Webhooks power modern application integrations — payment confirmations, CI/CD triggers, Slack notifications, e-commerce order events. But they have a dangerous trait: they fail silently. Your payment processor sends an event, your endpoint returns nothing, and neither side raises an alarm. Hours later you discover thousands of unprocessed orders.
This guide explains how to monitor webhook endpoints properly in 2026 so you catch failures before they become business problems.
Why Webhooks Fail Silently
Unlike APIs you call, webhooks are called by third parties. When something goes wrong, the failure usually surfaces on the sender's side — not yours. Common failure modes include:
- Endpoint downtime — your server is unreachable during a deployment or outage
- Timeout errors — your handler takes too long and the sender stops retrying
- Authentication failures — HMAC signature mismatch after a secret rotation
- Silent 200s — your server returns HTTP 200 but the payload was never actually processed
- SSL certificate expiry — the sender refuses to deliver over an untrusted connection
The insidious part: most webhook senders retry a handful of times over a few hours, then mark events as failed and move on. If your endpoint was down for 10 minutes during a deploy, you may have permanently lost events.
What You Need to Monitor
Effective webhook monitoring has three layers:
1. Endpoint Availability
Your webhook receiver must be reachable 24/7. An uptime monitor hitting your endpoint every 60 seconds will catch downtime immediately — before your sender's retry window expires.
Set up an HTTP monitor on the exact path receiving webhooks. For most frameworks this is a POST endpoint, but uptime monitors typically send GET or HEAD requests. Ensure your endpoint responds appropriately to health check probes (a 200 or 405 Method Not Allowed is fine; a 500 is not).
2. Keyword Checks for Delivery Confirmation
Beyond availability, you want to verify your endpoint is processing payloads correctly. Configure a keyword check that looks for a response body confirming successful receipt — for example {"status":"received"} or {"ok":true}.
If your handler crashes after returning 200 (common with async processing pipelines), the keyword check catches the divergence: the endpoint returns 200 but your expected confirmation body is missing.
3. SSL Certificate Health
Webhook senders validate SSL certificates. A certificate expiring at 2 AM on a Sunday will cause every webhook delivery to fail until you renew it. Certificate expiry monitoring sends you an alert 14–30 days before expiry so you never face this.
Setting Up Vigilmon for Webhook Monitoring
Vigilmon makes webhook endpoint monitoring straightforward:
- Add an HTTP monitor pointing at your webhook URL (e.g.
https://api.yourapp.com/webhooks/payments) - Set check interval to 1 minute — webhook retry windows are short; you want to detect downtime within one check cycle
- Enable keyword matching on your expected response body string
- Configure SSL monitoring with a 21-day advance warning
- Set up multi-region checks — a single-region monitor can report false positives if the monitoring server has a network blip; multi-region confirms the outage is real
For endpoints that only accept POST requests, use Vigilmon's custom HTTP method and body options to send a valid test payload. Many teams use a dedicated GET /webhooks/health path that returns 200 with a status body, keeping the actual webhook POST handler clean.
Alerting on Webhook Endpoint Downtime
Configure alerts that fire within two check cycles (2 minutes) to stay inside most sender retry windows. Useful alert channels:
- PagerDuty or OpsGenie for on-call wake-up when webhooks process critical business events
- Slack or Discord for lower-severity degradation that doesn't need immediate human response
- Email as a backup for all alert types
Vigilmon supports alert escalation: if the on-call engineer doesn't acknowledge within 5 minutes, the alert escalates to their manager. For payment webhooks and order processing, this matters — a 15-minute outage can mean thousands of unprocessed transactions.
Advanced: Monitoring Webhook Delivery Rates
Endpoint uptime is necessary but not sufficient. An endpoint can be up and still fail to process events correctly. Track:
- Delivery success rate — instrument your handler to emit a metric on success/failure and alert when the rate drops
- Processing latency — webhook senders time out requests; keep your handler under 5 seconds or immediately return 202 and process asynchronously
- Queue depth — if you use an async queue, monitor it for backlog growth
Pair Vigilmon's external endpoint monitoring with your internal application metrics for complete coverage.
Checklist: Webhook Monitoring Setup
- [ ] HTTP uptime monitor on webhook receiver URL, 1-minute interval
- [ ] Keyword check on expected success response body
- [ ] SSL certificate monitor with 21-day advance alert
- [ ] Multi-region checks enabled
- [ ] Alert channel configured with ≤2-minute notification delay
- [ ] Escalation policy set for critical webhook endpoints
- [ ] Dedicated health check path if webhook only accepts POST
Conclusion
Webhooks fail silently, but monitoring doesn't have to be complex. A well-configured uptime monitor with keyword checks and SSL monitoring catches the vast majority of webhook endpoint failures before they snowball into data loss. Set it up once in Vigilmon and you'll know within minutes — not hours — when your webhook receiver has a problem.
Start a free Vigilmon trial and have your first webhook monitor running in under five minutes.