curl -X POST https://api.up2data.ai/v1/signals/sig_9dk2m1xq/test-webhook \
  -H "X-API-Key: $UP2DATA_API_KEY" \
  -H "Idempotency-Key: agent-run-42"

resp = requests.post(
    f"https://api.up2data.ai/v1/signals/{signal_id}/test-webhook",
    headers={
        "X-API-Key": UP2DATA_API_KEY,
        "Idempotency-Key": "agent-run-42",
    },
)
delivery_id = resp.json()["data"]["delivery_id"]

const res = await fetch(
  `https://api.up2data.ai/v1/signals/${signalId}/test-webhook`,
  {
    method: "POST",
    headers: {
      "X-API-Key": apiKey,
      "Idempotency-Key": "agent-run-42",
    },
  },
);
const { data } = await res.json();
// Poll GET /v1/webhook-deliveries/${data.delivery_id}

{
  "data": {
    "delivery_id": "wh_stest_a1b2c3d4e5f6g7h8",
    "event": "signal.test",
    "url": "https://app.example.com/hooks/up2data",
    "status": "retrying",
    "attempts": 0,
    "created_at": "2026-07-21T12:00:00.000Z"
  },
  "meta": {
    "creditsUsed": 0,
    "billed": false,
    "reason": "webhook_test_enqueued",
    "requestId": "req_whtest1"
  }
}