API Reference
Webhook Scheduler runs on the same production domain as the dashboard. All API routes below exist in the codebase today.
Authentication
Public API calls require an API key created from the dashboard. Send it as eitherAuthorization: Bearer YOUR_KEY or x-api-key: YOUR_KEY.
Authorization: Bearer wh_live_xxxxxxxxx
Content-Type: application/jsonSchedule a webhook
/api/v1/scheduleCreates a future delivery. The target must be HTTPS and public; private networks, localhost, metadata endpoints, and unsafe redirects are blocked.
Request body
urlstringrequiredDestination HTTPS URL.
methodstringOne of GET, POST, PUT, PATCH, DELETE. Default is POST.
bodyjsonJSON payload sent to the destination. Alias: payload.
headersobjectCustom user headers. Unsafe hop-by-hop or proxy headers are stripped before dispatch.
runAtISO date stringrequiredFuture execution time.
idempotencyKeystringOptional key to avoid creating duplicate jobs for the same organization.
curl https://webhookscheduler.com/api/v1/schedule \
-H "Authorization: Bearer wh_live_xxxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
"url": "https://api.example.com/webhook",
"method": "POST",
"body": { "event": "user.created" },
"runAt": "2026-05-09T10:00:00.000Z",
"idempotencyKey": "user-created-123"
}'Response
{
"id": "job_...",
"status": "PENDING",
"scheduledFor": "2026-05-09T10:00:00.000Z",
"idempotencyKey": "user-created-123"
}Execute immediately
/api/v1/execute-nowDispatches a webhook immediately using the same SSRF policy and header sanitization as scheduled jobs.
urlstringrequiredDestination HTTPS URL.
methodstringOne of GET, POST, PUT, PATCH, DELETE. Default is POST.
headersobjectOptional headers after sanitization.
bodyjsonOptional JSON request body.
curl https://webhookscheduler.com/api/v1/execute-now \
-H "Authorization: Bearer wh_live_xxxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
"url": "https://api.example.com/webhook",
"body": { "event": "manual.test" }
}'Response
{
"success": true,
"status": 200,
"data": { "ok": true },
"durationMs": 143
}Job statuses
PENDINGQueued and waiting for Cloud Tasks.
PROCESSINGClaimed atomically by the worker.
SUCCESSDelivered successfully.
FAILEDFinal failure after all retries or unrecoverable scheduling failure.
RETRYINGLegacy/intermediate retry state retained for compatibility.
CANCELEDCanceled before delivery.
Errors
400Validation failed or unsafe target URL. SSRF failures return code UNSAFE_TARGET_URL.
401Missing or invalid API key.
403Plan quota exceeded.
405Unsupported HTTP method.
429Rate limit exceeded.
500Internal error. Retry later with backoff.
Security model
Outbound webhooks are HTTPS-only and revalidated immediately before dispatch.
Redirects are not followed automatically. A 3xx response from your endpoint is recorded as the webhook result.
DNS lookups are pinned to the validated public IP to reduce DNS rebinding risk.
Worker execution uses an atomic PENDING to PROCESSING claim to prevent duplicate delivery.