# Stumble Wake – Scheduled Webhook Callback

> Stumble Wake – Scheduled Webhook Callback is a paid API for AI agents from stumble.vimabrosta.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Schedules a one-time future webhook delivery: calls your URL at a specified time (or after N seconds, up to 30 days) with a JSON payload you stored, signed with a one-time secret, with automatic retries on failure.

## Facts

- Endpoint: POST https://stumble.vimabrosta.com/v1/wake
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stumble-wake-scheduled-webhook-callback-92d430da
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JAvpVtietP2tmpvqNLAHW

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 stumble-wake-scheduled-webhook-callback-92d430da -d '<json body>'
```

Example prompt: Schedule a webhook callback to https://myapp.example.com/resume in 3600 seconds, echoing back the JSON payload {"job_id": "abc123", "step": "review"} with a signed one-time secret so I can resume this workflow after my session ends.

## When to prefer this

Use this endpoint when an AI agent or serverless function needs to pause execution and resume at a future time without keeping a process alive or polling. It is ideal for long-horizon async agentic workflows where the session will expire before the callback is needed (up to 30 days). Prefer this over self-managed cron jobs or polling loops when simplicity, no-account setup, and signed delivery verification matter.

## Known failure modes

- Webhook URL unreachable at delivery time — Stumble retries but eventually gives up
- Timestamp too far in the future (>30 days limit) — request rejected
- Invalid or missing required fields (notify.url, notify.mode, at or after_seconds) — 400 error
- Payment not completed ($0.01 USDC) — wake not scheduled
- Webhook endpoint returns non-2xx repeatedly — retries exhausted, wake considered failed

## How this service works

Schedule a wake: Stumble calls your webhook at a time you set (up to 30 days ahead), echoing back a JSON payload you stored, signed with your one-time secret and retried on failure. Sleep for agents whose session will be gone by then: no process to keep alive, no polling, no cron. One-time $0.01, no account needed.

## Output

Returns a wake confirmation (schedule ID and scheduled time). At the appointed time, Stumble POSTs your stored JSON payload to your webhook URL, signed with a one-time HMAC secret for verification. If delivery fails, Stumble retries automatically. The signed body allows the receiving server to authenticate the callback.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "notify"
     ],
     "properties": {
      "at": {
       "type": "integer"
      },
      "notify": {
       "type": "object",
       "required": [
        "mode"
       ],
       "properties": {
        "url": {
         "type": "string"
        },
        "mode": {
         "enum": [
          "webhook",
          "poll"
         ],
         "type": "string"
        },
        "format": {
         "enum": [
          "json",
          "slack",
          "discord"
         ],
         "type": "string"
        }
       }
      },
      "payload": {},
      "resume_hint": {
       "type": "string",
       "maxLength": 500
      },
      "after_seconds": {
       "type": "integer"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stumble-wake-scheduled-webhook-callback-92d430da/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stumble.vimabrosta.com](https://www.zero.xyz/host/stumble.vimabrosta.com/llms.txt)