporary webhook bucket for me with a 10-minute TTL so I can receive the callback from Stripe after the payment completes, then poll it to drain whatever JSON payloads arrived.

## When to prefer this

Use this endpoint when an AI agent needs to receive asynchronous HTTP callbacks, webhooks, or form posts from external services but cannot host its own server. Ideal for multi-step agent workflows where a third-party service needs to call back with results between agent execution runs. Prefer over polling external APIs directly when you need a push-based delivery model with no infrastructure setup.

## Known failure modes

- Expired TTL — bucket no longer exists, GET returns empty or 404
- Invalid or missing token on GET — unauthorized, deliveries not returned
- Empty queue — no deliveries have arrived yet, returns empty array
- Bucket never created before attempting to drain — token not found
- External service posts malformed JSON — payload may be stored as-is or rejected

## How this service works

A durable inbound URL for agents that can't host a server. POST {ttl?} mints a bucket and a public capture URL; any external service can POST JSON to that URL (no payment); GET ?token= drains the queued deliveries. Use it to receive async callbacks, form posts, or another service's results between runs.

## Output

On POST (mint): returns a bucket ID and a public capture URL that third parties can POST JSON to. On GET with ?token=: returns an array of all queued delivery payloads that were posted to the capture URL since the bucket was created or last drained, clearing the queue.

## Request schema (JSON Schema)

```json
{
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "method"
   ],
   "properties": {
    "method": {
     "const": "GET"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "token"
     ],
     "properties": {
      "token": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "poll": "GET /webhook?token=AbC123…",
  "token": "AbC123…",
  "expires": 1784303600,
  "capture_url": "https://x402.shizu.me/wh/AbC123…"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-shizu-me-webhook-inbox-async-callback-bucket-520b584c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.shizu.me](https://www.zero.xyz/host/x402.shizu.me/llms.txt)